COLUMBIA LIBRARIES OFFSITE HEALTH SCIENCES STANDARD HX64085783 QM531 .T72 1 907 Surgical applied ana &M551 "T7£ Columbia Stotomitp mtijeCtipoOlfttigork College of iPfegtciang anb burgeons; Hibrarp MANUALS FOR Students of Medicine SURGICAL APPLIED ANATOMY. By SIR FREDERICK TREVES, Bart., G.C.V.O., C.B., LL.D., F.R.C.S. Sergeant Surgeon-in-Ordinary to H.M. the King ; Surgeon-in-Ordinary to H.R.H. the Prince of Wales ; Consulting Surgeon to the London Hospital ; Late Lecturer on Anatomy at the London Hospital Fifth Edition, Revised by ARTHUR KEITH, m.d., f.r.c.s. Lecturer on and Senior Demonstrator of Anatomy at the London Hospital ; Examiner in Anatomy, Royal College of Surgeons, England, and University of Leeds ; formerly Examiner in Universities of Aberdeen, Cambridge, etc. ILLUSTRATED WITH IO7 FIGURES, INCLUDING 4. 1 IN COLOUR PHILADELPHIA LEA BROTHERS AND CO. 0vM &> [ o -4 a r— ^ PREFACE TO THE FIFTH EDITION In the present edition the work has been carefully revised throughout ; certain sections have been rewritten, and much new matter has been added. Every effort has been made to bring each chapter of the book well up to date. Neither pains nor expense has been spared in the matter of illus- trations. Forty-three figures have been specially prepared for this edition ; fifteen of the former figures have been redrawn, and colours have been freely used to make the illustrations more effective. The editor is indebted to Messrs. S. J. A. Beale and E. H. Eainey for their assistance in the preparation of this edition. Arthur Keith. London Hospital Medical College, August, 1907. PEEFACE TO THE FIRST EDITION Applied Anatomy has, I imagine, a twofold func- tion. On the one hand it serves to give a precise basis to those incidents and procedures in practice that more especially involve anatomical knowledge ; on the other hand it endues the dull items of that knowledge with meaning and interest by the aid of illustrations drawn from common medical and surgical experience. In this latter aspect it bears somewhat the same relation to Systematic Anatomy that a series of experiments in Physics bears to a treatise dealing with the bare data of that science. The student of Human Anatomy has often a nebulous notion that what he is learning will sometime prove of service to him ; and may be conscious also that the study is a valuable, if somewhat unexciting, mental exercise. Beyond these impressions he must regard his efforts as concerned merely in the accumulation of a number of hard, unassimilable facts. It should be one object of Applied Anatomy to invest these facts with the interest derived from an association with the circumstances of daily life ; it should make the dry bones live. It must be owned also that all details in Anatomy have not the same practical value, and that the memory of many of them may fade with- out loss to the competency of the practitioner in medicine or surgery. It should be one other object, therefore, of a book having such a purpose as the present, to assist the student in judging of the comparative value of the matter he has x PREFACE learnt ; and should help him, when his recollection of anatomical facts grows dim, to encourage the survival of the fittest. In writing this manual I have endeavoured, so far as the space at my command would permit, to carry out the objects above described ; and while I believe that the chief matters usually dealt with in works on Surgical Anatomy have not been neglected, I have nevertheless tried to make the principle of the book the principle that under- lies Mr. Hilton's familiar lectures on " Rest and Pain." I have assumed that the reader has some know- ledge of Human Anatomy, and have not entered, except in a few instances, into any detailed anatomical descriptions. The bare accounts, for example, of the regions concerned in Hernia I have left to the systematic treatises, and have dealt only with the bearings of the anatomy of the parts upon the circumstances of practice. The limits of space have compelled me to omit all those parts of the " Surgery of the Arteries " that deal with ligature, collateral circulation, abnor- malities, and the like.^ This omission I do not regret, since those subjects are fully treated not only in works on operative surgery, but also in the manuals of general anatomy. The book is intended mainly for the use of students preparing for their final examination in surgery. I hope, however, that it will be of use also to practitioners whose memory of their dissecting-room work is growing a little grey, and who would wish to recall such anatomical matters as have the most direct bearing upon the details of practice. Moreover, it is possible that junior students may find some interest in the volume, and may have their studies rendered more in- telligent by learning how anatomy is concerned in actual dealings with disease. Frederick Treves. September, 1883. CONTENTS PART I.— THE HEAD AND NECK CHAPTER I.- PAGE —The Scalp 1 II.- —The Bony Vault op the Cranium . . 17 III.- —The Cranial Contents .... 31 IV.- V.- VI.- —The ISTose and Nasal Cavities ... 94 VIL- -The Face Ill VIII.- —The Mouth, Tongue, Palate, and Pharynx 137 IX.- PART II.— THE THORAX X. — The Thorax ... 195 PART m -THE UPPER EXTREMITY XI. — The Region of the Shoulder . XII.— The Arm XIII. — The Region op the Elbow XIV.— The Forearm . . . . . XV. -The Wrist and Hand . 214 255 263 282 290 xii CONTENTS PART IV,— THE ABDOMEN AND PELVIS CHAPTER PAGS XVI. — The Abdomen 321 XVII. — The Abdominal Viscera .... 358 XVIII. — The Pelvis and -Perineum . . . 424 I PART V— THE LOWER EXTREMITY XIX. — The Region of the Hip .... 478 XX.— The Thigh 5l| XXI. — The Region op the Knee .... 523 XXII.— The Leg ■ . . 550' i XXIII.— The Ankle and Foot 561 \ PART VI.-THE SPINE XXIV.— The Spine 600 Index 623 Surgical Applied Anatomy Part I.— THE HEAD AND NECK CHAPTER I THE SCALP The soft parts covering: the vault of the skull may be divided into five layers : (1) the skin, (2) the subcutaneous fatty tissue, (3) the occipito-frontalis muscle and its aponeurosis, (4) the subaponeurotic connective tissue, and (5) the pericranium. It is convenient to consider the term " scalp " as limited to the structure formed by the union of the first three layers above named The skin of the scalp is thicker than in any other part of the body. It is in all parts in- timately adherent, by means of the subcutaneous tissue, to the aponeurosis and muscle beneath it, and, from this adhesion, it follows that the skin moves in all movements of that muscle. The sub- cutaneous tissue is, like a similar tissue in the palm, admirably constructed to resist pressure, being composed of a multitude of fibrous bands enclosing fat lobules in more or less isolated spaces (Fig. 1, b). The density of the scalp is such, that in surface inflammations, such as cutaneous ery- sipelas, it is unable to present (except in a very slight degree) two conspicuous features of such inflammations, viz. redness and swelling. The skin B SURGICAL APPLIED ANATOMY LPart I is provided with a great number of sebaceous glands, which may develop into cystic tumours or wens, such cysts being more common upon the scalp than in any other part of the body. Being skin growths, these cysts, even when large, remain, ex- cept in rare instances, entirely outside the apo- Fig. 1 —Diagram showing the layers of the scalp and membranes of the R VJ; *brain in section. a, Skin; U, subcutaneous tissue with bail' roots and vessels; c, epicranium ; ii, subaponeurotic layer; e, pericranium; /, parietal bone; g, dura mater; /.-, arachnoid ; I, pia mater ; m, cortex ; n, in subdural space near a Pacchionian body projecting within the superior Longitudinal sinus. neurosis, and can therefore be removed without risk of opening up the area of loose connective tissue between the aponeurosis and the peri- cranium. There being no fatty tissue in any of the layers that cover the bony vault save in the subcutaneous layer, it happens that in cases of obesity the scalp Chap. I] THE SCALP 3 undergoes but little change, the fat in the subcu- taneous tissue being limited by the dense fibrous structures that enclose it. For the same reasons fatty tumours of the^ scalp are very rare. The attachment of the hairs collectively to the scalp is so strong that there are many cases where the entire weight of the body has been supported by the hair of the scalp. Agnew records the case of a woman whose hair became entangled in the re- volving shaft of a machine. The hair did not give way, but the entire scalp was torn off from the skull. The patient recovered. I have seen a pre- cisely similar case in a girl aged 13. (Museum, R. Coll. Surgeons, 87 F.) The dangerous area of the scalp. — Between the aponeurosis and the pericranium is an exten- sive layer of loose connective tissue, that may, for reasons to be presently given, be fairly called the dangerous area of the scalp (Fig. 1, d). The mobility of the scalp depends entirely upon the laxity of this layer of tissue. In extensive scalp wounds, when a part of the scalp is separated in the form of a large flap, a flap that may hang down and cover half the face, it is the very loose- ness of this tissue that permits such separation. In the Indian process of scalping, a taste that is becoming one of the past, the much-prized piece of skin is torn from the skull through this lax area of connective tissue, and, were there no such area, scalping would be an operation requiring some time and art. The exposure of the skull in a post-mortem examination is effected bv peeling off the scalp along this layer of loose tissue, and it is remark- able with what ease the skull can be exposed by this manoeuvre. Sutures may be safely applied to adjust scalp wounds, provided they are not too long retained. _ They probablv include the aponeurosis, and if long retained may act as setons and set up suppuration, which may find its way into the loose layer beneath the aponeu- rosis. 4 SUKGICAL APPLIED ANATOMY [Part I Wounds of the sculp never gape, unless the wound has involved the scalp muscle or its apo- neurosis. When this structure has been divided the lax layer beyond permits of great separation of the edges of even the simplest wounds. In uncom- plicated incised wounds, the amount of gaping of the cut depends upon the action of the occipito- frontalis muscle. Those wounds gape the most that are made across the muscle itself, and that are transverse to the direction of its fibres, while those show the least separation that involve the apo- neurosis and are made in an antero-posterior direction. The mobility of the scalp is more marked in the young than in the old. A case recorded by Agnew serves in a strange degree to illustrate this fact in the person of an infant. A midwife attending a woman in labour mistook the scalp of the infant for the membranes, and gashed it with a pair of scissors. Labour pains came on and the head was protruded through the scalp wound, so that the whole vault of the skull was peeled like an orange. The scalp being firmly stretched over the hard cranium beneath, it follows that contused wounds often appear as cleanly cut as are those that have been made by an incision. Such wounds may be compared to the clean cut that may be made in a kid glove when it is tightly stretched over the knuckles and those parts are sharply rapped. The scalp is extremely vascular, and presents therefore a great resistance to sloughing and gan- grenous conditions. Large flaps of a lacerated scalp, even when extensively separated and almost cut off from the rest of the head, are more prone to live than to die. A like flap of skin, separated from other parts of the surface, would most prob- ably perish ; but the scalp has this advantage, that the vessels run practically in the skin itself, or are, at least, in the tissue beyond the aponeurosis (Fig. 1). Thus, when a scalp flap is torn up, it still carries with it a very copious blood supply. Bleeding from these wounds is usually very free, Chap. I] THE SCALP o and often difficult to arrest. This depends not so much upon the number of vessels in the part as upon the density of the tissue through which these vessels run, the adherence of the outer arterial wall to the scalp structure, and the inability, therefore, of the artery to retract properly when divided. For the same reason it is almost impossible to pick up an artery divided in a scalp wound. The bleeding is checked by a hare-lip pin or by pres- sure. In all parts of the body where a dense bone is covered by a comparatively thin layer of soft tis- sues, sloughing of those tissues is apt to be in- duced by long and severe pressure. The scalp, by its vascularity, is saved to a great extent from this evil, and is much less liable to slough than are the soft parts covering such bones as the con- dyles of the humerus or the sacrum. But such an effect is sometimes produced, as in a case I saw, where the tissues over the frontal and occipital regions sloughed from the continued application of a tight bandage put on to arrest bleeding from a frontal wound. The pericranium is but slightly adherent to the bone, except at the sutures, where it is inti- mately united (Fig. 1, e). In lacerated wounds this membrane can be readily stripped from the skull, and often, in these injuries, extensive tracts of bone are laid bare. The pericranium differs somewhat in its functions from the periosteum that covers other bones. If the periosteum be removed to any extent from a bone, the part from whence it is removed will very probably perish, and necrosis from deficient blood supply result. But the pericranium may be stripped off a con- siderable part of the skull vault without any necrosis, save perhaps a little superficial exfolia- tion, following in consequence. This is explained by the fact that the cranial bones derive their blood supply mainly from the dura mater, and are therefore to a considerable extent independent of 6 SURGICAL APPLIED ANATOMY [Part I the pericranium. A like independence cannot be claimed for the periosteum covering other bones, since that membrane brings to the part it covers a very copious and essential contribution to its blood supply. This disposition of the pericran- ium is also well illustrated by its action in cases of necrosis of the cranial bones. In necrosis of a long bone, the separation of the sequestrum is attended with a vigorous periosteal growth of new bone, which repairs the gap left after the re- moval of such sequestra. In necrosis of the vault of the skull, however, no new bone is formed, as a rule, and the gap remains unrepaired. The general indisposition of the pericranium to form new bone in other circumstances is frequently illustrated. Abscesses in the scalp region may be situated (1) above the aponeurosis, (2) between the apo- neurosis and the pericranium, and (3) beneath the pericranium. Abscesses in the first situation must always be small and comparatively insignificant, since the density of the scalp tissue here is such that suppuration can only extend with the great- est difficulty. Suppuration, however, in the second situation (in the loose tissue beneath the aponeurosis) may prove very serious. The laxity of this tissue offers every inducement to the ab- scess to extend when once pus has found its way between the aponeurosis and the pericranium. Suppuration in this area may undermine the en- tire scalp, which in severe and unrelieved cases may rest upon the abscess beneath as upon a kind of water-bed. As in scalp wounds, the aponeu- rosis is often divided, and as suppuration may follow the injury, it will be seen that the chief danger of those lesions depends upon the spread- ing of such suppuration to the area of lax con- nective tissue now under notice. The significance of a small amount of bare bone in a scalp wound is not so much that evils will happen to the bone, but that the aponeurosis has been certainly divided, and the dangerous area of the scalp Chap. I] THE SCALP 7 opened up. Suppuration, when it occurs in this area, is only limited by the attachments of the occipito-frontalis muscle and its aponeurosis, and therefore the most dependent places through which pus can be evacuated are along a line drawn round the head, commencing in front, above the eyebrow, passing at the side a little above the zygoma, and ending behind at the superior curved line of the occipital bone. The scalp, even when extensively dissected up by such abscesses, does not perish, since it carries, as above explained, its blood supply with it. The abscess is often very slow to close, since its walls are prevented from obtaining perfect rest by the frequent movement of the epicranial muscle. To mitigate this evil, and to ensure closing of the sinuses in obstinate cases, Mr. Hilton advises that the whole scalp be firmly secured by strapping, so that the movement of the muscle is arrested. Abscesses beneath the pericranium must be limited to one bone, since the dipping in of the membrane at the sutures prevents a more exten- sive spreading of the suppuration. Hseuiatoumta, or 1>iood tumours of the scalp region, occur in the same localities as ab- scesses. The extravasation of blood above the apo- neurosis must be of a limited character, while that beneath it may be very extensive. It fortunately happens, however, that the cellular tissue between the aponeurosis and the pericranium contains but very few vessels, and hence large extravasations in this tissue are uncommon. Extravasations of blood beneath the peri- cranium are generally termed cephalhsematomata, and are of necessity limited to one bone. They are usually congenital, are due to pressure upon the head at birth, and are thus most commonly found over one parietal bone, that bone being probably the one most exposed to pressure. Their greater frequency in male children may depend upon the larger size of the head in the male fcetus. Such extravasations in early life are encouraged 8 SUEGICAL APPLIED ANATOMY [Part I by the laxity of the pericranium, and by the soft- ness and vascularity of the subjacent bone. In the temporal region, or the region corre- sponding to the temporal muscle, the layers of soft parts between the skin and the bone are somewhat different from those that have been already de- scribed as common to the chief parts of the scalp. There is a good deal of fat in the temporal fossa, and when this is absorbed it leads to more or less prominence of the zygoma and malar bone, and so produces the projecting " cheek bones ; ' of the emaciated. The temporal muscle above the zy- goma is covered in by a very dense fascia, the temporal fascia, which is attached above to the temporal ridge on the frontal and parietal bones, and below to the zygomatic arch. The unyielding nature of this fascia is well illustrated by a case recorded by Denonvilliers. It concerned a woman who had fallen in the street, and was ad- mitted into hospital with a deep wound in the temporal region. A piece of bone of several lines in length was found loose at the bottom of the wound, and was removed. After its removal the finger could be passed through an opening with an unyielding border, and came in contact with some soft substance beyond. The case was con- sidered to be one of compound fracture of the squamous bone, with separation of a fragment and exposure of the brain. A bystander, however, noticed that the bone removed was dry and white, and a more complete examination of the wound revealed the fact that the skull was uninjured, that the supposed hole in the skull was merely a laceration of the temporal fascia, that the soft matter beyond was muscle and not brain, and that the fragment removed was simply a piece of bone which, lying on the ground, had been driven into the soft parts when the woman fell. Abscesses in the temporal fossa are prevented by the fascia from opening anywhere above the zygoma, and are encouraged rather to spread into the pterygoid and maxillary regions and into the neck. Chap. I] THE SCALP The pericranium in the temporal region is much more adherent to the bone than it- is over the rest of the vault, and subpericranial extrava- sations of blood are therefore practically unknown in this part of the cranial wall. Trephining - .— This operation is frequently per- formed in the temporal region, its object being to reach extravasations of blood from the middle meningeal artery. This artery crosses the an- DREq/^A Sup .Tem.line Lambda Squamous Suture POST.DlV.OFfllD.MEn.AR- AsTEP-ION SupraMeatalTriamcle Lateral Sirtus IftIO Ext. Auditory /ieatus Occipital Art IflT. JUQULAR. VEIM Ext. Carotid Art Fig. 2. — Points to trephine for middle meningeal artery and lateral sinus- terior inferior angle of the parietal bone at a point 1| inches behind the external angular pro- cess of the frontal bone, and l| inches above the zygoma. In cutting down to expose this artery the following structures are met with in order : (1) The skin; (2) branches of the superficial tem- poral vessels and nerves ; (3) the fascia continued down from the epicranial aponeurosis ; (4) the temporal fascia; (5) the temporal muscle; (6) the deep temporal vessels; (7) the pericranium; (8) the anterior inferior angle of the parietal bone. 10 SURGICAL APPLIED ANATOMY [Part I Trephining for meningeal licemorrhage and cerebral abscess. — At the anterior inferior angle of the parietal bone the anterior division of the middle meningeal artery lies with its companion veins in a deep groove or even canal in the bone. A fracture of the bone, which is comparatively thin in the region of the pterion, is apt to involve the artery, leading to a subdural haemorrhage, with consequent compression of the brain. The pterion lies 1\ inches behind and | inch above the notch of the fronto-malar suture— a point which can be readily felt (Fig. 2) ; Similar mea- surements — namely, 1\ inches behind and \ inch above — taken from the centre of the external auditory meatus — the meatal point, gives the posi- tion of the posterior inferior angle of the parietal bone (asterion), beneath which lies the highest point of the lateral sinus (Fig. 2). A trephine opening, f inch in diameter, made over the as- terion, will expose the lateral sinus, and give access to the temporo-sphenoidal lobe above _ it and the cerebellum below it. The posterior division of the middle meningeal, in the majority of cases, will be exposed by trephining at a point 1 inch above the external auditory meatus. These measurements apply to the head of the average adult ; allowance must be made for youth and for the size and shape of the head. In finding the pterion the line is drawn backwards parallel to the upper border of the zygoma; in finding the asterion, the line is drawn backwards along the meato-inionic line (Fig. 2), which passes from the centre of the external meatus to the most promi- nent point of the external occipital protuberance —the inion. Intracranial abscess is often due to middle-ear disease, and is then very commonly found in the temporo-sphenoidal. lobe or in the cerebellum. It is estimated to be three times more common in the cerebrum than in the cerebellum. The abscess of the temporo-sphenoidal lobe is usually found in that part of the lobe which lies Ohap. I] THE SCALP 11 over the tegmen tympani — a thin plate of bone which forms the roof of the tympanum and of the antrum of the mastoid. The level of the tegmen may be indicated thus (Fig. 3) : a point is taken above the meatus in line with the upper border of the zygoma; this suprameatal point is joined with the asterion, which lies, it will be remem- bered, 1^ inches behind and ^ inch above the meatus ; the anterior half of the above line corre- sponds to the tegmen tympani. A trephine open- ing made 1 inch above the level of the tegmen is the most likely to give access to a temporo- sphenoidal abscess. In dealing with an abscess of the cerebellum the best spot to select is, in the adult, 1^ inches behind the centre of the meatus and \ inch below the meato-inionic line. In some cases it is impossible to say whether the abscess is situated in the temporo-sphenoidal lobe or cerebellum. In such cases Mr. Dean trephines at a point which lies l\ inches behind and \ inch above the centre of the meatus. The lateral sinus is thus exposed with a part of the dura mater above the tentorium cerebelli, through which the temporo-sphenoidal lobe may be explored. By ex- tending the trephine opening \ inch downwards the cerebellum may be examined. Trephining for cerebral tumour. — The position of the opening in the skull is obviously determined by the localising symptoms. It is remarkable that little trouble from haemorrhage has attended these operations. In any case, after trephining, the portion or portions of bone removed may — if properly treated — be replaced in the opening, and will serve, especially in youthful subjects, to make good the gap left by the operation. In trephining the skull generally, the compara- tive thickness of the cranial wall in various parts should be borne in mind (p. 30), and the large arteries of the scalp should be avoided if possible. In order to accommodate the instrument to the 12 SURGICAL APPLIED ANATOMY [Part I varying thickness of the skull, the pin of the trephine is not allowed to protrude more than iVth of an inch. The trephine should not be ap- plied over the frontal sinuses, which are often of large size in the aged, and should, when possi- ble, keep clear of the sutures, owing to the fre- quent exit of emissary veins at or about suture lines. The bone, moreover, at certain of these lines is of unequal thickness. Between the bones forming the sutures passes the sutural membrane. Upper Holamdic Poi/it Fissure of Rolamdo Parietal Eminence Parieto Occipital Fissure- Lambda For Lateral Ventricle Post. Ior/i Desc.Morm For Temp.Sp/ien Abscess Occipital Pole Iaiion Asterion T)vi panic Plate Suprameatal Triadcle Meatus Supra/i eatal Point , Fig. 3. — Diagram to show the position of the lateral ventricles, Island of Reil and temporal lobe. This structure blends with the dura mater, and laceration of it may conduce to meningitis. The zygoma may be broken by direct or in- direct violence. In the latter case the violence is such as tends to thrust the upper jaw or malar bone backwards. When due to direct violence, a fragment may be driven into the temporal muscle, and much pain caused in moving the jaw. In ordinary cases there is little or no displacement, since to both fragments the temporal fascia is attached above and the masseter below. The zy- goma serves as a most useful guide to the position Chap. I] THE SCALP 13 of deep parts. Its upper border, in its posterior three-fourths, corresponds to the floor of the mid- dle fossa of the skull, and marks the lower border of the temporal lobe of the brain which lies in that fossa (Fig. 3) ; the articular eminence, felt so plainly near its root, marks the point at which the middle meningeal artery _ perforates the base of the skull by the foramen spinosum (Fig. 2), and also the position of the Gasserian ganglion (Fig. 26, p. 119) ; the post-glenoid spine is directly over the carotid canal (S. Scott). The vessels and nerves of the scalp.— The supraorbital artery and nerve pass vertically up- wards from the supraorbital notch, which is situ- ate at the junction of the middle with the inner third of the upper orbital margin. Nearer the middle line the frontal artery and supratrochlear nerve ascend. This artery gives life to the flap that in rhinoplasty is taken from the forehead to form a new nose. The temporal artery, with the auriculotemporal nerve behind it, crosses the base of the zygoma just in front of the ear. The vessel divides into its two terminal branches (the anterior and posterior) 2 inches above the zygoma. The branches of this artery, especially the an- terior branch, are often very tortuous in the aged, and afford early evidence of arterial degeneration. Arteriotomy is sometimes practised on the an- terior branch of this vessel. The superficial tem- poral vessels are very liable to be the seat of cirsoid aneurism, as, to a less extent, are the other scalp arteries. Cirsoid aneurism is more often met with in the superficial temporal arteries than in any other artery in the body. The posterior auricular artery and nerve run in the groove be- tween the mastoid process and the ear, and the occipital artery and great occipital nerve reach the scalp just internally to a point midway be- tween the occipital protuberance and the mastoid process. Certain of the emissary veins are of import- ance in surgery. These veins pass through aper- 14 SURGICAL APPLIED ANATOMY [Part J tures in the cranial wall, and establish communi- cations between the venous circulation (the sinuses) within the skull and the superficial veins external to it. The principal emissary veins are the following : 1. A vein passing through the mas- toid foramen and connecting _ the lateral sinus with the posterior auricular vein or with an occi- pital vein. This is the largest and most constant of the series. The existence of this mastoid vein serves to answer the question, Why is it a com- mon practice to apply leeches and blisters behind the ear in certain cerebral affections 1 2. A vein connecting the superior longitudinal sinus with the veins of the scalp through the parietal fora- men. 3. A vein connecting the lateral sinus with the deep veins at the back of the neck through the posterior condylar foramen (inconstant). 4. Minute veins following the twelfth nerve through its foramen, and connecting the occipital sinus with the deep veins of the neck. 5. Minute veins passing through the foramen ovale, foramen of Vesalius, foramen lacerum medium, and carotid canal to connect the cavernous sinus with (respec- tively) the pterygoid venous plexus, the pharyn- geal plexus, and the internal jugular vein. Then, again, many minute veins connect the veins of the scalp with those of the diploe. Of the four diploic veins, two (the frontal and anterior temporal) enter into surface veins (the supra- orbital and deep temporal), and two (the pos- terior temporal and occipital) enter into the lateral sinus. Lastly, there is the well-known communication between the extra- and intracranial venous circu- lation effected by the commencement of the facial vein at the inner angle of the orbit. In this com- munication the angular and supraorbital veins unite with the superior ophthalmic vein, a tribu- tary of the cavernous sinus. The veins within the cavities of the nose and middle ear also communi- cate with those of the meninges. Through these various channels, and through Chap. I] THE SCALP 15 many probably still less conspicuous, inflammatory processes can spread from the surface to the in- terior of the skull. Thus we find such affections as Nerve areas of the face and scalp. a, a, Distribution of the first division of the fifth cranial nerve : a', nasal branch ; a", supratrochlear ; a'", supraorbital, n, b, distribution of the second division ; b', infraorbital branch j b", malar branch ; b"', temporal branch. c, c, distribution of the third division ; c', mental branch ; c", buccal branch ; c'", auriculo-temporal. 1, area of great occipital; 2, of small occipital; 3, of great auricular; 4, of superficial cervical ; .% of third occipital. erysipelas of the scalp, diffuse suppuration of the scalp, necrosis of the cranial bones, and the like, leading by extension to mischief within the diploe, to thrombosis of the sinuses, and to inflammation 16 SUEGICAL APPLIED ANATOMY [Part I of the meninges of the brain. If there were no emissary veins, injuries and diseases of the scalp and skull would lose half their seriousness. Mis- chief may even spread from within outwards along an emissary vein. Erichsen reports a case where the lateral sinus was exposed in a compound frac- ture. The aperture was plugged. Thrombosis and suppuration within the sinus followed, and some of the pus, escaping through the mastoid vein, led to an abscess in the neck. Certain venous tumours are met with on the skull. They consist of collections of venous blood under the pericranium that communicate, through holes in the skull, with the superior longitudinal sinus. They are median, are reducible on pressure, and receive a faint pulsation from the brain. The holes are sometimes the result of accident, others depend upon bone disease or atrophy over a Pac- chionian body, and a few are due to -a varicose emissary vein or to a congenital defect in the cranium, especially in the neighbourhood of the parietal foramina. The scalp nerves, especially such as are branches of the fifth pair, are often the seat of neuralgia (Fig. 4). To relieve one form of this affection, the supraorbital nerve has been divided (neurotomy) at its point of exit from the orbit, and a portion of the nerve has been resected (neurectomy) in the same situation. Some forms of frontal headache depend upon neuralgia of this nerve. The inner branch of the nerve reaches the middle of the parietal bone ; the outer branch, the lambdoid suture. The lymphatics from the occipital and pos- terior parietal regions of the scalp enter the oc- cipital and mastoid glands ; those from the frontal and anterior parietal regions go to the parotid glands, while some of the vessels from the frontal region join the lymphatics of the face and end in the submaxillary glands (Fig. 35, p. 190). CHAPTER II THE BONY VAULT OF THE CRANIUM Position of the sutures. — The bregma, or point of junction of the coronal and sagittal sutures, is in a line drawn vertically upwards from a point just in front of the external auditory meatus, the head being in normal position (Fig. 2). The lambda, or point of junction of the lambdoid and sagittal sutures, lies in the middle line, about 2\ inches above the occipital protuberance (Fig. 2). The lambdoid suture is fairly represented by the upper two-thirds of a line drawn from the lambda to the apex of the mastoid process on either side. The coronal suture lies along a line drawn from the bregma to the middle of the zygomatic arch. On this line, at a spot about 1^ inches behind and above the fronto-malar junction, is the pterion, the region where four bones meet, viz. the squamous bone, the great wing of the sphenoid, the frontal and parietal bones (Fig. 2). The summit of the squamous suture is If inches above the zygoma. In the normal subject all traces of the fon- tanelles and other unossified parts of the skull disappear before the age of two years (Fig. 6). The anterior fontanelle is the last to close, while the posterior is already filled at the time of birth. It is through or about the anterior fontanelle that the ventricles are usually as- nirated in cases of hydrocephalus. The needle is either entered at the sides of the fontan- elle at a sufficient distance from the middle c 17 18 SURGICAL APPLIED ANATOMY [Part I line to avoid the longitudinal sinus, or is intro- duced through the coronal suture at some spot other than its middle point. It may be noted that in severe hydrocephalus the coronal and other sutures of the vault are widely opened. The condition known as cr»nio-tal>es, a con- dition assigned by some to rickets and by others to inherited syphilis, is usually met with in the verti- cal part of the occipital bone, and in the adjacent parts of the parietal bones, but especially in the posterior inferior angles of these bones. In this condition the bone is greatly thinned in spots, and its tissue so reduced that the affected district feels to the finger as if occupied by parchment, or, as some suggest, by cartridge paper. The thinning is mainly at the expense of the inner table and diploe. The pits are situated over the impressions of early formed convolutions. It is, on the other hand, about the site of the anterior fontanelle that cer- tain osseous deposits are met with on the surface of the skull in some cases of hereditary syphilis (Parrot). These deposits appear as rounded ele- vations of porous bone situated upon the frontal and parietal bones, where they meet in the middle line. These bosses are separated by a crucial de- pression represented by the frontal and sagittal sutures on the one hand and the coronal suture on the other. They have been termed " natiform " elevations by M. Parrot from their supposed resem- blance, when viewed collectively, to the nates. To the- English mind they would rather suggest the outlines of a "hot-cross bun." It is necessary to refer to the development ol the skull in order to render intelligible certain conditions (for the most part those of congenital malformation) that are not unfrequently met with. Speaking generally, it may be said that the base of the skull is developed in cartilage, and the vault in membrane. The parts actually formed in mem- brane are represented in the completed skull by the frontal and parietal bones, the squamo-zygo- matic part of the temporal bone, and the greater Chap. Ill THE VAULT OF THE CRANIUM 19 part of the expanded portion of the occipital bone. The distinction between these two parts of the skull is often rendered very marked by disease. Thus there are, in the museum of the Royal College of Surgeons, the skulls of some young lions that were born in a menagerie, and that, in consequence of malnutrition, developed certain changes in their bones. A great part_ of each of these skulls shows considerable thickening, the bone being con- verted into a porous structure ; and it is remark- able to note that these changes are limited to such parts of the skull as are formed in membrane, the base remaining free. In hydrocephaly and in the condition known as achondroplasia, it is only the bones formed in membrane which are unduly ex- panded. Among the more common of the gross malforma- tions of the skull also is one that shows entire ab- sence of all that part of the cranium that is formed in membrane, while the base, or cartilaginous part, is more or less perfectly developed — the condition of anencephaly. Meningocele is the name given to a con- genital tumour that consists of a protrusion of a part of the cerebral mem- branes through a gap in an imperfectly developed skull. When the protrusion contains brain, it is called an encepha- locele, and w r hen that pro- truded brain is distended by an accumulation of fluid with- in the ventricles, it is called hydrencephalocele. These pro- trusions are most often met with in the occipital bone, and next in frequency in the f ronto-nasal suture, while in rarer cases they have been met with in the lambdoid, sagittal, and other sutures, and have projected through normal and abnormal fissures at the Fig. 5. — The occipital bone at birth. 20 SURGICAL APPLIED ANATOMY [Part I base of the skull into the orbit, nose, and mouth. Their frequency in the occipital bone may be in some degree explained by a refer- ence to the development of that part. This bone at birth consists of four separate parts (Fig. 5), a basilar, two condylar, and a tabular or expanded part. In the tabular part, about the seventh week of foetal life four nuclei appear, an upper and a lower pair. These nuclei are to some extent separated by fissures running inwards from the four angles of the bone to meet /ietopic Suture .Frontal Eminence ...BReqmatic Fontanelle ...Coronal suture .SAqiTTAL 5UTURE -Parietal Eminence Sagittal Fontanelle LambdoidalFo/uahelle Inter Parietal Supra Occipital Fig. 6.— Skull of newly born child from above. at the occipital protuberance. The gap running up in the median line from the inferior angle at the foramen magnum to the occipital protuberance is especially distinct (the temporary occipital fontanelle of Sutton). It exists from the beginning of the third to the end of the fourth month of intrauterine life. Meningoceles of the occiput are always in the middle line, and the protrusion probably occurs through this gap. The gap associ- ated with meningocele may extend through the whole vertical length of the occipital bone, and very commonly opens up the foramen magnum. The lateral or transverse fissures divide the bone into two parts. The upper part is developed from Chap. II] THE VAULT OF THE CRANIUM 21 membrane, the lower part from cartilage. The lateral fissures may persist, and may simulate frac- tures, for which they have, indeed, been mistaken ; or they may be so complete as entirely to separ- ate the highest part of the occipital bone from the remainder. The bone so separated is the os epactal of the French, the interparietal bone of some animals (Fig. 6). Parietal fissures. — In the developing parie- tal bone, fibres concerned in ossification radiate towards the periphery from two nuclei about the centre of the bone. An interfibrillar space, larger than the rest, is seen about the fifth month, to separate the loose osseous fibres which abut on the posterior part of the sagittal border from the stronger fibres which form the rest of this border (Pozzi). This is the parietal fissure (Fig. 6). It usually closes and leaves no trace, but it may per- sist in part as a suture-like fissure, and be mistaken for a fracture. If the fissure persists equally on the two sides an elongated lozenge-shaped gap is left, the sagittal fontanelle (Fig. 6). It is situate about an inch in front of the lambda, and occurs in over 4 per cent, of newly born children (Lea). The parietal foramina are remains of this interval. Wormian bones. — These irregular bones may be mistaken for fragments produced by frac- ture. They are most usually met with in the lamb- doid suture. One Wormian bone deserves special notice, as it may be met with in trephining over the middle meningeal artery. It exists between the anterior inferior angle of the parietal bone and the great wing of the sphenoid. It is scale-like, and gives the impression that the tip of the great wing has been separated. It is known as the cpipteric bone. Necrosis is fairly common on the vault of the skull, and most often attacks the frontal and parietal bones, while, for reasons that are not very obvious, it is rare in the occi- pital bone. The external table is frequently necrosed alone, it being more exposed to injury 22 SURGICAL APPLIED ANATOMY [Part I and less amply supplied with blood than is the internal table. From the converse of these reasons it happens that necrosis of the internal table alone is but rarely met with. Necrosis in- volving the entire thickness of the bone may prove very extensive, and in a case reported by Saviard, practically the whole of the cranial vault necrosed and came away. The patient was a woman, and the primary cause of the mischief was a fall upon the head when drunk. Necrosis of the skull, as well as caries of the part, is attended by certain special dangers that depend upon the anatomical relations of the cranial bones. Thus, when the whole thickness of the skull is involved by disease, or when the inner table is especially attacked, a collection of pus may form between the dura mater and the affected bone, and may produce compression of the brain. When the diploic tissue is implicated, the veins of that part may become thrombosed, or may be the seat of a suppurative phlebitis. The mischief thus com- menced may spread, the great intracranial sinuses may be closed by thrombus, or septic matter may be conveyed into the general circulation and lead to the development of pyaemia. Mere local extension may also cause meningitis. In cases of necrosis of the external table the growth of granulation tissue from the exposed and vascu- lar diploe plays a very important part in aiding the exfoliation of the lamella of dead bone. Fractures of the skull. — It is not easy to actually fracture the skull of a young infant. The skull as a whole at this age is imperfectly ossified, the sutures are wide, and between the bones there is much cartilage and membrane. Moreover, the bones themselves in early life are elastic, and com- paratively soft and yielding. If a blow be inflicted upon the vault in a young child the most probable effect, so far as the bone itself is concerned, is an indenting or bulging in of that bone unassociated with a fracture in the ordinary sense. In this par- Chap. II] THE VAULT OF THE CEANIUM 23 ticular relation, the skull of an infant is to that of an old man as a cranium of thin tin would be to a cranium of strong earthenware. The yielding char- acter of the young child's skull is well illustrated by the gross deformity of the head that certain Indian tribes produce in their offspring by apply- ing tight bandages to the part in infancy. In the Royal College of Surgeons museum are many skulls of "flat-headed" Indians, that show to what an extreme this artificial deformity may be carried. Gueniot also asserts that much deformity of the head may be produced in infants by the practice of allowing them to always lie upon one side of the body. Here the deforming agent is simply the weight of the brain. Even in adults the skull is much less brittle than is commonly supposed, and notions as to the breaking ability of the cranial bones derived from the study of the dried specimens are apt to be erroneous. During life a sharp knife properly directed may be driven through the cranial vault so as to cause only a simple perforating wound with- out splintering, and without fracture of the bone beyond the puncture. Such a wound may be as cleanly cut as a wound through thick leather, and a specimen in the London Hospital museum serves well to illustrate this. A case reported in the Lancet for 1881 affords a strange instance of a knife penetrating the skull without apparently splinter- ing the bone. A man wishing to commit suicide placed the point of a dagger against the skull in the upper frontal region, and then drove it well into the brain by a blow from a mallet. He ex- pected to fall dead, and was disappointed to find that no phenomena of interest developed. He then drove the dagger farther in by some dozen blows with the mallet, until the blade, which was four inches long, was brought to a standstill. The dagger was removed with great difficulty, the patient never lost consciousness, and recovered without a symptom. The following anatomical conditions tend to 24 SUBGtfCAL APPLIED ANATOMY [Part I minimise the effects of violence as applied to the skull : the density of the scalp and its great mobility ; the dome-like arrangement of the vault ; the number of the bones that compose the head, and the tendency of the violence to be broken up amongst the many segments ; the sutures which interrupt the continuity of any given force, and the sutural membrane, which acts as a kind of linear buffer ; the mobility of the head upon the spine ; and the elasticity of the cranial bones themselves. The skull is further strengthened by the pre- sence of six buttresses or pillars at the junction of the vault and base. Two of these are lateral, the orbito-sphenoid anteriorly and the petro-mastoid posteriorly, while the fronto-nasal and occipital strengthen the anterior and posterior ends of the skull. In children the membranous layer between the sutures is of considerable thickness, but as age advances this membrane disappears and the bones tend to fuse together (synostosis). The sutures begin to be obliterated about the age of forty, the change commencing on the inner aspect of the suture, and appearing first in the sagittal suture, then in the coronal and lambdoid, and last in the squamous. As age advances, moreover, the skull bones become thicker owing to a deposit over the inner table to replace the diminishing brain, and lose much of their elasticity. They are, there- fore, more readily fractured in the aged than in the young. As a rule, in fracture, the entire thickness of the bone is involved ; but the external table alone may be broken, and may even be alone depressed, being driven into the cliploe, or, in the case of the lower frontal region, into the frontal sinus. The internal table may be broken without a corresponding frac- ture in the outer plate ; and in nearly all cases of complete fracture, especially in such as are at- tended with depression, the internal table shows more extensive splintering than does the external. There are many reasons for this. The internal Chap. II] THE VAULT OF THE CRANIUM 25 plate is not only thinner than the external, but is so much more brittle as to receive the name of the "vitreous table. A force applied to the external table may be extremely limited, and produce, as in a sabre cut, but a limited lesion. As the force, however, travels through the diploe it becomes broken up, and reaches the inner plate as a much more diffused form of violence. This is especially the case when parts of the outer table are driven in. Then, again, the internal plate is a part of a smaller curve than is the external plate ; and, lastly, Agnew assigns a reason for the greater vul- nerability of the inner plate that has reference to the general yielding of the bone. In Fig. 7* a b represents a section of a part of the vault through both tables, and c d and e f two vertical and paral- lel lines. Now, if force be applied to the vault be- tween these parallel lines, the ends of the arch, 26 SUPGtfCAL APPLIED ANATOMY [Part 1 A b, will tend to become separated, and the whole arch, yielding, will tend to assume the curve shown in Fig 8. In such case, the lines c d and e f will converge above and diverge below (Fig. 8), so that the violence would tend to force the bone particles together at the outer table and asunder at the inner table. Fractures of the vault are due to direct violence. The construction of the skull is such that the fracturing force is resisted in many ways. (1) When a blow is received on the vertex in the parietal region, the force tends to drive the upper borders of the two parietal bones inwards. Such driving-in of these borders must be associated with a corresponding outward movement of the inferior borders. This latter movement is forcibly resisted by the squamous bone and the great wing of the sphenoid, which overlap the lower edge of the parietal bone. Moreover, the force transmitted to the squamous bone is passed on to the zygomatic arch, which takes its support from the superior maxillary and frontal bones. This arch then acts as a second resisting buttress, and this transmission of force from the vertex to the facial bones is said to be illustrated by the pain often felt in the face after blows upon the top of the head. (2) If the upper part of the frontal bone be struck, the force is at once transmitted to the parietal bones, be- cause the upper part of the frontal bone (owing to the manner in which its border is bevelled) actu- ally rests upon the two parietal bones, so the same resistance is again called into action. If there be any tendency for the inferior parts of the bone to move outwards, as would certainly be the case while the mid-frontal suture existed, such movement would be resisted by the great wings of the sphenoid and by the anterior inferior angles of the parietal bones which embrace or overlap these parts of the frontal. Thus it will be seen that much depends upon the manner in which the corresponding edges of the frontal and parietal bones are bevelled. (3) Blows upon the occiput are less distinctly pro- Chap. II] THE VAULT OF THE CRANIUM 27 vided for, and it must be owned that a by no means heavy fall is sufficient to break this bone. It must receive, however, much protection from its connections with the two parietal and tem- poral bones, and from its articulation with the elastic vertebral column. Fractures of the base of the skull may be due to (1) direct or to ^) indirect violence, or, most commonly of all, to (3) extension of a fracture from the vault. (1) The base has been fractured Iry direct violence due to foreign bodies thrust through the nasal roof, through the orbital roof, and through the base as it presents in the pharynx. The posterior fossa can also be fractured by vio- lence applied to the nape of the neck. (2) Of frac- tures by indirect violence the following examples may be given : Blows applied to the lower part of the frontal bone have been associated with no lesion other than a fracture of the cribriform plate or of the orbital part of the frontal, these parts being much disposed to fracture on account of their extreme tenuity. In 86 cases of fracture of the base of the skull, the orbital roof was involved in 79, the optic foramina in 63, and the cribriform plates in nearly all (Rawl- ing). In falls upon the chin, the condyle of the lower jaw has been so violently driven against the glenoid cavity as to fracture the middle fossa of the skull. The force of a "knock-out", blow applied to the point of the chin produces concussion of the brain without fracture of the skull. When the body in falling has alighted upon the feet, knees, or but- tocks, the force has been transmitted along the vertebral column, and has led to fracture of the base in the occipital region. Such accidents are most apt to occur when the spine is kept rigid by muscular action, and the mechanism involved is precisely similar to that whereby the head of a broom is driven more firmly on to the broom-handle by striking the extreme end of the stick against the ground. The theory that the base is often broken by contre-coup is pretty generally abandoned, 28 SUEGICAL APPLIED ANATOMY [Part I although there are a few cases that appear to sup- port the suggestion. Such a case was recorded by Mr. Hutchinson, and in it a fracture of the occipital bone was associated with a like lesion in the cribri- form plate, the intervening part of the skull being uninjured. (3) Fractures of the vault, and especi- ally linear fractures due to such diffused violence as obtains in a fall upo%the head, are very apt to spread to the base. In so spreading they reach the base by the shortest possible route, and without any regard to the sutures encountered or to the density of the bones involved. Thus, fractures of the frontal region of the vault spread to the an- terior fossa of the base, those of the parietal region to the middle fossa, and those of the occipital region to the posterior fossa. To this rule there are but few exceptions. To indicate more precisely the exact bones involved in these three districts, P. Hewett has divided the skull into three zones. The anterior zone includes the frontal, the upper part of the ethmoid, and the f ronto-sphenoid ; the middle, the parietals, the squamous and anterior part of the petrous of the temporals, and the greater part of the basi-sphenoid ; and the pos- terior, the occipital, the mastoid, the posterior part of the petrous bone, with a small part of the body of the sphenoid. In all fractures of the base there is usually a discharge of blood and of cerebro-spinal fluid ex- ternally. (1) In fractures of the anterior fossa the blood usually escapes from the nose, and is derived from the meningeal and ethmoidal vessels, or in greater degree probably from the torn mucous lin- ing of the nasal roof. To allow of the escape of cerebro-spinal fluid from the nose, there must be, in addition to the fracture in the nasal roof, a lacer- ation of the mucous membrane below that fracture, and of the sheaths of the olfactory nerves which are derived from the dura mater and arachnoid. A profuse discharge of cerebro-spinal fluid may take place through the nasal mucous membrane inde- pendently of injury. The discharge probably oc- Chap. II] THE VAULT OF THE CEANIUM 29 curs along the sheaths of the olfactory nerves, and is caused by a lessened absorption or increased secretion of cerebro-spinal fluid. In many cases of fracture in this part the blood finds its way into the orbit, and appears beneath the conjunctiva. (2) When the middle fossa is involved, the blood escapes from the external auditory meatus, through a rupture in the tympanic membrane, and is de- rived from the vessels of the tympanum and its membrane, or from an intracranial extravasation, and in some cases from a rupture of the cavernous or petrosal sinuses. The blood may follow the Eustachian tube, and may escape from the nose or mouth, or be swallowed and subsequently vomited. To allow of the escape of cerebro-spinal fluid by the ear ("the serous discharge "), (a) the fracture must have passed across the internal auditory meatus; (b) the tubular prolongation of the membranes in that meatus must have been torn ; (c) there must be a communication between the internal ear and the tympanum ; and (d) the membrana tympani must have been lacerated. (3) In fractures of the posterior fossa an extravasation of blood may ap- pear about the mastoid process or at the nape of the neck, or may even extend into the cervical region. It may be added that in compound fractures of the vault associated with tearing of the dura mater and arachnoid, an escape of cerebro-spinal fluid has in a few rare instances been noted. After simple fracture of the vault in children a swelling may form at the injured part which fluctuates, be- comes tenser when the patient cries, and may pos- sibly pulsate synchronously with the brain. Such swellings are clue to a collection of cerebro-spinal fluid beneath the scalp, and indicate a coincident rupture of the brain membranes. Separation of sutures. — This condition, as the result of injury, is practically restricted to the young skull. In later life, force applied at the site of an obliterated suture may cause a fracture, which accurately follows the old suture line. Separ- ation of the sutures, independent of fracture, is 30 SUEGICAL APPLIED ANATOMY [Part I very rare in the adult skull. In the few instances of such a condition the temporal bone has usually been the one displaced and the separation noted at the squamous suture. When associated with fracture, the coronal and sagittal sutures are those most frequently separated, and next in fre- quency is the lambdoid. The thickness of the skull cap varies greatly, not only in different parts of the same skull, but also in corresponding parts in different individuals. The average thickness is one-fifth of an inch. It varies with age ; at birth the parietal is less than T V inch ; at three years diploe appear, marking off the inner from the outer table of the skr: 11; in old people the parietal bone may be \ inch or \ inch in thickness. The thickest parts are at the occipital protuberance (where the section may measure half an inch), the. mastoid process, and the lower part of the frontal bone. The bone over the inferior occipital fossae and orbit is very thin, while it is thinnest over the squamous bone. Here. the bone may be no thicker in parts than a visiting card. The skull is also thinned over the sinuses and grooves for the meningeal vessels. It is especially thin over the anterior in- ferior angle of the parietal bone. It is important to remember in trephining that the inner table is not always parallel with the outer. Craniectomy. — This operation is carried out in cases of microcephaly in infants and chil- dren. It consists in the removal of a strip of bone from the vertex of the skull so as to give to the brain, as an American author expresses it, " more elbow room." The operation presumes that the arrest of growth in the brain is due to a retarded growth of the skull, but all the evidence at our dis- posal points to the arrest in the development of the brain as the primary lesion ; the condition of the skull being a consequence. In hydrocephaly the skull is seen to respond readily to the quick expansion of the brain ; if the growth of the brain is arrested, the skull remains small. CHAPTER III THE CRANIAL CONTENTS Membranes of tlie brain. — The dura mater, from its toughness, forms an excellent protec- tion to the brain. It is very intimately adherent to the bone over the whole of the base of the skull, and consequently in this situation extrava- sations between* the membrane and the bone are scarcely possible. Over the vault its attachments are comparatively loose, although it is more closely adherent along the lines of the sutures. This lax attachment allows large hsemorrhagic and puru- lent extravasations to collect between the dura mater and the bone. Such extravasations usually lead to compression of the brain, and it may be noted that in the great majority of all cases of compression the compressing force is outside the dura mater. Thus, in uncomplicated cases when symptoms of compression come on at the time of an accident, the cause is probably depressed bone ; when they appear after a short interval, the cause is probably extravasated blood between the mem- brane and the bone; and when a long interval (days or weeks) has elapsed after the accident, the cause is probably a collection of pus in the same situation. Sir C. Bell pointed out that the dura mater of the vault may be separated from the bone by the vibration produced by a blow. "Strike the skull of a subject with a heavy mallet ; on dissecting you find the dura mater to be shaken from the skull at 31 32 SUEGICAL APPLIED ANATOMY [Part I the point struck. Repeat the experiment on an- other subject, and inject the head minutely with size injection, and you will find a clot of injection lying betwixt the skull and dura mater at the part struck, and having an exact resemblance to the coagulum found after violent blows on the head." Tillaux has demonstrated that the adhesions be- tween the dura mater and the bone are particularly weak in the temporal fossae, the most usual site of meningeal haemorrhage. When blood is poured out between the dura mater and the bone in cases of fracture, the vessel that as a rule gives way is the middle menin- geal artery. In thirty-one cases of such haemorrhage, this vessel was the source of the bleeding in twenty-seven instances (P. Hewett). The vessel, having passed through the foramen spinosum, divides into two branches ; the anterior, the larger, runs upwards across the anterior in- ferior angle of the parietal bone and ascends the vault some distance behind the coronal suture ; the posterior runs backwards, with a horizontal sweep across the squamous bone, and takes the course of the second temporal convolution. (See Figs. 2, 3.) Mr. Jacobson has shown that the branches of the artery are more frequently ruptured than the trunk. The vessel is very frequently torn as it crosses the anterior angle of the parietal bone. There are many reasons for this : the bone where grooved by the artery is very thin ; the artery is often so embedded in the bone that fracture with- out laceration of the vessel would hardly be pos- sible ; and lastly, the particular region of the artery is a part of the skull peculiarly liable to be fractured. Mr. Jacobson shows that the artery may be ruptured by a force that does not fracture the skull, but merely leads to detachment of the dura mater. Failing this vessel, the most frequent source of extrameningeal haemorrhage is the lateral sinus, for reasons that will be obvious. Venous sinuses. — The flaccid-walled cerebral Chap. Ill] THE CRANIAL CONTENTS 33 veins, which are compressed with each pulsa- tion of the brain, empty into the venous sinuses, rigid-walled cavities formed between the outer or periosteal and inner or supporting layers of the dura mater. At the points where the superior cerebral veins enter the superior longitudinal sinus, and w T here the temporo-sphenoidal and occipital veins join the lateral sinus, the arach- noid, elsewhere free from dura mater, is firmly adherent to it. From a surgical point of view the lateral is the more important sinus; and as it turns downwards beneath the mastoid process it comes into close relationship with the antrum and cells of the mastoid, from which a septic con- dition may spread to the sinus, setting up throm- bosis (see Fig. 20, p. 86). The lateral sinus is marked out by taking the following three points (see Fig. 2, p. 9, and Fig. 3, p. 12) : (1) The inion, (2) the asterion, (3) a point h inch behind the lower border of the meatus. When these three points are joined, the upper and anterior borders of the sinus are marked out. The sinus is 10 mm. wide. The : lateral sinus escapes from the skull to form the internal jugular vein in line with the anterior border of the mastoid process, but situated deeply beneath the parotid gland (Fig. 2, p. 9). A line drawn over the vault of the skull from nasion to inion marks the line of the superior longitudinal sinus; beneath the posterior third of the sagittal suture it may not keep exactly to the middle line, and in this part of its course it frequently shows lateral extensions or diverti- cula known as parasinoids. In the majority of cases the superior longitudinal ends in the right lateral sinus, which is hence commonly larger than the left. < The cavernous sinus, enclosing the internal carotid artery and sixth cranial nerve, with the third, fourth and greater part of the fifth embedded in its wall, is situated over the sphenoidal air sinus^ from which septic conditions may extend to it, giving rise to thrombosis. In such cases the eyes become prominent owing to the D 34 SUEGICAL APPLIED ANATOMY [Part I distension of the ophthalmic veins, for the venous stream from the orbit flows through the cavernous sinus to reach the lateral sinus and jugular vein by means of the superior and inferior petrosal sinuses. Tumours of the pituitary necessarily compress the cavernous sinus. The relations between the inter- nal carotid artery and cavernous sinus are so in- timate that an arterio-venous aneurism has fol- lowed injury involving these parts. It will be seen also with what ease this sinus could become thrombosed in cases of inflammation within the orbit by the extension of the mischief along its great tributaries, the two ophthalmic veins. Between the dura mater and the arachnoid is the subdural space, which, like the pleural cavity, is merely a potential space, for in health the arachnoid is closely applied to the smooth inner surface of the dura mater^ A space is formed only when fluid, blood, or pus is collected between the two membranes (Fig. 1, p. 2). The subdural space contains a small amount of fluid, and acts, probably, like the pleural and peritoneal sacs, in preventing the effects of friction during the move- ments of the brain. A knowledge of the subarachnoid space is steadily becoming of greater surgical importance. The space which surrounds the spinal cord is in direct continuity with the subarachnoid spaces of the brain, and hence, when this space is tapped in the lumbar part of the spinal canal (Fig. 107, p. 612), the fluid situated in the subarachnoid spaces of the brain is also drained off (Fig. 9). In meningitis the cerebro-spinal fluid becomes turgid ; the subarachnoid space, or parts of it, may contain pus. In the spinal column the arachnoid is widely separated from the pia mater, hence the subarach- noid space is extensive. As the space passes into the skull it forms an expansion between the cere- bellum and roof of the fourth ventricle named the cisterna magna (Fig. 9); an opening in the roof of the fourth ventricle (the foramen of Majendie) allows the cerebro-spinal fluid in the ventricles of Chap. III1 THE CRANIAL CONTENTS 35 the brain to join that in the cisterna magna (Fig. 9). On the base of the skull, in front of the medulla and pons, the spinal subarachnoid space expands into the cisterna pontis, which in turn becomes continuous with a large space situated on the base of the brain between the temporal lobes and under the inter-peduncular space — the cisterna basalis (Fig. 9). In this cistern are situated the circle of Willis, the third, fourth, and root of the fifth Calloso /1arcinal Space Supra Cauosal Space Splenium Velum Interpositun Pl/IEAL C.LAND Tentorium Cerebelli Aqueduct ofSylvius Four.™ Ventricle Foramen of/IajendiEt Cisterna macna Cut edge of Arachnoid Supra- CallosalSpace Lateral Ventricie; Genu Foramen of aionro Third entricle Sub Callosal Space Cisterna Basalis Optic /terve Pituitary Body _ Internal arotid art- Temporal L0B& iro /Ierve Cisterna Spinalis Cisterna Pontis ^Cisterna /Iedullaris .Cisterna Spinalis Fig. 9. — Diagram of the cranial spaces containing cerebro-spinal fluid. nerves, the optic chiasma and tracts and infundi- bulum of the pituitary body. In basal meningitis it may become distended with pus. The inflam- matory adhesions which occur in the inferior medullary velum may lead to a condition of hydrocephaly by closing up the openings in that membrane. Over the convolutions of the brain the arachnoid is bound by the pia mater, which here serves as a loose subarachnoid tissue. Every- where extensions of the basilar cistern pass out with the arteries derived from the circle of Willis into the pia mater in the sulci of the brain. While 36 SURGICAL APPLIED ANATOMY [Part I the interpeduncular part of the base of the brain, pons and medulla rest on these basal cisterns, the temporal and frontal lobes lie directly on the base of the skull ; the occipital lobe rests on the tentor- ium cerebelli. > The three poles of the brain— the frontal, occipital and temporal — are in direct contact with the meninges and skull, and are therefore the parts of the brain that are most liable to laceration in cases of injury to the head. The cerebro-spinal fluid prevents the ill effects that irregularities in the blood circulation might have upon the brain, situate as it is within an un- yielding cavity. If the great nerve centres near the lateral ventricles are swollen by congestion, they are not met by an unyielding wall, but merely dis- place some of the cerebro-spmal fluid through the foramen of Majendie, until such time as their cir- culation is normal again. When the healthy brain is exposed by a trephine opening it is seen to pulsate with each beat of the heart; if it does not pulsate, this shows that the pressure within the skull is higher than the arterial pressure (100-130 mm. Hg.); normally, as Hill has shown, the intracranial pressure is that of the blood- pressure in the veins (10-15 mm. Hg.). With each pulsation of the heart about 5 cm. of arterial blood is thrown into the skull, causing the ejection of a similar amount of venous blood by the jugular vein. Fluid may pass from the lateral to the third ventricle by the foramen of Monro ; from the third to the fourth ventricle by the aqueduct of Sylvius ; and from the fourth ventricle to the cisterna magna by the foramen of Majendie (Fig. 9). Many still share the opinion of Hilton that blockage of the aqueduct, or closure of the foramen of Majendie, or of the other two openings at the lateral angles of the fourth ventricle — (the fora- mina of Key and Retzius) — may prevent the exit of cerebro-spinal fluid from the ventricles and thus produce the condition of hydrocephaly. The fluid also drains into the veins of Galen, hence pressure Chap. Ill] THE CRANIAL CONTENTS 37 on these may bring about a like result. It has been proposed to relieve the pressure within the lateral ventricles in cases of hydrocephaly by draining the cerebro-spinal fluid into the subdural space by means of a seton. It is absorbed under any pressure above that within the cerebral veins (Hill). If the brain, too, becomes enlarged by congestion, it is not met by unyielding bone, but rather by an ad- justable water-bed, and during its period of en- largement it merely displaces into the spinal part of the subarachnoid space some of the fluid that surrounds it. This mutual effect is well illustrated in a case reported by Hilton of a man with a frac- ture of the base, from whose ear cerebro-spinal fluid was escaping. The discharge of this fluid was at once greatly increased by expiratory efforts when the nose and mouth were held closed and the veins compressed in the neck. The surface relationships of the Drain (see Figs. 10 and 11). — The longitudinal fissure of the brain is indicated by a line drawn along the vertex from the glabella to the external occipital protu- berance. It is narrow in front, but as it contains the longitudinal sinus, which rapidly enlarges as it passes backwards, it becomes of considerable breadth behind, and as a rule lies somewhat to- wards the right of the median line, owing to the predominance of the left cerebral hemisphere. Between the external occipital protuberance and the ear, the lateral sinus bounds the lower level of the cerebrum and the upper of the cerebellum (Figs. 3 and 10). In front of the ear the upper border of the zygoma in its posterior three-fourths marks the lower border of the temporal lobe. The pole of the temporal lobe is f of an inch behind the outer margin of the orbit (see Fig. 3). The lower limit of the brain on the forehead may be indicated approximately by drawing a line from the glabella to the Sylvian point, ^ an inch above the upper margin of the orbit. The olfactory bulbs lie at the level of the nasio_n (Fig. 3). The cerebellum is best explored at a point 1^ 38 SUKGICAL APPLIED ANATOMY [Part I inch behind and | inch below the level of the external auditory meatus (see Fig. 3, p. 12). _ It is deeply placed, being covered by the insertions of the occipital muscles. FISSURE of ROLANDO. PARIETAL EMINENCE BREQMA r-NASION Fig. 10. — Showing the relation of the brain and sensori-motor areas of the cortex to the skull. {Modified from Quain.) The sensori-motor areas are shaded ; the leg and trunk areas with vert Lea] lines ; the arm and hand areas with lines slanting forwards; the face and mouth areas with lines slanting backwards; the tongue, pharynx, and larynx areas are stippled. The ascending frontal convolution, containing the areas which are strictly motor in function, is indicated by red lines. The motor centre for speech on Broca's convolution is shaded with horizontal lines. The "word- hearing" centre is indicated on the superior temporal convolution, and the' "word-seeing" centre on the angular convolution. The area shaded with horizontal lines on the posterior parts of the middle and inferior frontal convolutions is the centre for combined movements of I he head and eyes. Of the many methods which have been sug- gested for marking out the fissure of" Rolando, the most simple and accurate is the following : A point over the sagittal suture is taken midway Chap. Ill] THE CRANIAL CONTENTS 39 between the glabella and external occipital pro- tuberance. Half an inch behind the mid point terminates the upper end of the fissure (Fig. 11). A line 3h inches long drawn downwards and Upper rolandic POINT MID POINT. PARIETO- OCCIPITAL FISSURE PAf^EMIN. LAMBDA./S X BRECMA. WON. Fig. 11. — Showing the lines which indicate the position of the principal fissures of the brain. Reid's base line is drawn from the lower margin of the orbit backwards through the meatal point. forwards from this point, at an angle of 67° to the line of the sagittal suture, will indicate the position of the fissure of Rolando in the adult. In the child the fissure is shorter and the con- tained angle is 5° smaller. The angle is easily 40 SURGICAL APPLIED ANATOMY [Part I obtained by folding twice the corner of a square piece of paper and removing a fourth of the right angle. This line may not lie exactly oyer the fissure, for it varies somewhat in position according to the shape of head. The sensori- motor areas of the brain are mostly represented in the ascending frontal and parietal convolu- tions which bound the fissure of Rolando. The average width of each of these convolutions is J of an inch. The coronal suture is about 2 inches in front of the fissure of Rolando at its upper part and 1| inch at its lower. The fissure of Sylvius is indicated thus (Fig. 11) : — A point is taken 1| inch behind and \ inch above the fronto-malar junction, which is indicated by a distinct notch. This point on the temple overlies the anterior inferior angle of the parietal bone — the pterion. The pterion marks the junction of the three limbs of the fissure of Sylvius with its stem. A line drawn backwards and upwards from the pterion to a point | of an inch below the parietal eminence indicates the situation of the posterior horizontal limb or ramus (Fig. 11). If the parietal eminence be not well marked, then the fissure may be in- dicated by joining the fronto-malar notch with the pterion and prolonging the line thus formed straight backwards to the region of the parietal eminence, as shown in Fig. 3 (R. J. Berry). This ramus is bounded below by the superior temporal convolution, which contains in its middle third the "word-hearing" centre (Fig. 10). Above, it is bounded from before backwards by the basilar part of the inferior frontal convolution, the lower ends of the ascending frontal and parietal con- volutions, and the supramarginal gyrus. In the three parts first named are situated centres for movements of the tongue, larynx, pharynx and mouth. A penny piece placed directly behind the termination of the Sylvian line will cover the angular convolution in which the "word-seeing ;; centre is placed (Fig. 10). The parietal eminence Chap. Ill] THE CRANIAL CONTENTS 4,1 covers the supramarginal convolution. The ascend- ing limb of the fissure of Sylvius is indicated by a line f of an inch long drawn upwards and slightly forwards from the pterion, while the short anterior horizontal limb is indicated by a line \ an inch long drawn forwards from the same point. Between the ascending and anterior limbs is situated the pars triangularis of the inferior frontal convolution in which the centre for " motor speech ,; is placed. Broca regarded the left inferior frontal convolution (frequently called Broca's convolution) as specially connected with speech, but recently Pierre Marie has pub- lished accounts of a number of cases of disease of this part in which speech was unaffected. The stem of the Sylvian fissure is \ an inch long and runs downwards and forwards under the great wing of the sphenoid (Fig. 10). The temporal pole lies below it. The four angles of the parietal bone have im- portant relationships to the brain. The anterior inferior angle covers the posterior part of the in- ferior frontal convolution and the anterior hori- zontal and ascending limbs of the fissure of Syl- vius. The anterior branch of the middle meningeal artery ascends beneath it. The anterior superior angle at the bregma covers the terminal part of the superior frontal convolution and the centre for movements of the hip. The posterior superior angle at the lambda lies oyer the upper part of the occipital lobe and \ an inch behind the parieto- occipital fissure. The posterior inferior angle covers the convexity^ of the lateral sinus and marks the lower limit of the cerebrum. In its anterior half the posterior limb of the Sylvian fissure lies beneath the squamous suture, but be- hind it passes entirely beneath the parietal bone. It will be thus seen that the parietal bone covers the whole of the parietal lobe, the posterior parts of the frontal and temporo-sphenoidal lobes, and the upper margin of the occipital. The inferior temporal convolution passes 42 SURGICAL APPLIED ANATOMY [Part I backwards above the upper border of the zygoma and external auditory meatus and rests on the thin roof of the tympanum. Hence it is the_ most common site of abscess which may follow middle- ear disease. (Fig. 10.) The basal ganglia of the brain — the corpus striatum and optic thalamus — are capped on their outer aspect by the Island of Eeil. The Island lies buried in the anterior three-fourths of the fissure of Sylvius, and hence the surface markings for the fissure may be also used for the Island and the basal ganglia (see Fig. 3, p. 12). A half-circle, with a radius of ■§• an inch, drawn in front of the pterion, will indicate the anterior limit of the basal ganglia, while their posterior limit lies some distance in front of the point at which the lateral ventricles may be tapped (see Fig. 3, p. 12). That point is found thus : a line 5 cm. (2 inches) in length is drawn verti- cally upwards from the external auditory meatus ; the point for tapping the lateral ventricle lies 2 cm. ( f of an inch) behind the upper end of this line ; a trochar thrust in there enters the lateral ventricle at the junction of the body with the descending and posterior horns. (Jenkins.) The sensori-motor areas of the brain. — A knowledge of the position of these areas is most important in enabling certain brain lesions to be localised and in guiding the surgeon in operations upon the cerebral cortex. Formerly these areas were believed to be situ- ated in the ascending frontal (precentral) and also ascending parietal (postcentral) convolution, but by stimulating more accurately the cortex of these convolutions in anthropoid apes, Sherrington and Griinbaum found that motor reactions were elicited only from the ascending frontal. The arrangement of the motor areas is shown in Fig. 12 : in the upper third of the ascending frontal, passing also some distance on to the mesial aspect of the brain, the movements of the lower extremity and trunk are represented; in the middle third, Chap. IIIJ THE CRANIAL CONTENTS 43 those of the arm ; while in the lower third, those of the face, mouth, and larynx. Behind the fis- sure of Rolando, in the ascending parietal con- volution, are situated sensory areas corresponding to the motor areas in the ascending frontal con- volution. A tumour pressing on the surface of the brain first excites the cortex to action ; hence one situated over a motor area excites the move- Pirsf IzrnpoY^/^ Fig. 12.— Showing the localisation of motor areas in the precentral or ascending frontal convolution, and the sensory areas in the postcentral or ascending parietal convolution. ments represented in that area, or one over a sen- sory area excites the sensations represented there. Stimulation of the cortex is soon followed by its destruction and loss of function ; hence loss of movement or loss of sensation replaces the pre- liminary excitement. The symptoms produced by intracranial growths are apt not to be definitely localised, because even a small tumour may pro- duce widely distributed compression effects when it is situated within the rigid walls of the skull. 44 SUEGICAL APPLIED ANATOMY. [Part I Conjugate movements of the eyes are represented in the cortex at the posterior end of the mid- frontal convolution (Fig. 12). There are also several primary sensory areas of cortex — areas connected with sight, hearing, and smell — which may be affected by intracranial lesions, and give signs which assist the surgeon to localise the seat of disease. The visual cortex is situated near the calcarine fissure and round the occipital pole; the " word-seeing " centre occupies the angular gyrus (Fig. 10) ; the auditory cortex lies in a deep or buried part of the superior temporal convolu- tion, while the "word-hearing" centre is ascribed to the middle third of this convolution. The ol- factory cortex is placed in the uncus, which is situated to the inner side of the temporal lobe. Tumours in the neighbourhood of the uncus, besides producing disturbance of the olfactory sensations, frequently give rise to " dreamy states." Of the brain generally little has to be said. In a surgical sense, it presents itself simply as a large mass of soft tissue that may be damaged by shaking as gelatine may be shaken in a case. As it is of very yielding structure, and does not entirely fill the cranial cavity, it may," as it were, be thrown about with the skull, and be damaged by collision with its walls. In contusion or bruis- ing of the brain it is noticed that the lesion is very much more frequently situate on the under surface, both as regards the cerebrum and cere- bellum, than in any other part (see p. 36). To this statement, however, there is the striking exception that those parts of the base of the cerebrum that rest upon the large basal collection of the cerebro-spinal fluid are the least often con- tused. These parts include the medulla, the pons, and the interpeduncular space. The brain is very lavishly supplied with blood- vessels. The main arterial trunks (vertebral and internal carotid) are both rendered tortuous be- fore entering the skull, with the object probably of Chap. Ill] THE CRANIAL CONTENTS 45 diminishing the effects of the heart's systole upon the brain. On entering they are almost immedi- ately blended into an anastomosing circle (circle of Willis), which has the effect of equalising the cerebral circulation. Embolism of the middle cerebral artery leads to a wide-spread destruc- tion of the cerebral cortex. It supplies the third frontal, the upper and middle temporal, the angu- lar supramargpnal, and the lower two-thirds of the ascending frontal and parietal gyri. The only jd arts of the sensor i-motor areas which escape de- struction in such a case are those for the lower limbs and trunk. The anterior cerebral artery supplies these centres, the mesial surface of the frontal and parietal lobes, and the adjacent part of the cortex on the outer aspect. The occipital lobe and temporo-sphenoidal convolutions are supplied by the posterior cerebral artery. Liga- ture of one common carotid may produce no effect upon the brain, although the mortality afterthis operation is mainly due to cerebral complications. One carotid and the two vertebrals would appear to be able to bring enough blood to the brain, which blood will be as evenly distributed as hitherto by the circle of Willis. Both common carotids have been ligatured, or one carotid has been secured when its fellow of the opposite side has been occluded by disease, and no marked cere- bral disturbances have followed. In no case, how- ever, has the patient recovered when the interval between the closing of the two vessels was less than a few weeks. The vertebral arteries can carry a sufficient amount of blood to the brain if only the strain be thrown upon them gradu- ally, and the brain be allowed to accommodate itself slowly to the change. After ligaturing all four arteries in the dog, the anastomosis between the spinal and cerebral arteries within the fora- men magnum was sufficient to maintain life (Hill). Plugging of any of the smaller cerebral arteries by emboli, as a rule, leads at^ once to a marked disastrous result. Such embolism is met 46 SURGICAL APPLIED ANATOMY [Parti with in surgery in connection with aneurism of the common carotid. In simply examining such aneurisms, a little piece of the clot contained in the sac has been detached, has been carried up into the brain, and has produced a plugging of one of the cerebral vessels. Thus, hemiplegia has followed upon the mere examination of a carotid aneurism, as in a case recorded by Mr. Teale, of Leeds. Fergusson ; s treatment of aneurism at the root of the neck, by displacing the clots by manip- ulation, has been abandoned on this same score. In the second case treated by manipulation by this surgeon, a case of subclavian aneurism, paralysis of the left side of the body followed at once upon the first handling of the tumour. The pulsations of the brain may be communi- cated to any tumours or collections of fluid that reach the surface of the brain through an aper- ture in the skull. Such pulsations are synchron- ous with the arterial pulse, but the sphygmo- graphic tracings of the cerebral pulsations exhibit also the " respiratory curve/' conveyed directly from the thorax by the blood within the veins. The valve at the lower end of the jugular vein prevents direct regurgitation of blood from the heart to the brain, but it does not prevent the transmission of pressure. Although wounds of the brain bleed freely, the bleeding is checked without difficulty, the vessels being capable of ready contraction. Large tumours have been excised from the cortex of the brain, without undue trouble from haemor- rhage. The terminal branches of the cerebral arteries anastomose freely in the pia mater, but the minute arteries which perforate and supply the cortex are terminal. Hence any pressure ap- plied to the surface of the brain will lead to anaemia of that piece of. cortex, and, if the pres- sure is continued, to its destruction. Ligature of a cerebral vein usually leads to an atrophy of the cortex which it drains (Horsley). There is always one — sometimes more — anastomos- Chap. Ill] THE CliANIAL CONTENTS 47 ing vein on the surface of the cerebrum, uniting the upper with the lower cerebral veins. The lower cerebral veins are four in number — three of them leave the temporal and occipital lobes to end in the lateral sinus; the other, the superficial Sylvian vein, ends in the sinus of the jsmall wing of the sphenoid. The temporal and occipital lobes cannot be lifted off the tentorium without rup- turing the veins joining the lateral sinus. Nearly all the veins of the cerebellum end in the lateral sinus; its arteries are derived from vertebral and basilar. Tumours in the cerebel- lum give rise to muscular weakness and inco- ordination, giddiness, and loss of balance. The vermis, or middle part of the cerebellum, is more directly connected with bending movements of the trunk, while the lateral lobes are concerned in the co-ordination of turning movements — move- ments made round the vertical axis of the trunk (Horsley). CHAPTER IV THE ORBIT AND EYE The orJbit. — The antero-posterior diameter of the orbit is about If inches (44 mm.), its ver- tical diameter at the base a little over l\ inches (31 mm.), and its horizontal diameter at the base about lj inches (37 mm.). The diameters of the globe are as follow : transverse, 24 mm. ; antero - posterior, 24"5 mm. ; vertical, 23 mm. (Brailey). The eyeball is therefore nearer to the upper and lower margins of the orbit than it is to the sides, and the greatest interval be- tween the globe and the orbital wall is on the outer side. The interior of the orbit is most con- veniently reached by incisions made to the outer side of the globe, and, in excision of the eyeball, the scissors are usually introduced on that side when the optic nerve has to be divided. In excis- ing the left eye, however, it may be more con- venient to divide the optic nerve from the inner side. The bones forming the floor, the roof, and the inner wall of the orbital cavity are very thin, especially in the last-named situation. Thus, foreign bodies thrust into the orbit have readily penetrated into the cranial cavity, into the nose and ethmoidal cells, and, when directed from above, into the antrum. In several instances, a sharp-pointed instrument, such as the end of a stick or foil, has been thrust into the brain through the orbit, and has left but little external evidence of this serious lesion. Nelaton mentions 48 Chap. IV] THE ORBIT AND EYE 49 a case in which the internal carotid artery was wounded through the orbit. Certain cases of pulsating orbital tumour which depend upon a communication between the carotid artery and the cavernous sinus have a traumatic origin. A reference to the relations of the orbital walls will show that a tumour may readily invade the orbit by spreading (1) from the base of the skull, (2) from the nasal fossse, (3) from the antrum, and (4) from the temporal or zygomatic fossse.. In any of these instances the growth may enter the orbit by destroying the intervening thin layers of bone, and in tumours of the antrum this is the usual mode of entry. It may, however, ex- tend more readily from the cranial cavity through the optic foramen or sphenoidal fissure, from the nose through the nasal duct, and from the two fossse named through the spheno-maxillary fis- sure. After violent blows upon the temple blood has found its way into the orbit through the spheno-maxillary fissure, \ and has led to subcon- junctival ecchymosis. Distension of the frontal sinus by retained mucus or pus may lead to a prominent tumour at the upper and inner margin of the orbit, above the level of the tendo oculi, which may cause displacement of the globe down- wards, outwards, and forwards. The bones of the orbit are peculiarly apt to be the seat of ivory exostoses, which may in time entirely occupy the orbital cavity. The anterior third .of the outer wall of the orbit is formed by the temporal fossa (Fig. 13) ; the posterior two-thirds are separated from the middle fossa of the skull, which contains the tem- poral lobe, by the great wing of the sphenoid. Kronlein removes intraorbital tumours by open- ing the outer wall of the orbit in the temporal fossa. In a recent notorious case, in which a mur- derer attempted to commit suicide, the bullet entered the temporal fossa, perforated the outer wall of the orbit, and destroyed the eyeball, but left the brain untouched. The pole of the tem- E 50 SUEGICAL APPLIED ANATOMY [Part I poral lobe is situated from 2 to 2*5 cm. behind the outer margin of the orbit (see Fig. 3, p. 12). The capsule of Tenon. — The best description of this capsule has been given by Mr. Lockwood ; of his researches Prof. Cunningham provides the following resume: — Ext. Tarsal Lie Conjunctiva Ext.Chcck, Ext-£ec Int. Tarsal Lie Lach. Sac Int. Check. Liq. Capsule of-Tbnon Temporal Fossa Ext. Rectus JLCapsule-opTenon Int. Rectus Optic aierve 5 ME ATM Middle fossa Fig. 13. Diagram to show the arrangement of the capsule of Tenon and check ligaments. The eyeball is turned outwards so that the external check ligament is taut and the internal relaxed. " The capsule is a firm loose membrane spread over the posterior fths of the globe, the cornea alone being free from it. In front it lies under the ocular conjunctiva, with which it is intim- ately connected, and it ends by blending with that membrane close to the margin of the cornea (Fig. 13). Behind it fuses with the sheath of the optic nerve, where the latter pierces the sclerotic. The surface of the membrane towards the globe is smooth, and is connected to the eyeball by some Chap. IV] THE ORBIT AND EYE 51 soft yielding areolar tissue. It thus forms a kind of dome for the globe, a species of socket or bursa in which it moves. The posterior surface of the capsule is in contact with the orbital fat. The tendons of the ocular muscles pierce the capsule opposite the equator of the globe (Fig. 13). The lips of the openings through which the four recti pass are prolonged backwards upon the muscles, in the form of sheaths, very much as the infundi- buliform fascia is prolonged upon the cord from the internal abdominal ring." Where the internal and external recti perforate, strong expansions of the capsule spread out to the inner and outer wall of the orbit. Because these expansions limit the action of the two recti they are known as the check ligaments (Fig. 13). They allow a side-to- side movement of the cornea to the extent of about 45°. The external check ligament is the stronger, and is attached to the outer wall im- mediately behind the external tarsal ligament; the attachment of the internal ligament is close behind the lachrymal sac. A prolongation of the capsule passes to the trochlea round the tendon of the superior oblique. The suspensory ligament of the eyeball stretches across the orbit like a hammock, _ supporting the eyeball. It is really a thickening of the under part of the capsule of Tenon, its attachment to the orbital walls being made by means of the internal and external check ligaments. When the upper jaw is removed the surgeon should take care to preserve the attach- ments of the suspensory ligament. If these be destroyed the eyeball will sink downwards. The intimate relations of the capsule of Tenon to the eyeball, conjunctiva, orbital muscles, and orbital walls has to be kept in mind where opera- tions are undertaken to remedy squint. From Fig. 13, it will be seen that after the tendon of a rectus muscle is cut through as it lies within the capsule of Tenon, the muscle still possesses, through the continuity of its sheath with the cap- sule, an attachment to the eyeball and conjunc- 52 SURGICAL APPLIED ANATOMY [Part I tiva as well as to the orbital wall by the check ligament. Hence when the tendon of a muscle is completely cut it can still act on the eyeball ; its complete retraction is prevented by the check ligament. The orbit behind Tenon's capsule is occupied by a large quantity of loose fat, in addition to the ocular muscles, vessels, and nerves. It is by the absorption of this fat that the sunken eye is produced in cases of emaciation and prolonged illness. This tissue affords a ready means for the spread of orbital abscess. Such an abscess may follow injuries, certain ocular inflammations, periostitis, etc., or may spread from adjacent parts. The pus may occupy the entire cavity, dis- placing the eyeball forwards, limiting its move- ments, and causing, by interference with the cir- culation, great redness of the conjunctiva and swelling of the lids. Foreign bodies, some of them of remarkable size and shape, have lodged for long periods of time in the orbital fat without causing much trouble. Thus Lawson reports a case where a piece of an iron hat-peg, three inches long, was embedded in the orbit for several days without the patient being aware of it. A stranger case, in some ways, is that reported by Furneaux Jordan : " A man who was employed in threshing became the subject of severe ophthalmia. At the expira- tion of several weeks, the patient, whilst pressing his finger on the lower eyelid, suddenly ejected from a comfortable bed of warm pus a grain of wheat, which had shot forth a vigorous green sprout." The orbital fat affords also an excellent nidus for growing tumours. Fractures of the inner wall of the orbit involving the nasal fossae or sinuses may lead to extensive emphysema of the orbital cellular tissue. The air so introduced may cause the globe to protrude, may limit its movements, may spread to the lids, and will, in any case, be increased in amount by blowing the nose, etc. Chap. IV] THE ORBIT AND EYE 53 The orbital muscles. — The four recti muscles end in thin, flat membranous tendons. The ten- don of the external or internal rectus muscle is frequently divided for strabismus. The width of the tendons varies from 7 mm. to 9 mm. They are inserted into the sclerotic near the cornea. The internal rectus is inserted 6'5 mm. from the corneal margin, the external 6*8 mm., the inferior 7*2 mm., and the superior 8 mm. (Merkel). While the internal and external recti are pure internal and external rotators of the eyeball, the superior and inferior recti, owing to the line in which they pull, act as internal as well as up- ward and downward rotators. Their tendency to act as internal rotators is counterbalanced by the two oblique muscles, which serve as external as well as upward and downward rotators. The orbital arteries are small, and seldom give rise to trouble when divided in excising the globe, since they can be readily compressed against the bony walls of the cavity. Pulsating tumours of this part may be due to traumatic aneurisms of one of the orbital arteries, or may depend upon an arterio-venous aneurism formed between the internal carotid artery and the cavernous sinus. Pressure also upon the ophthal- mic vein (as it enters the sinus), by an aneurism of the internal carotid vessel, may produce all the symptoms associated with pulsating orbital tumours. Thrombosis of the cavernous sinus causes dilatation of the ophthalmic veins and proptosis. The orbital nerves may be damaged in wounds of the orbit, or in fractures of the orbit and of the base of the skull. They may be pressed upon by tumours from various parts, by aneur- isms, hemorrhagic and inflammatory effusions. Thus Lawson records a case in which the optic nerve was divided by a stab through the upper eyelid, without the globe being injured, and with- out any bone being fractured. The same nerve has also been completely torn across in fractures 54 SUEGICAL APPLIED ANATOMY [Part I of the orbit, and has been pressed upon in frac- tures involving the lesser wing of the sphenoid. The third, fourth, and sixth nerves, and the first division of the fifth, may be affected in cases of aneurism involving the internal carotid artery, where they lie in relation with the cavernous sinus. They may readily be pressed upon, also, by any growth involving the sphenoidal fissure, such as a periosteal node springing from the mar- gin of the fissure, while the sixth nerve, from its more intimate connection with the base of the skull, has been directly torn across in a fracture involving that part (Prescott Hewett). In paralysis of the third nerve there is drooping of the upper lid (ptosis)'; the eye_ is almost motionless, presents a divergent squint from unopposed action of the external rectus muscle, and cannot be moved either inwards, up- wards, or directly downwards. Rotation, in a direction downwards and outwards, can still be effected by the superior oblique and outer rectus muscles. The pupil is dilated and fixed; the power of accommodation is much impaired, there is diplopia, and sometimes a little protrusion of the globe from relaxation of the recti muscles. These symptoms refer tocomplete paralysis of the nerve. In cases of partial paralysis, only one or two of the above symptoms may be present. In paralysis of the fourth nerve there is often but little change to be seen, since the func- tion of the superior oblique muscle, supplied by this nerve, may, in part, be performed vicari- ously. " There is usually only very slight defect in the mobility of the eye ; what there is occurs chiefly in the inner and lower angle of the field of vision ; there is deviation of the eye inwards and upwards on lowering the object, and simply upwards when it is turned far towards the healthy side " (Erb). In any case there will be diplopia, especially in certain positions of the globe. In paralysis of the sixth nerve there is convergent strabismus, with consequent diplopia, Chap. IV THE ORBIT AND EYE 55 and an inability to rotate the eye directly out- wards. Paralysis of the sixth nerve may be ac- companied by paralysis of the nerve to the in- ternal rectus of the opposite side, giving rise to conjugate deviation of the eyes. Such a condi- tion indicates a lesion in the nucleus of the sixth nerve, for although the fibres for the internal rectus pass out with the third nerve they take their origin with the sixth. Sometimes all the oculo-motor nerves of the eye are paralysed, and in such cases the lesion is probably situated either < at their nuclei of origin or at the cavernous sinus, in the wall of which the nerves lie close together. In paralysis of the first division of the fifth there is a loss of sensation in all the conjunctiva, except such as covers the lower lid (supplied by the palpebral branch of the infraorbital nerve), loss of sensation in the globe, and in skin sup- plied by the supratrochlear and supraorbital nerves, and in the mucous and cutaneous surfaces supplied by the nasal nerve. The area of anaes- thesia is much less than the anatomical distri- bution of the nerve, owing to the extent to which cutaneous nerves overlap. No reflex movements (winking) follow upon irritation of the conjunc- tiva, although the patient can be made to wink on exposing the eye to a strong light, the optic nerve in this case transmitting the impression to the facial nerve. Sneezing also cannot be ex- cited by irritating the mucous membrane in the anterior part of the nose. Destructive ulceration of the cornea may follow this paralysis, due partly to damage to the trophic branches con- tained in the paralysed nerve, partly _to the anaes- thesia which renders the part readily injured, and partly to the loss of the reflex effect of the sensory nerves upon the calibre of the blood-vessels, whereby the inflammation is permitted to go un- controlled (Nettleship). In paralysis of the cervical sympathetic there is narrowing of the palpebral fissure from 56 SUKGICAL APPLIED ANATOMY [Part I some drooping of the upper lid, apparent reces- sion of the globe within the orbit, and some nar- rowing of the pupil from paralysis of the dilator muscle of the iris, which muscle is suppliedby the sympathetic. The drooping of the upper lid may be explained by the fact that each eyelid contains a layer of unstriated muscle fibre. That in the upper lid arises from the under surface of the levator palpebrse, and is attached to the tarsal cartilage near its upper margin (Fig. 16, p. 73). This layer of muscle, which, when in action, would keep up the lid, is under the influence of the cervical sympathetic. The recession of the globe is supposed by some to be due to paralysis of the orbitalis muscle of H. Miiller. This muscle bridges over the spheno-maxillary fissure, is com- posed of unstriated fibres, and is innervated by the sympathetic. Contraction of the muscle (as pro- duced by stimulation of the cervical sympathetic in animals) causes protrusion of the globe, while section of the sympathetic in the neck produces retraction of the eyeball (CI. Bernard). No changes are observed in the calibre of the blood- vessels of the globe. The non-striated muscle maintains the intraorbital pressure, and thus assists in the return of blood from. the ophthalmic veins. In animals such as the ox, in which the veins of the orbit become dilated when the head is carried low, as in browsing, this musculature attains a great development. The globe : the cornea. — The thickness of the cornea varies from "9 mm. in the central parts to ri mm. at the periphery. One is apt to be a little deceived as to its thickness, and on intro- ducing a knife into the cornea, the instrument, if not entered at the proper angle, may be thrust for some little distance among the laminse of the part. In front the cornea is covered by stratified epithelium. When this layer has been removed by abrasion, a white deposit of lead salts may take place in the exposed corneal tissue in cases whore lead lotions are used. The bulk of the Chap. IV] THE ORBIT AND EYE 57 cornea, is made up of a great number of fibrous lamella?, between which are anastomosing cell spaces containing the corneal corpuscles. If the nozzle of a fine syringe be thrust into the corneal tissue, the network of cell spaces can be filled with injection (Recklinghausen's canals). When suppuration takes place within the proper corneal tissue, it is probably along these canals, Fig. 14. — A horizontal section of the globe through the middle. a, Cornea ; b, sclerotic ; c, choroid ; <7, retina ; «, lens ; J\ iris : for the greater part accompany the lingual vein and artery and pour their lymph and emboli in the upper deep cervical glands, behind and below the angle of the jaw. The normal paths are soon choked, and the lymph has to follow circuitous by-paths. The lym- phatic glands over the submaxillary gland, the * For a full account of the lymphatics see Poirier's "Lymphatics," translated by Cecil Leaf, 1903. Chap. VIII] THE MOUTH 145 lymphoid tissue in that gland and in the sublin- gual, become the seats of secondary deposit. The submental gland may also be affected. In the strange congenital affection known as macroglossia the tongue becomes much enlarged, and in some cases may attain prodigious dimen- sions. The enlargement is primarily due to the greatly dilated condition of the lymphatic chan- nels of the organ (hence the name, lymphangioma cavernosum, proposed by Virchow), and to an in- creased development of lymph tissue throughout the part. The portion most conspicuously affected is the base of the tongue, where the lymphatics are usually the most numerous. A dermoid cyst may be met with on the under surface of the tongue. It is usually placed in the median line between the genio-hyo-glossi muscles. Such cysts are probably due to some infolding of the integumental layer during development. Accessory glands about the tongue.— Streckeisen states that accessory glands, belong- ing to the thyroid body, are frequently found in the vicinity of the hyoid bone. They are also found in the basal part of the tongue, near the foramen caecum (Makins). Some may be super- ficial to the mylo-hyoid muscle, others may be just above the hyoid bone, and others in the hollow of that bone. Cysts lined with ciliated epithelium may sometimes be found in the same situations. All these structures are the remains of the neck of the central diverticulum which is protruded from the ventral wall of the pharynx in the em- bryo, and from which the isthmus and pyramidal parts of the thyroid gland are formed. The fora- men ececum on the tongue indicates the spot where this diverticulum leaves the pharynx. Ducts lined with epithelium have been found leading from the foramen csecum to accessory glands about the hyoid bone. It is probably from these glandular and epithelial collections about the hyoid bone that cer- tain deep-seated forms of cancer of the neck are developed. Some of these take the form of malig- K 146 SUKGICAL APPLIED ANATOMY [Part I nant cysts described by the author (Path. Soc. Trans., 1886). Excision. — Many different methods have been adopted for the removal of the entire tongue. It has been removed through the mouth by the ecra- seur or the scissors, the latter operation being per- formed with or without previous ligature of the lingual arteries in the neck. It is difficult, however, to fully expose the deeper attachments of the organ through the comparatively small orifice of the mouth. To obtain more room the cheek has been slit up in one procedure, while the lower lip and symphysis of the lower jaw have been divided in another. In another series of operations the tongue has been reached, or the organ has been fully exposed, by an incision made between the hyoid bone and the inferior maxilla. More recently Kocher has exposed the tongue from the neck, and has reached it by an incision commencing near the ear and fol- lowing the anterior border of the sterno-mastoid muscle as far as the hyoid bone, whence it turns upwards along the anterior belly of the digastric muscle. This method allows free removal of the upper deep cervical glands, the lymphatic glands, and the tissue over and in the submaxillary and sublingual glands which form the seats of second- ary cancerous deposits. In the removal of the entire organ, the follow- ing parts are of necessity divided: The frsenum, the mucous membrane along the sides of the tongue, the glosso-epiglottic folds, the genio-hyo- glossus, hyo-glossus, stylo-glossus, palato-glossus muscles, the few fibres of the superior and inferior linguales muscles that are attached to the hyoid bone, the terminal branches of the gustatory, glosso-pharyngeal, and hypoglossal nerves, the lingual vessels, and, at the side of the tongue near its base, some branches of the ascending pharyn- geal artery, and of the tonsillar branch of the facial artery. Bleeding from the stump of the tongue, after Chap. VIII] THE PALATE 147 removal, can be instantly and almost entirely ar- rested by pressing the root of the tongue forwards with two fingers passed down behind it into the pharynx. The lingual arteries as they lie divided in the floor of the mouth are difficult to secure. They are embedded in muscle, and appear to be peculiarly brittle. When both Unguals have been ligatured in the neck (through the hyo-glossus muscle) before re- moving the tongue, bleeding still takes place from the dorsalis linguae branches of the lingual and Fig. 30. — Illustrating the relationship of the lateral incisor tooth to the palatal cleft. a, Normal hard palate. The premaxilla is stii>plecT ; the lateral incisor occurs in the suture between it and the maxilla. is, Double cleft Of palate, the lateral incisor being situated on the preniaxilla to the inner side of the cleft. The septum of the nose is exposed in the cleft between the maxillary bones, c, Double cleft palate, the lateral incisor being situated on the maxilla to the outer side of the cleft. from small branches of the ascending pharyngeal and facial arteries. The palate. — The arch of the hard palate varies in height and shape in different individuals, and it has been said that the arch is particularly narrow and high in congenital idiots . The outline of this arch is of some moment in operations upon the palate. Cleft palate. — In order to understand the various forms of cleft which occur in the palate and upper lip, it is necessary to review briefly the development of these parts ; for all forms of cleft palate and " hare-lip ' are due to an incomplete fusion of parts. In Fig. 30, a, the bony palate at 148 SURGICAL APPLIED ANATOMY [Part I birth is shown to be made up of three elements, (1) the premaxillary, carrying the four incisor teeth, (2) the right maxillary, (3) the left maxillary, bear- ing the right and left canine and milk molars. These three parts are different in origin : the pre- maxillary part is developed in the mesial nasal process (Fig. 24, p. 114) ; the maxillary parts from the right and left maxillary processes. Fusion of the various elements to form the palate com- mences anteriorly and proceeds backwards. In the posterior two-thirds of the palate the maxillary processes fuse with each other in the median line, but in the anterior third they unite with the pre- maxillary part. Thus the line of fusion is T-shaped, the premaxillary part occupying the fork. In the majority of cases the cleft occurs in the position of the main stem of the T, or it may affect only the soft palate ; or it may extend forwards to the alveolus on one side or on both, as is shown in Fig. 30, b, c. The lateral incisor is developed in the groove between the premaxillary and maxillary elements; if the condition of cleft palate occurs, the developmental elements separate as growth proceeds ; the bud of the lateral incisor may adhere to either side of the cleft thus formed ; hence in some cases this incisor is found on the premaxillary process; in others, in the maxillary (see Fig. 30, b, c). Each premaxilla may show two centres of ossification, but the cleft is not, as is so often said, the result of the failure of union of two centres of ossification, but is due to the separation of the developmental parts of the palate. As growth goes on, the cleft becomes wider. The upper lip is developed from the same three elements as the palate (Fig. 24, p. 114) ; if the palatal cleft extends to the alveolus the lip is also affected, but a cleft on one or both sides of the lip may occur without a cleft of the palate. The premaxillary or median element of the lip is also bilateral, but it is extremely rare to find a per- sistent separation of its two parts. In cases of Chap. VIII] THE PALATE 149 double hare-lip one sees occasionally two papillae on the lower lip, fitting into the clefts in the upper when the lips are in apposition. The mucous membrane covering the hard palate is peculiar in that it is practically one with the periosteum covering the bones ; and, therefore, in dissecting up this membrane the bone is bared, as the mucous membrane and the perios- teum cannot be separated. The membrane is thin in the middle line, but is much thicker at the sides near the alveoli, the increased thickness depend- ing mainly upon the introduction of a number of mucous glands beneath the surface layers, such glands being absent in the middle line. The density and toughness of the soft covering of the hard palate render it very easy to manipulate when dissected up in the form of flaps, as in the operation for cleft palate. The main bl ood supply of thp. houp s of ^ flip. hard palate and of its mucous covering is derived from the descending palatine branch of the inter- nal maxillary artery . This vessel, which is practically the only vessel of the hard palate, emerges from the posterior palatine canal near the junction of the hard palate with the soft, and close to the inner side of the last molar tooth. The vessel runs forwards and inwards, to end at the anterior palatine canal. Its pulsations on the palate can often be distinctly felt. In dis- secting up muco-periosteal flaps from the hard palate, it is most important to make the incision in the mucous membrane close to, and parallel with, the alveolus, so that this artery may be in- cluded in the flap and its vitality therefore not be endangered. By such an incision, also, un- necessary bleeding is avoided. In dissecting up the flap it should be remembered that the artery runs much nearer to the bone than to the mucous surface. The soft palate is of uniform thickness, its average measurement being estimated, at about 5 of an inch. When the soft palate is cleft, the 150 SURGICAL APPLIED ANATOMY [Part I edges of the fissure are approximated during swallowing by the uppermost fibres of the superior constrictor. This approximation may narrow the cleft to one-third or one-half of its previous size. The muscles that tend to widen the cleft are, in the main, the levator palati and tensor palati. It is necessary that these muscles should be divided before attempting to close the cleft by operation. The levator palati crosses the palate obliquely from above downwards and inwards on its way to the middle line, lying nearer to the posterior than the anterior surface of the velum. The tensor palati turns round the hamular pro- cess, and passes to the middle line in a nearly horizontal direction (Fig. 31). The hamular process can be felt through the soft palate just behind and to the inner side of the last upper molar tooth. There are three prin- cipal methods of dividing these muscles: (1) > Fergus- son's : A small knife, with the blade at right angles to the stem, is passed through the cleft, and is made to divide the levator palati by an incision on the posterior aspect of the palate, trans- verse to the direction of the muscle. The tensor is not divided in this procedure. (2) Pollock's : A thin narrow knife, with the cutting edge upwards, is introduced into the soft palate a little in front, and to the inner side, of the hamular process. The tendon of the tensor muscle is above the knife, and is cut as the knife is pushed upwards and inwards. The knife is inserted until its point presents at the upper part of the cleft. As it is being withdrawn, it is made to cut the posterior surface of the velum Fig. 31.— The muscles of the soft palate, from behind. a, Levator palati ; b, tensor palati ; c, hamular process ; d, wall of pharynx ; e, azy- gos uvulae ; /, the point of entry of the knife in Pol- lock's operation ; above it is the line of incision made on withdrawing the knife. Chap. VIII] THE PHAKYNX 151 to a sufficient depth to divide the levator palati (Fig. 31). (3) Bryant's : Here the palate muscles are divided by a cut with the scissors that in- volves the entire thickness of the velum, the cut being at the side of the velum, and nearly parallel with the cleft. The blood supply of the soft palate is derived from the descending palatine branch of the in- ternal maxillary artery, the ascending pharyn- geal artery, and the ascending palatine branch of the facial artery. The latter vessel reaches the velum by following the levator palati muscle, and must be divided in the section made of this muscle in the procedures just described. The muscles oi the palate are supplied by several nerves. The levator palati, azygos uvulse, and palato-pharyngeus are innervated with the muscles of the pharynx by the spinal accessory ; the palato-glossus with the muscles of the tongue from the hypo-glossal, and the tensor palati with the tensor tympani from the third division of the fifth nerve through the otic ganglion. The pharynx is about five inches in length. It is much wider from side to side than from before backwards. It is widest at the level of the tip of the greater cornua of the hyoid bone, where it measures about 2 inches. It is narrowest where it joins the gullet opposite the cricoid cartilage, its diameter here being less than f of an inch. The pharynx is not so large a space as supposed, for it must be remembered that during life it is viewed very obliquely, and erroneous notions are thus formed of its antero-posterior dimensions. The d istance from the arch of the teeth to the commencement ot tne gullet is about 6 to 7 innhps ^ p, Tnp.a.aurftTTlftnt that aVimilrj — Vip linrnp | n mind in extracting foreign bodies . Foreign bodies passed into the pharynx are most apt to lodge at the level of the cricoid cartilage, a point that, in the adult, is a little beyond the reach of the finger. The history of foreign bodies in the pharynx shows that that cavity is very dilatable, 152 SURGICAL APPLIED ANATOMY [Part I and can accommodate for some time large sub- stances. Thus, in a case reported by Dr. Geoghe- gan, a man of 60, who had had for months some trouble in his throat for which he could not account, was supposed to have cancer. On ex- amination, however, a plate carrying five false teeth, and presenting niches for five natural ones, was found embedded in the pharynx, where it had been lodged for five months. The plate had been swallowed during sleep {Med. Press, 1866). In the Lancet for 1868 is an account of a mutton chop that became lodged in the pharynx of a gluttonous individual. The chop presented the ordinary vertebral segment of bone, together with 1\ inch of rib, and was " pretty well covered with meat." Attempts to remove it failed, and it was finally vomited up. Dr. Hicks (Lancet, 1884) reports the case of a woman who committed suicide by cramming half a square yard of coarse calico (belonging to her nightdress) into her mouth and throat. The walls of the pharynx are in relation with the base of the skull, and with the upper six cer- vical vertebrae. The arch of the atlas is almos t ex actly on a line wi th the" hard pa.1a.tp The axis is on a line with the free edge of the upper teeth. The termination of the tmarynx corresponds ^o the six t h cervical vertebra . The upper vertebrae can be examined, as regards their anterior sur- face, from the mouth. When the bones about the pharynx are diseased, the necrosed parts may be discharged by that cavity. Thus portions of the atlas and axis have been expelled by the mouth, as also have been some fragments of comparatively large size thrown off by the occipital and sphenoid bones. The mucous membrane of the pharynx is vas- cular, and readily inflamed; and such inflamma- tions are peculiarly dangerous, in that they may spread to the lining membrane of the larynx. The submucous tissue of the aryteno-epiglottic folds and of the neighbouring part of the pharynx Chap. VIII] THE PHARYNX 153 is peculiarly loose, and in oedematous conditions the upper aperture of the larynx may be almost closed. Much adenoid tissue is distributed in the mucous membrane of the pharynx, and it is this tissue that is the primary seat of inflammation in scrofulous pharyngitis. A distinct collection of a d enoid tissue, stretches across the hinder wall of the pharvnx hRtwp.en the openings o? thft Eus- tachia n^ tubes. It is known as the pharyngeal tonsil. In and near the lateral recess, just be- hind the opening of the Eustachian tube, the lymphoid tissue forms a thick layer or mass (Fig. 22, p. 101). This deposit of adenoid tissue may undergo hypertrophic change and the condition known as " adenoid vegetations ;; or " post-nasal growths ;; be produced. These growths may cause deafness, and may block the posterior nares. They need to be removed by operation. The tissue immediately outside the pharyngeal walls is lax, and favours the spread of effusion. Thus, in acute inflammation of the pharynx the effusion has been found to extend along the oeso- phagus, reaching the posterior mediastinum, and advancing even to the diaphragm. In the lax connective tissue between the pharynx and the spine abscess is not infrequent, due, as a rule, to caries^ of the vertebrae (postpharyngeal abscess). In this connective tissue, and opposite the axis, is also found a lymphatic gland that receives lymphatics from the nasal cavity and naso- pharynx. This gland may prove the seat of a suppuration. Such collections may so push for- ward the posterior pharyngeal wall as to depress the soft palate, or may cause severe dyspnoea by interference with the larynx. The matter may discharge itself through the mouth, or may reach the neck by passing behind the great vessels and the parotid gland, presenting ultimately beneath or at one border of the sterno-mastoid muscle. _ Many structures of importance are in relation with the lateral walls of the pharynx, the prin- 154 SURGICAL APPLIED ANATOMY [Part I cipal being the internal carotid artery, the vagus, glossopharyngeal, and hypoglossal nerves (Fig. 27, p. 121). The internal carotid is so close to the pharynx that its pulsations may be felt by the finger introduced through the mouth. These, and other deep structures in the neck, may be wounded by foreign bodies that, passing in at the mouth, have been thrust through the pharynx into the cervical tissues. The internal jugular vein is at some distance from the pharynx, especi- ally at its upper part (Fig. 27, p. 121). The styloid process, when prominent, and an ossified stylo-hyoid ligament, can also be felt at the side of the pharynx immediately behind the tonsil. In more than one case an ossified stylo-hyoid liga- ment has been mistaken for a foreign body, and an attempt made to excise it. Langenbeck has three times extirpated the pharynx for malignant disease, but without success. He reaches it from the neck through an incision that, beginning below the jaw, midway between the symphysis and angle, is carried over the great cornu of the hyoid bone, and ends close to the cricoid cartilage. The posterior belly of the digastric and the stylo-hyoid muscles are detached from the hyoid bone, while the omo-hyoid muscle, the lingual, facial, and superior thyroid arteries and the superior laryn- geal nerve are divided. The tonsil is lodged bet we en th e anterior and posterior palatine arches. It is in relation ex- ternally with the superior constrictor muscle, and corresponds, as regards the surface, to the angle of the lower jaw. It is questionable whether the enlarged tonsil, when it is the subject of other than malignant enlargement, can ever be felt externally. When hypertrophied, the mass tends to develop towards the middle line, where no resistance is encountered, and to effect but little change in its external relations. The mass, often mistaken for the enlarged tonsil in the neck, is formed of enlarged glands, situate near the tip of the great cornu of the hyoid bone, and overlying Chap. VITI] . THE PHARYNX 156 the internal jugular vein. These glands receive the tonsillar lymphatics, and are almost invari- ably enlarged in all tonsil affections. The fact that these glands are so frequently the first to en- large when the cervical glands become tubercular points to the tonsil as a common site of primary infection. It must be remembered that many structures are interposed between the tonsil and the skin, and as the hypertrophied body projects freely into the pharygneal cavity, one would not expect that it could be readily felt, even were the interposed tissues less extensive than they are. The tonsil is closely enough attached to the pharyngeal wall to be affected by the movements of the pharyngeal muscles. Thus it is moved in- wards by the superior constrictor muscle during the act of swallowing, and may be drawn out- wards, on the other hand, by the stylo-pharyngeus muscle. The ease with which a tonsil can be reached depends, other things being equal, upon the extent to which it can be withdrawn by the stylo-pharyngeus, and upon the development of the anterior palatine arch, which, to some extent, hides the tonsil. A child with a prominent an- terior palatine arch, containing a well-developed palato-glossus muscle, and with a vigorous stylo- pharyngeus, can for a long time elude the tonsil guillotine. Deafness i s of ten complaine d o f when the tonsil is hypertrophie d. This is not due to closure of th ft F.iiRta^hifln tube hv t he direct pressure of the en larger] mass. Such pressure is anatomically im- possible. T-he —large tonsil may, however, af fect the patency of the tube, by disturbing the s oft pjki ate, and t hr ough it th e tensor pal ati muscle . which r s much con cerned in keep in g open the Enstflph ian tube . The deafness in these cases Ts probably due rather to an extension of the hyper- trophic process to the lining membrane of the tube than to any pressure effects, since it is usually not improved until some time after the tonsil has been removed. The tonsil tissue is for 156 SURGICAL APPLIED ANATOMY [Part I the most part collected around a number of re- cesses. The decomposition of retained epithelial structures within those recesses produces the foetid breath often noticed in cases of enlarged tonsil, and probably incites the attacks of inflammation to which such tonsils are liable Calculi may form in these crypts and give rise to a spasmodic cough. In this case the glosso-pharyngeal nerve conveys the afferent impulse to the respiratory centre. The tonsil is very vascular, rece iv ing blo o d from the tonsillar and pala~tirip hran ohps n f thp facial arter y, from thp. descen ding pglat.inp hranr- h of the internal maxillary , from thp dorsal is lin - guae Of thp lingual, aild frnrn thp agpPnrlincr pharyngeal Hence the operation of removing the tonsil is often associated with free bleeding. The internal carotid artery is close to the pharynx, but some way behind the gland (Fig. 27, p. 121). The vessel is, indeed, about f of an inch posterior to that body, and is in comparatively little danger of being wounded when the tonsil is excised. The internal jugular vein is a con- siderable distance from the tonsil. The facial artery, in its cervical stage, is close to the tonsil. Of im po rtant cervical structures, the nearest to the ton si l is the gloss o- pha,ry ngp« I tipt-vp, The ascending pharyngeal artery is also in, close re - fation with it . Although of small size, bleeding from this vessel has proved fatal, as the following interesting case, reported by Mr. Morrant Baker, will show : A man, aged 23, fell when drunk, and grazed his throat with the end of a tobacco- pipe he was smoking at the time. He thought nothing of the accident. In two days he came to the hospital with what appeared to be an acutely inflamed tonsil. The tonsil was punc- tured, but nothing escaped save a little blood. Several haemorrhages occurred from the tonsil wound, and on the fourth day after the accident 1 inch of the stem of a clay pipe was discovered deeply embedded in the glandular substance. It Chap. VIII] THE PHARYNX 157 was removed, and the common carotid tied. The patient, however, never rallied from the previous severe haemorrhages, and soon died. The autopsy showed that the stem of the pipe, which had not been missed by the patient, had divided the as- cending pharyngeal artery (St. Bart.'s Hosp. Reports, 1876). The tonsil is often the seat of malignant fl£oj/)tj3.s. Such tumours have been removed through the mouth, but are more conveniently dealt with through an incision in the neck along the anterior edge of the sterno-mastoid ( Cheaper/ s qpftration). CHAPTER IX THE NECK Surface anatomy; tooiiy points.— The hyoid bone is on a level with the fourth cervical vertebra, while the cricoid cartilage is opposite the sixth. The upper margin of the sternum is on a level with the disc between the second and third dorsal vertebrae. (See p. 173.) At the back of the neck there is a slight depression in the middle line which descends from the occipital protuber- ance, and lies between the prominences formed by the trapezius and complexus muscles of the two sides. At the upper part of this depression the spine of the axis can be made out on deep pres- sure. Below this, the bony ridge formed by the spines of the third, fourth, fifth, and sixth cervi- cal, vertebrse can be felt, but the individual spines cannot usually be distinguished. At the root of the neck the spinous process of the vertebra prominens is generally very obvious. The trans- verse process of the atlas may be felt just below and in front of the tip of the mastoid process. By deep pressure in the upper part of the supra- clavicular fossa, the transverse process of the seventh cervical vertebra can be distinguished. If pressure be made over the line of the carotid vessels at the level of the cricoid cartilage, the prominent anterior tubercle of the trans- verse process of the sixth cervical vertebra can be felt. This is known as the " carotid tuber- cle." The carotid artery lies directly over it, 158 Chap. IX] THE NECK 159 and in ligaturing that vessel some surgeons make important use of this tubercle as a landmark. If a horizontal section of the neck, in a muscular subject, taken about the level of the sixth cervical vertebra, be viewed, the whole of the body of the vertebra divided will be seen to lie within the anterior half of the section. The middle line. — In the receding angle be- low the chin the hyoid bone can be felt and its body and greater cornua well made out. About a finger's breadth below it is the thyroid cartilage. The details of this latter are readily distin- guished, and below it the cricoid cartilage, crico- thyroid space, and trachea can be easily recog- nised. The separate rings of the trachea cannot be felt. The trachea is less easily made out as it passes down the neck. As it descends it takes a deeper position, and at the upper border of the sternum lies nearly 1^ inches from the surface. The rima glottidis corresponds to the middle of the anterior margin of the thyroid cartilage. Unless enlarged, the thyroid gland cannot be made out with certainty. According to Mr. Holden, the pulse of the superior thyroid artery can be felt at its upper and anterior part. The anterior jugular veins descend on either side of the middle line upon the sterno-hyoid mus- cles. They commence in the submaxillary region, pierce the fascia just above the inner end of the clavicle, and, passing beneath the origin of the sterno-mastoid muscle, end in the external jugu- lar. The inferior thyroid veins lie in front of the trachea, below the isthmus. The side of the neck. — Muscles.— The sterno- mastoid muscle, especially in thin subjects and when thrown into action, is a prominent feature in the neck. The anterior border of the muscle is very distinct. The posterior border is less promi- nent, especially at its upper part. A communi- cating branch from the facial vein generally runs along the, anterior border of the muscle to meet the anterior jugular vein at the lower part of 160 SURGICAL APPLIED ANATOMY [Part I the neck. The interval between the sternal and clavicular parts of the muscle is generally well marked. If a needle be thrust through this in- terval, quite close to the clavicle, it would just touch the bifurcation of the innominate artery on the right side and would pierce the carotid vessel on the left. The posterior belly of the digastric muscle corresponds to a line drawn from the mastoid process to the anterior part of the hyoid bone. The anterior belly of the omo-hyoid follows an oblique line drawn downwards from the fore part of the hyoid bone, so as to cross the line of the carotid artery opposite the cricoid cartilage. The posterior belly can be made out in thin necks, especially when in action, running nearly parallel with and just above the clavicle. Although not taking quite the same direction, yet the posterior borders of the sterno-mastoid and anterior scalene muscles practically correspond to one another. Vessels. — The common carotid artery is repre- sented by a line drawn from the sterno-clavicular joint to a point midway between the angle of the jaw and the mastoid process. The vessel bifur- cates at the upper border of the thyroid cartilage, or not unfrequently nearly \ an inch above that point. The omo-hyoid crosses it opposite the cricoid cartilage, and at about the same level the artery is crossed by the middle thyroid vein. The line of the internal jugular vein is just external to that for the main artery. Both the artery and vein lie under the anterior border of the sterno- mastoid. The superior thyroid artery comes off below the great cornu of the hyoid bone, and curves forwards and downwards to the upper edge of the thyroid cartilage. The great cornu of the hyoid serves as an excellent guide to the lin- gual artery, which invariably forms a loop above the posterior end of that process before proceeding forwards beneath the hyo-glossus muscle (Fig. 28, p. 124). The facial artery is very tortuous, but its general course in the neck is represented *by a line Chap. IX] THE NECK 161 drawn from the anterior border of the masseter at the lower border of the jaw to a point just above the tip of the great cornu, while the occi- pital follows a line that starts from the latter point and runs across the base of the mastoid process. The external jugular vein follows a line drawn from the angle of the jaw to the middle of the clavicle. The subclavian artery describes a curve at the root of the neck. One end of the curve corre- sponds to the sterno-clavicular joint, the other end to the centre of the clavicle, the summit of the curve rising to a point about ^ an inch above that bone. In the angle between the posterior edge of the sterno-mastoid and the clavicle the pulsa- tions of the artery may be felt. Just above the bone the artery may be compressed against the first rib. The compression is most easily applied when the arm is well drawn down, and the direction of the pressure should be downwards and inwards. The subclavian vein lies below the artery, and is entirely under cover of the clavicle. The suprascapular and transverse cervical arteries run parallel with the clavicle, the former quite behind the bone, the latter just above it. The pulsations of the latter vessel can generally be felt. Nerves. — The position of the chief superficial nerves of the neck may be fairly indicated by six lines, all drawn from the middle of the pos- terior border of the sterno-mastoid muscle. A line drawn forwards from this spot so as to cross the sterno-mastoid at right angles to its long axis corresponds to the superficial cervical nerve. A second line drawn up across the muscle to the back of the pinna, so as to run parallel with the external jugular vein, corresponds to the great auricular nerve ; and a third line, running along the posterior border of the sterno-mastoid muscle to the scalp, marks the course of the small ocel- li 162 SUEGICAL APPLIED ANATOMY [Part I pital nerve. These lines, continued downwards, so as to cross the sternum, the middle of the clavi- cle, and the acromion, will indicate respectively the suprasternal, supraclavicular, and supra- acromial nerves. The spinal accessory nerve reaches the anterior border of the sterno-mastoid muscle at a point about 1 inch below the tip of the mastoid process. It emerges from beneath that muscle about the middle of its posterior border, crosses the pos- terior triangle, and passes beneath the trapezius between the middle and lower thirds of the anterior border of that muscle (Fig. 28, p. 124). The phrenic nerve commences deeply at the side of the neck, about the level of the mid point of the thyroid cartilage, and runs downwards to a point behind the sternal end of the clavicle. About the level of the cricoid cartilage it lies beneath the sterno-mastoid (which covers it wholly in the neck) about midway between the anterior and posterior borders of the muscle. The brachial plexus can be felt, and even seen in very thin subjects. Its upper limits may be represented by a line drawn across the side of the neck from a point about opposite to the crico-thyroid space to a spot a little external to the centre of the clavicle. The skin in the submaxillary region is lax and thin, and is often found of considerable value for making flaps in plastic operations about the mouth. The platysma myoides is closely con- nected with the skin, and to its action is due the turning-in of the edges of such wounds as are athwart the line of direction of the muscle. The amount of subcutaneous fat in the cervical region varies in different parts. In the suprahyoid region it is apt to undergo extensive development, producing the diffused lipoma known as " double- chin.'' The skin over the nape of the neck is very dense and adherent, and these two circumstances, in addition to the free nerve-supply of the parts, Chap. IX] THE NECK 163 serves to explain the severe pain that often accom- panies inflammation in this region. Common car- buncle is very often met with behind at the root of the neck, in the middle line. When the sterno-niastoid muscle of one side is rigidly contracted, either from paralysis of the opposite muscle or from spasmodic contraction, or from some congenital defect, the condition known as wry-neck is produced. The position of the head in wry-neck illustrates ^ precisely the effect of the sterno-mastoid when in full action. The head is bent a little forwards, the chin is turned towards the sound side, and the ear on the affected side leans towards the sterno-clavicular joint. In many cases the trapezius and splenitis muscles are also affected. Spasmodic contraction of the muscle may be due to reflex irritation. Thus, it has accompanied inflammation of the cer- vical glands in the posterior triangle. Such in- flammation has irritated some branches of the cervical plexus, and the sterno-mastoid muscle, although it is supplied mainly by the spinal acces- sory nerve, receives a nerve from that plexus (viz., from the second cervical). The course of the re- flex disturbance in such cases is therefore not diffi- cult to follow. It is to be remembered, too, that the spinal accessory nerve passes between the upper two or three deep cervical lymph glands which may compress it. A like contraction has also been produced by direct irritation of the second cervical nerve in cases of disease of the first two cervical vertebrae. For the relief of some forms of wry-neck, the sterno-mastoid muscle is divided subcutaneously, as in an ordinary teno- tomy operation, about ^ an inch above its attach- ment to the sternum and clavicle. Two structures stand considerable risk of being wounded in this operation, viz., the external jugular vein lying near the posterior border of the muscle, and the anterior jugular which follows its anterior border and passes behind the muscle, just above the clavicle, to terminate in the first-named vein. 164 SURGICAL APPLIED ANATOMY [Part I With common care, there should be no risk of wounding the great vessels at the root of the neck. For spasmodic wry-neck the spinal accessory nerve and the communicating branches of the third and fourth cervical nerves have been cut. The spinal accessory nerve is found at the an- terior border of the sterno-mastoid, 1 inch below the mastoid process. There is a curious congenital tumour, or in- duration, sometimes met with in this muscle in the newly born. It is usually ascribed to syphilis, but, in most cases, is probably due to some tear- ing of the muscle fibres during the process of delivery. The cervical fascia. — The layers of fascia that occupy the neck, and that are known col- lectively as the deep cervical fascia, are dense structures, having a somewhat complex arrange- ment and a great amount of importance from a surgical point of view. This fascia limits the growth of cervical tumours and abscesses, and modifies the direction of their progress, but I do not think that its effect in this matter is quite so definite as is usually maintained. It is true that deep-seated cervical abscesses are often found to follow just such a course as the arrangement of the fasciae would lead us to suppose, while, on the other hand, instances are by no means un- common where the abscess or growth appears to ignore these membranes and adopt a course of its own. The deep cervical fascia may be divided into (a) the superficial layer, and (b) the deeper pro- cesses (see Fig. 32). (a) The superficial layer forms a complete in- vestment for the neck, and covers in all the cer- vical structures, except the platvsma and some superficial veins and nerves, with the complete- ness of a perfectly fitting cravat. It commences behind at the spinous processes of the vertebra, and, having invested the trapezius muscle, starts, at the anterior border of that muscle, as a single Chap. IX] THE NECK 165 layer, to cross the posterior triangle. Arriving at the posterior border of the sterno-mastoid muscle, it splits to enclose that structure, appear- ing again as a single layer at the anterior border of the muscle, from whence it passes to the middle line of the neck to join the fascia of the opposite Fig. 32. — Transverse section through the lower part of the neck, to show the arrangement of the cervical fascia (diagrammatic). a. Trapezius ; b, sterno-mastoid ; c, depressors of hyoid bone ; d, platysma ; e anterior spinal muscles ; /, scalenus amicus j No. 2. ,, 8 mm. ,, 4 to 8 „ No. 3. „ 10 mm. „ 8 to 12 No. 4. „ 12 mm. ,, 12 to 15 For children under eighteen months the dia- meter of the tube should be about 4 mm. In performing tracheotomy it is most im- portant that the head be thrown as far back as possible, and that the chin be kept strictly in a line with the sternal notch, so that the relations of the middle line of the neck be preserved. Full extension of the head not only gives the surgeon increased room for the operation, but also brings the trachea nearer to the surface, and by stretch- ing the tube renders it much less mobile. In cutting down upon the trachea in the middle line of the neck from the cricoid cartilage to the sternum the following parts are met with : Beneath the integument lie the anterior jugular veins. As a rule these veins lie some little way apart on either side of the median line, and do not communicate except by a large transverse branch which lies in the interfascial space at the upper border of the sternum. Sometimes there are many communicating branches right in front of the tracheotomy district, or the veins may form almost a plexus in front of the trachea, or there may be a single vein which will follow the middle line. Then comes the cervical fascia, enclosing the sterno-hyoid and sterno-thyroid * The reader may be reminded that 12 mm. = about I an inch, and 6 mm., therefore, = about \ of an inch. Ohap. IX] THE NECK 179 muscles. The gap between the muscles of opposite sides is lozenge-shaped, and is such that the trachea can be exposed without dividing muscle fibres. The isthmus of the thyroid usually crosses the second, third, and fourth rings of the trachea. Above it a transverse communicating branch be- tween the superior thyroid veins is sometimes found. Over the isthmus is a venous plexus, from which the inferior thyroid veins arise, while be- low the isthmus these veins lie in front of the trachea together with the thyroidea ima < artery (when it exists). The inferior thyroid vein may be represented by a single trunk occupying the middle line. In the infant before the age of two years the thymus extends up for a variable dis- tance in front of the trachea. At the very root of the neck the trachea is crossed by the innomi- nate and left carotid arteries and by the left innominate vein ; and lastly, abnormal branches of the superior thyroid artery may cross the upper rings of the windpipe. The evil of wounding the thyroid isthmus is greatly exaggerated. I have frequently divided this structure in performing tracheotomy without any inconvenience resulting. Like other median raphes, the middle line of the thyroid isthmus has but a slight vascularity, and it has been shown that one side of the thyroid gland cannot be in- jected from the other (i.e. by injection that would cross the isthmus). The difficulty of tracheotomy in infants depends upon the shortness of the neck, the amount of the subcutaneous fat, the depth at which the trachea lies, its small size, its great mobility, and the ease with which it can be made to collapse on pressure. To the finger, roughly introduced, the infant's trachea offers little resistance. Its mobility is such that we hear of its being held aside unknowingly by re- tractors while the operator is scoring the oeso- phagus (Durham). In the child, too, the great vessels often cross the trachea higher up than in the adult, and some inconvenience may also arise 180 SURGICAL APPLIED ANATOMY [Part I from an unduly prominent thymus. In one case, in an infant, the end of a tracheotomy tube press- ing on the front of the trachea produced an ulcer that opened the innominate artery (Brit. Med. Jour., 1885). In introducing the cannula, if the tracheal wound be missed, it is easy to thrust the instrument into the lax tissue beneath the cervical fascia and imagine that it is within the windpipe. In laryngotomy the air passage is opened by a transverse cut through the crico-thyroid mem- brane. The crico-thyroid space only measures about | an inch in vertical height in well- developed adult subjects, while in children it is much too small to allow of a cannula being in- troduced. The crico-thyroid arteries cross the space, and can hardly escape division. They are, as a rule, of very insignificant size, and give no trouble. Occasionally, however, these vessels are large, and " cases are recorded in which serious and even fatal haemorrhage has occurred from these vessels ;; (Durham). In introducing the cannula it may readily slip between the crico- thyroid membrane and the mucous lining instead of entering the trachea. Foreign bodies often find their way into the air passages, and have been represented by articles of food, teeth, pills, buttons, small stones, and the like. They are usually inspired during the act of respiration, and may lodge in the superior aperture of the larynx, or in the rima, or find their way into the ventricle, or lodge in the trachea, or enter a bronchus. If a foreign substance enters a bronchus it usually selects the right, that bronchus having its aperture more immediately under the centre of the trachea than has the left tube. On one occasion, in a dissecting- room subject, I found two threepenny pieces lying side by side, in the right bronchus, so as to en- tirely block the tube. The danger of inhaled foreign substances depends not so much upon the mechanical obstruction they offer, as upon the spasm of the glottis they excite by reflex irrita- Chap. IX] THE NECK 181 tion. A body may, however, lodge in the ventricle for some time without causing much trouble, as in a case reported by Desault, where a cherry- stone lodged for fcwo years in this cavity without much inconvenience to its host. In one strange case a bronchial gland found its way into the trachea by producing ulceration of that tube, was coughed up, and became impacted in the rima glottidis. The patient was saved from immediate suffocation by tracheotomy. Foreign bodies have been removed from the right bronchus through a tracheotomy wound. In this way MacCormac removed from the bronchus the blade of a tooth forceps. The thyroid body.— Each lobe should mea- sure about 2 inches in length, about 1^ inches in breadth, and § of an inch in thickness at its largest part. When distinctly beyond these measurements the thyroid may be considered to be enlarged. Its usual weight is between one and two ounces. Of its three surfaces, the _ anterior is covered by the infrahyoid muscles,^ its inner rests on the larynx and trachea, while its outer or posterior covers the carotid sheath. Its promi- nent posterior border is in contact at its lower part with the recurrent laryngeal nerve and oesophagus. Each lobe extends from about the middle of the thyroid cartilage to the sixth ring of the trachea. It is larger in females than in males, and the right lobe is usually larger than the left. In connection with these matters it may be noted that thyroid enlargements (bronchocele, goitre) are more common in females than in males, and in any case are more apt to be first noticed on the right side. The body being closely adherent to the trachea and larynx, it follows that it moves up and down during deglutition, and this circumstance is of the utmost value in the diagnosis of bronchocele from other cervical tumours. A strong process of cervical fascia (the suspensory ligament of Berry) binds the gland to each side of the cricoid cartilage, and has to be 182 SUEGICAL APPLIED ANATOMY [Fart I severed before complete removal is possible. The thyroid when enlarged may distort and narrow the trachea, and this is all the more likely to be the case when the enlargement occurs rapidly, since the body is held down by the sterno-hyoid, sterno-thyroid, and omo-hyoid muscles. The en- larged gland is apt to press especially upon the veins of the neck, producing engorgement of the face and head, upon the sterno-mastoid muscle, and the other muscles named, upon the cervical nerves, and particularly the recurrent laryngeal. In some cases of dyspnoea produced by rapidly growing bronchoceles, Bonnet has proposed sub- cutaneous section of the muscles. Since the isth- mus must bind together the enlarging lobes of a bronchocele, Sir Duncan Gibb, on the other hand, proposed to divide the isthmus in cases where dyspnoea resulted. This operation he performed several times with great relief to the patient. The posterior or outer surface of the thyroid body being in contact with the sheath of the great ves- sels, it follows that the gland when enlarged may readily receive pulsations from those vessels. It generally touches also the lower part of the pharynx, and the upper part of the gullet behind, and enlargement in this direction may, in con- nection with the interference with the movement of the larynx in deglutition, serve to explain the difficulty in swallowing often noticed in broncho- cele. The isthmus of the thyroid gland is developed from a diverticulum which is protruded from the ventral wall of the pharynx in the embryo between the mandibular and hyoid parts of the tongue. The foramen csecum of the tongue represents the point at which the diverticulum grew out from the pharynx. From this foramen a duct (the thyro-glossal) may be found to lead to accessory gland masses about the hyoid bone. In the vicinity of this bone accessory glands and small cysts lined with epithelium are not unfrequently met with. These glands, together with the so-called pyramid Chap. IX] THE NECK 183 or middle lobe, are the remains of the neck of the primitive diverticulum. The pyramid, which is nearly always connected to the hyoid bone by the levator fchyroideae, exists in 79 per cent, of the subjects examined (Streckeisen). The lateral lobes are developed from the fourth visceral clefts. The median diverticulum occasionally fails to join one of the lateral, in which case the isthmus is partially absent. Small accessory thyroid bodies are frequently present. The parathyroid bodies appear to play an essential part in the function of the thyroid. They are of the size of small peas, and have a structure similar to that of the suprarenal bodies. Two are usually found on each side, one at the lower pole of the lateral lobe, the other behind the lobe amongst the terminal branches of the inferior thyroid artery. Parathyroid bodies be- come less numerous as age advances, so that in the aged none may be found (Forsyth). Atrophy of the thyroid gland, or its destruc- tion by disease, is apt to lead to a general con- dition of the body known as myxozdema. The con- dition closely resembles cretinism, especially as met with in goitrous subjects. Myxcedema may follow the entire excision of the gland by opera- tion, and has been produced in monkeys by ex- perimental removal of the same. One prominent feature in myxcedema is the swelling of the sub- cutaneous tissues from an accumulation therein of a mucinoid substance. Vasomotor nerves reach the thyroid through the lower part of the cervical sympathetic chain, and by the same course nerves pass upwards to the eye. These nerves appear to be connected cen- trally^ probably in the medulla, for in certain conditions enlargement of the thyroid is accom- panied by protrusion of the eye (exophthalmic goitre). The lymphatics of the thyroid are numerous, and pass to the deep cervical and superior mediastinal lymph glands. In excision of the thyroid gland a Y-shaped 184 SURGICAL APPLIED ANATOMY [Part I median cut is usually made that divides the skin, fascia, platysma, and anterior jugular veins. The sternohyoid, sterno-thyroid, omo-hyoid, and portion of the sterno-mastoid have usually to be divided. The tumour is carefully separated. The capsule that invests the vascular gland must not be torn through. The thyroid vessels are liga- tured in situ before the removal of the mass. The superior thyroid reaches the gland at the apex of the lateral lobe and is there secured. The in- ferior thyroid artery enters the lower part of the lobe at its posterior # aspect. In securing this vessel, and in liberating the lower part of the tumour, the recurrent laryngeal nerve is in great danger of being damaged. The thyroidea ima artery, an extra vessel to the thyroid body, usually arises from the innominate, and is found in one subject out of every ten. The gullet commences opposite the sixth cervical vertebra, and pierces the diaphragm opposite the tenth dorsal vertebra. The point is marked on the back by the overlapping spine of the ninth dorsal vertebra. By placing the stetho- scope a little to the left of this spine, fluid may be heard to enter the stomach. It presents three curves : one is antero-posterior, and corresponds to the curve of the spinal column ; the other two are lateral. The gullet, commencing at the middle line, deviates slightly to the left as far as the root of the neck ; from thence to the fifth dorsal vertebra it gradually returns to the middle line, and finally it turns again to the left, at the same time passing forwards, to pierce the diaphragm. Its length is from 9 to 10 inches. Its transverse diameter has been carefully estimated by Dr. Mouton, by filling the gullet with plaster-of-Paris in^ situ, and then measuring the cast thus ob- tained. Dr. Mouton found that there were three narrow parts in the gullet, one at its commence- ment, one about 2| inches from that point, and a third where the tube passes through the dia- phragm. The diameter at each of these points was Chap. IX] THE NECK 185 a little over | an inch (14 mm.); the diameter else- where was about f of an inch (17 mm. to 21 mm.)- Bv forcible distension the two upper narrow parts could be distended to a diameter of 18 to 19 mm., the lower part to 2b mm., and the rest of the gul- let to a diameter of nearly lh inches (35 mm.). It follows that foreign bodies when swallowed are most apt to lodge either at the commence- ment of the gullet or at the spot where it passes through the diaphragm. The same parts also are those most apt to show the effects of corrosives that have been swallowed. Among the relations of the oesophagus, the following may be noted as receiving illustration in surgical practice : The gullet is in nearly all its course in close relation with the front of the vertebral column. In the neck the trachea is immediately in front of it. In the thorax it has the left bronchus, left bronchial glands, pericardium, and left auricle in front of it, while the two vagi form a plexus on it. The left bronchial glands, when enlarged, may press on the gullet, adhere to it, or even cause localised soften- ing and diverticula to spring from it. The thoracic duct passes behind to reach the left side of the gullet in the upper part of the thorax, while in the lower part the aorta, at first to the left of the oesophagus, gradually becomes pos- terior to it. It is, moreover, partly in contact with both pleurae, but more especially with the membrane of the right side ; and, lastly, the re- current laryngeal nerve ascends between it and the trachea. (See Figs. 39 and 69, pp. 218 and 414.) Now, foreign bodies impacted in the gullet are very apt to lead to ulcerations that may open adjacent parts. Thus, in the Musee Dupuytren is a specimen showing a five-franc piece that had stuck in the gullet, and had produced an ulcer that had opened the aorta. In another instance a " smasher " swallowed a counterfeit half-crown piece. Eight months afterwards he died of haemorrhage. The coin had sloughed into his 186 SURGICAL APPLIED ANATOMY [Part I aorta. In another case (Lancet, 1871), a fish-bone, lodged in the gullet opposite the fourth dorsal vertebra, had caused two perforating ulcers ; one on the right side had caused plugging of the vena azygos major, while the other on the left had made a hole in the aorta. Less frequently impacted foreign substances have found their way into the trachea and into the posterior mediastinum. Dr. Ogle reports a case {Path. Soc. Trans., vol. iv. ) where a piece of bone impacted in the gullet induced ulceration of an intervertebral disc and subsequent disease of the spinal cord. Carcinoma of the gullet, also, when it spreads, is apt to invade adjacent parts, and especially to open into the trachea or bronchi. If it spreads to the pleura, it will usually involve the right pleura, as being the membrane more in relation with the gullet. Cancer of the gullet has so spread as to invade the thyroid body, the pericardium, and the lung, and has opened up the first intercostal artery in one case and the right subclavian in another (Butlin's " Sarcoma and Carcinoma/' 1882). The sensory nerve supply of the oesophagus comes mainly from the fifth dorsal segment of the cord (Head). In cases of cancer or burns of the gullet, pain is referred to the skin of this seg- ment (see Fig. 56, p. 333). (Esophageal malformations. — In the newly born the upper part of the oesophagus may end blindly, while the lower part commences by an opening in or near the bifurcation of the trachea, so that milk can only reach the stomach by first passing into the larynx and trachea. Death soon follows from suffocation or septic pneumonia. The condition is the result of a maldevelopment of the septum between the trachea and oesophagus. Hernial diverticula of the mucous membrane occa- sionally occur at the junction of the oesophagus and pharynx. They are usually named pharyngeal pouches, and protrude between the lower border of the inferior constrictor and commencement of Chap. IX] THE NEfitv 187 the oesophageal musculature, opposite the cricoid cartilage. Since the pouch lies against the spine, it necessarily compresses the commencement of the oesophagus when it becomes filled with food. The operation of «rsopliagotoniy consists in incising the gullet for the purpose of removing an impacted foreign body. The gullet is usually reached from the left side, since it projects more on that aspect. The incision is made between the sterno-mastoid and the trachea, in the same direc- tion as the incision for ligaturing the common carotid. The cut extends from the_ top of the thyroid cartilage to the sterno-clavicular joint. The omo-hyoid muscle is drawn outwards, or cut. The great vessels, larynx, and thyroid gland are drawn aside, and care must be taken not to wound these structures nor damage the thyroid vessels, thoracic duct, or the recurrent nerve. The gullet, when exposed, is opened by a vertical incision. Oreat vessels. — The course, relations, and abnormalities of the great cervical vessels, to- gether with the operations whereby they may be ligatured, and the details pertaining to those procedures, are so fully given, not only in works on operative surgery, but also in the chief ana- tomical text-books, that nothing need be said upon the matter in this place. The bifurcation of the common carotid is a favourite locality for aneur- ism, being a point where some resistance is offered to the blood current. These tumours, also, are common at the root of the neck, where they are often due to extension of aneurismal disease from the aorta, although in many cases they have an in- dependent origin. It is in the neck that the treat- ment of aneurism by the distal ligature is most often carried out. There is no place in the body where Brasdor's operation can be carried out with the completeness with which it can be adopted in the neck. In this procedure a main trunk is ligatured on the distal side of an aneurism, no branches intervening between the sac and the liga- ture. The cure by this measure depends upon the 188 SURGICAL APPLIED ANATOMY [Part I fact that blood does not continue to go to parts when once the need for blood in them is dimin- ished. Thus, after amputation at the hip joint, the femoral artery, having no need to carry to the stump the amount of blood it brought to the limb, often shrinks to a vessel no larger than the radial. When an aneurism low down in the carotid artery is treated by ligature of the vessel near its bifurcation by Brasdor's method, the blood, having now, as it were, no object in enter- ing the carotid trunk, soon ceases to fill the vessel entirely, and the artery (and in successful cases the aneurism) shrinks in consequence. Wardrop's operation, or the distal ligature of large branches for the relief of aneurism of a main trunk, is now, perhaps, quite limited as to its performance to the ligature of the carotid and subclavian arteries for innominate aneurism. Since in this procedure large branches come off be- tween the sac and the ligature, it is not easy to fully understand how the operation acts bene- ficially. It is assumed to owe its success to the same principle that underlies Brasdor's operation. The right carotid and subclavian have also been ligatured for aortic aneurism with some success, and here also the reason for the good effected by the operation is difficult to appreciate. It has been pointed out that the innominate artery lies more or less directly in the axis of the ascending aorta, while the left carotid and_ subclavian arteries arise at an angle to that axis, and it is upon this fact that reasons have been founded for selecting the vessels of the right side (Barwell). The matter is, however, complicated by the know- ledge that when vegetations are swept off the aortic valves they enter the left carotid with in- finitely greater frequency than they do the right. The whole subject, indeed, requires investigation. The cervical connective tissue being lax, aneur- isms in this part can grow and spread rapidly, and usually soon produce " pressure symptoms." As examples of these may be noted oedema and Chap. IX] THE NECK 189 lividity of the face and of the upper limb from pressure upon the main veins, laryngeal symptoms from pressure upon the recurrent nerve or trachea, spasm of the diaphragm from pressure upon the phrenic nerve, damage to the sympathetic, and giddiness and impaired vision from anaemia of the brain. The vertebral artery has been ligatured with doubtful benefit in cases of epilepsy. It is sur- rounded by vasomotor nerves derived from the inferior cervical ganglion, which also are neces- sarily tied. The artery is reached through an in- cision made along the posterior border of the sterno-mastoid muscle just above the clavicle. The " carotid tubercle " {see p. 158) is then sought for, and vertically below it lies the artery, in the gap between the scalenus anticus and longus colli muscles. The procedure is surrounded with considerable difficulties. In cases of bleeding from branches of the ex- ternal carotid it is better, when possible, to liga- ture the trunk of that vessel in preference to se- curing the common carotid. The latter procedure has a high death-rate (50 per cent.), due (1) to brain mischief, following the lessened blood- stream through the internal carotid, and (2) to secondary haemorrhage, due to the very free ana- stomosing channels. Air in veins. — The veins of the neck are under the influence of the respiratory movements. The veins do not collapse owing to attachments to the surrounding fasciae. During inspiration these vessels become more or less emptied; during ex- piration they become enlarged and turgid. With greatly impeded breathing they may attain for- midable size. Since ether usually causes some respiratory difficulty, it is seldom administered in operations on the neck. The only other veins that are under the influence of the aspiratory power of the thorax are the axillary vein and its larger tributaries. When any one of these vessels is wounded, and the wound is for the 190 SURGICAL APPLIED ANATOMY [Part I moment dry, air may very readily be drawn into it during the inspiratory act, just as air is drawn Fig. 35.— Showing the position of the lymphatic glands of the head and neck. The outlines of the sterno-mastoid (s.m.), trapezius (tr. ), internal jugular, subclavian, and right innominate veins are shown. 1, Submaxillary glands, 1' area drained ; 2, suprahyoid glands, 2' area drained : 3, parotid glands, 3' area drained; 4, postauricular glands, 4' area drained; 5, occipital glands, 5' area drained ; C, in front of external jugular vein, marking position of the superficial cervical glands ; 7, laryngeal gland ; 8, 8, 8, upper deep cervical glands; 9,9,9, lower deep cervical glands; 10 gland receiving lymph from thyroid ; 11, superior mediastinal glands ; 12, axillary glands. Chap. IX] THE NECK 191 into the trachea. The air causes embolism of the pulmonary capillaries. Valves in the veins of the neck. — The sub- clavian veins and their tributaries are liberally provided with valves, but the internal jugular has only one pair, situated at its termination in the innominate vein. There are no valves in the in- nominate veins nor in the superior vena cava. When the venous pressure within the^ thorax is greatly raised, as in lifting heavy weights, only the terminal valves of the internal jugular vein prevent the transmission of the pressure to the brain. In accidents which cause sudden compres- sion of the thorax, the head and neck may remain livid for days following the accident. The lividity is probably due to the jugular valves yielding, thus subjecting the capillaries of the head and neck to a higher pressure than they are able to withstand. The lymphatic glands of the head and neck are numerous, and arranged in the follow- ing sets (Fig. 35) : — (1) Submaxillary glands, 10 to 15 in number, situated at the lower border of the jaw beneath the cervical fascia ; (2) the suprahyoid, 1 or 2 in number, situated between the chin and hyoid bone near the middle line; (3) parotid or pre- auricular set, situated in and over the parotid gland ; (4) postauricular, or mastoid, 2 to 4 in number, situated over the mastoid process; (5) occipital, 3 to 5 in number, over the insertion of the complexus muscle ; (6) superficial cervical glands, often absent, situated over the sterno- mastoid along the ^ external jugular vein; (7) laryngeal, 1 to 3 in number, below the great horn of the hyoid ; (8)_ the upper deep cervical set, 10 to 20 in number, situated over the upper part of the internal jugular vein and bifurcation of the common carotid artery ; (9) lower deep cervical set, surrounding the terminal parts of the in- ternal jugular, subclavian, external jugular, and transverse cervical veins. This set becomes 192 SURGICAL APPLIED ANATOMY [Part I continuous with the axillary and mediastinal glands. These glands are very often enlarged and in- flamed, and it is in this part of the lymphatic system that the changes in scrofula are most com- monly met with. The inflammatory affections in glands would appear to be always of a secondary nature (if we exclude some cases of inflammation incited by injury, and perhaps by exposure to severe cold), and to follow disturbances in those parts of the periphery whence they respectively receive their lymph. It may be convenient, there- fore, to group the relations of certain glands to certain parts of the periphery. Scalp. — Posterior part = occipital and post- auricular glands. Frontal and parietal portions == parotid glands (Fig. 35). Vessels from the scalp also enter the super- ficial cervical set of glands. Skin of face and neck = submaxillary, parotid, and superficial cervical glands. External ear = superficial cervical glands. Lotver lip = submaxillary and suprahyoid glands. Buccal cavity = submaxillary glands and deep cervical glands (upper set). Gums of lower jaw = submaxillary glands. Tongue. — Anterior portion = suprahyoid and submaxillary glands. Posterior portion = deep cervical glands (upper set). Tonsils and palate == deep cervical glands (upper set). Pharynx. — Upper part = parotid and retro- pharyngeal glands. Lower part = deep cervical glands (upper set). Larynx, orbit, and roof of mouth = deep cer- vical glands (upper set). Nasal fossce — retropharyngeal glands, deep cervical glands (upper set). Some lymphatics from the posterior part of the fossae enter the parotid glands.*" * From "Scrofula, and its Gland Diseases," by the Author. Chap. IX] THE NECK 193 In the removal of the deep cervical glands a number of structures are liable to be wounded. The glands frequently become firmly adherent to the internal jugular vein; the uppermost glands surround the spinal accessory nerve ; the super- ficial cervical nerves pass among those of the lower deep cervical set ; the thoracic duct has been wounded in removing glands from the left supra- clavicular fossa. Thoracic duct in the neck. — A point taken on the upper border of the clavicle, 1 inch from its sternal end, will mark the angle between the internal jugular and subclavian veins where the thoracic duct ends. At its termination the duct curves outwards over the scalenus anticus and phrenic nerve above its point of entrance where it is furnished with valves. It may be double or triple at its termination. Ligature of the duct is followed by no untoward symptoms, as a rule, a result which is due to the free anastomosis which exists between it and the lymphatics of the right side of the thorax and to communications with the azygos veins (Leaf). Branchial nstiihr. — Certain congenital fis- tula? are sometimes met with in the neck, which are due to partial persistence of one of the branchial clefts. These clefts are placed in the foetus between the branchial arches. The arches are usually described as five in number. The first lays the foundation for the lower jaw and malleus. From the second are developed the styloid process, the stylo-hyoid ligament, and lesser cornu of the hyoid bone. From the third are formed the body and greater cornu of the hyoid bone, while the fourth and fifth take part in the formation of the soft parts of the neck below the hyoid bone. The first cleft is between the first and second arches. " The cervical branchial fistulse appear as very fine canals opening into minute orifices in one or both sides of the fore part of the neck and leading backwards and inwards or backwards and upwards towards the pharynx or N 194 SURGICAL APPLIED ANATOMY [Part I oesophagus ' ; (Paget). Their length is about lj to 2£ inches, and their diameter varies from that of a" bristle to that of an ordinary probe. They usually exist about the line of the third or fourth cleft, and are most often met with just above the sterno-clavicular joint. Others are found about the level of the top of the thyroid cartilage at the anterior edge of the sterno-mastoid muscle. About some of these fistulse, or in spots where they com- monly open, flat pieces of cartilage may be found. The more prominent of these have been^ termed supernumerary auricles. Certain dermoid cysts of the neck arise from unobliterated branchial spaces, and it would appear also, that certain polycystic congenital tumours, occurring as one form of " hydrocele of the neck, ;J may be de- veloped from an imperfectly closed cleft. I have elsewhere detailed the dissection of one of these tumours that appeared to be associated with a partially closed second branchial cleft (Path. Soc. Trans., 1881). His has shown that many branchial fistulse and cysts are formed from the cervical sinus. The cervical sinus is produced in the neck of the em- bryo by a rapid growth in the second and third arches which causes them to grow backwards and overlap the fourth and fifth. The piece of epiblast thus included in the neck usually disappears, but it may persist and give rise to a cyst or, if open, to a fistula. The common fistula, that which opens above the sterno-clavicular joint, is derived from the cervical sinus. It is to be remembered that the branchial clefts are only depressions in the wall of the pharynx, not complete fissures. Hence fistulas rarely communicate with the pharynx. The ventricle of the larynx, as is normally the case in many apes, may become prolonged into a sac which passes into the neck through the thyro- hyoid membrane, thus forming a cervical air cyst or sac, Part II.— THE THORAX CHAPTER X 1. The thoracic walls. — The two sides of the chest are seldom symmetrical, the circumference of the right side being usually the greater, a fact that is supposed to be explained by the unequal use of the upper limbs. In Pott's disease, involving the dorsal region, when the spine is much bent forwards the thorax becomes greatly deformed. Its antero-posterior diameter is increased, the sternum protrudes, and may even be bent by the bending of the spine, the ribs are crushed to- gether, and the body may be so shortened that the lower ribs overlap the iliac crest. In pigeou breast deformity the sternum and cartilages are rendered protuberant, so that the antero-posterior measurement of the chest is much increased, while a deep sulcus exists on either side along the line of junction of the ribs and their cartilages. It is by the sinking in of the parietes along the costo-chondral junctions that the protuberance is produced. In children, and especially in rickety children, the thorax is very pliable and elastic, and if a constant impediment exists to the entrance of air, as afforded, for example, by greatly enlarged tonsils, the thoracic walls may yield in time to the suction brought to bear upon them at each inspiration. The weakest part of the thorax is along the costo- chondral line on either side, and it is here that 195 196 SUKGICAL APPLIED ANATOMY [Part II the parietes yield most conspicuously in such cases, and by this yielding the deformity is pro- duced. Deformities of the chest result from abnor- mal curvatures of the dorsal part of the spinal column. The ribs are firmly bound to the verte- brae by the costo-vertebral and costo-transverse ligaments, and hence alteration in the position of vertebras is attended by changes in the costal series. Thus, when there is kyphosis in the dorsal region the upper part of the spine is bent for- wards and downwards, carrying with it the upper ribs and the sternum. The antero-posterior diameter of the thorax is thereby increased, but its vertical and transverse measurements are de- creased. When lateral curvature is produced in the dorsal region, the ribs, on the side towards which the bend occurs, are necessarily compressed, while on the opposite side they are separated. In scoliosis of the spine not only is a lateral curva- ture formed, but the vertebras undergo a rotation at the same time. The vertebral bodies move to- wards the convexity and their spines towards the concavity of the curvature (Fig. 36). The ribs on the concave side are carried forwards on the trans- verse processes and their angles open out, the side of the chest becoming flattened behind. On the other side (convex) the angles are unduly promi- nent, for the ribs are carried backwards at their vertebral extremities and bent inwards in front. The transverse diameter of the chest thus becomes oblique (Fig. 36). On the concave side the inter- costal spaces are diminished in size, the ribs even coming into contact, while on the convex side the spaces are increased in size. The thoracic viscera are necessarily distorted in shape and altered in position. The sternum.— The upper edge of the sternum corresponds to the disc between the second and third dorsal vertebrae, and the sterno-xiphoid joint to the middle of the tenth dorsal. In the foetus at full term the upper edge of the sternum Chap. X] THE THORAX 197 STERNUM AN OLE: Ari<;Le Fig. 36.— Showing the changes in the thorax which follow scoliosis of the spine. (After Redard.) The convexity of the spinal curvature is towards the right ; on that side the ribs are sharply bent at their angles. On the concave Cleft) side the ribs have an open angle. is opposite the middle of the first dorsal vertebra (Symington). A transverse ridge may be felt upon its anterior surface that- corresponds to the junction of the manubrium and gladiolus, and is in a line with the second costal cartilages. The skin over the sternal region is the part of the surface most fre- quently the seat of cheloid. The bone is rarely fractured, being soft and spongy, and supported by the elastic ribs and their cartil- ages, as by a series of springs. In the old, when the cartilages are ossified and the chest is more rigid, the tend- ency to fracture is increased. The sternum is most often found fractured in connection with injuries to the spine, although it may be broken by simple direct violence. The bone may be frac- tured by violent bending of the spine backwards, and by abrupt bending of it forwards. In the former instance the lesion is probably due to muscular violence, to the abdominal muscles and the sterno-mastoicl pulling one against the other. In the latter instance the lesion is commonly brought about by the violent contact of the chin with the bone. Dislocation may occur ^ at the sterno-manubrial joint. The manubrium in these injuries generally remains in situ, while the gladiolus with the ribs is displaced forwards in front of it. A considerable degree of respiratory movement takes place at this joint; only in very old people does it become obliterated by bony union. It possesses a distinct synovial cavity surrounded by strong fibrous and fibro-cartilagin- 198 SURGICAL APPLIED ANATOMY [Part II ous ligaments. Malgaigne cites the case of a youth who, from constant bending at his work as a watchmaker, caused the second piece of the sternum to glide backwards behind the manu- brium. From its exposed position and cancellous struc- ture, the sternum is liable to many affections, such as caries and gummatous periostitis. The com- parative softness also of the bone is such that it has been penetrated by a knife in homicidal wounds. The shape and position of the bone have also been altered by pressure, as seen sometimes in artisans following employments requiring in- struments, etc., to be pressed against the chest. Certain holes may appear in the middle of the sternum, and through them mediastinal abscesses may escape, and surface abscesses pass deeply into the thorax. These holes result from imperfect union of the right and left sternal bars, out of which the sternum is formed. In the case of E. Groux, the bone was separated vertically into two parts. The gap could be opened by muscular effort and the heart exposed, covered only by the soft parts. The sternum has been trephined for mediastinal abscess, and for paracentesis in peri- cardial effusion, and it has been proposed also to ligature the innominate artery through a trephine hole in the upper part of the bone. The ribs are placed so obliquely that the an- terior end of one rib is on a level with the pos- terior end of a rib some way below it in numerical order. Thus the second rib in front corresponds to the fifth rib behind, and the insertion of the seventh to the tenth. If a horizontal line be drawn round the body at the level of the inferior angle of the scapula, while the arms are at the side, the line would cut the sternum in front at the attachment of the sixth cartilage, would cut the fifth rib at the nipple line, and the ninth rib at the vertebral column. The second rib is indi- cated by the transverse ridge on the sternum already alluded to (angulus Ludovici). The lower Ohap. X] THE THOBAX. 199 border of the pectoralis major leads to the fifth rib, and the first visible serration of the serratus magnus corresponds to the sixth. The longest rib is the seventh, the shortest the first. The most oblique rib is the ninth. The ribs are elastic and much curved, and, being attached by many ligaments behind to the column, and in front to the yielding cartilages, resist injuries tending to produce fracture with the qualities possessed by a spring. A rib may be fractured by indirect violence, as by a wheel passing over the body when lying prostrate on the back. In such a case the force tends to approxi- mate the two ends of the bone, and to increase its curve. When it breaks, therefore, it breaks at the summit of its principal curve, i.e. about the centre of the bone. The fragments fracture out- wards, and the pleura stands no risk of being penetrated. When the rib is broken by direct violence, lesion occurs at the spot encountered by the force, the bone fractures inwards, the curve of the rib tends to be diminished rather than increased, and there is much risk of the fragments lacerating the pleura. Those most often broken are the sixth, seventh, and eighth, they being under ordinary circum- stances the most exposed. The rib least frequently fractured is the first, which lies under cover of the clavicle. In elderly people dying from phthisis the cartilage of the first rib is often found to be cal- cified and occasionally to be fractured. Fractures are more common in the elderly than in children, owing to the ossification of the cartilages that takes place in advancing life. When a rib is fractured, no shortening occurs, the bone being fixed both in front and behind, while vertical displacement is prevented by the attachments of the intercostal muscles. Thus no obvious de- formity is produced unless a number of consecu- tive ribs are the subjects of fracture. These bones have been broken by muscular violence, as during coughing, and in violent expulsive efforts such as 200 SURGICAL APPLIED ANATOMY [Part II are incident to labour. In such instances the ribs are probably weakened by atrophy or disease. In many instances of gun-shot wound the curve of the rib has saved the patient's life. In such cases the bullet has entered behind near the dorsal spine, has been conducted round the chest, along the curve of a rib beneath the skin, and has es- caped again near the sternum. This property, however, of the ribs for turning bullets refers rather to the days of round bullets, and not to modern conical projectiles. In rickets changes take place at the point of junction of the ribs and cartilages leading to bony elevations, which produce, when the ribs on both sides are affected, the condition known as the " rickety rosary.' ; The intercostal spaces are wider in front (than behind, and between the upper than the lower ribs. The widest of the spaces is the third, then the_ second, then the first. The seventh, eighth, ninth, and tenth interspaces are very nar- row in front of the angles of the ribs. The first five spaces are wide enough to admit the whole breadth of the index finger. The spaces are widened in_ inspiration, narrowed in expiration, and can be increased in width by bending the body over to the opposite side. 1 , Paracentesis is usually performed in the /sixth or seventh space, at a point midway between //the sternum and the spine, or midway between the / anterior and posterior axillary lines. The seventh space can be readily identified by its relation- ship to the angle of the scapula; when the arm is by the side of the body this space is slightly over- lappedby the angle. If a lower space be selected there _ is danger of wounding the diaphragm, especially upon the right side. If the eighth or ninth space be selected the incision is made just externally to the line of the angle of the scapula. The trochar should be entered during inspiration, the space being widened thereby, and should be kept as near as possible to the lower border of the Chap. X] THE THORAX 2C1 space, so as to avoid the intercostal vessels. Tap- ping of the chest through any space posterior to the angles of the ribs is not practicable, owing to the thick covering of muscles upon the thoracic wall in this place, and the fact that the inter- costal artery, having a more horizontal course than the corresponding ribs, crosses the middle of this part of the space obliquely. Beyond the angle the intercostal vessels lie in a groove on the inferior border of the rib forming ^ the upper boundary of the space. The vein lies immediately above the artery, and the nerve immediately below it. In the upper four or five spaces, however, the nerve is at first higher than the artery. Paracen- tesis of the thorax is occasionally followed by syn- cope or even death. It is difficult to account for such a result ; it may be a reflex inhibition of the heart set up during perforation of the parietal pleura, which is richly supplied by the intercostal nerves, or by injury to the lung, which is supplied by the vagus. Pus may readily be conducted along the loose tissue between the two layers of intercostal mus- cles. Thus, in suppuration following upon disease of the vertebrae, or of the posterior parts of the ribs, the pus may be conducted along the inter- costal spaces to the sternum, and may thus pre- sent at a considerable distance from the real seat of the disease. Removal of ribs. — In order to obtain a free opening into the pleural cavity a portion of one or even two ribs may be excised. In some cases of long-standing empyema with an open sinus, all that part of the bony wall of the thorax w T hich corresponds to the outer boundary of the suppurating cavity is removed in order that the cavity may collapse and be in a position to close. This latter measure is known as Estlander's operation, or thoracoplasty. In some instances portions of as many as nine ribs have been ex- cised, and the total length of bone removed has reached 50 to 60 inches. 202 SURGICAL APPLIED ANATOMY [Part II In removing a rib the bone is entirely bared of periosteum with the rugine, and the excision is extraperiosteal. In this way the intercostal vessels are not exposed, and, if divided subse- quently, can be readily secured when the ribs are out of the way. The internal mammary artery runs paral- lel to the border of the sternum, and about ^ an inch from it. It may give rise to rapidly fatal haemorrhage if wounded. The vessel may readily be secured in the first three intercostal spaces, and with some difficulty in the fourth or fifth space. It is most easily reached through the second space, and cannot be secured through any space below the fifth. The female breast extends from the second rib above to the sixth below, and from the side of the sternum to the mid-axillary line (Stiles). In cases of retained lactation the twelve to fifteen irregular lobes which make up the body of the gland can be felt radiating outwards from the nipple. The lactiferous ducts, which correspond in number to the lobes, open at the apex of the nipple, within which each shows a dilatation or ampulla. Branching processes of adjoining lobes unite and enclose spaces within the body of the gland, containing connective tissue and masses of fat. After the menopause, when the glandular tissue is absorbed in great part, and during the resting condition, fat forms the greater part of the female breast. Besides the main body of the gland, Stiles has drawn attention to numerous peripheral processes which lie in the surrounding connective tissue. Although the principal part of the breast rests on the pectoralis major, quite one-third of the gland crosses the outer border and rests on the serratus magnus within the axilla. It also covers the origins of the obliquus abdominis externus and rectus abdominis. In excision or inflammation of the breast it is important to bind the arm by the side to keep the parts from being disturbed Chap. X] THE THORAX 203 by the pectoralis major. Peripheral processes of the gland and many of its deep lymphatics enter the pectoral sheath, hence the removal of this structure with part, or even all, of the pectoral musculature if complete extirpation of cancer is to be assured. The loose retromammary tissue which binds the mamma loosely to the pectoral sheath may be the seat of abscess, or sometimes of a bursal cyst. The nipple, in the male and in the virgin female, is situated on the fourth intercostal space, about | of an inch from the junction of the ribs with their cartilages ; after lactation the breast becomes pendent, and the nipple no longer serves as a guide to the intercostal spaces. The nipple contains erectile and muscular tissue, and_ is richly supplied by cutaneous branches ofthe third and fourth spinal nerves. The skin is pigmented, thin and sensitive, and often the seat of painful fissures and excoriations. In painful diseases of the breast, tender areas occur over the fourth and fifth spinal segments (Fig. 56, p. 333) (Head). The breast is developed by a solid invagination of epiblast at the point afterwards marked by the nipple. About the sixth month of foetal life the primitive mammary bud branches out in all directions within the subcutaneous tissue. Thus it comes about that the subcutaneous fascia is con- densed around the gland, forming its capsule. The retromammary part of the capsule is connected at the interlobular spaces with the superficial layer, which in turn is fixed to the skin by subcutaneous bands, or skin ligaments. It is through lymph channels that cancer spreads, and those of the breast, which is one of the commonest sites of cancer, are of especial im- portance if complete eradication of the disease is to be obtained. The lymph vessels are arranged in the following sets : (1) Perilobular, round the acini and lobules ; (2) periductal, round the lac- tiferous ducts ; (3) interlobar, situated in the interlobar septa and joining (4) the retromam- 204 SUPGICAL APPLIED ANATOMY [Part II mary network with (5) the superficial mammary in the anterior part of the capsule. If the inter- lobar septa are invaded by cancer they contract, and through their cutaneous attachments cause depressions in the skin ; if the process invades the periductal vessels, the nipple is retracted. The mammary lymphatic system is connected with the subcutaneous network of vessels, to which cancer may spread, producing that variety of the disease known as cancer en cuirasse. Through communi- cations with the lymph channels of the pectoral fascia and muscle, cancer of the breast may spread to these structures. The gland then becomes firmly fixed to the deeply seated structures. The majority of the lymph vessels pass from the breast to the pectoral glands, six to eight in number, situated along the anterior border of the axilla, and to the central axillary set, twelve to fifteen in number, situated beneath the axillary tuft of hair and on the inner side of the axillary vein. From these two sets the lymph vessels pass to the deep axillary glands lying along the front and inner side of the axillary vessels. The deep axil- lary glands become continuous with the lower deep cervical glands. It is mainly along this path that cancer tends to spread, but vessels leave the inner segment of the breast and pass to the anterior intercostal glands situated in the upper four intercostal spaces and lying on each side of the internal mammary vessels, while occasionally a few vessels pass to the cephalic gland situated in the hiatus between the deltoid and pectoralis major muscles. Handley found a marked ten- dency for breast cancer to spread downwards in the lymphatics, passing to the epigastric triangle, where they perforate the belly wall to join lym- phatics both above and below the diaphragm ; it is probably owing to this communication that the liver is so often the seat of secondary deposit in cases of cancer of the breast. When the normal channels become clogged with cancerous emboli the lymph passes by circuitous paths. The subscapu- Chap. X] THE THORAX 205 lar glands, surrounding the subscapular vessels on the posterior wall of the axilla, may become in- filtrated; through the lymphatics of the arm, which end in the central axillary glands, the structures round the shoulder may become the seats of secondary deposit, and through the com- munication between the lymph system of one breast with that of the other, across the sternum, a secondary deposit may even occur in the oppo- site breast (Stiles). The breast is thinnest along a line drawn from the sterno-clavicular joint to the nipple. Abscesses situated beneath the breast not unfre- quently make their way through the gland at some point along this line. Abscesses of the breast should be opened by incisions radiating from the nipple, to avoid wounding the lactiferous ducts. The intercosto-humeral nerve pierces the cen- tral set of axillary glands. It becomes compressed when these glands are invaded by cancer, and pain is referred to the termination of the nerve over the posterior aspect of the arm above the elbow. Various parts of the brachial plexus may also become involved or the axillary vein or lym- phatics occluded, the arm being swollen and cedematous in consequence. The following groups of arteries supply the gland and are cut in excision of the organ : (l) the long thoracic, alar thoracic, thoracic branches of the acromio-thoracic axis ; (2) anterior perfor- ating branches from the internal mammary at the second, third, and fourth intercostal spaces ; (3) lateral branches from the second, third, and fourth intercostal arteries. Supernumerary nipples and breasts may occur. They are commonly found in a line between the axilla and the groin. In the embryonic stage of all mammals an epiblastic mammary ridge is found in this position. In man it disappears except at one point, but occasionally some isolated part may persist and proceed to form a breast. Embryology fails to explain the occurrence of 206 SURGICAL APPLIED ANATOMY [Part II breasts on the buttock or back, where they are occasionally found. 2. The thoracic viscera. The lung*. — The apex of the lung rises in the neck from 1 to 2 inches above the inner half of the clavicle. Its highest point in the majority of adults lies 1| inch above the sternal end of the clavicle, in the interval between the sternal Pulmonary Apex iX LAV I CLE: Pleural Lime .Stereo- AIanub. Point /ilPPLE Uncovered Area 5TER/10- ErtSIf ORN Poifll Pulmonary Line Pleural Line 2" Apex Point Pulmonary Line Pleural Line 2" Fig. 37. — Diagram showing the surface markings for the lungs and pleura. and clavicular heads of the sterno-mastoid muscle (Fig. 37). The anterior edges of the two lungs pass behind the sternoclavicular articulations, and meet in the middle line at the junction of the manubrium with the gladiolus. The edge of the right lung then continues vertically downwards behind the middle line of the sternum to the sixth chondro-sternal articulation, where it slopes off along the line of the sixth cartilage. The edge of the left lung keeps close to that of the right as far Chap. X] THE THORACIC VISCERA 207 as the fourth chondro-sternal articulation, where it turns off to the left, following a line drawn from the fourth cartilage to near the apex of the heart (Fig. 37). Occasionally it does not diverge, but completely covers the pericardium up to the edge of the sternum. In the child, owing to the thymus, the lungs are more separated in front. The right reaches the middle line, but the left only reaches the left edge of the sternum (Symington). The easiest and also the most accurate method of indicating the lower border of the lung is the fol- lowing (Fig. 37) : A line is drawn along the sixth costal cartilaere from its sternal end to its heel; from the heel the line is carried horizontally round the body; it will be found to cross the median line behind, at, or near the eleventh dorsal spine (the anticlinal spine). The corresponding border of the pleura is not parallel to the lower border of the lung ; it is indicated by a line drawn along the seventh costal cartilage from its sternal end to its heel ; from there the line is continued to a point 2 inches above the lowest part of the subcostal margin and then prolonged horizontally to the median line behind where it crosses at or near the twelfth dorsal spine. Between the pul- monary line above and the pleural line below, the diaphragm is in contact with the chest wall, separ- ated only by the costo-phrenic reflection of the pleura. On the left side these lines commence at a variable distance from the sternum — 1 inch should be allowed for the pleura; 2-§- inches for the lung (Fig. 37). The pleura is in relation with the twelfth rib, but occasionally it descends | an inch or more below this point, and may be wounded in operations on the kidney (Fig. 65, p. 402). It extends lower down in the child than in the adult. The left lung descends to a slightly lower level than the right. In penetrating wounds involving the pleura^ air may enter the pleural cavity, producing pneumothorax, and this air may be subsequently pressed by the respiratory movements into the 208 SURGICAL APPLIED ANATOMY [Part II subcutaneous tissues through the wound in the parietal pleura, and lead to surgical emphysema. The cohesion between the smooth pulmonary and parietal layers of pleura is such that occasionally collapse does not follow, but the intimate connec- tion between them makes it difficult for the pul- monary to escape when the parietal layer is wounded. In wounds of the lung without exter- nal wound, as when that organ is torn by a fractured rib, the air escapes from the lung into the pleura, and may thence pass into the subcu- taneous tissues through the pleural wound, thus producing both pneumothorax and emphysema. It is well to note that emphysema may occur about certain non-penetrating wounds of the thorax when they are of a valvular nature. In such cases the air is drawn into the subcutaneous tissues during one respiratory movement, and is forced by another into the cellular tissue, the valv- ular nature of the wound preventing its escape externally. When the pleural " cavity ; ' is opened, the lungs, owing to the amount of elastic tissue they contain, undergo some degree of collapse, but there is much misconception regarding the extent to which this takes place. Half the air in the lung, in some cases even two-thirds, is residual and cannot be expelled by the passive collapse of the lung; when the diaphragm is pushed up and the ribs are pulled down by the expiratory efforts of the muscles of the belly wall the thoracic space may be so reduced in size that the lung still more than fills it ; if the glottis be closed a hernia of the lung will occur through the wound in the chest wall. If, however, there is a valvular orifice into the pleural cavity, so that air can be sucked in but not expelled from it, every respiratory effort increases the amount of air in the pleural snace ; then compression of the lung and suffoca- tion quickly ensue. MacEwen is of opinion that collapse of the lung is prevented by the capillary attraction which exists between the visceral and parietal layers of the pleura. Chap. X] THE THORACIC YISCERA 209 In wounds of the lung the blood may escape in three directions : into the tissue of the organ (pulmonary apoplexy), into the bronchi (causing haemoptysis), and into the pleura (causing hsemo- thorax). In some instances the lung has been rup- tured without wound and without fracture to the ribs. These cases are difficult to interpret, and Right Int. Juc lilac Vewn Right Subclavian Ve Right Innoni- v ein 5tep.no ManuB.Poin SuPERKDR VENACAV Pericardium RiCmt Auricle JRiCulC -VENTRICULAR q«.oovE Dome: ,teknoE:nsiforn Line- mferioR Caval Point erno* cnsiforn poim nferiOR Vena Cava Left InnominateVein Arch op Aorta Pulmonary Artery Left Ventricle /ilPPLE- RlQHT VENTRICLE; Left Dome Apex Point Fig. 3S.— The relationship of the pericardium and heart to the sternum and ribs. probably the best explanation suggested is that put forward by M. Gosselin. This surgeon be- lieves that at the time of the injury the lungs are suddenly filled and distended with air by a full inspiration, and that the air, prevented from escaping by occlusion of the larynx, thus becomes 1 pent up in the pulmonary tissue, and the lung not being able to recede from the superincumbent pres- sure, its structure necessarily gives way. Owing to the fineness of its capillaries, and to o 210 SURGICAL APPLIED ANATOMY [Part II the fact that all venous blood returned to the heart must pass through the lungs before it can reach other parts of the body, it follows that pysemic and other secondary deposits are more commonly met with in the lung than in any other of the viscera. Lung cavities resulting from tuberculosis, gan- grene, or bronchiectasis have been successfully in- cised and drained, and the same measure has been applied to hydatid cysts of the lung. Deep in- cisions in the lung are followed by less haemor- rhage than might be expected from such a vascular organ. The trachea divides opposite the junction of the manubrium and gladiolus in front, and the fourth dorsal vertebra behind. Certain foreign substances that have been drawn into the air passages have shown a remark- able facility for escaping through the parietes. Thus Mr. Godlee records the case of a child, from an abscess in whose back there escaped a head of rye-grass that had found its way into the air pas- sages forty-three days previously. The root of the lung and bronchi can be ex- posed by opening the dorsal wall of the thorax behind the vertebral border of the scapula. Rus- sell and Fox record the case of a boy in whom a pin, 3 inches long, had slipped head downwards within the trachea, and ultimately lodged in the lower division of the left bronchus. They resected part of the eighth rib from the back, pushed the lung forwards to expose the bronchus at the root, and removed the pin. The root of the lung re- quires to be steadied; through the pericardium it is intimately bound to the diaphragm and follows the movements of that muscle. In the case men- tioned above, the boy was able to leave the hospital I twelve days after the operation. •^ The heart and pericardium.— The position and extent of the pericardium may be indicated thus on the surface of the thorax (Fig. 38) : Three points are taken: (1) the apical, over the apex beat, in the fifth left intercostal space, 3^ inches Ohap. X] THE THOKACIC VISCERA 211 from the sternum ; (2) the sterno-manubrial, mid- way between the insertions of the second costa] cartilages; (3) the inferior cava!, 1 inch to the right of the sterno-ensiform point and directly superficial to the termination of the inferior vena cava. When these three points are united by curved lines, as in Fig. 38, the area over the peri- cardium and its contents is marked out. The lower line crosses \ an inch or more below the sterno-ensiform point ; if a trochar be thrust back- wards in the angle between the ensiform process and seventh left costal cartilage, it enters the pericardium just above the diaphragm. Through this angle the pericardium may be drained ; by resecting part of the sixth and seventh cartilages its cavity may be explored. The right border of the pericardium is deeply placed and covered by the right lung (Fig.37); in health it should not project more than 1 inch beyond the right sternal border. Besides the auricles and ventricles the follow- ing parts are contained in the pericardium : The terminations of the inferior and superior venae cava?; the ascending aorta and pulmonary artery. The position of these parts, and of the arch of the aorta and its branches, is shown in Fig. 38. It will be observed that more than two-thirds of the anterior surface of the heart is made up of right ventricle and auricle ; consequently it is these ^ parts which are usually perforated in stabs of the// heart. / The heart may be exposed for operative treat- ment by removal of the terminal inch or more of the fourth and fifth left costal cartilages. The heart may be freely handled and sutured; the sur- geon's task is rendered difficult by its rapid motions and the respiratory movements of the pericardium and diaphragm. When the heart is wounded, blood escapes into the pericardium, lead- ing to compression of the auricles and the arrest of the inflow of blood. Hydrops of the pericardium may cause death in a similar manner. Other 212 SURGICAL APPLIED ANATOMY [Part II. things being equal, a wound of the ventricle is less rapidly fatal than is a wound of the auricle, owing to the thickness of the ventricular wall, and to its capacity for contracting and prevent- ing the escape of blood. Death in cases of wound of the heart would appear in a great number of cases to be due to an impression upon the nervous centres rather than to actual haemorrhage. Many instances have been recorded to show that the heart may be very tolerant of foreign bodies in its substance. Thus a man lived for twenty days with a skewer traversing the heart from side to side (Ferrus). In another case a lunatic pushed an iron rod, over 6 inches in length, into his chest, until it disappeared from view, although it could be felt beneath the skin receiving pulsation from the heart. He died a year following, and the metal was found to have pierced not only the lungs but also the ventricular cavities (Tillaux). Wounds of the heart have been sutured, the in- sertion of the stitches causing only momentary disturbance of its action. Recently Travers sutured a wound of the right ventricle into which he was able to place three fingers to prevent haemorrhage. A propos of chest wounds, Velpeau cites the case of a man in whose thorax was found a part of a foil that entirely transfixed the chest from ribs to spine, and that had been introduced fifteen years before death. In the museum of the Royal College of Surgeons is the shaft of a cart that had been forced through the ribs on the left side, had passed entirely through the chest, and had come out through the ribs on the right side. The patient had lived ten years. Paracentesis of tlie pericardium.— As al- ready mentioned, the pericardium may be tapped or drained through the left costo-ensiform angle (Fig. 38). The extent to which it is covered by the left pleura and lung is extremely variable, but in the majority of cases it may be tapped in the left fourth and fifth spaces, up to 1 inch from the sternum, without injuring the pleura. The Chap. X] THE THORACIC VISCERA 2l3 internal mammary artery descends in these spaces .7 an inch from the sternum, and divides, behind the seventh cartilage, into its superior epigastric and musculo-phrenic branches. The iiiediastiua. — Abscess in the anterior mediastinum may have developed in situ, or may have spread down from the neck. In like manner posterior mediastinal abscesses may arise from diseases of the adjacent spine, or lymphatic glands, or may be due to the spreading down- wards of a retropharyngeal or retro-oesophageal collection of matter. The azygos veins, commencing as they do below in the lumbar veins, and having more or less direct communications with the common iliac, renal, and other tributaries to the vena cava, are able to a great extent to carry on the venous circula- tion in cases of obstruction of the terminal part of the superior vena cava. In this they are as- sisted by the vense comites of the internal mam- mary artery and epigastric veins; the intraverte- bral veins also become greatly enlarged, and serve as anastomotic channels between the superior and inferior caval systems. These veins are apt to be pressed upon by tumours (such as enlarged gland masses) de- veloped in the posterior mediastinum, and to pro- duce in consequence some oedema of the chest walls by engorgement of those intercostal veins that they receive. Tumours growing in the pos- terior mediastinum may cause trouble by press- ing upon the trachea or gullet, or by disturbing the vagus nerve or the cord of the sympathetic. The numerous lymphatic glands which surround the trachea, bronchi, and oesophagus are often the seat of tuberculosis. They become adherent to these organs and may ulcerate into them. Krabbel reports a case of fracture of the ninth dorsal vertebra associated with rupture of the thoracic duct. The patient died in a few days, and the right pleura was found to contain more than a gallon of pure chyle. Part III.-THE UPPER EXTREMITY CHAPTER XI THE REGION OF THE SHOULDER A study of the region of the shoulder comprises the clavicle, the scapula, the upper end of the humerus, and the soft parts that surround them, together with the shoulder joint and axilla. Surface anatomy.— The clavicle, acromion process, and scapular spine are all subcutaneous, and can be readily felt. In the upright position, when the arm hangs by the side, the clavicle is, as a rule, not quite horizontal. In well-developed subjects it inclines a little upwards at its outer end.* In the recumbent posture, the weight of the limb being taken off, the outer end rises still higher above the sternal extremity. The degree of the elevation can be best estimated by a study of frozen sections. Thus, in making horizontal sections of the body, layer by layer, from above downwards, Braune found that by the time the sterno-clavicular articulation was reached, the head of the humerus would be cut across in the lateral part of the section (Fig. 39). The deltoid tubercle of the clavicle may, if large, be felt through the skin, and be mistaken for an exostosis. The acromio-clavicular joint lies in the plane of a vertical line passing up the middle of the front of the arm. A prominence is sometimes felt about this joint in place of the * Tn some women, in the feeble, and in some narrow-shouldered men the clavicle may be horizontal, or its outer end may incline downwards. 214 Chap. XI] EEGION OF THE SHOULDER 215 level surface that it should present. This is due to an enlargement of the end of the clavicle, or to a thickening of the fibro-cartilage sometimes found in the joint. In many cases it has ap- peared to me to be due to a trifling luxation up- wards of the clavicle depending upon some stretch- ing of the ligaments. It is certain that the dry- bone seldom shows such an enlargement as to account for this very common prominence at the acromial articulation. The sternal end of the clavicle is also, in muscular subjects, often large and unduly prominent, and sufficiently conspicu- ous to suggest a lesion of the bone or joint when none exists. The roundness and prominence of the point of the shoulder depend upon the development of the deltoid and the position of the upper end of the humerus. The deltoid hangs like a curtain from the shoulder girdle, and is bulged out, as it were, by the bone that it covers. If the head of the humerus, therefore, be diminished in bulk, as in some impacted fractures about the anatomical neck, or be removed from the glenoid cavity, as in dislocations, the deltoid becomes more or less flat- tened, and the acromion proportionately promi- nent. The part of the humerus felt beneath the deltoid is not the head, but the tuberosities, the greater_ tuberosity externally, the lesser in front. A considerable portion of the head of the bone can be felt by the fingers placed high up in the axilla, the arm being forcibly abducted so as to bring the head in contact with the lower part of the capsule. The head of the humerus faces very much in the direction of the internal condyle. As this relation, of course, holds good in every posi- tion of the bone, it is of value in examining injuries^ about the shoulder, and in reducing dislocations by manipulation, the condyle being used as an index to the position of the upper end of the bone. In thin subjects the outline and borders of the scapula can be more or less distinctly made 216 SURGICAL APPLIED ANATOMY [Part III out, but in fat and muscular subjects all parts of the bone, except the spine and acromion, are difficult of access in the ordinary positions of the limb. To bring out the superior angle and verte- bral border of the bone, the hand of the subject should be carried as far as possible over the oppo- site shoulder. To bring out the inferior angle and axillary border, the forearm should be placed behind the back. The angle formed at the point of junction of the spine of the scapula and the acromion is the best point from which to take measurement of the arm, the tape being carried down to the external condyle of the humerus. The upper border of the scapula lies on the second rib, its lower angle on the seventh. When the arm hangs from the side with the palm of the hand directed forwards, the acromion, external condyle, and styloid process of the radius all lie in the same line. The groove between the pectoralis major and deltoid muscles is usually to be made out. In it run the cephalic vein and a large branch of the acromio-thoracic artery. Near the groove, and a little below the clavicle, the coracoid process may be felt. The process, how- ever, does not actually present in the interval between the two muscles, but is covered by the innermost fibres of the deltoid. The position of the coraco-acromial ligament may be defined, and a knife thrust through the middle of it should strike the biceps tendon and open the shoulder joint. When the arm hangs at the side with the palm forwards, the bicipital groove may be defined directly below the acromioclavicular joint. Just below the clavicle is a depression, the sub- clavicular fossa, which varies considerably in depth in different subjects. It is obliterated in subcoracoid dislocations of the humerus, in frac- tures of the clavicle with displacement, by many axillary growths, and by some inflammations of the upper part of the thoracic wall. In sub- clavicular or infracoracoid dislocation, the fossa Chap. XI] REGION OF THE SHOULDER 217 is replaced by an eminence. In this region, at a spot to the inner side of the coracoid process, and corresponding nearly to the middle of the clavicle;, the pulsations of the axillary artery can be felt on deep pressure, and the vessel be compressed against the second rib. Just below the clavicle the interspace between the sternal and clavicular por- tions of the pectoralis major can often be made out. The anterior and posterior borders of the axilla are very distinct. The anterior border, formed by the lower edge of the pectoralis major, follows the line of the fifth rib. The depression of the armpit varies, other things being equal, with the position of the upper limb. It is most deep when the arm is raised from the side at an angle of about 45°, and when the muscles forming the bor- ders of the space are in a state of contraction. As the arm is raised above the horizontal line the depression becomes shallower, the head of the bone projects into the space and more or less obliterates it, while the width of the fossa is encroached upon by the approximation of the anterior and pos- terior folds. The coraco-brachialis muscle itself forms a distinct projection along the humeral side of the axilla when the arm is raised to a right angle with the body. If the arm be brought nearly close to the side, the surgeon's hand can be thrust well up into the axilla, and the thoracic wall explored as high up as the third rib. The axillary glands cannot be felt when they are in a normal condition. The central set lies beneath the axillary tuft of hair. The direction of the axillary artery, when the arm is raised from the side, is represented by a line drawn from the middle of the clavicle to the humerus at the inner side of the coraco-brachialis. A line drawn from the third rib near its cartilage to the tip of the coracoid process indicates the upper border of the pectoralis minor, and the spot where this line crosses the line of the axillary artery points out the position of the acromio- 218 SURGICAL APPLIED ANATOMY [Part III thoracic artery. A line drawn from the fifth rib near its cartilage to the tip of the coracoid process indicates the lower border of the pectoralis minor, and the position of the long thoracic artery which runs along that border. The line of the sub- scapular artery corresponds to the lower border 2 1 \? ,a T 9 r /•''£■' / / • ■' \ \ Fig. 39. f 8 -Horizontal section of the body just below the upper border of the manubrium. (Braune.) a, Manubrium ; b, head of humerus ; c, clavicle ; d, first rib ; e, second rib ; /; third dorsal vertebra; g, spine of second dorsal; ft, pectoralis major; i, deltoid; j, infraspinatus ; fc, subscapularis ; I, coraco-brachialis and biceps : m, pectoralis minor ; n, serratus magnus ; o, intercostals ; p, semispinalis and undtifidus spina?; q, biventer cervicis and complexus ; r, longissimus dorsi; s, splenius colli ; t, rhomboideus ; u, trapezius ; v } sterno-thyroid ; w, sterno-hyoid ; T, thymus ; l, lung ; 1, left innominate vein ; 2, left carotid artery ; 3, left sub- clavian artery ; 4, vertebral artery ; 5, left subclavian vein ; G, cephalic vein ; 7, phrenic nerve ; 8, vagus ; 9, transverse scapular artery. of the subscapularis muscle along which it runs, but the position of this border can only be ap- proximately indicated on the living or undissected sub j ect. The circumflex nerve and posterior circumflex artery cross the humerus in a horizontal line that is about a finger's breadth above the centre of the vertical axis of the deltoid muscle. This point Chap. XI] EEGION OF THE SHOULDEE 219 is of importance in cases of supposed contusion of the nerve. These various indications of the positions of the main branches of the axillary artery are made while the arm hangs in its natural position at the side. The clavicle. — The skin over the clavicle is loosely attached, and is easily displaced about the bone. This circumstance may serve to explain why the skin so often escapes actual wound in contusions of the clavicular region, and in part explains the infrequency of penetration of the integument in fractures of the clavicle. The posi- tion of the supraclavicular nerves in front of the bone renders them very liable to contusion, and accounts for the unusual amount of pain that is said to sometimes follow blows over the collar bone. Tillaux believes that the severe pain that in rare cases persists after fracture of the clavicle is due to the implication of these nerves in the callus formed. The three nerves that cross the clavicle are branches of the third and fourth cervical nerves, and it is well to note that pain over the collar bone is sometimes a marked feature in disease of the upper cervical spine. This symp- tom is then due to irritation of these nerves at their points of exit from the spinal canal. A communica- tion between the external jugular and cephalic veins is occasionally seen to cross the clavicle. Beneath the clavicle the great vessels and the great nerve-cords lie upon the first rib. The vein is the most internal, and occupies the acute angle between the collar-bone and the first rib. It will be seen that growths from the bone may readily press upon these important structures, and that the vein, from its position, as well as from the slighter resistance that it offers, is likely to be the first to be compressed. These structures have also been wounded by fragments of bone in frac- ture of the clavicle. Fortunately, between the clavicle and these large nerves and vessels the subclavius muscle is interposed. This muscle is closely attached to the under surface of the bone, 220 SURGICAL APPLIED ANATOMY [Part III is enveloped in a dense fascia, and forms one of the chief protections to the vessels in case of frac- ture. This interposing pad of muscle is also of great service in resection operations, as can _ be well understood. Braune states that by pressing the clavicle against the first rib in the dead body a stream of injection in the thoracic duct can, in some cases, be entirely arrested. Behind the clavicle the following structures may be noted ; viz., the innominate, subclavian, and external jugular veins, the subclavian, suprascapular, and internal mammary arteries, the cords of the brachial plexus, the phrenic nerve and nerve of Bell, the thoracic duct, the omo-hyoid, scalene, sterno-hyoid and sterno-thyroid muscles, and the apex of the lung. The sternal end of the bone is not far removed from the innominate or left carotid artery, the vagus and recurrent nerves, the trachea, and the oesophagus. These relations of the clavicle are given to show the dangers in the way of partial or. complete resections of the bone. The difficulties and risks of the operation increase as one progresses from the acromial to the sternal end. Resection of the acromial third of the bone is comparatively easy, but resection of the sternal portion is difficult and dangerous. The entire clavicle has been re- moved with success, and the operation has been followed by less impairment of the arm movements tt^an would be imagined. The clavicle forms the sole direct bony con- nection between the upper limb and the trunk, and in severe accidents, this connection being broken through, it is possible for the extremity to be torn off entire. Thus Billroth reports the case of a boy aged fourteen, whose right arm, with the scapula and clavicle, was so torn from the trunk by a machine accident that it was only attached by a strip of skin two inches wide. Other like cases of avulsion of the limb have been reported. Fractures of clavicle. — The clavicle is more Chap XI] EEGION OF THE SHOULDER 221 frequently broken than is any other single bone in the body. This frequency is explained by the fact that the bone is very superficial, is in a part ex- posed to injury, is slender and contains much compact tissue, is ossified at a very early period of life, and above all receives a large part of all shocks communicated to the upper extremity. The common fracture, that due to indirect violence, is oblique, and very constant in its position, viz. at the outer end of the middle third of the bone. So closely is the outer third of the clavicle bound by ligaments to the coracoid and acromion pro- cesses that it may be regarded as part of the scapula. Hence the impact resulting from a fall on the shoulder is transferred to the clavicle at the junction of its outer and middle thirds. The bone breaks at the point where the force is trans- ferred to the clavicle from the scapula. The posi- tion of the coraco-clavicular ligaments is no doubt of the greatest import in localising the fracture in this position, since a clavicle experimentally subjected to longitudinal compression does not break at this spot (Bennett). The displacement that occurs is as follows. The inner fragment remains unchanged in position, or its outer end is drawn a little upwards by the sterno-mastoid. It will be seen that any action of this muscle would be resisted by the pectoralis major and the rhomboid ligament. The outer frag- ment undergoes a threefold displacement. (1) It is carried directly do wti wards. This is effected mainly by the weight of the limb aided by the pectoralis minor, the lower fibres of the pectoralis major, and the latissimus dorsi. (2) It is carried directly inwards by the muscles that pass from the trunk to the shoulder, viz. the levator anguli scapulae, the latissimus dorsi, and especially by the pectorals. (3) The fragment is rotated in such a way that the outer end projects forwards, the inner end backwards. This rotation is brought about mainly by the two pectorals, as- sisted prominently by the serratus magnus. The 222 SUEGICAL APPLIED ANATOMY [Part III normal action of this latter muscle is to carry the scapula forwards, and the clavicle, acting as a kind of outrigger to keep the upper limb at a proper distance from the trunk, moves forwards at the same time and keeps the scapula direct. When this outrigger is broken the serratus can no longer carry the scapula directly forwards. The bone tends to turn towards the trunk, and the point of the shoulder is therefore seen to move inwards as well as forwards. The fragments in this fracture must consequently overlap, and as the displacement is difficult to remedy, it follows that in no bone save the femur is shortening so uniformly left as after an oblique fracture of the clavicle. The degree of shortening very seldom exceeds one inch. The deformity associated with this fracture is well remedied when the patient assumes the recumbent position. In this posture, the weight of the limb being taken off, the down- ward displacement is at once remedied. The point of the shoulder falling back also tends to relieve in part the inward displacement, and the rotation of the outer fragment forwards. It is through the scapula, however, that these two latter displacements are in the main removed. In the recumbent posture the scapula is pressed closely against the thorax, with the result that its outer extremity (and with it, of course, the outer frag- ment of the clavicle) is dragged outwards and backwards. Some surgeons, recognising this im- portant action of the scapula in remedying the displacement in these cases, strap the scapula firmly against the trunk, while at the same time they elevate the arm. Fractures due to direct violence are usually transverse, and may be at any part of the bone. When about the middle third they present the dis- placement just described. When the fracture is between the conoid and trapezoid ligaments no displacement is possible. When beyond these liga- ments, the outer end of the outer fragment is car- ried forwards by the pectorals and serratus, and Chap. XI] EEGION OF THE SHOULDER 223 its inner end is a little drawn up by the trapezius. In this fracture there is no general displacement downwards of the outer fragment, since it can- not move in that direction unless the scapula go with it, and the scapula remains fixed by the coraco-clavicular ligaments to the inner fragment of the clavicle. The clavicle may be broken by muscular vio- lence alone. Polaillon, from a careful analysis of the reported cases, concludes that the muscles that break the bone are the deltoid and clavicular part of the great pectoral. In no case does the fracture appear to have been produced by the sterno-mastoid muscle. The commonest movements producing fracture appear to be violent move- ments of the limb forwards and inwards, or up- wards. These fractures are usually about the middle of the bone, and show no displacement other than that of both fragments forwards, i.e. in the direction of the fibres of the two muscles first named. The clavicle is more frequently the seat of green-stick fracture than is any other bone in the body. Indeed, one-half of the cases of broken collar-bone occur before the age of five years. This is explained by the fact that the bone is ossified at a very early period, and is in a break- able condition at a time when most of the other long bones still present much unossified cartilage in their parts. Moreover, the periosteum of the clavicle is unduly thick, and not very closely attached to the bone, circumstances that greatly favour subperiosteal fracture. A reference to the relations of the bone will show that important structures may be wounded in severe fractures associated with much displace- ment and with sharp fragments. Several cases are reported of paralysis of the upper limb (as a rule incomplete) following upon fracture of this bone. In some _ cases this symptom was due to actual compression or tearing of some of the great nerve cords by the displaced fragments. In other 224 SURGICAL APPLIED ANATOMY [Part III cases the nerve injury, while due to the original accident, was yet independent of the broken clavi- cle. Paralysis of the biceps, brachialis anticus, and supinator longus, muscles supplied through the upper cord, may result from heavy weights being carried on the shoulder. Cases are reported of wound of the subclavian artery, of the sub- clavian vein, of the internal jugular vein, and of the acromio-thoracic artery. -In several instances the fracture has been associated with wound of the lung, with or without a fracture of the upper ribs. The clavicle begins to ossify before any bone in the body. At birth the entire shaft is bony, the two ends being still cartilaginous. The bone has one epiphysis for its sternal end that appears be- tween the eighteenth and twentieth year, and joins the shaft about twenty-five. It is a mere shell, is closely surrounded by the ligaments of the sternal joint, and cannot, therefore, be well separated by accident.'"" In cases where the clavicle is described as congenitally absent, the membrane-formed part of the bone is represented by a ligamentous cord ; the cartilage-formed extremities are repre- sented by bony nodules. Steriio-clavicular joint. — Although this is the onlv articulation that directly connects the upper limb with the trunk, yet it is possessed of such considerable strength that luxation at the joint is comparatively rare. The amount of move- ment in the joint deDends to a great extent upon the lack of adaptability between the facets on the sternum and the sternal end of the clavicle. The disproportion between these parts is maintained by the interarticular cartilage, which reproduces onlv the outline of the clavicular surface. The cavity of the joint is V-shaped, since the clavicle only touches the socket at its inferior angle when the arm hangs by the side. When the arm is * Mr. Heath {Lancet, Nov. is, 1882) reports a case which is probably vrainue. Tt concerns a lad, aged 14, who. when in the act of bowling at cricket, tore the clavicle away from its epiphyseal cartilage, which remained in sitv. The muscle producing the accident was apparently the pectoralis major. Chap. XI] REGION OF THE SHOULDER 225 elevated, however, the two bones are brought in more immediate contact, and the joint cavity be- comes a mere slit. Thus, in disease of this articu- lation it will be found that of all movements of the joint the movement of the limb upwards is the most constant in producing pain. The joint is supplied by the suprasternal nerve. The movements permitted at this joint are limited, owing to the anterior and posterior sterno-clavicular ligaments being moderately tense in all positions of the clavicle. Movement forwards of the clavicle on the sternum is checked by the posterior ligament, and resisted by the an- terior ligament. This latter ligament is more lax and less substantial than is the posterior band. Its weakness serves in part to explain the fre- quency of the dislocation forwards. Movement of the clavicle backwards on the sternum is checked by the anterior ligament, while the passage of the head of the bone is resisted by the powerful posterior band. The movement is also opposed by the rhomboid ligament. To pro- duce, therefore, a dislocation backwards consider- able force must be used. Movement of the clavicle upwards on the sternum is checked by the rhom- boid ligament, the interclavicular ligament, the interarticular cartilage, and in a less direct man- ner by the two remaining ligaments of the joint. Thus it happens that dislocation upwards is the least common of the luxations at this articulation. Disease of the sterno-clavicular joint. — This articulation is really divided into two joints by the interarticular cartilage, each being pro- vided with a distinct synovial membrane. These joints are liable to the ordinary maladies of joints, and it would appear that the disease may commence in, and be for some time limited to, only one of the synovial sacs. In time the whole articulation usually becomes involved, but even in advanced cases the mischief is sometimes restricted to the synovial cavity on one side of the cartilage. According to some authors, this joint p 226 SURGICAL APPLIED ANATOMY [Part III is more frequently involved in pysemia than is any other. When effusion has taken place into the sterno-clavicular joint, and especially after sup- puration has ensued, the swelling usually makes itself evident in front, owing to the fact that the anterior sterno-clavicular ligament is the thinnest and least resisting of the ligamentous structures about the articulation. For the same reason the pus usually escapes from the anterior surface when it discaarges itself spontaneously. It may, however, make an opening for escape through the posterior ligament, and in these circumstances has found its way into the mediastinum. The rela- tions of this joint to the great vessels at the root of the neck should be borne in mind. In one case reported by Hilton a large abscess formed in the articulation, and the collection, receiving pulsa- tions from the subjacent artery (the innominate or right subclavian), was supposed at one time to be an aneurism. It is remarkable that disease of this joint never leads to ankylosis. This circum- stance may be explained (1) by the constant slight movement in the part, which prevents the diseased structures from being kept at rest, (2) by the occasional persistence of the interarticular cartilage, and (3) by the utter lack of adapta- bility of the two bony surfaces involved. Dislocations of the sterno-clavicular joint. — The clavicle may be dislocated from the sternum in one of three directions, which, given in order of frequency, are : (1) forwards, (2) backwards, (3) upwards. The relative frequency of these dis- locations can be understood from what has been already^ said as to the action of the ligaments in restricting movements. The displacement for- wards involves entire rupture of the capsule, and I more or less damage to the rhomboid ligament. The head of the bone, carrying with it the sterno- mastoid, rests on the front of the manubrium. The dislocation backwards may be due to direct or indirect violence, and has occurred spontane- ously in connection with the chest deformity in Chap. XI] REGION OF THE SHOULDER 227 Pott's disease. The capsule is entirely torn, as is also the rhomboid ligament. The head is found in the connective tissue behind the sterno-hyoid and sterno-thyroid muscles. In this position it may cause severe dyspnoea, or dysphagia, by pressure upon the trachea or gullet. It may so compress the subclavian artery as to arrest the pulse at the wrist, or so occlude the innominate vein as to produce semi-coma (Fig. 39, p. 218). In one case the head of the bone had to be ex- cised to relieve a troublesome dysphagia. In the luxation upwards, due usually to indirect vio- lence, the head rests on the upper border of the sternum between the sterno-mastoid and sterno- hyoid muscles. It involves more or less complete tearing of all the ligaments of the joint, together with avulsion of the interarticular nbro-cartilage. The non-adaptability of the joint surfaces in this part serves to explain the ease with which these luxations are usually reduced, and the diffi- culty of retaining the clavicle in position after it is replaced. 4 croon io-cl a vicul a .r joint. — This articulation is shallow, and the outlines of the two bones that enter into its formation are such that no obstacle is offered to the displacement of the clavicle from the acromion. The joint, indeed, depends for its strength almost entirely upon its ligaments. The plane of the joint would be represented by a line drawn from above downwards and inwards be- tween the two bones. This inclination of the joint surfaces serves to explain the fact that the usual luxation of this part takes the form of a displace- ment of the clavicle upwards on to the acromion. The capsule that surrounds the joint is lax and feeble, and it is partly from its comparative thin- ness that effusion into this joint, when it is the seat of disease, makes itself so soon visible. The joint, however, depends mainly for its strength upon the powerful conoid and trapezoid liga- ments. The effects of shock at this joint are les- sened by the presence of a partial nbro-cartilage 228 SURGICAL APPLIED ANATOMY [Part III which projects between the bones from the upper part of the capsule. As the movements permitted in this joint may be impaired by accident or disease, it is well to note the part the articulation takes in the move- ments of the extremity. The scapula (and with it, of course, the arm), as it glides forwards and backwards upon the thorax, moves in the arc of a circle whose centre is at the sterno-clavicular joint, and whose radius is the clavicle. As the bone moves forwards it is important, for reasons to be immediately given, that the glenoid cavity should also be directed obliquely forwards. This latter desirable condition is brought about by means of the acromio-clavicular joint. Without this joint the whole scapula as it passed forwards with the outer end of the clavicle would precisely follow the line of the circle above mentioned, and the glenoid cavity would look in an increasingly inward direction. It is essential that the surface of the glenoid cavity should be maintained as far as possible at right angles to the long axis of the humerus. When these relations are satisfied, the humerus has the support behind of a stout sur- face of bone, and it is partly to obtain the value of this support that the boxer strikes out from the side, i.e. with his humerus well backed up by the scapula. If there were no acromio-clavicular joint the glenoid fossa would offer little support to the humerus when the limb was stretched for- wards, and a blow given with the limb in that position, or a fall upon the hand under like con- ditions, would tend to throw the humerus against the capsule of the shoulder joint, and so produce dislocation. Normally, therefore, as the scapula and arm advance, the angle between the acromion and the adjacent portion of the clavicle becomes more and more acute, and the glenoid fossa is maintained with a sufficiently forward direction to give substantial support to the humerus. * It * For an excellent account of the mechanism of these joints see Morris's " Anatomy of the Joints," p. 202 et se, supeiUc. volae : q, median nerve, and (on inner side) ulnar artery and nerve ; r, deep palmar areli ; 1, palmar fascia ; l', outer septum ; :% inner septum: -4, deep fascia of palm. enclosed in all directions, and are capable, though \ only in a feeble way, of limiting suppuration 1 when it commences in them. Between these two/ spaces is a third space, which is roofed in by/ the palmar fascia. This cavity is closed in at the) sides, but is open above and below. Above there/ is a free opening beneath the annular ligament and along the flexor tendons into the forearm, while below there are the seven passages provided for by the division of the palmar fascia. Of these seven passages, four, situate at the roots of the 300 i SURGICAL APPLIED ANATOMY [Part III several fingers, give passage to the flexor tendons, while the remaining three correspond to the webs between the lingers, and give passage to the lum- bricales and the digital vessels and nerves. When pus, therefore, forms on the palm, beneath the palmar fascia, it cannot come forward through that dense membrane, but escapes rather along the fingers or makes its way up into the forearm. So rigid is the resistance offered by the palmar fascia, that pent-up pus will make its way through the interosseous spaces and appear on the dorsum of the hand, rather than come through the cover- ings of the palm. The passage of pus, however, towards the dorsum is resisted by a layer of fascia that lies deeply beneath the flexor tendons, and covers in the interossei muscles, the bones, and the deep palmar arch. This fascia joins on either side the fasciae enclosing the thenar and hypo- thenar " spaces " (Fig. 51). In opening a palmar abscess, when it points above the wrist, the incision should be in the long axis of the forearm, should be above the annular ligament, and is most conveniently made a little to the ulnar side of the palmaris longus, for a cut in this position would escape both the ulnar and radial arteries and also the median nerve. The tendons about the wrist are bound down and held in place by the annular ligaments. So dense is the anterior ligament, that even in ex- tensive abscess of the palm reaching into the fore- arm, and in severe distension of the synovial sheaths beneath the ligament, it remains firm, and will not yield. The lower border of the poster in r annular ligament corresponds to the u ppeT~~edge of the anterio r band, and these structures togeth er act the parE of the leather bracele t that the labourer sometimes wears arou nd his wrist, ah d that, in fact, takes the function of an additi onal ann ular ligame nt The fibrous slieatlis for the flexor tendons extend from the metacarpophalangeal joints to the upper ends of the distal phalanges. The pulp Chap. XVJ THE WRIST AND HAND 301 h of the third phalanx, therefore, rests practically upon the periosteum. Opposite the finger-joints the sheaths are lax and thin, and spaces may occur between the decussating fibres of the sheaths, through which the synovial membrane lining the sheath may protrude. It is, I believe, through this less protected part of the sheath that suppuration without often finds its way into the interior of the sheath. The sheaths in the rest of their course are dense and rigid, and when cut across remain, in virtue of this rigidity, wide open (Fig. 52). Thus, after the division of the sheath, as in amputation, an open channel is left leading into the palm of the hand, and offering the greatest facility for the spread of pus into that part. It is this rigidly open fibrous sheath that probably may ex- plain the frequency of suppuration in the palm after amputation of a part of a finger, and I am decidedly of opinion that some steps should be taken to protect or shut off this channel in any case where the sheath has been accidentally or intentionally divided. The tendons accurately fill the fibrous sheaths. A gangliform growth on the tendon as it enters the sheath, or a constriction of the sheath with an inequality in the tendon, gives rise to the con- dition known as " snap ; ' finger. Such a digit cannot be extended by will, but when pushed a little way " springs back with a snap like the blade of a pocket knife ,: (Abbe). " Congenital " of the little finger is very common degree. In marked cases, the prox- imal phalanx is hyper-extended and the middle flexed. Lock wood found in such a case that the condition was due to a contraction in the fibrous sheath in front of the joint. Contracted finger following whitlow is due to an adhesion of the Fig. 52. — Hori- zontal section through middle of second phal- anx. (TiUaitx.) a, Flexor tendon j b, fibrous sheath of tendon ; r, ex- tensor tendon ; d, digital artery and nerve., contraction slight in a 302 SURGICAL APPLIED ANATOMY [Part III tendons to their sheath. Paralytic contraction of the flexor muscles also brings about permanent contracture of the fingers. Synovial sacs and sheaths.— There are two synovial sacs beneath the annular ligament for the flexor tendons, one for the flexor longus pollicis, the other for the flexor sublimis and profundus tendons (Fig. 53). The former extends up into the forearm for about l\ inch above the annular ligament, and follows its tendon to its insertion in the last phalanx of the thumb. The latter rises about \\ inch above the annular band, and ends in diverticula for the four fingers. The process for the little finger usually extends to the insertion of the. flexor profundus tendon in the last phalanx. The remaining three diverticula end about the middle of the corresponding meta- carpal bones. The synovial sheaths for the digital part of the tendons to the index, middle, and ring fingers end above about the neck of the meta- carpal bones, and are thus separated by about \ to \ an inch from the great synovial sac beneath the annular ligament. Thus there is an open channel from the ends of the thumb and little finger to a point in the forearm some lh inch above the annular ligament. The arrangement explains the well-known surgical fact that ab- scesses of the thumb anu little finger are apt to be followed by _ abscesses in the forearm, while such a complication is not usual after suppuration in the remaining fingers. The synovial sac for the flexor tendons is narrowed as it passes beneath the annular ligament, and thus it happens that when distended with fluid or with pus, it presents an hour-glass outline, the waist of the hour-glass corresponding to the ligament. The two synovial sacs beneath the ligament sometimes communicate with one another. The tendon of the flexor carpi radialis perforates the insertion of the annular ligament to the trapezium; it is surrounded by a synovial sheath (Fig. 53). In one form of whitlow, that form where the Chap. XV] THE WRIST AND HAND 303 pus occupies the synovial sheaths of the tendons on the fingers (thecal abscess), the suppuration can often be seen to end abruptly where the sheath ends, when the index, middle, or ring finger is involved, viz. opposite the neck of the corre- sponding metacarpal bones. In another form of Flexor Digitorum Unciform Pisiform Wrist Folds Styloid Process Flex. Longus Pollicis Trapezium Ant. Annular Ligament Scaphoid Flexor Carp. Radialis Styolid Process Fig. 53.— The anterior annular ligament of the wrist and synovial sheaths of the wrist and hand. The creases of the hand are indicated by black lines ; the synovial sheaths are shown in red. whitlow (the abscess in the pulp at the end of the finger) the periosteum of the third phalanx is readily attacked, there being no intervening ten- don sheath over that bone. In this affection the bone often necroses and comes away, but it is sig- nificant to note that it is very seldom that the whole of the phalanx perishes. The upper part, or base, of the bone usually remains sound, and is probably preserved by the insertion of the flexor 304 SUEGICAL APPLIED ANATOMY [Part III profundus tendon. It is also interesting to bear in mind that the base of the bone is an epi- physis that does not unite to the shaft until the eighteenth or twentieth year. The tendons do not lie free within the sac, but are bound to it by folds of synovial membrane in much the same way as the bowel is bound to the abdominal parietes by its mesentery. These folds may be ruptured in severe sprains, when the nutrient vessels for the tendon, which are con- tained in them, may be torn: Rupture is followed by effusion into the sac. These folds are almost absent within the digital sheaths, the slight liga- menta longa and brevia, near the insertion of the tendons, being their sole representatives. Syn- ovial sacs are lined by a squamous epithelium, and have extremely free communication with the lym- phatic vessels of the part. Hence the free absorp- tion of infective matter from such cavities. Beneath the posterior annular ligament there are six synovial sheaths for tendons, correspond- ing to the six canals formed by that ligament. The sheath most frequently inflamed is that for the extensores ossi metacarpi and brevis pollicis. It runs from a point about f of an inch above the radial styloid process to the first carpo-meta- carpal joint. The other sheaths reach above to the upper border of the annular ligament, that for the two radial extensors, however, beginning about | an inch above the ligament. The sheaths for the extensor communis and the extensor minimi digiti extend below to the middle of the metacarpus. That for the extensor indicis barely reaches the metacarpus. The other sheaths follow the tendons to their insertions. The synovial lin- ing and folds of these sheaths are injured in Colles' fracture of the radius. The tendons be- come adherent and fixed to their sheaths unless this be prevented by passive movements of the tendons. Blood-vessels and lymphatics.— The hand is very well supplied with blood, and indeed the Chap. XV] THE WRIST AND HAND 305 finger pulp is one of the most vascular parts in the body. Cases arc recorded where the tip of the finger has been accidentally cut off, and has grown again to the limb on being immediately re- applied. The position of the palmar arches has been pointed out. Wounds of these arches, and indeed of most of the arteries of the palm and wrist, are serious, on account of the difficulty of reaching the bleeding point without severely damaging important structures, and on account of the free anastomoses that exist between the vessels of the part. The deep palmar arch may be wounded by a penetrating wound from the dor- sum, and indeed Delorme has pointed out that this arch may be ligatured from the dorsum after a preliminary resection of the upper part of the third metacarpal bone. It is well known that haemorrhage from either of the palmar arches can- not be checked by ligature of the radial or ulnar artery alone, on account of the connection of the arches with those vessels; and it is als o^ known that simultaneous ligation of tne tw"o~vessels may have no better effect, owing to the anastomoses between the palmar arches and the interosseous vessels. The anastomosis between the two palmar arches is well known, and is freely established both by the main vessels themselves and by the communion that exists between the digital arteries from the superficial arch and the palmar inter- osseous branches from the deeper vessels. In bleeding from the palm, the simultaneous ligature of the radial and ulnar arteries may also entirely fail in those cases where the arches are freely joined, or are more or less replaced by large and abnormal interosseous vessels, or by a large " median " artery. When either the radial or the ulnar part of the arches is defective, the lack is usually supplied by the other vessel ; and it is well to note that the deficiency is most common in the superficial or ulnar arch. Pressure ap- plied to the palm to arrest bleeding is apt to cause gangrene, owing to the rigidity of the parts and u 306 SUKGICAL APPLIED ANATOMY [Part III the ease with which considerable pressure can be applied. The radial artery, as it curves round the back of the hand to reach the deeper part of the palm, is in close contact with the carpo-metacarpal joint of the thumb. This fact must be borne in mind in amputation of the entire thumb, and also in resection of the first metacarpal bone. The superficialis volae, if large, may bleed seriously. It adheres to the surface of the annular ligament, and may therefore be difficult to pick up when wounded. From the larger size and great number of the lymphatics about the fingers and on the dorsum of the hand, it follows that lymphangitis is more common after wounds of those parts than it is after wounds of the palm. The l>ones and joints. — The inferior radio- ulnar joint is supported by the powerful tri- angular fibro-cartilage, which forms the strong- est and most important of all the ligamentous connections between the two bones. The synovial sheath of the extensor minimi digiti sometimes communicates with this joint, and may therefore be involved when that articulation is diseased. The strength of the wrist-joint depends not so much upon its mechanical outline or its liga- ments as upon the numerous strong tendons that surround it, and that are so closely bound down to the bones about the articulation. Moreover, in the case of the wrist the long lever does not exist on the distal side of the joint. The anterior liga- ment of the wrist is the strongest ligament of the joint, while the posterior is the weakest. The former structure limits extension, and the latter flexion ; and in connection with this arrangement it is interesting to note that injury from forced extension is more common than from forced flexion. Thus, when a man falls upon the hand, he more usually falls upon the palm (forced ex- tension) than upon the dorsum (forced flexion). Owing to the thinness of the posterior ligament, Chap. XV] THE WRIST AND HAND 307 together with the more superficial position of the hinder part of the joint, it follows that the effu- sion in wrist-joint disease is first noticed at the back of the hand. Movemeuts at the wrist take place as freely in the intercarpal joint (between the first and second row of carpal bones) as in the radio-carpal joint. The axis of the radio-carpal joint is such that in flexion the palm turns towards the ulnar side of the forearm ; while in flexion at the mid- carpal joint the palm moves towards the radial side. When movement takes place at both joints these tendencies are balanced and pure flexion is produced. The tendon of the extensor carpi ul- naris is placed anteriorly to the axis of the mid- carpal joint, but behind the radio-carpal, and therefore produces flexion in one joint and exten- sion in the other (Ashdowne). The muscles which act on the wrist exemplify the various parts which muscles play in producing a purposeful move- ment. A muscle may act as (1) a prime mover, (2) an antagonist, (3) a synergic muscle, (4) a fixation muscle. For instance, when the fingers are flexed : the deep and superficial flexors are the prime movers; the antagonists in action are the exten- sors of the fingers ; the flexors of the fingers would also produce flexion at the wrist were not the ex- tensors of the wrist also thrown into action as synergic muscles ; when the extensors of the fingers act, the flexors of the wrist contract; in flexing and extending the fingers the wrist can be ren- dered immovable by the flexors and extensors of the carpus, which then act as muscles of fixation. Thus a movement which appears simple results from the action of groups of muscles, and it is this complexity which makes the diagnosis of nerve lesions from a study of the action of mus- cles so difficult. What has been said of the muscles of the wrist applies equally to all the muscles of the body. (See Beevor's Croonian Lectures, 1903.) But little movement is allowed in the carpo- 308 SURGICAL APPLIED ANATOMY [Part III metacarpal joints of the first three fingers, but in the like joints of the thumb and little finger movements are free, and their preservation is of great importance to the general usefulness of the hand. The glenoid ligaments in front of the three finger-joints are firmly attached to the distal bone, and but loosely to the proximal. Thus it happens that in dislocation of the distal bone backwards, the glenoid ligament is carried with it, and offers a great obstacle to reduction. In flexing the middle and distal phalanges alone, it will be seen that the proximal phalanx is steadied by the extensor tendon as a preliminary measure, and in paralysis of the extensors, flexion of these two joints alone is not possible. Very few persons have the power of flexing the last finger-joint without at the same time bending the articulation above it; but in certain inflam- matory affections about the last phalanges the terminal joint is sometimes seen to be fixed in a flexed posture while the other finger-j'oints are straight. In the condition known as " mallet " finger the distal phalanx is fixed in a flexed posi- tion. The condition is due to a partial or com- plete rupture of the extensor tendon of the finger, commonly the result' of a blow over the terminal knuckles. Colles' fracture. — This name is given to a transverse fracture through the lower end of the radius, from \ to 1 inch above the wrist-joint. It is associated with a certain definite deformity, and is always the result of indirect violence, a fall upon the outstretched hand. There are good reasons why the bone should break in this situa- tion. The lower end of the radius is very can- cellous, while the shaft contains a good deal of compact bone. At about f of an inch from the articular surface these two parts of the bone meet, and their very unequal density greatly tends to localise the fracture in this situation. As to the mechanism of this lesion, many different opinions are still held, and a vast deal has been written Chap. XV] THE WRIST AND HaND 309 on the subject. I subjoin Professor Ohiene's ac count of this lesion, because it may be taken as representing with admirable clearness the views most generally accepted at the present time as to the nature of this injury. Into the discussion itself I do not propose to enter. The deformity in Colles' fracture is entirely due to the displace- ment of the lower fragment. " The displacement is a triple one : (a) backwards, as regards the antero-posterior diameter of the forearm; (6) rotation backwards of the carpal surface on the transverse diameter of the forearm ; (c) rotation through the arc of a circle, the centre of which is situated at the ulnar attachment of the tri- angular ligament, the radius of the circle being a line from the ulnar attachment of the triangular ligament to the tip of the styloid process of the radius, (a) When a person in falling puts out his hand to save himself, at the moment the hand reaches the ground the force is received princi- pally by the ball of the thumb, and passes into the carpus, and thence into the lower end of the radius. If, at the moment of impact, the angle between the axis of the forearm and the ground is less than 60°, the line representing the direction of the force passes upwards in front of the axis of the forearm ; the whole shock is therefore borne by the lower end of the radius, which is broken off, and, the force being continued, the lower frag- ment is driven backwards. When at the moment of impact the angle is greater than 60°, the line of the force, instead of passing in front of the axis of the arm, passes up the arm, and the usual result is either a severe sprain of the wrist or a dislocation of the bones of the forearm backwards at the elbow-joint, (b) The carpal surface of the radius slopes forwards, and therefore the pos- terior edge of the bone receives the greater part of the shock ; there is, as a result, rotation of the lower fragment backwards on the transverse dia meter of the forearm, (c) The carpal surface of the radius slopes downwards and outwards 310 SUEGICAr APPLIED ANATOMY [Part III to the radial edge of the arm ; therefore the radial edge of the bone receives the principal part of the shock through the ball of the thumb. As a result, this edge of the lower fragment is dis- placed upwards to a greater extent than the ulnar edge of the fragment, which remains firmly attached to the ulna by the triangular liga- ment." In over 50 per cent, of cases, the styloid process of the ulna is also broken by the force transmitted to it through the triangular fibro-cartilage (Mor- ton). By means of this rotatory displacement, the tips of the two styloid processes come to occupy the same level, or the radial process may even mount above the ulnar. In nearly every case there is some penetration of the fragments, the compact tissue on the dorsal aspect of the upper fragment being driven (by a continuation of the force that broke the bone) into the cancellous tissue on the palmar aspect of the lower fragment. It is only in very rare instances that the fragments are so separated as to ride the one over the other. In such cases the radio-ulnar ligaments are probably ruptured, and the wrist ceases to present the typi- cal deformity of a Colles' fracture. In studying the radiographs of 170 cases diagnosed as Colles' fracture, Dr. R. Morton found there was disloca- tion as well as fracture in 3 and separation of the lower radial epiphysis in 11 cases. This epiphysis is often separated by accidental vio- lence. It joins the shaft about the twentieth year. Its junction with the shaft is represented by a nearly horizontal line, and the epiphysis includes the facet for the ulna and the insertion of the supinator longus. Since the introduction of radiographic methods of examination, it has been found that many in- juries, formerly regarded as mere sprains, were really due to fracture or displacement of carpal bones or fracture of a metacarpal. The semilunar is most frequently displaced and the fifth meta- carpal most frequently fractured. Chap. XV] THE WRIST AND HAND 311 Dislocations. — (1) At the wrist-joint. So strong is this articulation, for the reasons above given (p. 306), that carpo-radial luxations are extremely rare. For the same reasons, when they do occur they are usually complicated, and are associated with tearing of the skin, or rupture of tendons or fractures of the adjacent bones. The luxations of the carpus may be either back- wards or forwards, the latter being extremely rare. They would appear to be produced with equal ease by a fall upon either the front or the back of the hand. Bransby Cooper gives the case of a lad who fell upon the outstretched palms of both his hands : both wrists were dislocated, one backwards, the other forwards. There are five articular synovial cavities con- nected with the carpus. They occur in the follow- ing situations : (a) Between the carpus and fore- arm bones; it may communicate with the lower radio-ulnar cavity through the triangular fibro- cartilage ; (b) between the unciform and the fourth and fifth metacarpals; (c) between the metacarpal of the thumb and trapezium; (d) between all the carpal bones and extending to the carpo-metacarpal joints of the second and third digits; (e) between the pisiform and cuneiform bones. Hernial protrusions and gangliform growths from these synovial membranes are fre- quently seen on the dorsum of the carpus. (2) Some dislocations about the hand (os mag- num). In forcible flexion of the hand, the os magnum naturally glides backwards and projects upon the dorsum. In very extreme flexion (as in falls upon the knuckles and dorsum of the meta- carpus), this movement of the bone backwards may be such as to lead to its partial dislocation, the luxation being associated with some rupture of ligaments. In one recorded case this luxation was produced by muscular force. The patient, a lady, while in labour, " seized violently the edge of her mattress, and squeezed it forcibly." Some- thing was felt to give way in the hand, and the 312 SURGICAL APPLIED ANATOMY [Part III head of the os magnum was found to be dislocated backwards. Dislocations at the metacarpophalangeal joint of the thumb. In this luxation the phalanx is usually displaced backwards, and the lesion is of interest on account of the great difficulty often experienced in reducing the bone. Many ana- tomical reasons have been given to explain this difficulty, which are well summarised by Hamil- ton in the following passage : " Hey believes the resistance to be in the lateral ligaments, between which the lower end of the metacarpal bone escapes and becomes imprisoned. Ballingall, Malgaigne, Erichsen, and Vidal think the meta- carpal bone is locked between the two heads of the flexor brevis, or, rather, between the opposing sets of muscles which centre in the sesamoid bones, as a button is fastened into a button-hole. Pail- loux and others affirm that the anterior ligament, being torn from one of its attachments, falls be- tween the joint surfaces, and interposes an effec- tual obstacle to reduction. Dupuytren ascribes the difficulty to the altered relations of the lateral ligaments, ... to the spasm of the muscles, and to the shortness of the member, in consequence of which the force of extension has to be applied very near to the seat of the dislocation. Lisfranc found in an ancient luxation the tendon of the long flexor so displaced inwards, and entangled behind the extremity of the bone, as to prevent reduction." Mr. Jonathan Hutchinson, jun., has recently investigated some cases and found that reduction is prevented by the fibro-cartilaginous plate on the palmar aspect of the joint. The plate is firmly attached to the phalanx and is dis- located with it. When subcutaneously divided from the extensor aspect of the thumb, the dis- location may be reduced with ease. \vnlsioii of one or more fingers may be effected by severe violence. In such cases the finger torn off usually takes with it some or all of its tendons. These tendons are practically Chap. XV] THE WRIST AND HAND 313 drawn out of the forearm, and may be of con- siderable length. Billroth figures a case where the middle finger w r as torn out, taking with it the two flexor and extensor tendons in their entire length. When one tendon only is torn away with the finger, it is usually that of the flexor profundus. Amputation sit the wrist- joint by the cir- cular method. (See the author's " Operative Surgery/' In the dorsal wound will be cutthe following tendons : the extensores longus, indicis, communis, minimi digiti, and ulnaris, the radial nerve, and the dorsal branch of the ulnar nerve. The two radial extensors will be cut short in the radial angle of the wound, as will also be the ex- tensores ossis and brevis. The radial artery will be divided close to the radius. In the palmar wound will be found the ulnar artery, the superficialis volse, the ulnar and median nerves, the opponens, flexor brevis, and abductor pollicis in part, ihe flexor brevis, opponens, and abductor minimi digiti in part (the bulk of the opponens being- left behind on the hand), and the tendons of the flexor sublimis and flexor carpi radialis. The ten- dons of the flexor profundus and flexor longus pollicis are usually cut short close to the bones. Amputation of the thumb at the carpo- metacarpal joint by flaps. In the palmar flap will be cut the abductor, the short and long flexor, the opponens, and the adductor pollicis. The extensores ossis and brevis will be cut short in the posterior angle of the flap. The extensor longus and a considerable portion of the abductor indicis will be found in the dorsal flap. The vessels divided will be the two dorsal arteries of the thumb and the princeps pollicis. There is great danger, in this operation, of wounding the radialis indicis and the radial artery itself where it begins to dip into the palm. Nerve supply ot the upper limb. — The symptoms which follow a lesion to the nerves of the upper limb depend on the point injured. If the fifth spinal nerve be crushed between its 314 SURGICAL APPLIED ANATOMY [Part III origin in the spinal cord and its exit from the intervertebral foramen, either from fracture or caries of the cervical vertebrae, the injury is fol- lowed by paralysis, partial or complete, of the rhomboids, spinati, deltoid, biceps, brachialis anticus, and supinator longus, but strangely enough the lesion is not accompanied by loss of sensation. Perhaps the fact that the posterior root of the fifth cervical nerve is very small may assist to explain this fact (W. Harris). Injury to the cord just above the origin of the eighth cervical vertebra will leave the skin of the ulnar half of the arm anaesthetic, while the muscles of the fingers, hand, and wrist, and some of those at the elbow and shoulder, will be paralysed. The fibres for the innervation of the various groups of arm muscles pass out in quite an orderly man- ner by the fifth cervical to the first dorsal nerve from corresponding segments of the cord. Those for the abductors of the shoulder pass out by the fifth; for the adductors by the sixth and seventh; for the flexors of the elbow by the fifth and sixth; for the extensors by the seventh and eighth ; for the extensors of the wrist and fingers by the sixth and seventh ; and those for the flexors by the eighth and first dorsal. _ It is important to remem- ber that a cervical spinal nerve makes its exit from the canal opposite the origin of the next spinal nerve. Further, the nerve to each muscle is made up of fibres derived from two or more spinal nerves. The following is Dr. Herringham's account of the usual spinal origin of the fibres in the nerves of the upper limb, and of the usual supply of the chief muscles. (The figures indicate the fifth, sixth, seventh, and eighth cervical nerves, and the first dorsal nerve.) Nerves. — Nerve of Bell, 5, 6, 7 ; suprascapular, 5 or 5, 6; external cutaneous, 5, 6, 7; internal cutaneous, 1 or 8, 1 ; nerve of Wrisberg, 1 ; circum- flex, 5, 6 ; median, 6, 7, 8, 1 ; ulnar, 8, 1 ; musculo- spiral, 6, 7, 8, or 5, 6, 7, 8. Chap. XV] THE WRIST AND HAND 315 V ->. 1 / 3 \ 5\\ \\6 IP 6 Irl Fig. 54. — Cutaneous nerve supply of upper limb. Anterior aspect: l, Cervical plexus; 2, circumflex; 3, ext, cut. of muse, spiral; 4, ext. cutaneous ; o, median ; 6, ulnar ; 7, int. cutaneous ; 8, n. of Wrisberg. I'v.itt-rinr aspect: 1, Cervical plexus; 2, circumflex; 3, int. cut. of muse, spiral; 4, intercosto-humeral ; 5, u. of Wrisberg ; 6, int. cutaneous; 7. ext. cut. oi muse, spiral ; 8, ext. cutaneous ; 9, uluar ; 10, radial. 316 SURGICAL APPLIED ANATOMY [Part III Muscles. — 3, 4, 5, lev. anguli scap. ; 5, rhom- boids; 5 or 5, 6, biceps, brachialis ant., supra- and inf ra-spinatus, teres minor ; 5, 6, deltoid, sub- scapulars; 6, teres major, pronator teres, flexor carpi rad., supin. longus and brevis, superficial thenar muscles; 5, 6, 7, serratus magnus; 6 or 7, extensores carpi rad. ; 7, coraco-brachialis, latiss. dorsi, extensors at back of forearm, outer head of triceps; 7, 8, inner head of triceps; 7, 8, 1, flexor sublimis, flexores profund., carpi uln., long, poll., pronator quad. ; 8, long head of tri- ceps, hypothenar muscles, interossei, deep thenar muscles. In the cutaneous nerve supply of the fingers, it must be remembered that on the palmar aspect the thumb, the two outer fingers, and the radial side of the ring linger are supplied by the median, the remaining one and a half fingers by the ulnar (Fig. 54). On the dorsal aspect, the thumb is supplied by the radial ; the index and middle fingers are supplied (as far as the base of the second phalanx) by the radial, and over the second and third phalanges by the median. The little finger and the ulnar side of the ring finger are supplied by the ulnar. The radial side of the ring finger, as far as the base of the second phalanx, is supplied by the radial, and the rest of this side of the digit by the median (Fig. 54). The cleft between the middle and ring fingers is occasionally supplied by the ulnar, or partly by the ulnar and partly by the radial. The roots and spinal segments to which these nerves belong may be ascertained from Fig. 54a. The roots are distributed in order of origin, the fifth cervical beginning on the radial or outer side of the shoulder and the second dorsal, or sometimes the third, ending on the ulnar or inner aspect of the upper arm. The hand is mainly supplied by the seventh. The neighbouring spinal nerves, as is also the case with ordinary terminal branches, overlap widely in their distribution. The area of anaes- thesia is much less than the area of anatomical Chap. XV] THE WRIST AND HAND D.lll' Fig. 54a. Showing the sensory distribution of the spinal nerves in the upper limb. The dotted lines indicate approximately the area of each nerve. No attempt is made to show the extent bo which the root areas overlap. (For the nerves supplying each area see Fig. 54.) 318 SURGICAL APPLIED ANATOMY [Part III distribution. The nerves along the ulnar side of the arm are derived from cord segments which also give off sympathetic (sensory) nerves to the heart ; in angina pectoris the heart is really^ the cause of the pain, but the patient feels it on, 'and refers it to, the ulnar side of the arm. Paralysis of the muscnlo-spiral nerve.— When complete, the hand is flexed and hangs flaccid (" drop wrist "), and neither the wrist nor the fingers can be extended. The latter are bent and cover the thumb, which is also flexed and adducted. When attempts are made to extend the fingers, the interossei and lumbricales alone act, producing extension of the two distal phalanges and flexion of the proximal. Supina- tion is lost, especially if the elbow be extended so as to exclude the action of the biceps muscle. Extension at the elbow is lost, but there is practi- cally no loss of sensation unless the nerve is cut above the origin of its cutaneous branches. Sec- tion of the radial nerve in the upper part of the forearm gives no loss of sensation (Head and Sherren). Paralysis of the median nerve.— Flexion of the middle phalanx is impossible in every finger, as is also a like movement of the distal joint of the index and middle fingers. Partial flexion of the distal phalanges of the two inner digits is possible, the inner part of the flexor pro- fundus being supplied by the ulnar nerve. Flexion of the proximal phalanx with extension of the second and third can still be performed in all the fingers by the interossei. The thumb is extended and adducted, and can neither be flexed nor opposed. Bending of the wrist is only possible when the hand is forcibly adducted by means of the flexor carpi ulnaris, which is not paralysed. Pronation is lost. Section of the median or ulnar nerves at the wrist does not give rise to the results which one would expect from their anatomical distribution. Such lesions have been recently in- Chap. XV] THE WRIST AND HAND 319 vestigated by Head and Sherren. After section of the ulnar nerve in the forearm — taking this nerve as an example to explain their obseryations on nerves generally — they found that a certain form of sensibility, which they name epicritic, is lost over the area of anatomical distribution /Fig. 55). Over this area the patient is unable to distinguish light touch (tested by cotton wool) and degrees of temperature between 22°-40° C. In a small area of the fifth digit (see Fig. 55) neither pricks, very coM nor very hot things can be felt ; in this area, besides epicritic sensibility, there is also A B Fig. 55. — Results of section of the ulnar nerve (a, b), and of the median nerve (c, d). (Head and Sherren.) Black: Area in which epicritic and protopathic sensibilities are lost. Stippled : Area in which only epicritic sensibility is lost. lost another form which they name protopathic. But everywhere over the area of the ulnar nerve deep pressure is felt ; deep sensibility remains because the nerves which subserve it arise in the forearm and reach the fingers by the tendons. If the tendons are cut, deep sensibility also is lost. The effect of cutting any nerve depends on the nature of the fibres it contains ; a nerve may contain epicritic fibres for a small area and proto- pathic for a much wider, or vice versa. Paralysis of the ulnar nerve.— Ulnar flexion and adduction of the hand are limited. Com- plete flexion of the two inner fingers is impossible. The little finger can scarcely be moved at all. 320 SURGICAL APPLIED ANATOMY [Part III The action of the interossei and two inner lum- bricales is lost. The patient is unable to adduct the thumb. In testing for paralysis of muscles in the hand it is extremely important to observe closely the muscles which flex, extend, abduct, and adduct the thumb. The ulnar border of the metacarpal of the thumb can be approximated to the radial border of the corresponding bone of the index finger by only two muscles — the adductor pollicis and first dorsal interosseus. These are paralysed when the ulnar nerve is cut. Their action may be simulated by the flexor longus pollicis, brevis pollicis, or opponens pollicis, but in such cases it will be observed that it is not the ulnar border but the flexor surface of the thumb which is moved towards the metacarpal bone of the index finger. Epiphyses of the upper limb. — The epi- physes about the elbow join the shafts of their respective bones at 17 years (except the tip of the internal condyle, which joins at 18). * The epi- physes at the shoulder and wrist extremities of the bones join at 20. The nutrient canals of the three bones run towards the elbow. The nutrient artery of the humerus comes from the brachial or inferior profunda, those of the radius and ulna from the anterior interosseous. The nerve supplying the humerus is the mus- culocutaneous. The radius and ulna are sup- plied by the anterior interosseous of the median. It may be taken as a general law that the nerve supply of a bone is the same as that of the muscles which are attached to it. Fart IV.— THE ABDOMEN AND PELVIS CHAPTER XVI THE ABDOMEN The abdominal parietes. — Surface anatomy. The degree of prominence of the abdomen varies greatly. The protuberance of the belly in young children is mainly due to the relatively large size of the liver, which occupies a considerable part of the cavity in early life. It also depends upon the small size of the pelvis, which is not only unable to accommodate any abdominal structure (strictly so called), but can scarcely provide room for the pelvic organs themselves. Thus in in- fancy the bladder and a great part of the rectum are virtually abdominal viscera. After long- continued distension, as, for example, after preg- nancy, ascites, etc.. the abdomen usually remains unduly prominent and pendulous. In cases of great emaciation it becomes much sunken, and its anterior wall appears to have collapsed. This change is most conspicuous about the upper part of the region. Here the anterior parietes immediately below the line of the costal cartilages, instead of being in the same plane with the anterior thoracic wall, may so sink in as to be almost at right angles with that wall on the one hand, and with the lower part of the ab- dominal parietes on the other. In such cases the abdominal walls just below the thoracic line may appear to be almost vertical when the patient is v 321 322 SURGICAL APPLIED ANATOMY [Part IV in the recumbent posture. This change of sur- face is of importance in gastrostomy, since the subjects for that operation are usually much emaciated, and the incision has to be made close below the costal line. The position of the linea alba above the um- bilicus is indicated by a slight median groove, but no such indication exists below the navel. The linea semilunaris may be represented by a slightly curved line drawn from about the tip of the ninth costal cartilage to the pubic spine. In the adult it would be placed about 3 inches from the navel. Above the umbilicus the line is indicated on the surface by a shallow depression. The outline of the rectus can be well seen when the muscle is in action. It presents three " linear transversa," one usually opposite the xiphoid cartilage, one opposite the umbilicus, and a third between the two. The two upper of these lines are obvious on the surface in well-developed sub- jects. The site of the umbilicus varies with the obesity of the individual and the laxity of the abdomen. It is always below the centre of the line between the xiphoid cartilage and the pubes. In the adult it is some way above the centre of the body, as measured from head to foot, while in the foetus at birth it is below that point. It corre- sponds in front to the disc between the third and fourth lumbar vertebrae, and behind to the tip of the third lumbar spinous process. It is situated about | of an inch above a line drawn between the highest points of the two iliac crests. The anterior superior spine, the pubic spine, and Poupart's ligament are all conspicuous and important landmarks. The pubic spine is nearly in the same horizontal line as the upper edge of the great trochanter. It is very distinct in thin subjects. In the obese it is entirely lost beneath the pubic fat. In such individuals, however, it can be detected, when the subject is a male, by invaginating the scrotum so as to pass the finger Chap. XVI] THE ABDOMEN 323 beneath the subcutaneous fat. In the female the position of the process may be made out by ad- ducting the thigh and thus making prominent the tendon of origin of the adductor longus mus- cle. This muscle arises from the body of the pubes immediately below the spine, and by run- ning the finger along the muscle the bony promi- nence may be reached. If the finger be placed upon the pubic spine it may be said that a hernia descending to the inner side of the finger will be inguinal, while one presenting to the outer side will be femoral. In the erect position of the body the anterior superior spine is a little below the level of the promontory of the sacrum, while a point taken over the junction of sternum and ensiform process — the sterno-ensiform point — is opposite the upper part of the tenth dorsal ver- tebra. This point can be readily recognised in even fat subjects by the depression below the sternal insertions of the seventh pair of costal cartilages, and, as will be seen presently, forms a valuable landmark. A point taken midway be- tween the umbilicus and sterno-ensiform — the mid-epigastric point — lies opposite the disc be- tween the first and second lumbar vertebrae and is a surface marking of great clinical utility (Addison). In that part of the back which corresponds to the abdominal region the erector spinse masses are distinct, and in any but fat subjects their outer edges can be well defined. Between these masses is the spinal furrow, which ends below in an angle formed by the two great gluteal muscles. Immediately behind the middle of the crest of the ilium is Petit's triangle, or the gap between the external oblique and latissimus dorsi muscles. The fourth lumbar spine is about on -a level with the highest part of the iliac crest. In counting the ribs it is well to commence from above, since the last rib may not project beyond the outer edge of the erector spinse, and may consequently be overlooked. 324 SURGICAL APPLIED ANATOMY [Part IV The aorta bifurcates opposite the middle of the body of the fourth lumbar vertebra just to the left of the middle line about | of an inch below and to the left of the umbilicus. A line drawn on either side from the point of bifurcation to the middle of Poupart's ligament will correspond to the course of the common and external iliac arteries. The first two inches of this line would cover the common iliac, the remainder the ex- ternal. The coeliac axis comes off opposite the lower part of the twelfth dorsal vertebra, at a spot about lh inch above the mid-epigastric point, and that corresponds behind to the twelfth dorsal spine. The superior mesenteric and suprarenal arteries are just below the axis. The renal vessels arise about ^ an inch below the superior mesen- teric, opposite the mid-epigastric point. The in- ferior mesenteric artery comes off from the aorta about 1 inch above the umbilicus. The deep epi- gastric artery follows a line drawn from the middle of Poupart's ligament to the umbilicus. Along the same line may sometimes be seen the superficial epigastric vein. The abdominal " rings " will be referred to under Hernia (p. 339). Anterior abdominal parietes.— The si- in over the front of the abdomen is loosely attached in the region of the groin. It is more adherent to the deeper parts in the middle line than else- where, but not so adherent as to hinder the spread of inflammation from one side of the abdomen to the other. In cases of great obesity two transverse creases form across the belly, one crossing the umbilicus and the other passing just above the pubes. In the former of the two creases the navel is usually hidden from sight. In cases of anky- losed hip-joints transverse creases are often noted running across the middle of the belly. They are produced by the freer bending of the spine that is usually required in ankylosis, some of the simpler movements of the hip-joint being trans- Chap. XVII THE ABDOMEN 325 ferred to the column when the articulation is rendered useless. After the skin has been stretched, from any gross distension of the abdomen, certain silvery streaks appear in the integument over its lower part. They are due to an atrophy of the skin produced by the stretching, and their position serves to indicate the parts of the parietes upon which distending forces within the abdomen act most vigorously. They are well seen after preg- nancy, ascites, ovarian tumours, etc. Beneath the skin is the superficial fascia, which over the lower half of the abdomen can be readily divided into two layers. The great bulk of the subcutaneous fat of this region is lodged in the more superficial of the two layers. In cases of great obesity the accumulation of fat is perhaps more marked beneath the skin of the abdomen than it is elsewhere. A layer of fat 6 inches in depth has been found in this region in cases of great corpulence. The superficial vessels and nerves lie for the most part between the two layers of the fascia, so that in obese subjects incisions may be made over the abdomen to the depth of an inch or so without encountering blood-vessels of any magnitude. The deep layer of the superficial fascia con- tains elastic fibres, and corresponds to the tunica abdominalis or " abdominal belt " of animals. It is attached to the deeper parts along the middle line as far as the symphysis, and to the fascia lata just beyond Poupart's ligament. In the in- terval between the symphysis and the pubic spine it has no attachment, but passes down into the scrotum and becomes the dartos tissue. Extrava- sated urine that has reached the scrotum may mount up on to the abdomen through this in- terval, and will then be limited by the deeper layer of the fascia. It will not be able to pass down into the thigh on account of the attachments of the fascia, nor, for a like reason, will it tend to pass over the middle line. In the same way 326 SURGICAL APPLIED ANATOMY [Part IV emphysematous collections following injuries to the chest, when beneath the deeper layer of the fascia, receive a check at the groin, and lipomata also that grow beneath the membrane tend to be limited by the middle line and that of Poupart's ligament. The anterior abdominal parietes vary in thick- ness in different subjects. In cases of great emaciation the outlines of some of the viscera may be readily made out or even seen through the thinned wall. In some cases of chronic intestinal obstruction the outlines of the distended intestine are visible, and their movements can be watched ; in instances of obstruction of the pylorus the movements of the dilated and hypertrophied stomach can often be seen. The relative thickness of the abdominal wall in various subjects depends rather upon the amount of the subcutaneous fat than upon the thickness of the muscles. This muscular boundary affords an admirable protec- tion to the viscera within. By contracting the abdominal muscles the front of the belly can be made as hard as a board, and in acute peritonitis this contraction can sometimes be seen to produce a remarkable degree of rigidity. A blow upon the abdomen when the muscles are firmly contracted will probably do no injury to' the viscera unless the violence be extreme. The rigid muscular wall acts with the efficacy of a dense indiarubber plate. It may be bruised or torn, but it will itself receive the main shock of the contusion. The probable effect on the contained viscera of a blow upon the abdomen will depend upon many factors ; but, so far as the walls themselves are concerned, the effect greatly depends upon whether the blow was anticipated or not, and upon the extent of the padding of fat that is fur- nished to the parietes. If the blow be anticipated the muscles of the belly will be instinctively contracted, and the viscera at once provided with a firm but elastic shield. Thus the abdo- Chap. XVI] THE ABDOMEN 327 minal muscles have been found bruised and torn while the viscera were intact, and, on the other hand, in cases probably where the muscles were inert or taken unawares, a viscus has been found to be damaged without there being any con- spicuous lesion in the belly wall. If the blow be anticipated also the body will probably be abruptly bent and the viscera be — as it were — removed from danger. Along the linea alba the abdominal wall is thin, dense, and free from visible blood-vessels. Hence in many operations upon the abdominal cavity the incision is made in the middle line. Along the outer border of the rectus muscle {i.e. about and just beyond the linea semilunaris) the parietes are also thin and lacking in vessels, and consequently that situation is well suited for an incision. Except in some operations on the kidney, stomach, or gall bladder, incisions are seldom so placed. In most cases it is a question of either opening the abdomen in the middle line or in one of the iliac regions. About 1 inch below the navel the two recti muscles are almost in contact, and here the linea alba can scarcely be said to exist, while above, the muscles remain apart, the linea alba being normally f of an inch wide. In pregnancy, obesity, and ascites the supra- umbilical part may become 2 or more inches wide, but the narrow infraumbilical part is unaffected; when this part of the linea alba widens the con- dition is known as divarication of the recti. When this is the case the contents of the abdomen bulge out between the recti when these two muscles are thrown into action, as when a patient at- tempts to assume the sitting from a supine posture unaided by the arms. Pellets of sub- peritoneal fat may grow through interstices in the linea alba and give rise to what are called " fatty hernise." The fibrous ring of the umbilicus is derived from the linea alba. To this ring the adjacent structures, skin, fascia, and peritoneum, are all 328 SURGICAL APPLIED ANATOMY [Part IV closely adherent. The adhesion is such, and the amount of tissue between the skin and peritoneum is so scanty, that in operating upon an umbilical hernia it is scarcely possible to avoid opening the sac. The umbilicus represents the point where the lateral abdominal walls finally close. At the sixth week the opening is funnel-shaped and con- tains the yolk sac and a fold of the bowel to which it is attached. This condition may persist and give rise to a congenital umbilical hernia. In the foetus three vessels enter at the navel, and immediately separate on reaching the abdominal cavity, the vein passing directly upwards and the arteries obliquely downwards. Running down from the umbilicus in the middle line is also the remains of the urachus. In the foetus, the spot where the three vessels part company is about the centre of the navel, and it thus happens that in a congenital umbilical hernia the gut as it escapes separates the three vessels, which become to some extent spread over it. The congenital hernia, in- deed, works its way in among the structures of the cord and receives its main coverings from them. These hernise are fortunately rare, for in certain instances they extend some way into the cord, and in at least two reported cases the gut was cut across by the accoucheur in dividing the cord at birth.* As the abdomen increases in height the contraction of the two obliterated arteries and of the urachus drags upon the cica- trix and pulls it backwards and downwards. Thus, in the adult umbilical ring, as viewed from the inner side, the cords representing not only the obliterated arteries and the urachus, but also the vein, appear to start from the lower border of the cicatrix. In adult hernise, indeed, the gut escapes above both the obliterated arteries and the vein. The upper half of the cicatrix is thin * The congenital hernia must be distinguished from the infantile umbilical hernia so commonly met with after separation of the cord. For an account of these congenital hernia*., see paper by the Author in the Lancet, vol. i., 1881, p. 323. Chap. XVI] THE ABDOMEN 329 when compared to the lower half, and is sup- ported also by less firm adhesions. In some cases a fistula is found at the navel that discharges urine. This is due to a patent urachus. The urinary bladder is formed by a dilatation of the stalk of the allantois. The part below this dilatation becomes the first part of the urethra, that above becomes the urachus. In one instance of patent urachus the abnormal open- ing was 1 inch in diameter. The patient, a man aged 40, had a stone, which was extracted by passing the finger into the bladder through the opening at the umbilicus. Sometimes a fistula discharging faeces is met with at the navel. This depends upon the per- sistence of the vitello-intestinal duct, a duct that at one time connects the intestine of the early foetus with the yolk sac, and which generally dis- appears without leaving any trace. The per- sistent duct, when it occurs, is known as Meckel's diverticulum, and springs from the ileum some two or more feet above the ileo-csecal orifice. This fcetal relationship also explains the presence of a fibrous cord which is sometimes seen con- necting Meckel's diverticulum with the umbilicus. This fibrous cord may cause strangulation of the bowel. The position of the transverse intersections of the rectus muscle should be borne in mind. They adhere to the anterior layer of the rectus sheath, but not to the posterior. They are able, therefore, to some extent to limit suppurative collections and haemorrhages beneath the sheath on its anterior aspect. This muscle is often the seat of one form of " phantom tumour. ;; These tumours are mostly met with in the hysterical and hypochondriac, and when associated with some vague abdominal symptoms are apt to mis- lead. They are due to a partial contraction of the muscle, usually to a part between two inter- sections, and are said to be more common in the upper part of the rectus. When the fibres of the 330 SURGICAL APPLIED ANATOMY [Part IV muscle are contracted the " tumour " is obvious, but when they relax it disappears. The phantom tumour, however, is not always a matter of little moment. It may be associated with grave disease within the abdomen, and be due to reflex muscular contraction, the starting point of such reflex act being in the viscera. These localised contractions may provide a clue to the seat of visceral disease. Thus the stomach derives its chief sensory nerve supply from the eighth dorsal segment of the cord; the section of the rectus between the upper and middle inscriptions is also supplied from this segment through the eighth dorsal nerve ; hence contraction of this section may be asso- ciated with disease of the stomach. The rectus receives nerves from the lower six dorsal nerves ; the section at the umbilicus is supplied by the tenth. I have, for example, seen a conspicuous phan- tom tumour in the upper part of the right rectus associated with cancer of the stomach, with ulcer of the duodenum, and with malignant disease of the peritoneum. Other vanishing tumours depend upon disten- sion of the intestines by flatus or by faecal matter. In great distension of the abdomen the fibres of the rectus may be much stretched, since they bear the brunt of the distending force. The direction of the fibres also renders them liable to be torn in opisthotonos, or extreme arch- ing of the back, or tetanus. Portions of the muscle have also been ruptured by muscular violence, as in vaulting. The lateral muscles of the front abdominal wall are separated from one another by layers of loose connective tissue. In the tissue between the internal oblique and transversalis are found the chief nerves and arteries. Everywhere the peritoneum is bound to the abdominal wall by subperitoneal connective tissue. In the pelvis this tissue is lax to allow the viscera of the pelvis — the bladder, rectum, Chap. XVI] THE ABDOMEN 331 and uterus — to expand; so, too, over the iliac fossae and on the anterior abdominal wall for two inches above Poupart's ligament and the symphysis pubis ; but above this level and on the under surface of the diaphragm it binds the peritoneum down closely. The looseness of this layer greatly favours the spread of abscess, to the progress of which it offers little resistance. Such an abscess may spread from the viscera, especially from those that have an imperfect peritoneal covering, as, for example, the kidney, the vertical parts of the colon, etc. The laxity of this tissue has been of service in certain surgical procedures. Thus the external and common iliac arteries can be reached by an in- cision made some way to the outer side of the vessels and without opening the peritoneum. That membrane having been exposed in the lateral wound, the artery is reached by working a way with the finger through the subperitoneal tissue, and by actually stripping the serous mem- brane from its attachments. Ligature of the iliac vessels at the present day is usually effected through a direct incision which opens the peri- toneal cavity. The method just detailed belongs to pre-antiseptic days. The laxity of the sub- serous layer also favours that stretching of the peritoneum which occurs under certain circum- stances. Wounds of the abdomen may give trouble in their treatment, since, when inflicted, they may open up several layers of fascia and so lead to bagging of pus and to the spread of suppura- tion should an abscess follow the lesion. The constant respiratory movements of the belly walls do not favour that rest which is so essential to the healing of wounds. In penetrating wounds the contraction of the muscles may encourage the protrusion of the viscera, especially when the incision is transverse to the direction of the muscular fibres. In reducing small portions of protruded viscera it is quite possible to push 332 SURGICAL APPLIED ANATOMY [Part IV them into one of the connective tissue spaces be- tween the muscles or into the subserous tissue in- stead of into the peritoneal cavity. In applying sutures to wounds involving the whole thickness of the parietes it is necessary that the threads should include the peritoneum, so that early healing of that membrane may be brought about. Without such precaution a gap may be left in the surface of the peritoneum which would favour the formation of a hernia in the site of the old wound. Blood-vessels. — The only arteries of any mag- nitude in the abdominal walls are the two epigastric arteries, some branches of the deep circumflex iliac, the last two intercostal vessels, the epigastric branch of the internal mammary, and the abdominal divisions of the lumbar arteries. The superficial vessels are of small size, although Verneuil reports a case of fatal haemorrhage from the superficial epigastric vessel. The superficial veins on the front of the abdomen are numerous, and are very distinct when varicose. A lateral vein, extending from the axilla to the groin, uniting the axillary and femoral veins, is often rendered in this way very prominent. The surface abdominal veins may take no part as alternative blood channels in cases of obstruction of the inferior vena cava. Clinical experience shows that these veins may be also enormously varicose in instances where the inferior cava is quite patent. In one case under my care there was extensive varicosity of the surface veins from the pectoral region to the groin that involved one side of the body only. It has been shown, moreover, that the valves of these vessels are so arranged that the blood in the surface veins above the navel goes to the axilla, while that in the veins of the subumbilical region runs to the groin. In the neighbourhood of the umbilicus these veins are connected with the portal vein in the liver through anastomotic Chap. XVI] THE ABDOMEN 333 venous channels in the falciform ligament of the liver (Sappey). As regards the surface lymphatics of the front of the abdomen, it may be said in general terms that those above the umbilicus go to the axillary Diaphragmatic Cardiac Oesophageal C.A5TRIC Mepatic mtestimal Colic Vesical Re/nalTesticular Fig. 56. — Showing approximately the areas of skin supplied hy spinal nerves on the anterior surface of the trunk. The areas are marked on the left side by dotted lines, and the number of the spinal nerve by which each is supplied is indicated. The nerves are shows on the right side. The red stippled areas show the regions to which pain in commonly referred in connection with visceral disease— according to the observations of Dr. .lames Mackenzie. The pain radiates towards the unen- closed part of each area. glands, and those below to the glands of the groin. IVerves. — The abdominal wall is supplied by the lowest six dorsal or intercostal nerves, and by the first lumbar nerve. These nerves run obliquely to the long axis of the abdomen down- wards and inwards from the sides to the middle line and hence are damaged more extensively in vertical than in oblique incisions. Their direc- 334 SUEGICAL APPLIED ANATOMY [Part IV tion is represented by a continuation of the lines of the ribs : they are placed parallel to one another and at fairly equal distances apart. It is important to note that they supply not only the abdominal integument, but also the muscles of the belly, viz., the rectus, the two oblique muscles, and the transversalis. The segments of the spinal cord which supply the skin also innervate the underlying muscles, an association of great importance (Fig. 56). If a cold hand be suddenly placed upon the belly the muscles at once contract and the abdomen is instinctively rendered rigid. The safety of the viscera, at least so far as protection from contusions is con- cerned, depends upon the readiness with which the muscles can contract at the first indication of danger. As has been already stated, the viscera have a very efficient protection against the effects of blows when the belly muscles are in a state of rigid contraction. The sensitive skin acts the part of a sentinel, and the intimate asso- ciation of the surface nerves with the muscular nerves allows the warnings of this sentinel to be readily given and immediately acted upon. The rigidity of the muscles in certain painful affec- tions of the skin over the abdomen is often very conspicuous. I might instance the case of a man with a burn over the belly. While the burn is protected by the dressings the abdominal muscles are lax and the parietes move with the respiratory act. The moment the dressings are removed, the surface becoming painful, its spinal centre becomes excited and the muscles at once contract and the belly becomes rigid. It will be noticed that six of the abdominal nerves supply intercostal muscles, and are thus intimately associated with the movements of re- spiration. The abdominal muscles are of course -concerned! in the same movements. These asso- ciations are illustrated when cold water is sud- denly dashed upon the belly. The subject of such experiment at once experiences a violent Chap. XVI] THE ABDOMEN 335 respiratory movement in the form of a deep gasp. When the abdominal muscles are firmly fixed the lower ribs are also rigid, and respiration is limited to the higher ribs and to the thorax proper. There are other practical points about these nerves. In caries of the spine, and in certain injuries to the column, the spinal nerves may suffer injury as they issue from the vertebral canal. This injury may show itself by modified sensation in the parts supplied by such nerves. Thus in Pott's disease the patient often com- plains of a sense of tightness about the abdomen, as if a cord were tied around it. This sense of constriction depends upon an impaired sensation in the parts supplied by a certain pair of nerves ; or, if the sense of constriction be wider spread, by two or more pairs of nerves. In other cases a sense of pain may take the place of that of constriction. It would hardly be believed that spinal disease has been mistaken for " belly- ache." But many such cases have been recorded. A child complains of pain over the pit of the stomach or about the umbilicus, and this feature may quite absorb for a while the surgeon's atten- tion. The abdomen is carefully poulticed, while the only mischief is in the vertebral column. Other symptoms, however, develop, and it be- comes evident that the pain is due to pressure upon the nerves supplying the skin over the epigastric or umbilical regions, and that that pressure is a circumstance in the course of spinal bone disease. A case came under my notice in which a man complained of intense and abiding pain over the stomach. The pain was made worse by food, and as all means used failed to relieve it, the abdomen was opened by an explor- atory incision. Nothing abnormal was dis- covered. A little later it became evident that the pain was due to a malignant tumour situated in the bodies of the dorsal vertebrae. There had never, before the operation, been any suspicion 336 SURGICAL APPLIED ANATOMY [Part IV of spinal disease. The site of the painful part depends, of course, upon the position of the spinal ailment, and thus the cutaneous symptoms may serve to localise the caries in the vertebrae. Thus the skin over the " pit of the stomach " is supplied by the sixth and seventh dorsal nerves, and the tenth nerve is nearly in a line with the umbilicus. The position of the areas supplied by each spinal nerve on the trunk is shown in Fig. 56. The umbilicus may be at the upper or lower border of the area of the tenth, according to the individual, A spinal root may be cut and yet scarcely a trace of anaesthesia result owing to the overlapping of the nerve distributions. Not only may a lesion at the origin of a spinal nerve give rise to a pain referred by the patient to the abdomen, but, as may be readily understood from the fact that the nerves of the abdominal wall also supply the lower half of the thorax, thoracic lesions may also give rise to symptoms which are referred to the abdomen. Pain or tender areas in the upper part of the abdomen may be actually due to a pleurisy in the lower part of the thorax. Although the course of the spinal nerves in the body wall is oblique — following the axes of the ribs — yet in their final distribution they supply zones of skin which approximately pass horizont- ally round the body. This is due to the fact that the posterior primary divisions and lateral cutaneous branches, before they reach their areas of skin, descend to the same level as the anterior cutaneous nerves — the terminal branches of the anterior divisions. Indeed, the lateral cutaneous nerves of the lower segments, as the lower limb is approached, actually descend further than the anterior cutaneous nerves (Fig. 56). The hori- zontal arrangement of the skin areas is demon- strated bv the distribution of herpes zoster — a disease which is now ascribed to a lesion of the ganglia of the posterior roots. The nerves of the body wall have still more Chap. XVI] THE ABDOMEN 337 important associations. The cord segments with which they are connected are also in communica- tion with the viscera of the abdomen and thorax through the sympathetic system. Hence diseased conditions in the abdominal viscera give rise to disturbances in the corresponding cord segments, and the brain, being accustomed to localise pain only along the spinal nerves, makes a mistake and refers the pain along the spinal nerve of the seg- ment disturbed. Not only is pain referred, but the skin supplied from the disturbed spinal seg- ments becomes tender, and through a study of these areas of tenderness, Head has been able to localise the visceral centres in the spinal cord, thus affording the surgeon a means for increased accuracy of diagnosis. The abdominal viscera are supplied from the sixth dorsal to the first lumbar spinal segments, the nerves passing to their destinations through the rami communi- cantes, splanchnic nerves and sympathetic plexuses of the abdomen. JSTo visceral nerves es- cape by the second, third, or fourth lumbar nerve roots, hence these are never the seats of visceral referred pains. The pelvic viscera are supplied from the fifth lumbar to the third or sometimes fourth sacral nerve through the nervi erigentes. It is important to remember, too, that there are three systems of nerves in the belly wall : (1) the nerves to the skin; (2) the nerves to the muscles (motor and sensory) ; (3) the nerves to the parietal peritoneum. Any one or all of these three sets may be the seat of referred pain, the most common being the muscular nerves. The pain elicited^ by pressure on the muscles or by move- ments is usually, but erroneously, regarded as situated in the diseased viscus. The tonus and condition of the muscles of the abdominal pari- etes are influenced by the condition of the viscera through the interconnection of their nerve systems in the spinal cord. The following are the segments with which w 338 SURGICAL APPLIED ANATOMY [Part IV each viscus is connected (Head) : — Stomach, 6, 7, 8, 9 D. ; intestine, 9, 10, 11, 12 D. ; rectum, 2, 3, 4 S. ; liver and gall bladder, 7, 8, 9, 10 D. ; kidney and ureter, 10, 11, 12 D., 1 L. ; prostate, 10, 11 D., 5 L., 1, 2, 3 S. ; epididymis, 11, 12 D., 1 L. ; testis and ovary, 10 D. ; appendages of uterus, 11, 12 D., 1 L. ; uterus, 10, 11, 12 D., 1 L., 3, 4 S. This nerve relationship is illustrated in dis- ease in many ways. Thus, in acute peritonitis and in laceration of certain of the viscera the abdominal muscles become rigidly contracted, so as to insure as complete rest as possible to the injured parts. In acute peritonitis the belly is very hard, the respirations are purely thoracic, and so entirely do the cutaneous portions of these nerves enter into the situation, that the patient is often unable to tolerate even the most trifling pressure upon his abdomen. Congenital deformities of the abdomen.— At the end of the second month of development, part of the intestine projects through the widely open umbilicus within the cord when it is only covered by the transparent covering membrane of that structure. In the third month the intestines retreat within the abdomen, the cavity within the cord becoming obliterated and the umbilicus closed. The process of retraction of the intestine may fail or even an opposite process may occur — other contents being added to those normally found within the cord. Thus result the various forms of congenital exomphalos, which may vary in severity from a small hernia to a protrusion of the whole of the more movable viscera. One of the most remarkable deformities is that known as extroversion of the bladder. Here, not only is a part of the belly wall absent, but also a part of the genito-urinary apparatus. In complete cases there is an absence of the umbilicus and of the anterior abdominal wall below it. There is no symphysis pubis, an absence of the anterior wall of the bladder, of the principal part of the penis, and the whole of the roof of the urethra. The Chap. XVI] TEJE ABDOMEN 339 scrotum, also, as may be expected from a refer- ence to the development of that part, is bifid. Hernia.— 1. Inguinal hernia. In this form of rupture the herniated bowel occupies the in- guinal canal for the whole or part of its entire length. This canal runs obliquely from the in- ternal to the external abdominal ring, and is about lh inch in length. It represents the track followed by the testis in its descent. It is, in a sense, apassage^ right through the abdominal wall, and is occupied by the spermatic cord. It is not a free canal, however, in the same sense as one would speak of an open tube, but is rather a potential one, a tract of tissue so arranged as to permit of a body being thrust along it. It is a breach in the abdominal wall, not a doorway ; a breach that is forcibly opened up and widened in the acquired forms of hernia. When a hernia occupies the inguinal canal it is covered in front by the integuments, the external oblique aponeurosis, and the lower fibres of the inter- nal, oblique and transversalis muscles. It rests behind upon the transversalis fascia, the con- joined tendon, and the triangular fascia ; over it arch the transverse and internal oblique muscles, while below it is the angle formed by the union of Poupart's ligament with the trans- versalis fascia. The herniated bowel is con- tained within a " sac," which is always formed of _ peritoneum. In congenital hernia the sac exists already formed as an abnormally patent " processus vaginalis." In acquired hernise the sac consists of that part of the parietal peri- toneum which the gut pushes before it in its descent. The external abdominal ring, half an inch ex- ternal to and above the pubic spine, is readily felt by invaginating the scrotum with the point of the finger, and then passing the digit up in front of the cord. If the nail be kept against the cord the pulp of the finger can readily recognise the triangular slit-like opening. Under ordinary 340 SURGICAL APPLIED ANATOMY [Part IV circumstances in adults it will just admit the tip of the little finger.* The internal ring is situate about \ an inch above Poupart's liga- ment, midway between the symphysis pubis and anterior superior iliac spine. This is the femoral point; it lies directly over the femoral artery as that vessel escapes from the abdomen beneath Poupart's ligament (Fig. 57). UnBiLlCUS 4->- K LunBAB Vert. COfinO" Iliac Art Ext. Iliac Art. Rectus Abdominis DEEP ElPiCASTRiC Art. /lESSELBACtt'S TBIA/1CLE Course of Vas , Ext.Aboomiial Rimc 5y/iPHysis Pubic 5pime QlMBECflATS Lica^e^t _ From rhe FemOBAl Ri/iC Course o/ vas #nd Cord Fig. 57. — Surface markings for the inguinal and femoral canals. a.s.s., Anterior superior spine of ilium. There are two principal forms of inguinal hernia, which can be best understood by a view of the anterior abdominal parietes from within. From such an aspect it will be seen that the peritoneum is marked by three linear ridges that run, roughly speaking, from the umbilicus to the In cases of congenital or acquired absence of the cord the external ring maybe almost, obliterated. Paulet quotes from Malgaigne the case of an old man wliu.se testicle had been removed iii infancy, and in whom the external ring was so small as to be scarcely recognisable. Chap. XVI] THE ABDOMEN 34] pelvic brim. One of these ridges follows the middle line from the navel to the symphysis and represents the urachus; a second, that may be indicated by a line drawn from the femoral point to the navel, represents the deep epigastric artery; while between these two, and much nearer to the epigastric vessel than to the middle line, is the line formed by the obliterated hypo- gastric artery. By means of these ridges the peritoneum is made to present three fossse, an external to the outer side of the epigastric artery, an internal between the urachus and the hypo- gastric artery, and a middle between the track of the latter vessel and the epigastric trunk. The internal ring (so called) is just to the outer side of the epigastric artery, and the site of the summit of the inguinal canal is indicated by a depression in the peritoneum (Fig. 57). When a hernia follows the inguinal canal throughout its entire length, it is called oblique, indirect, or external; " oblique " or " indirect ,; from its taking the oblique direction of the canal, " ex- ternal ;; from the position of its neck with refer- ence to the epigastric vessel. The coverings of such a hernia would be the same as those of the cord, viz., the skin, the superficial, inter- columnar, cremasteric and infundibuliform layers of fascia, the subserous tissue, and the peri- toneum. When the hernia escapes to the inner side of the deep epigastric artery, through the space known as Hesselbach's triangle, it is called a direct or internal hernia, for reasons that will be obvious. There may be two forms of direct hernia. In one form the gut escapes through the middle fossa above described, in the other through the inner fossa between the hypogastric artery and the outer edge of the rectus muscle. The middle fossa is nearly opposite to the sum- mit of the external ring. A hernia escaping through that fossa would enter the inguinal canal some little way below the point of entrance of an oblique hernia, and would have the same coverings 342 SURGICAL APPLIED ANATOMY [Part IV as that hernia, with the exception of the infundi- buliform fascia. The first covering, indeed, that it would receive from the canal structures would be the cremasteric fascia. The inner fossa cor- responds, so far as the inguinal canal is con- cerned, with the external ring. A hernia escap- ing through this fossa would be resisted by the conjoined tendon and the triangular fascia. These structures are either stretched over the hernia so as to form one of its coverings, or the conjoined tendon is perforated by the hernia, or lastly the gut deviates a little in an outward direction so as to avoid the tendon and appear at its outer side (Velpeau). In any case the hernia is forced almost directly into the external abdo- minal ring. The coverings of such hernise are the skin and superficial fascia, the intercolumnar fascia, the triangular fascia and conjoined tendon (with the exceptions above mentioned), the trans- versalis fascia, subserous tissue, and peritoneum. An examination of the abdominal wall, apart from clinical experience, would lead one to sus- pect that the direct hernia would be more com- mon than the indirect, since the parietes are cer- tainly less resisting opposite Hesselbach's triangle than they are in the parts immediately external to the epigastric artery. Indeed, just to the outer side of the conjoined tendon the belly wall is remarkably thin. These conditions, however, seem to offer less facilities for the escape of a hernia than does the inguinal canal itself. The funnel- shaped depression in the peritoneum at the sum- mit of that canal seems to offer particular induce- ment for rupture, and there are, besides, certain congenital defects in the vaginal process of the peritoneum that render hernia almost unavoid- able along the inguinal canal. Direct versus indirect inguinal hernia. — The indirect hernia, as just hinted, may be con- genital, the direct is never congenital. In the congenital oblique hernia the outline of the in- guinal canal and the relations of the various Chap. XVI] THE ABDOMEN 343 parts concerned are but little disturbed, and the differences between this form of rupture and the direct variety are conspicuous. The acquired oblique hernia, however, does not present such a contrast to the direct form as might be expected. In the first-named rupture, from constant drag- ging upon the parts, the internal ring becomes more or less approximated to the external ring, and the length of the canal, and consequently the obliquity of the hernia, are considerably reduced. Thus the axes of the two forms of rupture do not present such differences as to make their nature at once obvious. The direct hernia, however, on re- duction, will pass directly back into the belly, while the indirect will, even in old cases, take a slight but appreciable direction outwards. After the reduction of the direct hernia, the edge of the rectus muscle may be readily felt to the inner side of the aperture, the protrusion being, indeed, at the semilunar line. The direct hernia is usually small and globular, while the oblique rupture may attain large size, and tends to assume a pyriform outline. Forms of oblique hernia, depending* upon congenital defects in the " vaginal process.*" —The descent of the testis. It is well known that the testis in the foetus descends from the region of the kidney into the scrotum by a way through the abdominal wall that is afterwards known as the inguinal canal (see p. 339). Its descent is preceded by the passage into the scrotum of a process of the peritoneum, the vaginal process. The testicle usually enters the internal ring about the seventh month of fcetal life, and by the eighth month is in the scrotum. The testis is guided to its final resting place by the gubernaculum, a band of muscular fibres. This > band is attached below to the anterior ab- dominal parietes, to the pubes near the root of the penis, to the bottom of the scrotum, and to the tuber ischii and sphincter ani (Lockwood). The last-named attachments serve to explain the 344 SUKGICAL APPLIED ANATOMY [Part IV occasional passage of the testis beyond the scrotum into the perineum (testis in perineo). In one example of this condition I found it necessary to divide a band passing from the tuber ischii to the testis before I could place the gland in the scrotum. Following the gubernaculum upwards, it is attached, first of all, to the vaginal process, which, therefore, descends before the testis, then to the gland and epididymis, and, lastly, to the peri- toneum about the bowel (caecum, ileum, or mesen- tery on the right side, and sigmoid flexure on the left side). The vaginal process is often found open at birth; one may infer from the observations of Zuckerkandl and of Sachs that, even in children three or four months old, the communication re- mains open in 30 to 40 per cent, of cases. The part of the processus vaginalis which surrounds the testicle becomes the tunica vaginalis, while the elongated tubular part between it and the internal abdominal ring is known as the processus funicu- laris. The manner in which the processus vaginalis is cut off is as follows. It becomes obliterated in two places, at the internal ring and at a spot just above the epididymis, the obliteration usually beginning at the higher point first. Supposing obliteration to have taken place at these two points, the vaginal process between them will be represented by an isolated tube. This soon shrinks, closes, and dwindles to an insignificant fibrous cord. It may, however, remain patent in part, and if fluid accumulates in this patent portion, an " encysted hydrocele of the cord " is produced. As regards the mode of closure, three contingencies may happen, each giving rise to a particular form of hernia: (1) the "pro- cess ;; may not close at all; (2) it may close at the upper point only; and (3) it may close at the lower point only. (1) When the vaginal process is entirely open, gut can readily descend at once into the scrotum. Chap. XVI] THE ABDOMEN 345 Such a condition is called a congenital hernia. Here the intestine is found to occupy a large sac of the peritoneum, the open orifice of which is placed at the internal inguinal ring. The term " congenital ;; is misleading, as the hernia is very rarely present at birth, although it is com- mon in early life. (2) When the process is closed only at the in- ternal ring the unduly large tunica vaginalis is found to extend up to that orifice. If a hernia forms itf may invaginate the processus vaginalis. This is known as an infantile or encysted hernia. In such a case the tunica vaginalis lies in front of the sac, and therefore three layers of peritoneum would have to be cut through before the gut could be reached. The term " infantile ;; was given to this rupture because the first cases reported were met with in infants ; the term "encysted,"' because the hernial sac was con- sidered to be enclosed by the sac of the tunica vaginalis. (3) The funicular process may remain open from the internal abdominal ring to the top of the testicle and there end, the normal tunica vaginalis being beyond. Hernia into this process is called a hernia into the funicular process. In the first of these forms the testicle is quite enveloped in the hernia. In the second and third forms, as well as in the acquired form, it is to be felt quite distinct from the rupture, being actually behind and below it. Congenital hernia frequently occurs in cases of imperfect descent of the^ testicle ; this can be readily understood when it is remembered that the processus vaginalis is completely formed before the testicle passes into the inguinal canal. In such cases the processus remains open. In these instances the vaginal pro- cess may occupy the would-be canal, and along this process a hernia may descend. It is well known that the testicle may make its first appear- ance in the scrotum months and even years after birth. 346 SURGICAL APPLIED ANATOMY [Part IV There is another possible congenital defect that may predispose to hernia, viz. an abnormally long mesentery. If, in the dead subject, the inguinal canal be opened up, and an attempt made to draw a piece of gut down from the abdomen into the scrotum, it will be found that this cannot be done, owing to the shortness of the mesentery. In any case of scrotal hernia, therefore, the mesentery must become lengthened, and it is a question whether or not an abnormally long mesentery may exist as a congenital defect, and so predispose tjie patient to rupture. More information is required upon the subject. The inguinal canal in the female is much smaller and narrower, although a trifle longer, than it is in the male. It is occupied by the round ligament, and offers such slight induce- ment to the formation of a rupture, that acquired inguinal hernia is as rare among females as it is common among men. In the female foetus a pro- cess of peritoneum descends for a little way along the round ligament. It corresponds to the pro- cessus vaginalis of males, and is known as the canal of Nuck. If this process remains patent, as it not unfrequently does, it may lead to a rup- ture that corresponds to the congenital hernia of males. Indeed, in quite early life the inguinal rupture is about the only form met with in female children, if exception be made of umbilical hernia. Not uncommonly the ovary is found as one of the contents of the hernial sac — for in the newly-born child the ovarv lies above the level of the pelvic brim and relatively near the internal abdominal ring. In all such instances of early in- guinal hernia the gut has travelled down a patent canal of Nuck. It only remains to be said, that in endeavour- ing to reduce an inguinal hernia by taxis the thi^h should be flexed and adducted, for in this position the abdominal parietes that bound the inguinal canal are the most relaxed. This posi- tion of the thigh affects the inguinal region Chap. XVI] THE ABDOMEN 347 mainly through the attachments of the fascia lata to Poupart's ligament. In Herniotomy an incision is made along the middle of the tumour and in its long axis, being so arranged that its centre shall correspond to the external ring. The superficial external pudic artery is usually divided in the operation. It is impossible to distinguish the various layers of tissue that cover the hernia, the only one, as a rule, that is recognisable being the layer from the cremaster. In dividing the constriction it is usually recommended to cut upwards in all forms of inguinal hernia. The only vessel in risk of being damaged is the deep epigastric. In the oblique form of rupture an incision directly up- wards would quite avoid this artery; but in a direct hernia, where there is reason to suppose that the vessel is in close connection with the neck of the sac, it is well that the incision be directed a little inwards as well as upwards. It should be remembered that the incision required to re- lieve a constriction is, if properly applied, of the most insignificant character. 2. Femoral hernia.— In this form of rupture the gut leaves the abdomen through the femoral ring and passes down into the thigh along the crural canal (Fig. 57). The name " crural canal " is given to the narrow interval between the femoral vein and the inner wall of the femoral sheath. Like the inguinal canal, it is a potential rather than an actual canal, and exists only when the sheath has been separated from the vein by dissection or by a hernial protrusion of some kind. The canal is funnel-shaped, about ^ an inch in length, and ends opposite the saphenous opening. A point taken on Poupart's ligament midway be- tween the pubic spine and femoral point lies directly over the femoral ring ; the centre of the saphenous opening is situated f of an inch below this point (Fig. 57). Femoral hernise are always acquired, and possess a sac, made by themselves out of the parietal peritoneum covering the crural 348 SUKGICAL APPLIED ANATOMY [Part IV ring and its vicinity. The canal is larger in women than in men, and thus it happens that this species of rupture is much more common in the former sex. The tendency to this hernia in women appears also to be increased by the weak- ening effects of pregnancy upon the abdominal walls. As the gut descends it pushes in front of it its sac of peritoneum and the septum crurale (the name given to the subserous tissue that covers in the femoral ring) and enters the crural sheath. The adhesions of the sheath limit its downward progress when it has travelled about £ an inch, and it therefore passes forwards through the saphenous opening, pushing before it the cribri- form fascia. It then receives a covering from the superficial fascia and the skin. Owing to the rigidity of the structures about the femoral ring, the neck of the sac must always be small. For similar reasons its dimensions while in the femoral canal must of necessity be insignificant, but when once it has escaped through the saphenous open- ing the loose subcutaneous fasciae of the groin afford it ample opportunity for increase. When the hernia has passed through the saphenous open- ing it tends to mount upwards over Poupart's ligament, in the direction of the anterior superior iliac spine. Even when it overlaps the ligament considerably it can hardly be mistaken for an inguinal hernia, since it must always lie to the outer side of the pubic spine. The upward ten- dency of a femoral hernia has been variously explained. It has been ascribed to a supposed curve in the crural canal, the concavity of which is forwards. Scarpa believed it to receive its direction from the frequent flexion of the thigh. Probably one of the most important factors in the matter is the unyielding character of the lower edge of the saphenous opening. If an elas- tic capsule be dilated within the femoral canal it will be found to turn upwards and inwards oyer Poupart's ligament; the direction of expan- sion is determined by the circumstances just men- Chap. XVI] THE ABDOMEN 349 tioned and by the yielding character of the an- terior wall of the femoral sheath. The hernial sac is superficial to Scarpa's fascia. Relations.- — When a hernia occupies the crural canal there are in front of it the skin and super- ficial fasciae, the iliac part of the fascia lata, the cribriform fascia, and the anterior wall of the crural sheath. Behind are the posterior wall of the crural sheath and pubic portion of the fascia lata, the pectineus muscle, and the bone. The boundaries of the femoral ring are, in front, Pou- part ; s ligament and the deep crural arch; behind, the bone covered by the fascia lata and the pec- tineus; on the inner side, the conjoined tendon, Gimbernat's ligament, and the inner part of the deep crural arch; on the outer side, the femoral vein in its sheath (Fig. 57). The sper- matic cord lies (in the male) just above the an- terior border of the ring, and the epigastric artery skirts its upper and outer part. The little pubic branch of this artery passes round the ring to ramify over Gimbernat's ligament. In two cases out of seven the obturator artery arises from the epigastric. In 10 per cent, of cases the abnormal obturator passes on the inner side of the femoral ring and is in danger of being wounded in opera- tions for strangulation ; in other cases the artery descends to the outer side of the ring or may cross it (R. Quain). In one instance where the vessel was placed internally to the femoral ring the pul- sations of the abnormal artery were felt before the parts were divided. In addition to the vessels about the ring there is also a pubic vein, which, ascending from the obturator vein in the thyroid foramen, enters the external iliac vein. Its rela- tion to the crural ring varies in the same way as the abnormal artery last named. The size of the femoral canal and the degree of tension of its orifices vary greatly with the position of the limb. If the thigh be extended, abducted, and rotated outwards, these parts are made very tense, while they are the most lax when 350 SURGICAL APPLIED ANATOMY [Part IV the limb is flexed, adducted, and rotated inwards. It is consequently in the latter position that the thigh should be placed when taxis is being at- tempted. In herniotomy the incision is made along the inner side of the tumour, and is so arranged that its centre corresponds to about the upper part of the saphenous opening. The constriction is usually at the neck of ^ the sac, and caused by Gimbernat's ligament. It is divided by an incision directed upwards and inwards. 3. Obturator hernia. — In this form the gut, pushing before it the peritoneum, the subperi- toneal fat, and the pelvic fascia, escapes through the obturator canal. The direction of this canal is, from behind, downwards, forwards, and in- wards. The inguinal is separated from the femoral canal by the inner part of Poupart's ligament; the femoral is separated from the ob- turator bv the horizontal ramus of the pubis. Beyond the canal the hernia may pass between the obturator membrane and the obturator exter- nus muscle and remain deeply placed, or it may make its way through the muscle or emerge above it and be then covered by the pectineus and adduc- tor brevis. The obturator artery is, as a rule, at the outer and posterior part of the sac. It is very rarely in front of it. The obturator nerve is generally found to the outer side of the sac, less commonly it is in front of it. The proximity of the nerve renders it very liable to be pressed upon, and pain along the nerve is often a marked feature of the rupture. The hernia presents be- neath the pectineus muscle, to the inner side of the capsule of the hip, behind and to the inner side of the femoral vessels, and to the outer side of the adductor longus tendon. Pain on moving the hip is generally a conspicuous symptom. The obturator externus may be made tense bv rotation inwards of the slightly abducted thigh. This hernia is much more common in females ; and it is worthy of note that the orifice of the obturator canal can be examined, to some extent, through Chap. XVI] THE ABDOMEN 351 the vagina. Professor Wood reports a remarkable case where a hernial protrusion of a part of the adductor longus through a rent in the fascia lata was mistaken for an obturator hernia. 1. Rare forms of hernia. — In perineal hernia the sac, covered by the recto-vesical fascia, escapes through the anterior fibres of the levator ani muscle, between the prostate and the rectum. In the ischio-rectal hernia the protrusion takes place into the ischio-rectal fossa. In pudendal hernia the sac lies in the posterior inferior half of the labium pudendi, escaping between the ascending ramus of the ischium and the vagina ; it has been mistaken for a cyst. In sciatic hernia the gut escapes through the great sacro-sciatic notch in front of the internal iliac vessels, above or below the pyriformis, and appears under the gluteus maximus muscle. As regards umbilical hernia, nothing remains to be added to what has been already said (p. 328), save that the sac from its position nearly always contains omentum, and may contain stomach. In lumbar hernia the gut escapes in front of the quadratus lumborum muscle, and appears on the surface through the triangle of Petit (the gap between the latissimus dorsi and external oblique muscles), and there- fore just above the highest point of the iliac crest. The sac must either force before it or (in cases of injury) come through the fascia lumborum and internal oblique muscles, since these structures form the floor of the triangle. The hernia may escape through the " upper lumbar triangle " — a gap near the last rib where the aponeurosis of the transversalis is covered only bv the latissimus dorsi. Macready (Lancet, Nov. 8th, 1890) has col- lected twentv-five examples of this hernia. Dia- vhraqmatic hernias may be congenital or acquired. The former variety is by far the more common, and is due to simple arrest in the development of the diaphragm and persistence of the original connec- tion between the thorax and abdomen ; the position of this connection is marked by the fibrous interval 352 SUEGICAL APPLIED ANATOMY [Part IV between the muscular fibres rising from the last rib and those springing from the external arcuate liga- ment. The congenital form very rarely occurs on the right side, the development of the liver secur- ing the closure of the pleuro-peritoneal opening on that side. In the acquired form, which is usually the result of a crushing accident, the dia- phragm may be lacerated at any point, but in the majority of instances the lesion is situated in the left dome over the stomach. In an adult subject recently dissected by Dr. N. Paterson the ab- dominal contents of the left hypochondrium occu- pied the left pleural cavity ; there was a large aperture in the left dome ; the condition had not been recognised during life and apparently had given rise to no marked symptom. Of the organs, the stomach is the most frequently dislodged, then the transverse colon, omentum, small gut, spleen, liver, pancreas, and kidneys, in the order named (Leichtenstern). The hernia may escape through the foramen for the gullet, but never through that for the vena cava, nor through the hiatus aorticus. The parts commonly selected are the connective tissue intervals between the sternal and costal origins of the diaphragm in front and its verte- bral and costal origins behind. These hernise are more common in males. Femoral and inguinal diverticula. — Re- cently Mr. It. W. Murray has called attention to the frequency with which diverticula of peri- toneum are found over the openings of the femoral and inguinal canals. In 200 post-mortem ex- aminations he found 52 femoral and 13 inguinal diverticula and yet no hernia. In some cases the inguinal sacs may be formed from the processus vaginalis, but all the femoral forms and probablv the majority of the inguinal are caused by yield- ing of the fibrous tissue of the parietes over the femoral and internal abdominal rings. In these regions the peritoneum is so loosely bound to the abdominal wall that it may be evaginated by a low degree of intra-abdominal pressure. Chap. XVI] THE ABDOMEN 353 Posterior abdominal parietes. — The lateral and posterior walls of the abdomen are lined in- side with two fasciae, the transversalis and iliac. The transversalis fascia lines the whole of the transversalis muscle, and is much thicker below than above. Above, it joins the fascia covering the diaphragm, while below it is attached to the iliac crest and to the whole of Poupart's ligament, save at that spot where it passes into the thigh to form the anterior layer of the crural sheath. The iliac fascia encloses the ilio-psoas muscle, the part over the psoas being the thinner. This part is attached on the inner side to the sacrum, and to the spine at the points corresponding to the psoas origin. Above, it is attached to the ligamentum arcuatum internum, and on the outer side to the anterior layer of the lumbar fascia along the outer edge of the psoas. Below, the fascia en- closes the iliacus, and is attached to the iliac crest, to the pelvic brim, and to Poupart's ligament, save at that part where the membrane passes be- neath the ligament to form the posterior wall of the crural sheath. It follows the ilio-psoas muscle to its insertion, and ends by blending with the fascia lata. The arrangement of these fasciae greatly influ- ences the progress and direction of abscess. Thus an abscess placed beneath the transversalis fascia will point either just above the iliac crest or Pou- part's ligament, or run down along the spermatic cord and distend the inguinal canal. The iliac fascia encloses the ilio-psoas in a very distinct osseo-aponeurotic space. Between the fascia and the muscle (especially its iliac division) there is a good deal of loose connective tissue, and thus every facility is offered for the progress of subfascial abscesses in this region. The osseo- aponeurotic space is practically closed on all sides within the abdomen, and is only open below where the fascia passes with its muscle into the thigh. This opening being at the most dependent part of the space, it follows that the psoas or iliac abscess x 354 SUKGICAL APPLIED ANATOMY [Part IV very commonly points on the upper part of the thigh, just to the outer side of the femoral vessels. An abscess in the iliac fossa, although most likely to reach the thigh, might mount up to the superior attachments of the fascia, and point at the iliac crest or at the outer part of Poupart's ligament. Or it may disregard the inner attachments of the fascia and gravitate into the pelvis. If the patient should occupy for long the recumbent pos- ture, there is no reason why it should not extend upwards along the psoas muscle. The term iliac abscess, however, is often ap- plied to collections that are not within the space formed by the iliac fascia, but that are situated rather in the subperitoneal connective tissue. This tissue is very extensive and lax in the iliac fossa in order to allow the expansion of the peritoneum which necessarily attends the filling and emptying of the caecum, colon, bladder, uterus, and rectum. Large collections of puru- lent matter may form in it or may spread into it from the pelvis. Some distance above Poupart ; s ligament (1^ to 2 inches) the subserous tissue be- comes dense and the peritoneum closely bound down. Hence such abscesses remain in the iliac fossa, bulging out the abdominal wall just above Poupart's ligament, and occupying the angle formed by the union of the iliac and transversalis fasciae. In some cases they are disposed to extend into the pelvis. The abscess, when in the subserous tissue, is brought in close contact with certain of the vis- cera, especially with the caecum and sigmoid flexure, and into these portions of the colon it may open. Thus, I have seen a case of iliac abscess due to pelvic necrosis that opened into the sigmoid flexure, and at the same time discharged through sinuses about the groin. In this case some pus passed by the anus, while on the other hand some faecal matter escaped by the groin. Retroperitoneal abscesses in the pelvis (pelvic cellulitis) may mount up into the iliac fossae, may Chap. XVI] THE ABDOMEN 355 appear as " iliac abscesses," and may ultimately discharge themselves by many openings in the lower parts of the anterior abdominal wall. It may be well to note that the common and external iliac vessels, the lymphatics, and the ureters are outside the iliac fascia, and rest upon its abdominal surface, while the anterior crural nerves and abdominal parts of the lumbar nerves are within the osseo-aponeurotic space. Thus the intrafascial abscess may, with little difficulty, reach the thigh by following the iliac vessels; while the subfascial collection would pursue the anterior crural nerve. A psoas abscess, or abscess within the fascial sheath of the psoas muscle, is usually due to spinal caries, although it may appear independently of that disease. If the lumbar spine be involved the matter can pass directly into the substance of the muscle, which it will more or less entirely destroy. If the mischief be in the dorsal spine, the matter gravitates along the front of the column until it reaches the diaphragm, which it pierces by an inflammatory process. It is now brought into re- lation with the heads of the psoas, and has to pass through a narrow strait. The pus, following the muscle, at last reaches the thigh, and usually points, just below the groin, to the outer side of the femoral vessels. The substance of the psoas may be completely replaced by an abscess cavity. The abscess, however, often shows much varia- tion. It may avoid the psoas, or leave it when once it has entered it, and make its way into the lumbar region to find an exit in the loin. Or it may extend into the iliac fossae and open above the groin, or mount up over the iliac crest and discharge in the gluteal region. It may pass along the inguinal canal and be mistaken for a hernia. It may sink into the pelvis, and may open into the bladder, or discharge itself through the great sciatic foramen, or through a sinus in the perineum. Some of the latter cases have led to much confusion in diagnosis, since there would 356 * SURGICAL APPLIED ANATOMY [Part IV appear to be little connection between caries of the spine and a perineal abscess. Lumbar region. — The muscles that form the lateral and posterior walls of the abdomen, and that fill in the interval between the iliac crest and the lowest rib, are the external oblique and latis- simus dorsi, the internal oblique, the transver- salis muscle and fascia lumborum, the erector spinse and quadratus lumborum. The distance from the iliac crest to the tip of the nearest rib (usually the eleventh) varies from 3 to 7 cm, the average being 4'8 cm., a little less than 2 inches (Addison). The external oblique and latissimus dorsi mus- cles are separated by a small triangular interval below (the triangle of Petit), but above they over-, lap. The interval is best marked in women. The outer border of the erector spinse affords a useful landmark in the lumbar region. At the crest of the ilium the outer border of the quadratus lum- borum extends an inch beyond the erector spinse, but at the twelfth rib it lies an inch internally to that muscle (Fig. 68). The triangle of Petit is l\ to 2 inches beyond the erector spinas, or just behind the mid-point of the iliac crest. The sub- cutaneous tissue in the lumbar region is very extensive, and is a favourite locality for chronic abscess. The looseness and extent of the tissue also permit of large extravasations of blood. It is in the muscles and fascia along the spine in this region that the rheumatic affection known as lumbago has its seat. Between the last rib and the iliac crest is stretched the dense fascia lumborum, the posterior aponeurosis of the transversalis muscle. It is pierced near the rib by the last intercostal artery and nerve, and near the ilium by the ilio-hypo- gastric nerve and its accompanying artery. It is along these structures that an abscess may possi- bly find its way through the fascia in certain cases. The fascia divides behind into three layers, to enclose in definite spaces the quadratus and Chap. XVI] THE ABDOMEN 357 erector spinas muscles, the middle layer passing between these two muscles to the tips of the trans- verse processes. Within these spaces or compart- ments suppuration may be for some time limited. A lumbar abscess commencing in some adjacent part, as in the spine or in the loose tissue around the kidneys, usually spreads backwards by pierc- ing the fascia lumborum or the quadratus muscle. It then finds its way through the internal oblique, and appears on the surface between the external oblique and latissimus dorsi muscles, and at the outer border of the erector spinse. Tlie author's operation for caries of the lumbar vertebra?. — The lumbar vertebrae, and, possibly, the last dorsal, may be reached by an in- cision through the loin. A vertical cut is made along the outer edge of the erector spines muscle. The fibres of that muscle having been drawn aside, the middle layer of the fascia lumborum is incised, and the quadratus lumborum is ex- posed. This muscle is divided vertically, and then the front of the vertebras may be reached by in- troducing the finger under the psoas muscle. Through this incision the author has removed the whole of the body of the first lumbar vertebra that had been separated as a sequestrum. (Med.-Chir. Trans., 1884.) The lumbar arteries are avoided by keeping close to the transverse processes of the vertebras. Through this incision a psoas abscess may be most conveniently opened. CHAPTER XVII THE ABDOMINAL VISCERA The peritoneum. — Certain of the viscera, as, for example, the stomach, spleen, and small in- testines, are so closely invested with peritoneum that theycould not be wounded without that mem- brane being wounded also. Inflammatory affec- tions of such viscera are also very apt to involve the peritoneum. Other organs, such as the kid- ney, descending colon, pancreas, etc., are so im- perfectly covered with the serous membrane that a wound of those organs need not involve it, nor need it be implicated in even extensive inflamma- tory changes. Large abscesses may, for instance, form about the kidney and discharge themselves through the skin without any peritonitis being induced. Spontaneous perforation of the small intestine must involve the peritoneum, while, on the other hand, the duodenum and ascending colon may become perforated, and the matter escape into the subserous tissue without the serous membrane being in any way involved. It is note- worthy in connection with bacterial infection that it is singularly easy to set up inflammation of the peritoneum if the membrane be approached from its inner surface, but comparatively difficult if it be approached from without. Thus a small puncture of the membrane may, on the one hand, lead to fatal peritonitis, while, on the other, it may be extensively torn from its attachments (as in ligaturing the common iliac artery from 358 Chap. XVII] ABDOMINAL VISCERA 359 the side) without any peritonitis following. Or, again, a little pus escaping on the inner surface of the membrane may lead to inflammation, while the outer surface may be bathed with pus for a long while (as in large perirenal abscesses) with- out any peritonitis being produced. Fluid is rapidly absorbed from the peritoneal cavity ; carmine particles are found within the thoracic duct seven minutes from their injection within the cavity; absorption takes place most rapidly in the subdiaphragmatic area (Dunbar and Remy). Inflammation of the peritoneum may lead to the formation of a great variety of bands and ad- hesions, beneath which pieces of intestine may be caught and_ strangulated. The peritoneum will allow of very consider- able stretching if only that stretching be effected gradually.^ This is frequently seen in cases of gradual distension of the bowel, in the formation of the sac in hernia, and in the growth of retro- peritoneal tumours. Abrupt stretching of the membrane leads to certain rupture of it. The parietal peritoneum may be ruptured by violence without damage to any of the viscera. The great omentum is, from its position, very apt to be wounded. In small wounds of the front of the belly it very often protrudes and acts as an excellent plug to prevent the escape of other and more important structures. It is often found in hernia, especially in umbilical hernia, where it is almost constant. Its limits vary, and it has an inclination to the left side. This depends upon the fact that the omentum is developed from the rnesogaster, and accounts for the fact that hernise containing omentum are much more common on the left side. The omen- tum, like the other parts of the peritoneum, is apt to inflame, and to contract adhesions to the neighbouring parts. These adhesions are often of the greatest service in limiting inflammatory and hsemorrhagic extravasations, by matting the bowels together and forming spaces between them. 360 SUKGICAL APPLIED ANATOMY [Part IV In perforation of the bowels from disease, an opportune adhesion of the omentum over the aper- ture may prevent escape of the intestinal con- tents. Large masses of tissue may be nourished through an adherent omentum. Thus when the proper blood supply of an ovarian tumour has been cut off by twisting of its pedicle, the growth may be nourished through the omentum, if that structure is adherent to it. Rutherford Morri- son proposes to relieve congestion of the portal circulation by setting up an anastomosis between the omental vessels and the systemic circulation. When an adhesion between the omentum and parietal peritoneum is produced artificially, large anastomotic vessels open up and communicate with the vascular network beneath the parietal peritoneum, thus possibly relieving tension in cases of obstructed portal circulation. In cases of obesity fat collects conspicuously in the great omentum. In hernise the omentum generally con- tracts adhesions to the sac, and becomes irreduc- ible, or it may form a kind of second sac about the gut itself (" omental sac ,; ). The end of the omen- tum, by becoming adherent to distant parts, as to the pelvic viscera, may form itself into a firmly attached band, beneath which the bowel may be fatally strangled. In like manner the intestine has been strangulated through slits and holes that have developed in the omentum, usually as a re- sult of inflammatory adhesions. The functional meaning of the great omentum is by no means definitely established, but it undoubtedly increases the absorptive area of the peritoneum, and evi- dence is not lacking to show that it takes an active part in repelling bacterial invasions of the peri- toneal cavity. The mesentery. — The parietal attachment of the mesentery is liable to some variation. The point at which this attachment commences above is practically constant. It corresponds with the ending of. the duodenum, is about on a level with Chap. XVII] ABDOMINAL VISCEEA 361 the lower border of the pancreas, and is just to the left of the second lumbar vertebra. (See p. 366.) From this point the insertion of the mesentery follows an oblique line that runs downwards and to the right, crossing the great vessels, and then ending in a somewhat uncertain manner on the right iliac fossa (Fig. 58, p. 363). The parietal attachment of the mesentery measures, as a rule, about 6 inches. From its oblique attachment it follows that, when haemorrhage takes place in the abdomen on the right side of the mesentery, the blood first is conducted into the right iliac fossa ; when on the left side, into the pelvis. This may explain the circumstance that collections of blood are more common in the right than in the left iliac fossa. The length of the mesentery from the spine to the bowel varies in different parts of the canal ; its average length is 8 inches. The longest part is that which goes to the coils of intestine that lie between a point 6 feet from the duodenum, and a point 11 feet from the same part of the gut (Author).* Such coils will, therefore, include 5 feet of the intestine, and the mesentery here may reach the length of 10 inches. These coils are apt to hang in the pelvis, and may be easily herniated. The length of the mesentery plays an important part in hernia. If the fresh body of an adult be opened, and the condition of the vis- cera and peritoneum be normal, it will be found that it is impossible to drag a loop of small in- testine through the femoral canal (artificially en- larged) on to the thigh, or down the inguinal canal into the scrotum. In fact, no coil can, in any part, be drawn out of the abdomen below a horizontal line on a level with the spine of the pubes. It is evident, therefore, that in femoral or scrotal hernia the mesentery must be elongated or its attachments lowered. The mesentery is relatively longest in infancy See " The Anatomy of the Intestinal Canal ami Peritoneum in Man " by the Author. London, 1SS5 362 SUEGICAL APPLIED ANATOMY [Part IV and childhood, and a freer escape of the intestines from the abdomen is allowed in subjects under puberty. The disposition of the membrane per- mits also a freer downward excursion of the bowels on the right side, and this has been offered as an explanation of the undue frequency of right- sided inguinal hernise in childhood (Lockwood). Mr. Lockwood states that in acquired hernia the mesentery is found to have had its attachments lowered rather than to have been increased in length. Certain holes are sometimes found in the mesentery, through which intestine has been strangulated. Some of these holes, especially those that are slit-like, are due to injury, others are due to congenital defect of the mesentery. I have shown that the latter holes are round, are in the mesentery of the lower ileum, and occupy an oval area, circumscribed by an anastomotic arch between the ileo-colic branch of the superior mesenteric artery and the last of the intestinal arteries. This area is often the seat of atrophied peritoneum, and shows an absence of fat, of visible blood-vessels, and of glands. It would be easy for a knuckle of gut to be forced through the thinned membrane, which is sometimes already cribriform. Peritoneal spaces and communications. — Owing to the arrangement of the peritoneum the cavity of the abdomen is divided into a number of potential spaces which are connected together by certain definite communications or routes. Alimentary contents, pus, or blood escaping within the peritoneal cavity tend to collect in certain of these spaces and overflow into neigh- bouring spaces in well-defined directions. Some writers see in this arrangement of the peritoneum a resemblance to the watersheds of a country, and hence the potential spaces and routes are some- times spoken of as the " watersheds of the peri- toneum." The chief of these spaces are : (1) the lesser sac ; it communicates with (2) the subhepatic Chap. XVItj ABDOMINAL VISCERA 3G3 space by the foramen of Winslow ; this space is bounded above by the under surface of the liver and below by the duodenum, hepatic flexure of colon, transverse mesocolon, right kidney, and right costo-phrenic ligament (Fig. 58) ; (3) the Subphrenic Space Call Bladder Subhepatic 5pace Pericardium -A 0E"5DT7r'0RIFICE. .Stomach Spleen / Paracolic C,r Ileo-Colic Jiw ft/HT Sup I li .Spleaiic Flexure "Duode/io Je J. Flexure G Paracolic Groove Iliac Colon / r> Fig. 58. -Diagram showing the average position of the abdominal viscera with their surface markings. (After Addison.) A, Stsrno-ensiform point; a 'a', sterno-ensiform line; b, mid-epigastric point; b'b', mid-epigastric or transpyloric line; c, umbilical point; c'c', umbilical line; d, mid-bypoffastric point; d'd', mid-hypogastric line; e,e, outer border of the right and left rectus abdominis ; F.Monro's point— on the fight spino- umbilical line at the outer border of tlie rectus abdominis. right subphrenic space between the diaphragm and liver ; it is bounded towards the middle line by the falciform and coronary ligaments; below it opens into the subhepatic space ; (4) left sub- phrenic space, between the diaphragm above and left lobe of liver and stomach below; it is 364 SURGICAL APPLIED ANATOMY [Part IV separated from the corresponding right space by the falciform ligament ; below it communicates with (5) the perisplenic space; this space is bounded below by the splenic flexure and its mesocolon, the left costo-phrenic ligament and left kidney. These five spaces lie in the supra-omental region of the abdomen — above the transverse mesocolon ; below the transverse mesocolon there are two spaces, normally occupied by small intestine; (6) the right infra-omental, bounded above by the transverse mesocolon, below and to the left by the duodenojejunal junction and root of the mesen- tery ; (7) the left infra- omental, bounded above by the transverse mesocolon; it is separated from the right space by the duodenojejunal junction and mesentery of the small bowel. The remaining space — the eighth — lies in the pelvis, the recto- uterine in the female, the recto-vesical in the male. Communications between the supra- and infra- omental spaces exist only at the two extremities of the transverse mesocolon. Overflow from the subhepatic spaces tends to pass down the groove external to the ascending colon (right external paracolic groove) ; by that groove it reaches the iliac fossa ; from the iliac fossa, the pelvic space ; from the pelvis it may mount to the left infra- omental pouch, and from there the fluid matter may make its way to the left external paracolic groove and thence to the perisplenic space. In this description the writings of Barnard, Wallace, Box, Jenkins, and Maynard Smith have been followed. Surface markings of the abdominal vis- cera. —In Fig. 58 is shown the position of the abdominal viscera in an average individual, while in Fig. 59 is represented the position assumed by these viscera in a well-marked case of visceroptosis (Glenard's disease). Study of such cases, especi- ally by the aid of X-rays, shows the need of an accurate and simple method of indicating the normal position of the abdominal contents. The upper limit of the viscera is best indicated bv the Chap. XVII] ABDOMINAL VISCERA 365 sterno-ensiform point and line. The position of the sterno-ensiform point is indicated by a dis- tinct depression under the insertion of the seventh Fig. 59. — Diagram showing the position of the viscera in the condition of visceroptosis. a,a, [Sterno-ensiform line : it crosses above the fifth costal cartilage ; b,b, mid- epigastric line ; c,c, umbilical line ; n,D, mid-hypogastric line ; a, pericardium : b, stomach (greatly elongated and dilated) ; c, liver ; c', Riedel's lobe ; d, duo- denum ; e, CiBcum ; /, transverse colon ; g, rectum ; h, elongated gastro-hepatic omentum. pair of costal cartilages ; the sterno-ensiform line is drawn transversely on the body through this point and should cross the fifth pair of costal cartilages if the thorax is of normal shape. The right dome of the diaphragm, in the standing 366 SURGICAL APPLIED ANATOMY LPart IV posture, reaches this line ; the left dome is £ an inch below it; in the supine position the domes rise upwards ^ an inch. The central tendon is \ an inch below the sterno-ensiform point. In visceroptosis the domes of the dia- phragm and viscera within them sink downwards until they lie 1 inch or more below their normal position (see Fig. 59). The mid-epigastric point is taken on the linea alba half-way between the umbilical and sterno-ensiform points; the mid- epigastric line (transpyloric plane of Addison) crosses the body at this point; it marks the level of the pylorus, pancreas, with the beginning and termination of the duodenum (Fig. 58). In vis- ceroptosis the parts sink until they reach the um- bilical line (Fig. 59). The umbilical line, drawn through the umbilicus, usually crosses somewhat below the highest point on the iliac crests ; the transverse colon and duodenum cross the abdomen above the line, the bifurcation of the aorta is below it. In visceroptosis the transverse colon and duodenum descend well below the umbilical line (Fig. 59). The mid-hypogastric point is taken on the linea alba half way between the umbilicus and symphysis pubis; it lies about 1 inch below the promontory of the sacrum. The mid-hypo- gastric line crosses the iliac colon in the left groin and the fundus of the caecum in the right. The outer border of the rectus abdominis (linea semi- lunaris) also serves as a useful guide ; at the point where it crosses the costal margin on the right side (right costo-rectal point) is situated the gall- bladder ; on the left side the greater curvature of the stomach emerges from the hypogastrium at this point (Fig. 58). A line drawn from the umbilicus to the right anterior superior iliac spine (spino-umbilical line) provides a useful guide to the ileo-C83cal region. Monro's point is situated on this line at the outer border of the rectus abdominis ; the ileo-csecal orifice lies to the right of Monro's point immediately below the spino- umbilical line. Chap. XVII] ABDOMINAL VISCERA 367 The viscera arc maintained in position by the action of several structures, but by far the chief are the muscles of the abdominal wall — the external and internal oblique, transversalis, rec- tus abdominis, diaphragm and levator ani. By their contraction or tonus they maintain the vis- cera firmly pressed together ; in the upright pos- ture the weight of the upper viscera rests on the lower viscera. That the muscles are the chief agents in maintaining the viscera in position can be shown in many ways. In rising from the supine to the upright posture the upper viscera and diaphragm are seen in the living body (by aid of X-rays) to descend about ^ an inch. When the muscles and belly walls are cut away, and the dead body raised to the upright position, all the viscera drop downwards to the extent of 2 inches or more. The peritoneal ligaments, reflections, omenta, and mesenteries merely limit the degree of movement ; the viscera are freely movable to allow the extensive respiratory action of the dia- phragm. Besides the peritoneal, there are other visceral supports formed by vessels and their sheaths of connective tissue, such as the attach- ment of the liver to the diaphragm by the in- ferior vena cava, the kidneys and small intestine to the posterior abdominal wall by their vessels. It is only when the muscles of the belly wall are thrown out of action that any strain or weight falls on the peritoneal and vascular supports. The stomach — Its relationships are :— Above. Liver, small omentum, diaphragm. Behind Li front. (From left to right) dia- phragm, abdominal wall, liver. Stomach. Transverse -mesocolon, lesser sac, pancreas, crura, solar plexus, great vessels, spleen, left kid- ney, and suprarenal. Below. Great omentum, small intestines, transverse colon, gastro-splenic omentum. m The oesophagus perforates the diaphragm slightly to the left of the middle line and ends at 368 SURGICAL APPLIED ANATOMY [Part IV the cardiac orifice of the stomach, 3 to 4 inches deep to the terminal inch of the seventh left costal cartilage. The pyloric orifice, permanently closed by its sphincter except when the contents of the stomach are passing to the duodenum, is situ- ated in the mid-epigastric line, about half-way between the epigastric point and the right costal margin (Fig. 58). Being situated under the quad- rate lobe of the liver and bound to the transverse fissure by the gastro-hepatic omentum, enlarge- ment or displacement of the liver necessarily causes a displacement of the pylorus; in cases of visceroptosis it may drop to the umbilical line (Fig. 59). Normally the lesser curvature is over- lapped by the liver, and the gastro-hepatic omen- tum is hid (Fig. 58), but when the stomach be- comes dilated, elongated, or falls down, the lesser curvature and gastro-hepatic omentum are ex- posed (Fig. 59). A curved line drawn from the position of the cardiac orifice (on the seventh costal cartilage, 1 inch from the sternum) to the position of the pylorus (mid-way between the epi- gastric point and right costal margin) indicates the normal position of the lesser curvature. While the lesser curvature is comparatively fixed, owing to the attachment of the gastro-hepatic omentum, the greater curvature is freely movable ; its posi- tion alters as the stomach is full or empty, con- tracted or relaxed. A curved line drawn from the position of the pylorus to the left costal mar- gin, so as to cross the linea alba 2 inches below the mid-epigastric line, will indicate the normal position of that part of the greater curvature which may be exposed in the epigastric space. Simple dilatation of the stomach leads to a low position of the greater curvature without altering the position of the lesser curvature ; in ptosis of the stomach both curvatures descend, but the greater descends most owing to dilatation being always present (Fig. 59). In ptosis the curva- tures become more vertical in position (Fig. 59). The shape of the stomach depends on the Chap. XVII] ABDOMINAL VISCERA 369 state of each of its three functional divisions. The fundus lies in the left hypochondrium ; it becomes continuous with the body of the stomach at or just abov3 the left subcostal margin (Fig. 58); the body joins the pyloric canal, the third division, about \\ inch from the pyloric orifice. The fundus is saccular in form and serves as a receptacle for the food ; it undergoes no active movements ; the body, on the other hand, is the part where digestive move- ments occur, and changes in shape are constantly taking place, but it is always more or less tubular in form. When empty it may be found in a con- dition of diastole or systole; if systolic it is usually covered by the transverse colon, and does not present when the epigastrium is laid open. The two extremities of the stomach are its most fixed points. The cardiac extremity is loosely fixed to the diaphragm by the oesophagus, lax pericesophageal tissue, and gastro-phrenic reflec- tions of peritoneum; the pyloric end is fixed to the liver and posterior abdominal wall by the gastro-hepatic omentum, by the hepatic branch of the coeliac axis and the tissue surrounding that vessel. The close relations of the stomach to the diaphragm and thoracic viscera serve in part to explain the shortness of breath and possible pal- pitation of the heart, etc., that may follow upon distension of the organ (Fig. 58, p. 363). The near proximity of the heart to the stomach is illus- trated by a case where a thorn (of the Primus spinosa), \ an inch long, had been swallowed and had then found its way through the diaphragm and pericardium into the wall and cavity of the right ventricle. The viscus is susceptible of enormous dilatation when the pylorus is obstructed. The distended organ may reach as low as Poupart's ligament. The stomach rests behind on the lesser sac of the peritoneum, which plays the part of a bursa to it. Gastric ulcers rarely perforate into the lesser sac, but when they do the contents can only Y 370 SUEGICAL APPLIED ANATOMY [Part IV escape by the foramen of Winslow, and may not be seen when the abdomen is opened. The sac is opened by incising the great omentum at the greater curvature of the stomach. The stomach has been frequently wounded. In most cases a fatal result rapidly follows upon these injuries, for the contents of the stomach escape into the peritonea! cavity and set up an acute peritonitis. The most certainly and rapidly fatal cases, therefore, are those in which the stomach was full of food at the time of the acci- dent. The empty stomach, being deeply placed and lying against the posterior abdominal wall in a collapsed state, is but little exposed to injury. A small punctured wound of the stomach need not be followed by escape of contents, since the loosely attached mucous membrane may escape from the wound and effectually plug it. This was illustrated many times in the Boer war, the viscus having been perforated by a Mauser bullet. The stomach has protruded through wounds in the abdominal walls, and has been returned, with no evil results following. In a few cases the belly wall in front of the stomach has been wounded, the viscus has protruded, its anterior wall has been wounded by the same injury that penetrated the parietes, and a fistulous opening leading into the stomach cavity _ has resulted. The best ex- ample of such cases is afforded by the well-known instance of Alexis St. Martin, the subject of so many physiological experiments. In this man the abdominal parietes in front of the stomach were torn away by a gunshot wound, a part of the an- terior wall of the stomach sloughed, and a per- manent fistula resulted. Dr. Murchison reports the case of a woman in whom a gastric fistula was produced by the continued pressure of a cop- per coin worn over the epigastric region. This coin was deliberately worn by the patient in order to excite a lesion that would arouse the sympathy of her friends. The pressure led to an ulcera- tion that finally opened up the stomach. In many Ohap. XVII] ABDOMINAL VISCERA 371 cases the fistula has been due to ulcerative diseases commencing in the stomach itself and spreading outwards. Some remarkable cases have been recorded where foreign substances have been swallowed and have lodged in the stomach. Certain of these cases serve to illustrate the capacity of the stomach, and among the most striking is an in- stance where the viscus at death was found to contain thirty-one entire spoon-handles, each about 5 inches long, four half-handles, nine nails, half an iron shoe-heel, a screw, a button, and four pebbles. The whole mass weighed 2 lb. 8 oz. The patient was a lunatic. The pylorus has an average diameter of 16 mm., about that of a sixpenny-piece. It is normally in a closed state, and should, when open, be capable of taking the fore-finger. In spite of the narrow- ness of the pylorus, large substances that have been swallowed have been passed by the anus without trouble. Among these may be noted a metal pencil-case, 4| inches long, 10 ounces of garden nails, and fragments of crockery-ware swallowed by a lunatic ; a fork, a door-key, and other strange bodies. Needles and similar sharp substances that have been swallowed have travelled out of the stomach or bowels and have found their way to the surface at various points in the body. In a patient under my care at the London Hospital I extracted from beneath the skin, near the groin, a needle swallowed some months pre- viously. In a case reported in the Lancet a needle was extracted from the middle of the thigh six months after it had been swallowed, and like instances are recorded elsewhere. Hypertrophy may occur in the pyloric sphincter leading to a functional stenosis of the orifice. It occurs soon after birth, and its cause has to be sought for in the reflex mechanism which regulates it. Relaxation normally follows when the chyme expelled from the stomach has been neutralised in the duodenum. 372 SURGICAL APPLIED ANATOMY [Part IV The lymphatics of the stomach pass mostly to the glands situated between the layers of the small omentum along the lesser curvature. Some also pass to the glands scattered along the greater curvature of the stomach. In can- cer of the pylorus, the glands along the lesser curvature are the first t6 become affected, and from these the disease spreads along vessels which accompany the coronary artery of the stomach to the coeliac glands near the commencement of the thoracic duct. Lymphatics also pass from the pylorus to the coeliac glands along the curve of the pyloric and hepatic arteries. Owing to a free communication between the lymphatics of the pylorus, pancreas, and liver, the disease fre- quently involves these organs. Oastrotosny and gastrostomy. — Gastrotomy consists in opening the stomach through the an- terior abdominal wall for the purpose of removing a foreign body, for making an examination, or for dealing with a simple or malignant ulcer ; gastrostomy, in opening the stomach in a like situation with the object of establishing a gastric fistula through which the patient may be fed in cases where the gullet is occluded by disease. The uncovered part of the stomach, accessible in these operations, is represented by a triangular area, bounded on the right by the edge of the liver, on the left by the cartilages of the eighth and ninth ribs, and below by a horizontal line passing be- tween the tips of the tenth costal cartilages (Fig. 58). In the empty condition five-sixths of the stomach lies beneath the left hypochondriac region, only part of the pyloric end being exposed in the triangular area. The incision in these operations must be situate in this triangle, and may be made either parallel to, and about two fingers' breadth from, the free border of the costse, or along the left semilunar line. In the former incision the three flat muscles of the abdomen are cut through. In gastrostomy the stomach is not opened at the time of the operation, but is merely secured to the Chap. XVII] ABDOMINAL VISCERA 373 wound, and a few days are then allowed to elapse so that adhesions may (orm. At the end of this time the viscus is opened. The opening must needs be very small. Resection of" the pylorus. — The pylorus is frequently the seat of cancer. As a means of re- lieving the patient, the whole of the diseased pylorus has been removed, and the divided ends of the stomach and duodenum united by sutures. The situation of the cancerous pylorus within the abdomen varies considerably, as the diseased part is very apt to shift its position. It is often found to have sunk down by its weight to a point below the umbilicus, and to have contracted adhesions to adjacent organs. The diseased part has to be isolated and the omental connections of the right end of the stomach freely divided. The vessels that are almost certainly divided are the pyloric, the gastro-epiploica dextra, and the gastro-duo- denal. The operation has not been attended with much success. The cancer is apt to become diffuse, to spread to adjacent tissues, and to lead to early lymphatic invasion of the greater and lesser omenta. Oastrectomy. — Considerable portions of the stomach have been excised in cases of cancer, and the entire organ has been removed (total gastrec- tomy) for the same cause. Up to the time of writing some fifteen examples of this operation have been recorded with more or less imme- diate death in five. Schlatter's first case of gas- trectomy, performed in 1897, died in fourteen months from secondary deposits. Ricord pub- lished a case in which he removed the whole stomach, the first piece of the duodenum, and part of the pancreas. The patient was alive and well eleven months after the operation (Gaz. des Hopitaux, March 22nd, 1900). It has yet to be shown that the operation is of genuine value. There is difficulty in uniting the gullet to the small intestine ; both vagi nerves are divided as they emerge through the diaphragm, and the 374 SURGICAL APPLIED ANATOMY [Part IV solar plexus is apt to be roughly handled ; the operation is an extreme test for a weakened patient, and the after condition of those who survive is not free from distress. There is, how- ever, less disturbance of digestion than would be imagined. Other operations on the stomach. — Many other operations are performed upon the stomach which call merely for mention in this place. One of the most useful and the most fre- quently performed is gastroenterostomy. Here an opening (or stoma) is made between the stomach and the upper part of the jejunum. An opening has also to be made in the transverse mesocolon in order that the bowel may be applied to the posterior aspect of the stomach. In making the opening the middle colic artery and its larger branches are to be avoided. The operation is per- formed in cases of stenosis of the pylorus, in cases of dilatation of the stomach without much stenosis, in certain examples of ulcer, and in many other conditions. In the operation of pyloroplasty, a non-malignant stricture of the pylorus is divided and the pyloric passage thus made free. In gastroplication certain conditions of dilated stomach are dealt with by taking in a fold or pleat in the stomach wall and in thus lessening its capacity. The small intestines.* — The average length of the small intestine in the adult is 22^ feet, the extremes being 30 feet and 15 feet, the length, to a considerable extent, depending on the degree of contraction of the longitudinal muscular coat. In the foetus, at full term, the lesser bowel mea- sures about 9j feet. It is roughly reckoned that the first 8 or 9 feet of the adult bowel belongs to the jejunum, and the remaining 12 or 13 feet to the ileum. The division into jejunum and ileum is quite arbitrary. There is no one point where it can * The account of the intestines is derived from the Author's work "On the Intestinal Canal and Peritoneum in Man." London. 1885. Chap. XVIIJ ABDOMINAL VISCERA 375 be said that the jejunum ends and the ileum commences. When the small intestines are ex- posed by accident or operation, it is often diffi- cult, especially when there is abdominal disease, to recognise the upper from the lower part of the gut. It may be noted, however, that the jejunum is wider than the ileum (its diameter being £ of an inch greater than that of the ileum), and its coats are thicker and more vascular. If the gut be empty, and can be rendered translucent by being held against a light, the lines of the valvulse conniventes can be well seen. These folds are large and numerous in the jejunum, but become small and scanty in the upper ileum, and are wanting in the lower third of that bowel. In- juries of the jejunum are more serious than are those of the ileum, since an intestinal lesion is (other things being equal) the more serious the nearer it approaches to the stomach. The fatality of umbilical hernise probably depends in part upon the fact that the contained bowel is often jejunum. The coils of small intestine occupy no certain position in the abdomen. In the foetus, and during the earliest part of extra-uterine life, the bulk of the small intestine is placed to the left of the middle line. This is on account of the re- latively large size of the liver, to the weight of which the lesser bowel no doubt acts as a counter- poise. In the majority of adult bodies the small intestine is disposed in an irregularly curved manner from left to right. The gut, starting from the duodenum, will first occupy the contigu- ous parts of the left side of the epigastric and umbilical regions ; the coils then fill some part of the left hypochondriac and lumbar regions; they now commonly descend into the pelvis, re-appear in the left iliac quarter, and then occupy in order the hypogastric, lower umbilical, right lumbar, and right iliac regions. Before reaching the lat- ter situation they commonly descend again into the pelvis. Much interest attaches to the coils of small 376 SURGICAL APPLIED ANATOMY [Part IV intestine that are found in the pelvis. These are the coils that are apt to become involved and ad- herent in cases of pelvic peritonitis, and that would probably form the protrusion in most cases of obturator, sciatic, and pudendal hernia. No small intestine occupies the foetal pelvis. The amount found in the adult pelvis depends mainly upon the state of distension of the bladder and rectum, and upon the position of the sigmoid flexure. The coils that are most usually found in this position belong to the terminal part of the ileum, and to that part of the intestine that has been already alluded to as possessing the longest mesentery ^ (page 360). The ileum is the part of the intestine that is most frequently found in inguinal and femoral hernise. It is also the part most usually involved in cases of strangulation by internal bands, by holes in the mesentery, etc. Of all the viscera the small intestines are the most exposed to injury, and at the same time it must be noted that by their elasticity, and by the ease with which their coils slide over one another and so elude the effects of pressure, they are the best adapted to meet such injuries as contusions and the like. A minute punctured wound of the small gut does not lead to extravasation of con- tents. The muscular coat contracts and closes the little opening. Thus, in excessive tympanitis the bowels are often freely punctured in many places with a fine capillary trochar, to allow the gas to escape, without any evil resulting. A case of in- testinal obstruction of sixteen weeks' duration is reported, in which the abdomen was punctured 150 times {Boston Med. Journ.). If the wound be a little larger the loose mucous membrane be- comes everted or protruded through the wound and effectually plugs it. Gross found that a longitudinal cut in the small bowel 2^ lines in length was immediately reduced to a wound If lines in length by muscular contraction, and that the eversion of the mucous membrane in addi- tion to this contraction entirely sealed the open- Chap. XVII] ABDOMINAL VISCERA 377 ing. Even the opening made in the intestine — for example, in the jejunum — by the penetration of a Mauser bullet may be attended by no escape of contents. A contracted empty piece of bowel becomes nearly twice as long when distended. Owing to the greater power of the circular layer of muscle a longitudinal wound gapes more than a transverse wound, and, in consequence of the greater muscular development of the jejunum, wounds of that part gape more than do those of the ileum. Transverse wounds gape most when inflicted across the free border of the gut, since in that place the longitudinal muscular fibres are thickest. In one remarkable case a man was stabbed in the belly. It was subsequently found that there was a small puncture in the ileum, which had been plugged by the mucous membrane and further secured by recent lymph. The man did well until the fourth day, when he died somewhat suddenly. It was then found that an intestinal worm (Ascaris lumbricoides) had worked its way through the wound, breaking down the adhesions, and had escaped into the peritoneal cavity. Ex- travasation followed, and thus the worm was the immediate cause of the man's death. The calibre of any portion of the small in- testine depends mainly upon the condition of its muscular wall. The tube may become much con- tracted when empty. In peritonitis and in cer- tain other conditions the muscular coat is para- lysed and the bowel becomes intensely dilated by gas (tympanites). Meckel's diverticulum. — From one to four feet from the end of the ileum is sometimes seen a diverticulum (Meckel's) that represents the remains of the vitello-intestinal duct (p. 329). It may be expected in 2 per cent, of the bodies examined. This diverticulum usually exists as a tube of the same structure as the intestine. Its length varies. It may sometimes extend as a patent tube as far as the umbilicus. It is more 378 SURGICAL APPLIED ANATOMY [Part IV often but a few inches long, and may then end in a free conical or globular extremity, or in a fibrous cord. This diverticulum may cause in- testinal obstruction in many ways. Its end may contract adhesions, and beneath the bridge thus formed a loop of bowel may be strangled. It may twist itself about a piece of intestine so as to form a knot round it. It may, from its adhesions, so drag upon the ileum as to cause " kinking ;; of the tube at its point of origin. In more than one case it has been found in an external hernia. It may become invaginated and start an intussus- ception of the bowel. The lumen of the gut is often considerably diminished at or near the site of the diverticulum, and at this narrowing in- tussusception of the bowel may commence. The duodenum and fossa duodeno- jejunal! s.— The first portion of the duodenum is nearly horizontal. It measures about 2 inches in length and passes backwards from the pylorus to near the upper end of the right kidney. The second portion, about 3 inches in length, descends vertically in front of the inner border of the right kidney to the level of the third lumbar vertebra. The third portion, some 5 inches in length, crosses from right to left in front of the third vertebra, and then ascends for a short dis- tance on the surface of the left psoas muscle, to end in the jejunum to the left of the second lumbar vertebra (Fig. 58, p. 363). The first por- tion, which is movable, is invested by peritoneum in the same manner as the stomach. The second part is covered by peritoneum in front only, ex- cept at the spot where it is crossed by the trans- verse colon. The third part is also covered by peritoneum on its anterior aspect only, this mem- brane being, however, free of the gut where the superior mesenteric vessels cross it. A constric- tion, probably functional in nature, is usually found at the termination of the third stage. The end of the duodenum, the duodeno- jejunal bend, is very firmly held in place by a Chap. XVII] ABDOMINAL VISCEEA 379 band of fibrous tissue that descends upon it from the left crus of the diaphragm and the tissue about the coeliac axis. This band is called the suspensory muscle of the duodenum (Treitz). It serves also to support the mesentery. In ptosis of the viscera the neck of the pancreas and duodeno- jejunal bend are the least displaced parts be- cause of their attachment to the posterior wall by the fibrous tissue round the cceliac axis and origin of the superior mesenteric artery. All sections of the duodenum have been ruptured by violence. Owing to its large non-peritoneal surface, the bowel, if approached from behind, may be wounded without opening the peritoneum. Brunner's glands occur in the first stage of the duodenum; their secretion probably protects this part of the gut against the acid chyme which is only neutralised as it reaches the second stage. It is probably because of the nature of its con- tents that the first stage of the duodenum is so frequently the site of ulceration ; over 90 per cent, of duodenal ulcers occur in the first stage (Collin). The ulcer may perforate and the contents escape into the subhepatic space, or adhesions may form to surrounding organs — the gall bladder, the liver, the head of the pancreas, the right kidney, or the hepatic flexure of the colon. A diverticulum is frequently found just above the entrance of the common bile duct (Rolleston), especially in cases of ptosis. Congenital constrictions of the duo- denum occur. Passing from the front of the terminal (as- cending) part of the duodenum^ a fold of peri- toneum is often seen, that joins the parietal peritoneum to the left of the piece of gut in ques- tion. This fold marks off a fossa of triangular outline, the orifice of which is directed upwards. I have found the fossa in about 50 per cent, of the bodies examined. It is called the fossa diiodeiio-jejmialis ; it is usually large enough to lodge the tip of the finger, and its opening lies just below the duodeno-jejunal bend (Fig. 60). 380 SURGICAL APPLIED ANATOMY [Part IV This fossa is the anatomical cause of mesen- teric^ mesocolic, meso gastric, or retroperitoneal hernia. The commencement of the jejunum presses into the fossa, enlarges its cavity, and ultimately separates the peritoneum from its posterior at- tachments. More and more of the small intestine passes into the increasing pouch, until at last, as in the case reported by Sir Astley Cooper and in many others, nearly the whole of the small intes- ferioh^meseWteriicmein W &s- li lib ~ DUODENAL FOLD Fig. 60.— The fossa duodenojejunalis. (Treves.) tine may be found lodged in an enormous median retroperitoneal sac, the mouth of which is the orifice of the fossa duodeno-jejunalis. The duo- denum can be seen to enter the sac and the end of the ileum to leave it. The sac usually extends downwards on the left side, and may reach the promontory of the sacrum. These hernise vary in size, but are as a rule large. The caecum and ascending colon have their normal position, but the transverse and descending parts of the colon are stretched over and displaced by the sac. The Chap. XVII] ABDOMINAL VISCERA 381 renal artery is behind the hernia, and the in- ferior mesenteric artery is in front of it and to the left. A branch of this vessel, the colica sinis- tra, is near to the orifice of the sac in its lower part. Numerous modifications occur in the form and boundaries of this peritoneal fossa, and a hernia may enlarge in any direction, but usually towards the left, where it passes behind a peri- toneal fold containing the inferior mesenteric vein. Operations on the small intestine. — Enter- otomy is the operation of opening the small in- testine above some obstruction that threatens to be fatal or insuperable. An incision is made in the linea alba, below the umbilicus, or in one or other iliac region, as is considered more convenient. This if some 2 or 3 inches in length will prob- ably suffice. The peritoneum having been opened, a knuckle of small bowel close above the ob- struction is seized, secured to the parietal wound, and then opened. The small intestine has also been opened to remove impacted foreign bodies and large gall stones. In such cases the intes- tinal wound is usually closed immediately. E uterectomy. — Parts of the small intestine have been resected with success for various diseased conditions. In one case more than two yards of the small intestine was cut away on account of multiple stricture. The patient, a young woman, made an excellent recovery. Resections have also been successfully performed in cases of bullet wound or stab involving the lesser bowel, and in other injuries. Tumours of the gut have been removed by a partial resection. Non-malignant strictures of the bowel have been treated by in- cision and dilatation. The bowel above an obstruction has been con- nected to the bowel below an obstruction by the operation called intestinal anastomosis or short circuiting, « In uniting divided intestine by suture (enter- oraphy) it is essential that the serous coat of the 382 SUEGICAL APPLIED ANATOMY [Part IV ends of the bowel should be brought together. This is best effected by the suture known as Lem- bert ; s, with the addition of a special and separate line of sutures for the mucous membrane. Ex- perience shows that if leakage occurs after re- section or suture of intestine it will most likely occur along the attachment of the mesentery. This circumstance is thus explained by Mr. An- derson : The two layers of the mesentery diverge as they approach the bowel, and so leave a tri- angular space, the base of which, averaging about 1% ths of an inch in width, is formed by the un- covered muscular tissue. It is the existence of this bare piece of intestine that renders adjust- ment of the serous coat at the attachment of the mesentery a matter of some difficulty. The ileo-cseeal region. — The caecum is, to a certain extent, rudimentary in man, as it is also in the carnivora. In herbivorous animals it is of great size, and appears to serve as a reservoir for the elaboration and absorption of food. It has been said that the caecum in man exists as an anatomical protest against vegetarianism. The appendix persists as the remains of the larger caecum of lower mammals. In the human foetus it can be seen to be but the narrowed ex- tremity of a capacious caecum. The foetal type of caecum, which is very characteristic, may per- sist throughout life. From the point of view of evolution the appendix would appear to be becom- ing obliterated. Like other functionless parts that persist as developmental relics, it is very fre- quently the seat of disease, and it is worthy of note that such disease tends to cause the entire obliteration of the part (as after many forms of so-called appendicitis). It must be understood that the term ccecum is applied to that part of the colon that lies below the entrance of the ileum. The average breadth of the adult caecum is 3 inches, its average length (vertical measurement) 2| inches. The caecum normally contains gas, and gives a high, tym- Chap. XVII 1 ABDOMINAL VISCERA 383 panitic note on percussion ; Glenard found that in cases of ptosis of the viscera it was often con- tracted, and when palpated had the consistency of a sausage. The caecum is usually lodged in the right iliac fossa, and is so placed that its apex corresponds with a point a little to the inner side of the middle of Poupart ; s ligament. When distended with gas or faecal contents it occupies the whole of the right iliac fossa. The ileo-caecal orifice is situated immediately below the spino-umbilical MESO COLON ILEOCOLIC FOSSA BLOODLESS FOLD REXROCAECAL ILEOCECAL FOSSA Fig. 61. — The peritoneal fossae of the ileo-cEecal region. line and externally to Monro's point {see Fig. 58, p 363). A slightly distended caecum so located may be emptied by flexing the thigh upon the abdomen. The caecum is always entirely invested by peri- toneum. Its posterior surface is never in con- nection with the areolar tissue of the iliac fossa. The peritoneum is reflected from the commence- ment of the ascending colon on to the posterior parietes below the level of the iliac crest. A mobile caecum may hang over the pelvic brim, or occupy the pelvis, or even find its way into an inguinal hernia of the left side. The caecum is not unfrequently found in an inguinal or femoral 384 SUKGICAL APPLIED ANATOMY [Part IV hernia of right side (csecal hernia). Such herniae are, except in a few rare instances, provided with a proper and complete peritoneal sac. Foreign bodies that have been swallowed are very apt to lodge in the caecum, and in that situation may cause ulceration and even perforation of the bowel, producing one form of typhlitis. In cases of faecal retention, also, 'the largest accumulation of faecal matter is very usually met with in the caecum, and upon that part of the bowel when distension is extreme the greatest strain usually comes. Stercoral ulcers (ulcers due to the pres- sure and irritation of retained faeces) are more often met with in the caecum than in any other part of the colon. Solitary follicles are numerous in the mucous membrane of the caecum, especially near the ileo-caecal orifice. Intestinal concretions also are not uncommon in this part. The caecum is susceptible of enormous disten- sion, provided that this be gradually effected, and, in certain instances, a dilated caecum has been found to occupy a large part of the abdominal cavity. When the abdomen is opened in any doubtful case of intestinal obstruction, the con- dition of the caecum is of great value in pointing to the seat of the obstacle. In stenosis of the colon it will be found greatly distended, while in obstruction of the small gut it will be empty, or, at least, in a normal condition. Three kinds of movement occur in the caecum : (1) a churning movement, which has been ob- served to commence within an hour of taking food ; (2) antiperistaltic movements which begin in the colon and end in the caecum; (3) pro- pulsive or emptying movements. Water is ab- sorbed, and the faeces commence to assume a solid consistency as they reach the transverse colon. The ileo-caecal orifice is guarded by a muscular sphincter (ileo-ccecal sphincter) ; it is innervated by the sympathetic system and regulates the escape of chyme from the ileum (Elliot and B. Smith) ; MacEwen has seen it in action in the case Chap. XVII] ABDOMINAL VISCERA 385 of a soldier in whom a wide caecal fistula resulted from a gunshot injury. MacEwen also observed a secretion escaping from the mouth of the appen- dix, which is situated about 1 inch below the ileo-csecal orifice. The appendix varies in length. Its average measurement in the adult is 4 inches, the extremes being 1 inch and 6 inches. Its position varies, although, as a rule, it is seen to lie behind the end of the ileum and its mesentery, and to point in the direction of the spleen. It frequently also lies behind the caecum. I have seen the appendix so placed with reference to the bowel that it would have been encountered in a right lumbar colotomy. In such cases the appendix has been pushed be- hind the caecum and caught in the mesocolon during the later months of foetal life, when the colon migrates from the neighbourhood of the liver to the right iliac fossa.^ The appendix may hang within the pelvis and, in inflammatory con- ditions, contract adhesions to the ovary or other pelvic structures. I have found an inflamed ap- pendix adherent to the liver and another in the left iliac fossa. It has found its way down both the right and the left inguinal canals. The tip of the process may adhere to a neigh- bouring peritoneal surface, and thus forin a " band," beneath which a piece of small intestine may be strangulated. Foreign bodies occasionally lodge in the ap- pendix, and it is very often found to be occupied by a faecal concretion or calculus. These sub- stances excite inflammation, and, as a result, the appendix may become perforated. Troubles in the vermiform process are the most frequent causes of perityphlitis, a term applied to^ localised inflammation of the peritoneum in the vicinity of the caecum. The mesentery of the appendix (Fig. 61), whiph contains an artery derived from the ileo-colic, may be so short as to produce obstructive kinks in the appendix. The mucous lining is so crowded z 386 SURGICAL APPLIED ANATOMY [Part IV with solitary lymphoid follicles as almost to oc- clude its lumen. Like other lymphoid structures these follicles begin to atrophy soon after adult life is reached. In some forms of appendicitis these follicles are involved. They are surrounded by lymph spaces, from which vessels pass to the lymph glands in the mesentery, especially to a group situated in the ileo-colic angle — the ileo- colic group ; others pass upwards behind the as- cending colon (Lockwood). It is probably through these latter vessels that infection passes from the appendix and gives rise to abscesses in the sub- diaphragmatic region. The muscular coat of the appendix is scanty, and through breaks in it the submucous tissue communicates with the sub- serous. It is in the ileo-csecal region that intussuscep- tion most frequently occurs. In this condition one part of the intestine is prolapsed or " tele- scoped " into the lumen of an immediately adjoin- ing part. In the ileo-csecal variety (the common- est form) the narrow ileum, and subsequently the caecum, are prolapsed into the colon. The ileo- csecal valve forms the summit of the protrusion or intussusceptum. By a gradual increase of the condition the intussuscepted bowel may at last reach the rectum, and the ileo-csecal valve has, in fact, been recognised protruding from the anus. In the ileo-colic variety (the rare form) the end of the ileum is prolapsed through the valve. The valve and the csecum remain in their normal situations, and the summit of the intus- susceptum is formed only by the ileum. In another variety, which is also common, the apex of the intussusceptum is formed by the fundus of the invaginated csecum. There are three fairly constant peritoneal fossae, which are sometimes the seat of hernia, in the ileo-csecal region (Fig. 61). They are (1) the ileo-colic, situated between the ascending colon and termination of the ileum; a fold containing the anterior caecal artery bounds it above; (2) the Chap. XVII] ABDOMINAL VISCERA 387 ileo-csecal fossa, between the termination of the ileum and the caecum; it is bounded in front by the bloodless fold and behind by the mesentery of the appendix; (3) the retrocecal fossa, behind the caecum ; it is bounded on the right by the lower termination of the ascending mesocolon. The large intestine. — From the caecum tc the sigmoid flexure, this portion of the bowel is accessible to pressure except at the hepatic and splenic flexures, which are deeply placed. The hepatic flexure is under the shadow of the liver, and the splenic curve, which reaches a higher level, is behind the stomach (Fig. 58, p. 363). The position of the transverse colon can often be well marked out. It crosses the belly transversely , so that its lower border is nearly on a level with the umbilicus (Fig. 58). In cases of faecal accu- mulation, the outline of the colon, with the exception of the two flexures above named, may be distinctly defined. In distensions of the small intestine the belly tends to present the greatest degree of swelling in front, and about and below the navel. In distension of the larger gut, the front of the abdomen may remain (for a while at least) comparatively flat, while the distension will be most obvious in the two flanks and in the region just above the umbilicus. Tumours of the transverse colon, and of the lower two-thirds of the ascending and descending colon, can be well defined, even when of moderate size, and in cases of intussusception the progress of the mass along the colon can often be traced with great ease, and the effects of enemata and other methods of re- duction carefully watched. The diameter of the large intestine (excluding the rectum) gradually diminishes from the caecum to the sigmoid flexure, the diameter of the former being about 2^ inches, of the latter 1 1^ inch. The narrowest part of this segment of the bowel is at the point of junction of the sigmoid flexure with the rectum, and it is significant that it is at this point that stricture is the most common. 388 SURGICAL APPLIED ANATOMY [Part IV The tendency to stricture increases as one pro- ceeds downwards from the caecum to the anus. A stricture is frequent in the descending colon, less frequent in the transverse colon, while in the ascending colon it is comparatively rare. Stric- tures are not uncommon about the flexures of the bowels.* The ascending and the descending colon are placed vertically. The average length of the as- cending colon in the adult (as measured from the tip of the csecum to the hepatic flexure) is 8 inches. The average length of the descending colon (from the splenic bend to the commencement of the sig- moid flexure) is 8^ inches. The descending colon is very little liable to variation, and is always found in a semi-contracted condition. That part of the descending colon which lies in the left iliac fossa, from the iliac crest to the left psoas muscle, is now distinguished as the iliac colon. In cases of non-descent of the csecum the ascend- ing colon may be absent (p. 385). I have pointed out that in 52 per cent, of adult bodies there is neither an ascending nor a descending mesocolon, and that a mesocolon may be expected on the left side in 36 per cent, of all cases, and on the right side in 26 per cent. These points are of importance in connection with the some- what uncommon operation of lumbar colotomy. The breadth of the mesocolon, when it exists, varies from 1 to 3 inches. The line of attach- ment of the left mesocolon is usually along the outer border of the kidney, and is vertical. That of the right mesocolon is, as a rule, less vertical, runs along the outer border of the kidney, and crosses its lower end obliquely from right to left. The transverse colon has an average measure- ment of 20 inches. It is not quite horizontal, since the splenic flexure is on a higher level than the hepatic flexure, as well as posterior to it, and always shows a number of bends, one occurring near its commencement and another near its end. * See "Intestinal Obstruction." By the Author. London. 1899. Chap. XVII] ABDOMINAL VISCERA 38«J Faecal masses lodged in the transverse colon have given rise to many errors in diagnosis. In some instances this part of the colon is displaced to- wards the pelvis, so that V- or U-shaped bends are produced. In such cases the point of the V or U may reach the symphysis pubis, while the two colic flexures occupy their proper situations. These deviations are described in detail in my work on Intestinal Obstruction. The right-hand part of the transverse colon is in intimate relation with the gall-bladder, and is commonly found to be bile-stained after death. In some cases where gall stones have been lodged within the gall-bladder, the walls of that struc- ture have ulcerated from pressure, the ulceration has involved the subjacent transverse colon, and thus a fistula has been established between the gall-bladder and the gut, through which large stones have been passed. Hepatic abscesses also have discharged themselves through the trans- verse colon. The transverse colon often finds its way into an umbilical hernia, and has been found to be concerned in many of the cases of hernia into the foramen of Winslow. The sigmoid flexure. — The segments of gut termed the sigmoid flexure and " the first part of the rectum ;; form together a single simple loop that cannot be divided into parts. This loop be- gins where the descending colon ends, and ends at the commencement of the so-called " second part of the rectum ;; ; at a spot, in fact, where the meso- rectum ceases, opposite about the third piece of the sacrum. This loop, when unfolded, describes a figure that, if it must be compared to a letter, resembles the capital Omega. It may well be termed the Omega loop, and the term rectum be limited to the short piece of practically straight gut that is now described as the second and third parts of the rectum. By the majority of anato- mists and surgeons the Omega loop is now named the " pelvic colon," although at birth and fre- quently in the adult it is not pelvic in position. 390 SURGICAL APPLIED ANATOMY [Part IV The average length of the loop in the adult is 1*7^ inches. The two extremities of the loop are about 3 or 4 inches apart. If they are approxi- mated to one another, as by contracting peri- tonitis at the root of the sigmoid mesocolon, a kind of pedicle is established, about which the loop may readily become twisted. Such a twist of the bowel constitutes a volvulus of the sigmoid flexure; and it may be here said that volvulus of the intestine is more commonly met with in this loop than in any other part of the canal. The line of attachment of the mesocolon of the Omega loop (the sigmoid mesocolon) crosses the left psoas muscle and the iliac vessels near their bifurcation ; it then turns abruptly down, and running nearly vertical, terminates at the middle line. In the left wall of this mesocolon, close to the point where it lies over the iliac vessels, a fossa is sometimes to be found. It is produced by the sigmoid artery, and is about l| inch in depth. It is called the intersigmoid fossa, and is the seat of sigmoid hernia (Fig. 62, mc). Two cases of strangulated hernia in this fossa have been recorded. The sigmoid flexure, or Omega loop, when empty, normally occupies the pelvis. When dis- tended this piece of bowel may become so enor- mously dilated as to reach the liver. The chief examples of extraordinary dilatation of the colon concern this loop. Faecal masses are very fre- quently lodged in the free end of the loop, and certain intestinal concretions have been met with in the same situation. I have shown by experiment that the " long tube," when introduced through the anus, cannot be passed beyond the sigmoid flexure in ordinary cases, and with a normal disposition of the bowel. In cases of congenital absence or deficiency of the rectum, the sigmoid flexure is often opened in the groin and an artificial anus established there. This operation, known as Littre's opera- Chap. XVII] ABDOMINAL VISCERA 391 tion, is, it must be confessed, not very successful. One difficulty has been said to depend upon the uncertain position of the sigmoid flexure in cases of congenital deformity, it being sometimes on the right side and sometimes in the pelvis at» the middle line. It is rarely, however, found in these Pig. 62. — Sigmoid flexure turned upwards to show the intersigmoid fossa. (Jonnesco.) s f, Sigmoid flexure ; a s, sigmoid artery ; 31 c, mesosigmoid fossa, \~a e, external iliac artery ; r, ureter in front of internal iliac vessels. positions. _ Out of 100 post-mortem examinations on young infants, Curling found the loop on the left side in eighty-five cases. Out of ten children who were operated on for imperforate anus, the loop was found in the left fossa in only one case (Montgomery). The sigmoid flexure is the part of the colon, opened in the operation of left iliac or inguinal 392 SUEGICAL APPLIED ANATOMY ' [Part IS colotomy. In performing this operation the length of the sigmoid mesocolon and the conse- quent mobility of the coil are of much importance. The sigmoid flexure, when empty and contracted, can be felt through the parietes in moderately thin subjects. Congenital malformation of the colon. — These are of moment with regard to _ operative procedures. It may be very briefly said that in the foetus the small bowel occupies at one time the right side of the abdomen, while the large gut is represented by a straight tube that passes on the left side vertically from the region of the umbilicus to the pelvis. The caecum is at first situated within the umbilicus, and then ascends in the abdomen towards the left hypochondrium. It next passes transversely to the right hypochon- drium, and then descends into the corresponding iliac fossa. It may be permanently arrested at any part of its course. Thus the caecum may be found about the umbilicus, or in a congenital umbilical hernia, or in the left hypochondriac region (the ascending and transverse parts of the colon being absent), or it may. be found in the right hypochondrium, the ascending colon only being unrepresented. The whole of the large intestine has at one time an extensive mesentery, and in some rare cases this condition may persist throughout life. When it does persist, it may lead to one form of volvulus of the bowel. Lumbar colotomy. — The operation so named consists^ in opening the colon in the loin behind the peritoneum, for the purpose of establishing an artificial anus. The operation is performed, when possible, # upon the left side, in preference to the right, inasmuch as the descending colon ii nearer to the anus. The operation has, how- ever, been almost entirely superseded by iliac colotomy except in a few uncommon conditions. The position of the descending colon in the loin may be represented by a line drawn vertically Chap. XVIIJ ABDOMINAL VISCERA 3&«? upwards from a point on the iliac crest 1 inch external to the outer border of the erector spinse. An incision is made across the centre of this line parallel to the last rib, and so planned that the Fig. 63. — Horizontal section through the body at the level of the umbilicus. {After Braune.) a, Spine of the fourth lumbar vertebra ; b, disc between third and fourth verte- brae ; c, umbilicus ; d, quadratus lumborum ; e, psoas ; /, external oblique, with internal oblique and transversalis muscles beyond ; g, rectus ; 'h, descending colon ; i, transverse colon ; j, aorta ; Jc, inferior vena cava ; I, ureter. centre of the incision corresponds to the centre of the line. The superficial tissues having been in- cised, the following structures are divided in layers in the following order (Fig. 63) : (1) The latissimus dorsi and external oblique muscles to an equal extent ; (2) the internal oblique in the 394 SURGICAL APPLIED ANATOMY [Part IV entire length of the incision ; (3) the fascia lum- borum, with a few of the most posterior fibres, of the transversalis muscle; (4) the transversalis fascia. The quadratus lumborum will be^ exposed in the posterior inch or so of the incision, and usually does not need to be cut. At the seat of the operation the descending colon occupies the angle between the psoas and quadratus lumborum mus- cles, and the non-peritoneal surface is exactly re- presented by that part of the bowel that faces this angle (Fig. 63). Thus, if during the opera- tion the curved finger be placed in this angle, and the patient be rolled over to the left side, the bowel that falls into the finger cannot well be other than the descending colon. The gut is drawn forwards, stitched to the wound, and opened by a transverse cut. The width of the non-peritoneal surface varies from fths of an inch to 1 inch in the empty state, and may attain to 2 inches or more in the distended condition (Braune). Iliac or iiagisiiial colotomy. — In this very common, excellent, and simple operation the sig- moid flexure is exposed and opened in the left iliac region. A line is drawn* from the anterior superior iliac spine to the umbilicus, and an in- cision some 2 inches in length is made at right angles to this line and at a distance of about l| inch from the point of the bone. The three muscles of the abdomen and the peritoneum hav- ing been divided, the loop of the sigmoid flexure is Drought into the wound, is secured, and is (at once or at a later period) opened. The caecum may be opened on the right side, and as a rule the most convenient incision is an oblique one placed externally to the deep epigastric artery. Colectomy consists in excising a portion of the colon. The caecum has been removed, and con- siderable segments of the rest of the large in- testine. ^ The m treatment of cancer of the colon by excision is attended with considerable sue- Chap. XVII J ABDOMINAL VISCERA 395 cess. Portions of the ascending and descending parts of the colon have been excised through an incision in the loin, but colectomy is much more readily carried out through an anterior wound. I have reported a case in a young girl, in which I excised the whole rectum and anus, the sig- moid flexure, and the whole of the descending colon. The divided transverse colon was brought out at the anus. The child made a perfect re- covery. The parts removed are in the Museum of the Royal College of Surgeons. The operation of intestinal anastomosis or short circuiting is very frequently practised on the colon. Thus, in an obstruction on the descending colon incapable of removal, the transverse colon may be united to the sigmoid flexure. The liver. — The liver is moulded to the arch of the diaphragm, and lies over a part of the stomach (Fig. 64). Properly speaking, it has only two surfaces — a visceral surface, which in the upright posture rests on the stomach, duodenum, gastro-hepatic omentum, neck of the pancreas, hepatic flexure of colon, right kidney, and right suprarenal bodv; and a parietal surface, in con- tact with the diaphragm and anterior belly wall in the subcostal angle. As seen from the front it is triangular in outline, with its apex near the apex of the heart (Fig. 64); its upper border is best indicated by a line commencing at the apex beat (Fig. 64) and passing across the mid line \ an inch below the sterno-ensiform point : it ascends as it reaches the nipple line to the level of the sterno-ensiform plane. The lower border com- mences at the apex beat, crosses the mid line about 1 inch above the mid-epigastric point, reaches the costal margin at the outer border of the rectus, and the remainder of its lower border corresponds to the costal margin as far as the tip of the eleventh rib. The liver is in contact with the right kidney along the lower margin of that rib (Fig. 68). For surgical purposes the liver in the right hypochondrium may be regarded as 396 SUEGICAL APPLIED ANATOMY [Part IV made up of three zones — an upper or pulmonary, a middle or pleural, and a lower or diaphrag- matic (Fig. 64). In the lower zone, which is 1| to 2 inches wide in the mid-axillary line, the liver may be incised or explored ; in the middle zone, which is of equal width, the pleural reflection is encountered. In the erect posture the lower edge on the right side is about \ or \ of an inch below STEB/lO-EflSIF. LlAE Apex Poi/it Pulmonary Lime Pleural Line /Iepatic Duct Cystic Duct Pancreas Duodenum Alio Epiqastric Line Pylorus Stomach COMMON6lLEDUCT DUODENUM * ^ Linea Alba <*• " > Umbilical Line i lLlNEA5ENILUNARI5 Fig. 64. — Diagram showing the position of the liver, gall-bladder, bile- ducts, and pancreas. The lower limits'of the pleura and lung are indicated. the margins of the costal cartilages. In the re- cumbent position the liver ascends about an inch, and is entirely covered by the costse, except at the subcostal angle. It descends also in inspiration and rises in expiration. The fundus of the gall-bladder approaches the surface behind the ninth costal cartilage, close to the outer border of the right rectus muscle (Fig. 64). Its position is extremely variable ; it fre- quently occupies a position considerably below and external to the one mentioned. Chap. XVII] ABDOMINAL VISCERA 397 The liver is retained in shape by, and moulded upon, the diaphragm above and the abdominal organs below. When removed from the body the shape is lost which it possesses clinically. It pre- sents many variations in form. One of the com- monest is a linguiform process, usually known as UiedeVs lobe, which projects from the margin of the right lobe under the tenth costal cartilage (Fig. 59, p. 365). It is found more frequently in women than in men, and may be mistaken for a floating kidney or an abdominal tumour. In the condition know as ptosis of the liver the organ slides from the dome of the diaphragm, and may descend to the level of the umbilicus or reach the iliac fossa (Fig. 59). With the descent there is also a rotation on its transverse axis, so that its diaphragmatic surface comes almost com- pletely to the front. In such a case the factors which maintain the liver in position have to be considered. They are : (l) its fixation to the diaphragm by the inferior vena cava and the fibrous tissue on the non-peritoneal posterior sur- face of the right lobe in the neighbourhood of the inferior vena cava. (2) The peritoneal folds, which include the right and left lateral, coronary, and falciform ligament, also attach it to the dia- phragm. These folds are lax, in order to allow the free movements of the liver which occur during respiration and in filling and emptying of the stomach. (3) The muscular abdominal walls. These keep the other abdominal viscera constantly pressed against the lower surface of the liver. The muscles constitute the chief means for main- taining the liver in position. In many women over forty the right lobe of the liver projects quite 2 inches below the eleventh rib, and as in the child, the extremity of the left lobe frequently comes in contact with, or even overlaps, the upper part of the spleen. The liver is more often ruptured from con- tusion than is anv other abdominal viscus. This is explained by its large size, its comparatively 398 SURGICAL APPLIED ANATOMY [Part IV fixed position, its great friability of structure, and the large quantity of blood contained in its vessels. A normal liver will take its own weight of blood if its veins be injected at ventricular pressure (Salaman). Death in such injuries usually ensues from haemorrhage, since the walls of the portal and hepatic veins, being incorpo- rated with the liver substance, are unable to re- tract or to collapse. The hepatic veins also open direct into the vena cava, and, being unprovided with valves, could allow of the escape of an im- mense quantity of blood, if any retrograde cur- rent were established. The hepatic vessels are thin-walled, and it is almost impossible to liga- ture them, except by buried sutures. It is possi- ble for the liver to be ruptured without the peritoneal coat being damaged. Such injuries may be readily recovered from. The liver pre sents, behind, a fairly extensive non-peritoneal surface, at which rupture or wound may occur without extravasation into the abdominal cavity. From the relation of the liver to the right lower ribs, it follows that this viscus may be damaged when the ribs are fractured, and in some cases the broken ends of the bones have been driven through the diaphragm into the liver substance. Stabs through the sixth or seventh right inter- costal space, over the liver region, would wound both the lung and the liver, would involve the diaphragm, and open up both the pleural and peritoneal cavities. The intimate relation of the liver to the transverse colon is illustrated by a case where a toothpick, 4 inches in length, was found in the substance of the liver. It had worked its way there, from the colon, along an abscess cavity that connected the two viscera. The relation of the liver to the heart may be illus- trated by a case still more remarkable. In this instance a loose piece of liver, weighing 1 drachm, was found in the pulmonary artery. The patient had been crushed between two waggons, Chap. XVII ABDOMINAL VISCEEA 399 the liver was ruptured, and the diaphragm torn. A piece of the liver had been squeezed along the vena cava into the right auricle, whence it had passed into the right ventricle, and so into the pulmonary artery. The heart itself was quite uninjured. Portions of the liver may protrude through abdominal wounds, and are usually easy to reduce. In one instance of such protrusion the surgeon did not find the reduction easy, so he placed a ligature round the projecting part of the viscus, and then cut this obstinate portion of the liver off. The patient recovered. Con- siderable portions of the liver have been removed with success. It is remarkable from what grave injuries of the liver recovery is possible. Thus, Dr. Gann (Lancet, June, 1894) reports the case of a man of 28, who had a harpoon driven through the whole thickness of the right lobe of the liver, so that it projected at the posterior border. The blade was 7 inches long, and had two barbs. It was removed by operation twenty-eight hours after the accident, and the patient made a good recovery. f/roni a reference to the relations of the liver, it will be readily understood that an hepatic ab- scess may open into the pleura, and in some cases, indeed, the pus from the liver has been discharged from the bronchi. Thus, it has been possible for a patient to cough up some portion of his liver, although, of course, in a very disintegrated and minute form. Hepatic abscess may burst in one or other of the following directions, placed in order of their frequency : (1) into the right lung; (2) into the bowel; (3) upon the surface of the body. Such abscesses have, in rare cases, opened into the stomach. The liver is very frequently the seat of the secondary abscess of pyaemia, and, according to Mr. Bryant's statistics, abscesses in this viscus are more common after injuries to the head than after injuries elsewhere. They are rare in pyaemia following affections of the urinary organs, and are equally rare in the pyaemia after 400 SURGICAL APPLIED ANATOMY [Part IV burns. Secondary deposits of tumours and ab- scesses are frequently limited to the right or to the left of a line drawn from the fundus of the gall-bladder to the inferior vena cava. This re- markable limitation is to be explained by the fact that the liver to the right of this line is supplied only by the right terminal division of the portal vein, while the part to the left receives blood only from the left division (Cantlie). The gall-bladder may be absent, as is the case with some animals, or reduced to a cica- trix from disease. Its mucous membrane has a peculiar reticulated, honeycomb appearance. It is often occupied by gall stones. These concretions are composed mostly of cholesterin, a normal con- stituent of bile, and vary in size from a hemp seed to a hen's egg. The escape of gall stones is rendered more difficult by the presence of a spiral fold of mucous membrane in the neck and duct of the gall-bladder. The gall-bladder, at its neck, forms an acute angle with the cystic duct, the spinal fold being necessary to keep the passage open. In the erect position the long axis of the gall-bladder is directed upwards and backwards, and the cystic duct downwards and forwards (Fig. 64). The cystic duct lies in the gastro- hepatic omentum, where it joins the hepatic to form the common bile-duct. It is accompanied by the cystic artery. The cystic veins pass directly into the liver and end in the portal capillary sys- tem. In cases of cystitis the part of the liver receiving the cystic veins is seen to be contracted or atrophied. A gall stone may be arrested in, and require removal from, any part of the cystic or common bile-ducts. The common bile-duct is 3 inches long, and its lumen ith of an inch wide, but by the pas- sage of the gall stones it may become three times its normal diameter. The upper half of the com- mon bile-duct lies in the gastro-hepatic omentum, in front of the foramen of Winslow, with the portal vein behind it and to the right. The Chap. XVII] ABDOMINAL VISCERA 401 hepatic artery lies close to it on the left, and its branch, the superior pancreatico-duodenal, crosses the common bile-duct as it passes to its second or deeper stage. ' A stone arrested in the lower half of the duct is difficult of access. The duct lies buried between the head of the pancreas be- hind and the duodenum in front and to the outer side. It may be necessary in such a case to open the duodenum and extract the stone through its posterior and inner wall, or the duodenum and head of the pancreas may be turned forwards from the inner border of the right kidney, thus expos- ing the lower half (post-duodenal, stage) of the common bile-duct in the groove between the duo- denum and pancreas. The terminal half-inch is embedded in the wall of the duodenum and ends in the ampulla of Vater. At its termination it is surrounded by a sphincter which regulates the flow of bile. The lumen of the lower half of the duct is less than that of the upper half. Two lymphatic glands lie in the gastro-hepatic omen- tum by the side of the bile-duct, and have been mistaken for gall stones when calcified. The gall-bladder receives its nerve supply from the eighth and ninth segments of the cord (Head) through the great splanchnic and cceliac plexus. The intense colic caused by gall stones, believed to be due to spasm of the non-striated muscular coat of the bile-ducts, is reflected along the ninth dorsal nerve to the anterior abdominal wall. Stimulation of the sympathetic nerves causes the muscle of the cystic duct to contract, but relaxes that of the gall-bladder (T. R. Elliot). The gall-bladder and the bile-duct have been ruptured alone without rupture of the liver. The injury is rapidly fatal, owing to the escape of bile into the peritoneal cavity. Large gall stones may be passed direct into the bowel through a fistulous tract that has been established between the gall- bladder and the intestine. Gall stones have sup- purated out through the anterior belly wall, and have been removed from abscesses in the parietes. 2 a 402 SUEGICAL APPLIED ANATOMY [Part IV Thus Dr. Burney Yeo reports a case where more than one hundred gall stones were discharged through a spontaneous fistula in the hypogastric region, 5 inches below the umbilicus. In cases where the bile-duct is occluded by gall stones, or by other causes, the gall-bladder may become enormously distended, and may form a tumour l/iFE-atOR Vena Cava ■Stermi-Bisiform Li/ie- FUNDUS OFSTOMACfl Liver Oesophageal Orifice 5PLEE/1 Pulmonary l\ne Riq/it Suprarenal fllD-EPICASTR.IC LlflE Pl_E URAL LI/SE Pelvis of Kidney R-iq/jT Kid/hey Erector Spimae Asce/idinc Colon quadratus lumboeum Umbilical Line Ureter Post. 5up Iliac 5pm& Fig. 65. — The position and relationships of the abdominal viscera from behind. The lower limits of the pleura and lung are shown in red. extending some way beyond the umbilicus. So large a tumour has been formed that the mass has been mistaken for an ovarian cyst. The gall- bladder as it enlarges tends to follow a line extending from the tip of the right tenth car- tilage across the median line of the abdomen below the umbilicus. For the relief of this condition, cholecystotomy, or incision into the gall-bladder, has been performed. In this operation the in- Chap. XVII] ABDOMINAL VISCERA 403 cision or puncture is made over the most promi- nent part of the tumour. Impacted gall stones have been removed entire from the bile-duct through an incision so made, or the stone has been crushed in situ and extracted in fragments. In cholecystectomy the whole of the gall-blad- der is excised and the cystic duct closed. The bile finds its way into the intestine direct through the common duct. o f, h ^-^ i ST Fig. 66. — Horizontal section through upper part of abdomen. {Rudinger.) a, Liver; h, stomach; c, transverse colon; d, spleen; e, kidneys; /, pancreas The organ may be so displaced as to reach the iliac fossa. Injuries. — Although extremely friable in struc- ture, the normal spleen is not very frequently ruptured. Its connections, indeed, tend to mini- mise the effects of concussions and contusions. When the spleen, however, is enlarged, it is very readily ruptured, and often by quite insignifi- cant violence. Thus, several cases have been re- corded of rupture of an enlarged spleen by mus- cular violence. For instance, a woman ruptured her spleen in an attempt to save herself from fall- ing, and another in springing aside to avoid a blow. The patients in each instance were natives of India, and the latter case gave rise to a charge of homicide. The spleen being extremely vas- Chap. XVII] ABDOMINAL VISCERA 405 cular, it follows that ruptures of the viscus are usually, but not necessarily, fatal from haemor- rhage. It is well to note, in connection with this matter, that the spleen contains most blood during digestion. A case is reported, however, of a boy who met with an accident just after dinner, and who managed to walk some distance, although his spleen, as the autopsy revealed, was separated into three portions. He lived some days. In severe fractures of the ninth, tenth, and eleventh ribs the spleen may be damaged and lacerated. The capsule of the spleen contains muscular tissue, and must possess some contractile power. This fact may serve to explain cases of recovery from limited wounds of the organ, such as small gunshot wounds. In such lesions the capsule may contract and greatly narrow the hole in the viscus, while the track of the bullet or knife may become filled with blood-clot, and the bleeding thus be stayed. The spleen may be greatly enlarged in certain diseased conditions. The hypertrophied spleen may attain such dimensions as to fill nearly the whole abdomen, and in one case a cystic tumour so completely occupied both iliac fossae that it was mistaken for an ovarian cyst, and the operation for ovariotomy was commenced. Extirpation of the spleen has been suc- cessful in cases of abdominal wounds with pro- trusion of the viscus. It has also been performed with fair results in many cases of hypertrophied spleen, and of wandering spleen. The operation is not justifiable in cases of leukaemic enlargement of the organ, it having proved invariably fatal in such, instances. In cases of wounds with pro- trusion, the spleen is, of course, removed through the wound. In other instances the incision is usually made in the middle line, the most con- venient being one so arranged that the umbilicus corresponds to the centre of the cut. Some sur- geons prefer an incision along the outer edge of the left rectus muscle. The viscus is then slowly 406 SUEGICAL APPLIED ANATOMY [Part IV pressed out of the wound. The great difficulty is with the gastro-splenic omentum, which has to be divided and its vessels secured. In drawing out the spleen there is much risk of tearing the splenic vessels, especially the vein. Special care has to be taken to avoid damage to the pancreas. The splenic artery, with its large accompanying vein, lies in the lieno-renal ligament, in contact with the tail of the pancreas below. The pancreas lies behind the stomach, in front of the first and second lumbar vertebrae (Fig. 64). It crosses the middle line behind the mid-epigastric line (Fig. 64). In emaciated sub- jects, and when the stomach and colon are empty, it may sometimes be felt on deep pressure, espe- cially in those who are the subjects of visceroptosis ; prolapse of the stomach leaves the pancreas ex- posed above the lesser curvature. It is in relation with many most important structures. So closely is it mixed up with the solar plexus that this structure is necessarily involved in any operative procedures on its head and neck. It has, I be- lieve, never been ruptured alone, and it could scarcely be wounded without the wound implicat- ing other and more important viscera. It has been found herniated in some very rare cases of diaphragmatic hernia, but never alone. The main duct (duct of Wirsung) usually terminates with the common bile-duct in the ampulla of Vater (Fig. 67, a), so that a gall stone arrested at this point may occlude both ducts or possibly cause a reflux of the bile within the pancreatic duct. Not uncommonly (in 30 per cent, of cases) the ampulla is partly (Fig. 67, b) or completely divided (Fig. 67, c), so that the orifices of the two ducts are separated ; in such cases occlusion of the termination of the bile passage leaves the pan- creatic duct free. A secondary duct (the duct of Santorini) is present in a more or less de- veloped condition in 50 per cent, of subjects. It may form a connection with the main duct, as in Fig. 67, a, or be merely a minute ductule, as in Chap. XVII] ABDOMINAL VISCERA 407 Fig. 67, b. The accessory duct opens nearer the pylorus, being f of an inch above the ampulla of Vater. The ampulla _ usually extends into a papilla which projects within the duodenum, but this papillated condition is not always present. Septic conditions may spread from the duodenum to the pancreas or gall-bladder by means of their ducts. The common bile-duct in its second stage lies between the head of the pancreas and the duo- Fig. 67. — Diagrams to show the variations in the manner of termination of the pancreatic and bile ducts. A, Form in which the common bile-cluctl(c, b, n) and main pancreatic duct (b) end in an ampulla (e). a. Duct of Santorini; i., ii., iii, first, second, and third stages of the duodenum. B, Form in which the ampulla is partly divided. The duct of Santorini is shown in its reduced form. C, Form in which the common bile-duct and pancreatic duct have separate openings into the duodenum. The duct of Santorini is absent. denum. It thus happens that in carcinoma of this part of the gland the duct may become en- tirely occluded and jaundice result. Or the duo- denum and even the colon may be more or less obstructed by pressure, or the neighbouring vessels be closed. Cancer of the pylorus may spread to the head of the pancreas by direct extension. The lymphatics of the two parts also freely communicate. The pancreas lies behind the lesser sac of the peritoneum, its anterior surface being covered by the posterior wall of the sac. It lies in front of the aorta, in the fork between the coeliac axis 408 SURGICAL APPLIED ANATOMY [Part IV above and the superior mesenteric artery below. The portal vein passes upwards behind the neck of the gland. Certain remarkable cysts are sometimes de- veloped in the pancreas. They may attain great size and nearly fill the abdomen. The kidney. — Its relations are as follows : — In front. Right. Left. Visceral surface of liver. Fundus of stomach. Second part of duodenum. Descending colon. Commencement of transverse colon. Pancreas. Ascending colon. Spleen. Externally. Liver. Kidney. Externally. Spleen. Behind. Lower part of arch of diaphragm. Quadratus lumborum. Psoas. Transversalis. Last rib and transverse proeesses of upper two lumbar vertebra. The kidneys are deeply placed, and cannot be felt or distinctly identified when normal. They are most accessible to pressure at the outer edge of the erector spinse, just below the last rib (Figs. 65 and 68). The dulness of the right kidney merges above in that of the liver, while on the left side it is impossible to distinguish between the dulness of the kidney and spleen. The right kid- ney lies usually lower down than does the left ; but even the lower pole of the right kidney is an inch above the crest of the ilium — or what for practical purposes is the same level — above the umbilical line (Fig. 58, p. 363). The simplest manner of indicating the position of a kidney is to mark out the position of the upper and lower pole and between those two points mark on the well-known form of the kidney. The lower pole of the right organ lies about \ an inch outside the prominent lateral border of the erector spinse and 1 inch above the iliac crest (Fig. 65) ; since the kidney is about 4 inches long and is situated obliquely — its long axis corresponding to that of the twelfth rib — its upper pole is sufficiently in- Chai). XVII I ABDOMINAL VISCERA 409 clicated, by taking a point 4 inches above and lh inch internal to the position of the lower pole. The spine of the eleventh dorsal vertebra — which may be identified when the patient bends by its f AV\\^ a>'\. ■♦t-^\V fit Fig. 68. — Showing the relationships of the kidney and colon in the lumbar region from behind. (Adapted from Merkel.) * p.l., Lower line of pleura ; xi., eleventh rib ; xil, twelfth rib ; 12th d.n., twelfth dorsal nerve ; 1st l.n.,, ilioinguinal and ilio-hypogastric nerves; a.b., vertical line representing position of descending colon (desc. c.) ; q.l., quadratus lum- borum ; e.s., erector spinas ; peritoneum (perit.) is shown reflected from the front of the kidney to the colon on the right side. anti-clinal direction and semilumbar form — is just below the level of the upper pole. On an average the left kidney lies \ an inch higher than the right (Addison). In many instances in the * The kidneys are represented in the position they assume when the body is turned on its face ; in the supine position they fall inwards and backwards into the position described in the text. In the subject figured above, the 12th rib is shorter than is common. 410 SURGICAL APPLIED ANATOMY [Part IV female its lower end reaches the iliac crest, and may even go below it. Such positions are much less common in the male. The hilum lies about 2 inches from the middle line, and is opposite to the first lumbar spine and usually in the gap between the transverse processes of the first and second lumbar vertebrae (Fig. 65, p. 402). In radiograms of the injected ureter, the shadow of the pelvis of the kidney is seen to fall across those of the transverse processes just mentioned, and also that of the last rib (Fig. 70, p. 418). The anterior surface is but slightly covered by peritoneum, being only in contact with that mem- brane in such parts as are not in relation with the cellular tissue at the back of the colon and at the back of the duodenum or pancreas. _ The ex- ternal border is more closely in connection with the peritoneum, while the posterior surface is quite devoid of that membrane (Figs. 65 and 66). Crossing the posterior surface of the kidney obliquely from above downwards and outwards are branches of the last dorsal nerve and of the first lumbar artery, together with the ilio-hypo- gastric and ilio-inguinal nerves (Fig. 68). Rup- ture of the kidney is more often recovered from than is a like lesion of any other of the more commonly injured abdominal viscera. This de- pends upon its extensive non-peritoneal surface, whereby the extravasation of blood and urine that follows the accident is very often entirely extra- peritoneal. The gland may be readily wounded from behind or from the loin, without the peri- toneum being injured. When the spine is much bent forwards, the kidney lies in the angle of the bend, at a part where the flexion of the column is the most acute. In extreme flexion, therefore, of the spine, it may be squeezed betweenthe ilium and the lower ribs. Thus, hematuria is not un- common after injuries to the back associated with extreme bending of the spine forwards, as when a heavy weight falls upon the bowed shoulders. The kidney is embedded in a large quantity Chap. XVII] ABDOMINAL VISCERA 411 of loose fatty tissue constituting the perirenal capsule, and suppuration extending in this tissue constitutes a perinephritic abscess. Such an ab- scess may be due to disease of the kidney itself, to affections of the adjacent parts (spine, colon, etc.), or to injuries. The pus is at first in front of the quadratus 1 umbo rum, and then usually makes its way through that muscle or through the lumbar fascia. It then presents itself at the outer edge of the erector spinse, having passed between the adjacent borders of the ex- ternal oblique and latissimus dorsi muscles. It may, however, spread into the iliac fossa, or ex- tend into the pelvis along the loose connective tissue behind the descending colon and rectum, or open into the colon or bladder, or even into the lung. Most rarely of all does it perforate the peritoneum. Renal abscess usually opens upon the non-peritoneal surface of the gland. It may open into the adjacent colon. In one case a renal abscess, due to stone, made its way from the right kidney into the pyloric end of the stomach, so that a communication was established between those two organs. The perirenal fat is of much surgical importance, as its laxity permits of a ready enucleation of the organ. It is more abund- ant behind than in front. When this tissue has been destroyed or modified by inflammation, the kidney becomes fixed, and its removal a matter of great difficulty. This is illustrated by the re- moval of a large tuberculous kidney which has been long diseased. Besides the perirenal cap- sule, the kidney also possesses its proper capsule, which can be easily stripped from the normal orgam Incision of the capsule has been proposed to relieve congested conditions of the kidney. Movable kidney.— The kidneys, being closely applied to the diaphragm, necessarily follow its respiratory movements; in normal breathing the up and down excursion of the kidney is about h an inch in extent. The perirenal capsule in which the kidney is loosely embedded is merely a 412 SUEGICAL APPLIED ANATOMY [Part IV specialised part _ of the subperitoneal connective tissue; above it is continuous with the dense sub- peritoneal tissue on the diaphragm, externally with the equally dense layer over the transversalis, internally it fuses with the sheaths of the in- ferior vena cava and aorta, while below it is continued downwards, as the lax subperitoneal tissue surrounding the ureter, to become con- tinuous with the corresponding tissue in the pelvis. Hence only downward displacements are possible. The perirenal capsule and the renal vessels, while they restrict and determine the direction of the renal movements, only come into action when the normal limits have been exceeded. The force which retains the kidneys in position is the intra-abdominal tension maintained by the musculature of the abdominal wall, by which the other viscera are compressed against the kid- neys. With the absorption of fat from the cap- sule the tissue of the perirenal capsule becomes more lax and the renal movements more free. Hence movable kidney is often met with in the badly nourished. It is far more common in women than in men. In the former sex the influ- ence of pregnancy appears to have especial effect, acting, probably, by dragging upon the peri- toneum, and by loosening its connections, as well as by inducing, after delivery, a general laxity of the abdominal walls. The right kidney is far more often movable than is the left, owing prob- ably to the displacing influence of the liver. I have recorded (in conjunction with Dr. Mac- lagan) three cases in which a movable kidney pressed against the neck of the gall-bladder and obstructed the flow of bile. The movable kidney can, of course, only be displaced within a seg- ment of a circle whose radius corresponds to the length of the renal vessels, and yet this displace- ment may be considerable. # The dragging pains which are felt with a movable kidney are due to a stretching of the renal plexus, which is connected with the solar Chap. XVII] ABDOMINAL VISCERA 413 plexus and enters the kidney with the arteries. The kidney receives its nerve supply from the tenth, eleventh, twelfth dorsal, and first lumbar segments of the spinal cord through the small and lesser splanchnics (Head). Pain is referred to the wall of the abdomen along the sensory nerves derived from these segments. Abnormalities of the kidneys. — One, or less frequently both, kidneys may be misplaced. The left is more often out of place than the right, and may be found over the sacro-iliac synchon- drosis, or the promontory of the sacrum, or be discovered in the iliac fossa or pelvis. The mis- placed kidney is often misshaped. The kidney may exhibit a more or less extreme degree of lobulation, a condition present in the newly born. The ureter may be double. Supernumerary arteries are frequently present; cases have been recorded where such vessels, passing to the lower pole of the kidney, have caused constriction or kinking of the ureter. The two kidneys may be fused. " The lowest degree of fusion is seen in the horse-shoe kidney. The two kidneys are united at their inferior por- tions by a flat, riband-like, or rounded bridge of tissue, which crosses the vertebral column. In the higher degrees the two lateral portions approach one another more and more until they reach the highest degree, in which a single disc-like kidney, lying in the median line, and provided with a double or single calyx, represents complete fusion" (Rokitansky). When _ the two kidneys are united by a web of connective tissue, the con- dition is no bar to operation. There may be an entire absence of one kidney. The single kidney may he lateral or median in position. Henry Morris gives the following estimate of the fre- quency of these abnormal conditions : Congenital absence or extreme atrophy of one kidney may be expected in about one in 4,000 cases, the horse- shoe kidney in one in 1,600, and the single fused kidney in one in 8,000 cases. 414 SUKGICAL APPLIED ANATOMY [Part IV nc. Sinus LAR Vein 1/IMOMlNATE art. Trachea « Oesophagus Vena Azyqos Major Right Luhc Thoracic Duct Diaphraqm Richt Kidney Ureter Spermatic Vessels nf. Vena Cava Bifurcation of Aorta Cluteus AIedius Psoas Rectum Sup. AIaemorrh.Art. Gluteus Maximus Fig. 69.— View of the kidneys, etc., from behind. (After RMinger.) Chap. XVII] ABDOMINAL VISCERA 415 ■ 5 j Operations on the kidney. — (1) Nephrotomy. Incision into the kidney for exploration, or the evacuation of pus. (2) Nephro-lithotomy. In- cision into the gland for the removal of a calculus. (3) Nephrectomy. Removal of the entire organ. (4) Nephroraphy. The operation of securing a movable kidney in its normal position. In the first, second, and fourth operations the kidney is reached through the loin by an oblique incision, such as is used in colotomy (p. 392), the cut, however, being carried a little farther backwards. In nephrectomy a like incision may be used. The cut is carried backwards about 1 inch over the erector spinse, and a part of the quadratus lum- borum will probably have to be divided. The costo-vertehral ligament, a specialised part of the middle layer of the lumbar fascia which binds the last rib to the tips of the upper two lumbar transverse processes, also falls in the line of the incision. The perirenal tissue is opened up, and the gland enucleated from the capsule of fat in which it lies. In some instances the last rib has been resected to obtain more space for the operation. The pleura reaches the neck of the twelfth rib and occasion- ally it descends as far as the transverse process of the first lumbar vertebra (Figs. 65 and 68). In one case the twelfth rib was rudimentary, and the eleventh rib was removed under the impression that it was the twelfth. The pleura was opened and death ensued. When the kidney is free from its fatty capsule, the vessels at the hilum are secured separately by ligatures. The numerous nerves to the kidney are no doubt included with the vessels. They con- stitute a surgical pedicle of the kidney. At the hilum the vein lies in front, the artery and its branches next, and the ureter behind and towards the lower > part. The artery is about the size of the brachial, and usually divides into four, five, or _ six branches before it reaches the kidney. This fact must be borne in mind if the structures 416 SUEGICAL APPLIED ANATOMY [Part IV at the hilum are separately secured. One-third of these branches constantly enter the hilum be- hind the ureter and are liable to injury in ex- ploration of the pelvis of the kidney. The vein is also represented at the hilum by three or four branches. Accessory renal arteries may be present. Some may enter the upper end of the kidney or its anterior surface. In removing large renal tumours an abdominal incision is advised, the cut being made either along the corresponding semilunar line, and on a level with the diseased mass, or in the linea alba. The abdominal operation is the more usual one, and has the advantages of greater ease and rapidity in performance and gives an opportunity of examining the condition of both kidneys. In chronically inflamed conditions of the kidney — as, for example, in long standing tuberculous disease — the kidney becomes adherent, and on the right side is apt to become closely bound down to^ the vena cava. _ Much care is needed in clearing the great vein when so ad- herent. In removing a very adherent kidney the diaphragm has been torn. The ureters are strong tubes about 15 inches long, with thick muscular walls, and are placed entirely behind the peritoneum. The average width is that of a goose-quill. The ureter rests from above, downwards upon (1) the psoas muscle and the genito-crural nerve ; (2) the common iliac vessels on the left side, and the external iliac vessels on the right; (3) after passing downwards on the internal iliac artery it then enters the posterior false ligament of the bladder, and so reaches the bladder wall. In the female it passes through the base of the broad ligament, where the uterine artery loops over it f of an inch from the neck of the uterus. It rests on the roof of the upper part of the vagina before entering the bladder, and a calculus arrested in that stage may be distinctly felt. The narrowest part of the tube is the portion within the bladder walls, and when renal calculi pass along the ureter they are Chap. XVII] ABDOMINAL VISCERA 417 often arrested at this point. There are two other narrow points at which calculi may be stopped : at its junction with the pelvis of the kidney, and where it crosses the pelvic brim. The ureters per- mit of great distension, and in certain cases of gradual dilatation they have attained a width equal to that of the thumb and even of the small intestine. Several cases are recorded of rupture of the ureter from external violence. When such an accident occurs a large urinary collection usually forms behind the peritoneum, which, lead- ing to suppuration, will produce a fluctuating tumour beneath the parietes. The ureter expands in the hilum of the kidney into a funnel-shaped cavity — the pelvis. This in turn divides into the calyces. In the pelvis or calyces, calculi are frequently lodged. The calyces are too narrow to admit an exploring finger. The ureter has been successfully resected and sutured. It is supplied by nerves from the renal plexus and by vessels from the renal, inferior vesical and subperitoneal plexus. In the search for impacted calculi by the aid of X-rays the following method will be found useful for indicating the course of the ureter. The pelvis of the kidney lies between the trans- verse processes of the two upper lumbar vertebrae (Fig. TO) ; its position on the surface of the body may be indicated by taking a point just internal to that used for the gall-bladder (p. 396). At the brim of the pelvis the ureter crosses at or near the bifurcation of the common iliac artery, a point which lies at the junction of the upper with the lower two-thirds of a line drawn from the aortic bifurcation to the femoral point (see Figs. TO and 57, pp. 418 and 340). Its pelvic course is curved (Fig. TO), the convexity of its out- ward bend lying \ an inch in front of the ischial spine. The vesical orifice is to be sought for in a skiagram at some distance above and internal to the pubic spines. Mr. Rigbj r has shown that the ureter may be exposed from behind through 2 B 418 SUKGICAL APPLIED ANATOMY [Part IV the sacro-sciatic notch and calculi thus removed from it when the anterior operation is imprac- ticable on account of pelvic adhesions. He uses the ischial spine as a guide in finding the ureter. The nerve supply of the abdominal viscera. — Some account has already been given of these rIBAE 1/tRTEBOA IS OF KlDfEV ETEB MBIUCUS Aootic Bifurcation FtJrtDl!\5 ofUTERUS Ubetes Fig. 70.— Diagram to show the course of the ureters and position of the bladder, As they appear in a skiagram when they have been injected with a bismuth solution. The positions of the fundus of the uterus, Fallopian tubes and ovaries are also indicated. nerves and the spinal segments from which they are derived (p. 337). The abdominal viscera are mainly supplied by the sympathetic system through a series of remarkable plexuses. The most important of these is the solar, from which is more or less directly derived the nerve supply of the stomach, liver, spleen, kidneys, suprarenal Chap. XVII] ABDOMINAL YISCEEA 419 capsules, pancreas, and such parts of the intestine as are in connection with the superior mesenteric artery. The solar plexus and its appendages re- ceive the splanchnic nerves and some branches from the vagus, while communications from the phrenic go to the hepatic and suprarenal plexuses. Through these nerves the calibre of the blood- vessels and the amount of blood in the abdomen are regulated. They contain not only sensory fibres for the abdominal viscera but constrictor and dilator fibres for the bowel. It may be well understood that an impression brought to bear upon extensive net-works with such wide central connections and with such important relations would produce considerable effects. These effects we see in the profound collapse, vomiting, and other grave symptoms that attend severe injuries to the viscera, and especially to those that are the most directly associated with these large plexuses. The descending colon and sigmoid flexure are sup- plied by the inferior mesenteric plexus, a cord that has but an indirect connection with the solar plexus : and this fact may serve to account for the less serious symptoms often seen in strangulation of the colon when compared with a like lesion of the small gut. The upper part of the colon, although supplied by the superior mesenteric plexus, is only supplied by that part of it that is most remote from the great centres, and it is a conspicuous fact that the nearer the lesion is to the stomach, the graver, other things being equal, are the nervous phenomena produced. It would appear that some lesion of these nerve plexuses is sometimes active in producing a remarkable pigmentation of the skin. This is seen in Addi- son's disease, a disease marked by a general bronz- ing of the surface, and usually associated with some disintegration of the suprarenal capsules. The very direct relation of these bodies to the solar plexus is well known. In pregnancy also, in abdominal tuberculosis, in cancer of the stomach, and in liver diseases, a pigmentation of 420 SUEGICAL APPLIED ANATOMY [Part IV the face is sometimes seen, that may in such instances be probably ascribed to a disturbance of the great abdominal nerve centres. In some diseases of the liver and stomach " sympathetic ' ; pains are complained of between the shoulders or about the inferior angles of the scapulae. They commonly appear some distance below the angle of the scapula. The nerves for the stomach are derived principally from the seventh and eighth and those for the liver from the eighth and ninth spinal segments. The skin areas of these segments may become tender when the organs are diseased and to some point in these areas pain is referred (Fig. 56, p. 333). The shoulder-tip pain that often accompanies liver disease is situated in the area supplied by the fourth cervical segment, the same segment as sup- plies sensory fibres to the diaphragm and sub- diaphragmatic connective tissue through the phrenic nerves. It will be remembered that these nerves are distributed on the under surface of the diaphragm. There would seem to be but little connection between a disease in the sigmoid flexure and a pain in the knee, yet in cases of cancer in the flexure, and in instances where it has been dis- tended with fseces, such pain has been complained of. The pain is conveyed along the obturator nerve, which lies beneath the sigmoid flexure, and could be readily pressed upon by the gut when diseased. Pain arising from the small in- testine is usually referred to the neighbourhood of the umbilicus — the distribution of the tenth dorsal nerve (Fig. 56, p. 333). It seems remark- able that such pains should be restricted to so narrow an area, but a full explanation of this is to be found in the fact that the whole of the small intestine arises from an extremely small part of the embryonic alimentary tract. Pains along the groin (along the twelfth dorsal and first lumbar nerves) arise from many sources — from disease of the kidney, ureter, ovary, testicles, Chap. XVII] ABDOMINAL VISCERA 421 Fallopian tubes, uterus, appendix, hip-joint, and from hernia?. The blood-vessels of the abdomen. — Some of the visceral branches of the abdominal aorta are of large size, and would bleed very copiously if wounded. Thus, the coeliac axis and the superior mesenteric artery are as large as the common carotid ; the splenic, hepatic, and renal vessels are about the size of the brachial; while the largest part of the inferior mesenteric trunk has dimensions equal to those of the ulnar artery. Aneurisms of the aorta are especially apt to occur at the coeliac axis, that being a point where a number of large branches are abruptly given off, and where the course of the circulation undergoes in consequence a sudden deviation. Although two, or in some places three, anastomotic arches occur between the branches of the superior mesen- teric artery before they form a final net-work in the bowel, yet embolism of a comparatively small branch may lead to gangrene of the gut (Lock- wood). When it is remembered that the lumbar glands lie about the vena cava and iliac veins, it will be understood that great enlargement of those bodies may cause cedenia from pressure. Gan- grene of the whole of the small intestine may result from an embolism of the portal vein. In a case reported by Mr. Barnard the embolism was caused by a constriction at the point where the vein passes behind the neck of the pancreas. The inferior vena cava has been ligatured success- fully ; amongst the collateral veins which enlarge, the chief are the azygos, epigastric, and intra- vertebral veins. A number of minute but most important anas- tomoses exist between some of the visceral branches of the abdominal aorta and certain of the vessels supplied to the abdominal parietes. These anasto- moses are situated behind the peritoneum, and mostly concern such viscera as have a fair surface uncovered by that membrane. The visceral 422 SUEGICAL APPLIED ANATOMY [Part IV branches that join the anastomoses are derived from the hepatic, renal, and suprarenal arteries, and from the vessels supplying the lower part of the duodenum, the pancreas, the csecum, and the ascending and descending segments of the colon. The parietal vessels joining with the above are derived from the phrenic, lumbar, ilio-lumbar, lower intercostal, epigastric, and circumflex iliac trunks. In a case detailed by Professor Chiene {Joum. Anat. and Phys., vol. iii.) the cceliac axis and mesenteric vessels were plugged, but blood in sufficient amount to supply the viscera had reached branches of these arteries through their parietal communications. When the portal circulation becomes obstructed owing to disease of the liver, blood from the portal vein may pass into the systemic veins at the following points : (1) lower part of the rectum, from the superior to the inferior and middle hemorrhoidal veins; (2) at the oesophagus, from the coronary to the oesophageal veins; (3) in the falciform and round ligaments, from the portal vein to tributaries of the epigastric ; (4) in the subperitoneal tissue of the posterior wall of the abdomen, whereby the renal, phrenic, lumbar, and intercostal veins re- ceive blood from mesenteric, pancreatic, and other veins. By bringing about adhesions between the omentum or visceral peritoneum and the parietal peritoneum, as is done in the Talma-Morrison operation, new and large communications are formed between the portal and systemic venous circulations. Cases have been recorded of com- munications between the external iliac vein and the portal vein. These have generally been effected by the deep epigastric vein joining with a pervious umbilical vein in the vicinity of the navel. Thoracic duct. — The thoracic duct may be wounded in the course of removing tubercular glands from beneath the lower part of the left sterno-mastoid ; or, as in some reported cases, may be severed by a stab in the neck. In each case Chap. XVII] ABDOMINAL VISCERA 423 lymph and chyle in large quantities escaped from the wound. The duct has been found to have been obliterated, and that, too, without pro- ducing any marked symptoms during life. It has been cut and ligatured during removal of glands from the supraclavicular triangle, with no bad result. Mr. Leaf has shown that the thoracic duct communicates freely with the azygos veins in the posterior mediastinum and with the lym- phatic vessels of the right side of the thorax and neck. It frequently serves as a channel for the spread of malignant tumours situated in the upper part of the abdomen. Enlargement of the inferior deep cervical glands in the left side of the neck niav be the first sign of cancer of the stomach (W. M. 'Stevens). CHAPTER XVIII THE PELVIS AND PERINEUM The mechanism of the pelvis. — Besides form- ing a cavity for certain viscera, a support for some abdominal organs, and a point for the at- tachment of the lower limb and of many muscles, the pelvis serves to transmit the weight of the body both in the standing and sitting postures. The transmission is effected through two arches, one available for the erect position, the other for the posture when sitting. When standing, the arch is represented by the sacrum, the sacro-iliac synchondroses, the acetabula, and the masses of bone extending between the two last-named points. If all other parts of the pelvis were to be cut away but these 2 the portions left would still be able to support the weight of the body, and would represent in its simplicity the arch through which that weight is transmitted. When sitting, tb? arch is represented by the sacrum, the sacro-iliac syn- chondroses, the tubera ischii, and the strong masses of bone that extend between the two last- named parts. Morris terms these two arches the femoro-sacral and the ischio-sacral. On examin- ing the innominate bone it will be seen that its thickest and strongest parts are such as are situ- ate in the line of these. ' When very considerable strength is requisite in an arch, it is continued into a ring so as to form a counter-arch, or what is called a tie is made to connect together the ends of the arch, and thus to prevent them from 424 Chap. XVIII] PELVIS AND PERINEUM 425 starting outwards. By these means a portion of the superincumbent weight is conveyed to. the centre of the counter-arch, and borne in what is called the sine of the arch. The body and hori- zontal rami of the pubes form the tie or counter- arch of the femoro-sacral, and the united rami of the pubes and ischium the tie of the ischio-sacral arch. Thus the ties of both arches are united in front at the symphysis pubis, which, like the sacrum or keystone, is common to both arches. . . . . This explains how it is that so much strain is made upon the symphysis when any increased weight has to be supported by the pelvis, as in pregnancy ; why there is such powerlessness, with inability to stand or sit, in cases in which this joint is weakened or diseased; and why the anterior portion of the pelvis yields under the weight of the body and becomes deformed in rickets and mollities ossium." * The pelvic de- formity in rickets, it may be here observed, varies greatly according to the age at which the disease sets in, and the usual attitude of the child when it becomes affected. The deformity sometimes pro- duced in very young infants has been ascribed to muscular contraction (ilio-psoas, erector spinse, gluteus medius, etc.). In the rickety pelvis, par excellence, the two acetabula approach one another, the anterior part of the pelvis yields, so that the symphysis is pushed forward, and the cavity becomes greatly narrowed in its transverse diameter. In severe cases the anterior arch may practically collapse, and the horizontal rami of the pubes be for some little way parallel to one another. In the erect attitude the pelvis is so inclined that the plane of the brim of the true pelvis forms with the horizon an angle of from 60° to 65°; the base of the sacrum is about 3| inches above the upper border of the symphysis, while the tip of the coccyx is a little higher than its lower border. * Henry Morris on "The Joints," p. 116, where a most valuable account of the mechanism of the pelvis will be found. 426 SURGICAL APPLIED ANATOMY [Part IV The centre of gravity of the whole body (adult) is at a spot just above the sacro-lumbar angle, and exactly over the mid-point of a line drawn between the heads of the femora. Fractures of the pelvis. — From what has been already said, it may be surmised that the weakest parts of the pelvis are at the symphysis and the sacro-iliac joints. The bones of these parts, however, are so very firmly knit together by powerful ligaments that it is very rare for these articulations to give way, fracture of the adjacent bones being more common. The com- monest fracture of the pelvis is in the weak counter arch, and involves the rami of both the pubes and the ischium. . The fracture is often associated with some tearing of ligaments about the sacro-iliac synchondrosis, and is met with in accidents due to the most varied forms of vio- lence. This last remarkable circumstance is thus explained by Tillaux. If the pelvis be compressed in (a) an antero-posterior direction, the main brunt of the force comes upon the weak counter arch, which fractures from direct violence. The force, continuing, tends to push asunder the two iliac bones, and so cause rupture of the anterior ligaments at the sacro-iliac joint. If the force be applied (b) transversely, the two acetabula tend to be pressed towards one another, the counter arch becomes more bent, and ultimately gives way by indirect violence. The violence, continuing, forces the two ilia towards one another, the strain then falls upon the sacro-iliac synchondrosis, and the posterior ligaments of that joint are apt to yield, or portions of the bone adjacent to the joint are torn away. In cases of falls, when the patient alights upon the feet or ischial tuberosities, it can be understood how in many instances the main arches will escape injury owing to their great strength, while the counter arch becomes frac- tured. Any part of the pelvis, including the sacrum, may be broken by well-localised direct violence. More or less of the iliac crest, the an- Chap. XVIII] PELVIS AND PERINEUM 427 terior superior and posterior superior spines, have been knocked off. The first-named part may be separated as an epiphysis. It joins the bone at about the twenty-fourth year. In one case the anterior inferior spinous process was torn off by the rectus muscle during the act of running a race. The os innominatum has been broken into its three anatomical portions. This accident can- not take place after about the seventeenth year, since by that time the Y-shaped cartilage is usually fully ossified, and the three elementary bones are fully united. Before such consolidation occurs, abscess in the hip-joint not unfrequently makes its way through the cartilage into the pelvis. The acetabulum has been fractured, and the head of the femur driven through its thinnest part into the pelvis. In fractures of the pubes and ischium the bladder has been torn by the sharp fragments. In one case a loose piece of bone that had been driven into the bladder became the nucleus for a stone. The urethra and vagina also have been lacerated or seriously compressed by the displaced bones. In fractures of the sacrum the rectum has been torn, or has been so compressed by the lower fragment (which is al- most always carried forwards) as to be nearly closed. Special parts of the pelvis. Symphysis.— Separation of the bones at the symphysis without fracture has occurred from severe violence. Mal- gaigne reports three cases where the separation was brought about by muscular violence only, by ex- treme action of the adductor muscles of the two sides. The Sigaultean operation consisted in dividing the symphysis pubis in cases of con- tracted pelvis, with the idea of obtaining more room during labour, and of so avoiding Csesarian section. The union consists of fibro-cartilage and transverse peripheral fibrous bands. It varies in depth from lh to If inch, and may be divided subcutaneously, when the bones gape quite i an inch. It has been shown, however, that to gain 428 SUKGICAL APPLIED ANATOMY [Part IV 4 an inch in the anteroposterior diameter the bones must be separated to the extent of 2 inches. Such a separation involves laceration of the sacro- iliac ligaments, and more or less damage to the attachments of the pelvic viscera. The sacro-iliac synchondrosis may be the seat of disease. Normally, there is a synovial space and a slight degree of movement in this joint. As this joint lies in the line of the great arches of the pelvis, it follows that when inflamed, much pain is felt in the part, both when the patient is standing and when sitting. When abscess forms it tends to come forwards, owing to the anterior ligaments being slight while the pos- terior ligament is dense, thick, and of great strength. Having reached the pelvic aspect of the joint, the pus may occupy the iliac fossa, or gain the ilio-psoas sheath. Or it may follow the lumbo- sacral cord and great sciatic nerve and point in the thigh behind the great trochanter, or it may be guided by the obturator vessels to the inner side of the thyroid foramen, and ultimately appear at the inner side of the thigh. The abscess may, however, proceed backwards, and point over the posterior aspect of the joint. The nerve relations of this joint are important. It is supplied by the superior gluteal, by the lumbo-sacral cord and the first sacral nerve, and bv the first and second posterior sacral nerves (Morris). The lumbo-sacral cord and the obtura- tor nerve pass over the front of the joint, the former being very closely connected with the articulation. It will be understood from these relations that in sacro-iliac disease pain is felt over the sacral region (upper sacral nerves) and in the buttock (gluteal nerve). Much pain is also often complained of in the hip or knee- joint, and along the inner part of the thigh (ob- turator nerve). In one or two reported cases there has been severe pain in the calf and back of the thigh, with painful twitchings in the muscles of those parts (lumbo-sacral cord and connection Chap. XVIIIJ PELVIS AND PERINEUM 429 with great sciatic nerve). Dislocation of the sacrum at this joint is prevented by the remark- able double wedge-shaped outline of the bone, and by the very dense ligaments that bind it in its place. The bone is set very obliquely, so that the weight of the body tends to force its base into the pelvis and tilt its apex upwards. The strong posterior sacro-iliac ligaments prevent the first movement, the great sacro-sciatic the second. Trendelenburg's operation. — In order to bring the two pubic bones and the deficient soft parts together in ectopia vesicas, Trendelenburg divides the sacro-iliae synchondroses on either side. The operation, which has been very succcessful, is limited to children between the ages of two and five. The distance between the anterior superior iliac spines has — in a child aged two and a half years — been lessened 2 inches by this operation. Sacro-coccygeal tumours. — The sacro-coccygeal region is very often the seat of congenital tumours, some of them of such a shape as to form " human tails " ; and to this part of the pelvis has also been found attached a third lower limb leading to the condition known as " tripodism." Parasitic foetuses are also frequently found attached to this segment of the spine. In many of the instances of attached foetuses the two in- dividuals have been joined together at this part of the column. Some of the sacro-coccygeal tumours contain epithelial cysts and fragments of skin, muscle, nerve, bone, cartilage, and mucous membrane. These strange masses spring from the anterior part of the coccyx, between it and the rectum. By some they are supposed to arise from coccygeal body, by others (Sutton) from the struc- tures known to embryologists as the postanal gut and the neurenteric passage. The sacro-coccygeal joint may be dislocated or diseased. In either affection great pain is kept up from the frequent movement of the part by the muscles attached to the coccyx (the gluteus niaxi- mus, coccygeus, levator ani, and sphincter). In 430 SURGICAL APPLIED ANATOMY [Part IV the luxation the bone may project into the rectum, and thus give trouble. The joint and the parts about it may be the seat of such severe neuralgia (" coccygodynia ") as to require excision of the coccyx, or a free division of the structures that cover it behind. The joint and the fibrous tissue about it are supplied by the following nerves : the posterior divisions of the second, third, and fourth sacral, and the anterior and posterior divisions of the fifth sacral and coccygeal. In old age the coccyx becomes ossified to the sacrum. The floor of the pelvis and the _ pelvic fascia. — The outlet of the bony pelvis is occu- pied in the recent state by the following struc- tures from behind forwards : the pyriformis, the sacro-sciatic ligaments, the coccygeus, the levator ani, and the triangular ligament of the perineum. These form the floor of the pelvis. The three structures last named serve to separate the pelvic cavity from the perineum and provide a ham- mock-like support for the viscera of the pelvis. The walls and floor of the pelvis are lined by a fascia, the pelvic fascia, of which a brief general description may be given. This fascia is divided into two distinct parts, a parietal layer and a visceral layer, (l) The parietal layer begins at the brim of the true pelvis, to which it is at- tached. From this attachment it passes down along the pelvic wall, forming a lining for that part, covering in the obturator internus muscle, and becoming adherent below to the rami of the pubes and ischium, and to the tuber ischii. More posteriorly it gives a thin covering to the pyri- formis muscle. (2) The visceral layer comes off from the parietal along a ligamentous strand run- ning from the lower part of the symphysis pubis to the ischial spine and known as the white line. The bladder, prostate, and vagina are supported from the white line by the visceral layer of the fascia. Starting from this line the visceral layer passes down into the pelvis on the abdominal surface of the levator ani, and attaches itself to all the pelvic Chap. XVIII] PELVIS AND PERINEUM 431 viscera with which it comes in contact, forming fibrous expansions or " ligaments/' that serve to hold the viscera in place. Were there no pelvic viscera, this layer of the fascia would be con- tinued evenly across the pelvic floor from one side to the other, just as the subperitoneal fascia is continued over the under surface of the dia- phragm. Having given " reflections ,; to the pelvic organs the visceral layer passes on, and, covering the opposite levator muscle, ends at the opposite white line. This visceral layer is usually known as the recto-vesical fascia. As regards the parietal division, it will be seen that that part of it above the origin of the visceral layer (i.e. above the white line) is in the pelvic cavity, while that part below the line is in the perineum. To this lower segment the name obturator fascia is commonly given. Now, the peritoneum lines some part of the pelvic floor, and covers a great part of the pelvic viscera. Be- tween this peritoneum and the visceral layer of the pelvic fascia is a good deal of loose connec- tive tissue. Inflammation may be set up in this tissue, may spread readily in it, and may of course lead to suppuration. Such suppuration will be limited to the pelvic cavity, and will be hindered from escaping from that cavity by the pelvic fascia. Inflammations of any extent so located^ are included under the term pelvic cellulitis. Suppuration, therefore, above the visceral layer of the pelvic fascia will be limited to the pelvic cavity, while that below this layer will be limited to the perineum, to either the urethral or the anal segment of that _ district. _ Thus it will be seen that the pelvic fascia is of much surgical importance. Wounds through the perineum that involve this fascia will_ be serious, in that they will open up the loose tissue on the pelvic aspect of the fascia in which inflammation so readily spreads, while unless the fascia be wounded the pelvic cavity cannot be said to have been opened. 432 SURGICAL APPLIED ANATOMY [Part IV The fascia is so reflected upon the viscera that certain parts of them are excluded by the attach- ments of the membrane from the pelvic cavity. The parts so excluded are the prostate in the male and part of the vagina in the female. Over that part of the pelvic floor occupied by the rectum and over the rectum itself the pelvic fascia is so thin as scarcely to be distinguishable from the subperitoneal and loose pelvic tissue surrounding it. The rectum is loosely embedded, so that it may the more easily expand and contract; indeed, the only part which is at all firmly attached is the anal canal, which is fixed in the pelvic floor. Pelvic cellulitis, to use the term in the strict sense, means inflammation of the connective tissue between the pelvic , fascia and the peritoneum.* This connective tissue is chiefly situated between the anterior wall of the bladder and the pelvis, about the base and neck of the bladder, between the latter viscus and the rectum; and in the female, between the layers of the broad ligament and about the lower part of the uterus and com- mencement of the vagina. All this connective tissue is continuous, and inflammation in one part of it may spread to the other parts. In women the mischief is often found between the folds of the broad ligament, or in the hollow between the uterus and the rectum. As may be supposed, the abscess formed in such cases tends to mount up in the pelvis, being unable to escape below, and usually points in the inguinal region, or in the suprapubic region, having spread along the obliterated hypogastric artery (see p. 330). It may, however, open into one of the pelvic viscera or into the peritoneum, but both these termina- tions are rare. Out of thirty-seven cases of puer- peral pelvic cellulitis with suppuration, twenty- four burst externally, and for the most part in the inguinal region (McClintock). * Clinically the term pelvic cellulitis includes also pelvic peritonitis, and often inflammation of one or other of the viscera. Indeed, many- so-called oases of pelvic cellulitis are examples of localised pelvic peritonitis with or without suppuration. Chap. XVIII] PELVIS AND PERINEUM 433 It should be borne in mind that the blood- vessels of the pur is are placed on the peritoneal aspect of the fascia. The branches of the internal iliac artery, therefore, that leave the pelvis, escape by piercing that membrane. The obturator artery is an exception to this rule, since it passes over the upper border of the parietal pelvic fascia (Cunningham). The nerves in the pelvis lie be hind or outside the fascia, and, therefore, the pelvic vessels and the pelvic nerves are, excepting the obturator, separated from one another by this layer of tissue. The male perineum. — The perineum is a lozenge-shaped space bounded by the symphysis, the rami of the pubes and the ischia, the ischial tuberosities, the great sacro-sciatic ligaments, the edges of the two great gluteal muscles, and the coccyx. A transverse line drawn across the space between the anterior extremities of the tubera ischii, and just in front of the anus, divides the perineum into two parts. The anterior part forms nearly an equilateral triangle, measuring about 3^ inches on all sides. It is called the urethral triangle. The posterior part is also somewhat triangular, contains the rectum and ischio-rectal fossse, and is called the anal triangle. The whole space measures about o\ inches from side to side, and about 4 inches from before back- wards in the middle line. The average antero- posterior diameter of the pelvic outlet in the male averages 3^ inches. This measurement in the un- dissected subject is increased to 4 inches by the curving of the surface. The average transverse diameter of the male pelvic outlet is 3i inches, and corresponds to the measurement of the perin- eum above given. The bony framework of the perineum can be felt more or less distinctly all round, and in thin subjects the great sacro-sciatic ligaments can be made out beneath the great gluteal muscle. The anus is in the middle line between the tubera ischii, its centre being about lh inches from the tip 2 C 434 SUEGICAL APPLIED ANATOMY [Part IV of the coccyx. The raphe, a central mark or ridge in the skin, can be followed from the anus along the middle line of the perineum, scrotum, Fig. 11.— The male perineum. (After Rudinger.) a, Gluteus niaximus: b, semi-tendinosus and biceps; c, adductor magnus ; d, gracilis ; e, pyritormis ; /, obturator interims ; f small sciatic nerve. and penis. No vessels cross this line, and, there- fore, in making incisions into the perineum this line is always chosen when possible. In the middle line, midway between the centre of the anus and the spot where the scrotum joins the perineum, is Chap. XVIII] PELVIS AND PEEINEUM 435 the central point of the perineum. The two trans- verse perineal muscles, the accelerator urinse and the sphincter ani, meet at this point, which also corresponds to the centre of the inferior edge of the triangular ligament. The bulb is just in front of it, as is also the artery to the bulb, and in lithotomy, therefore, the incision should never commence in front of this spot. The perineal space is separated from the pelvic cavity by the levator ani muscles and recto-vesical fascia, as already mentioned. The depth of the perineum means the distance between the skin and the pelvic floor. This depth depends, to a great extent, upon the amount of fat under the integu- ment. It varies considerably in different parts, measuring from 2 to 3 inches in the hinder and outer parts of the perineum, and less than 1 inch in the anterior parts of the space. The ischio-rectal fossa is of pyramidal shape, its apex being at the white line, and its base being formed by the skin between the anus and the ischial tuberosity. It measures about 2 inches from before back, 1 inch from side to side, and is between 2 and 3 inches in depth. Its boundaries are : on the outer side, the obturator internus muscle, covered by the obturator layer of the pelvic fascia ; on the inner side, the levator ani, covered by the anal fascia; in front, the base of the triangular ligament and the transversus perinei muscle; and behind, the gluteus maximus, great sacro-sciatic ligament, and coccygeus. The pudic vessels and nerves are on the outer wall, embedded in the fascia over the obturator muscle, and are placed about \\ inch above the lower border of the tuber ischii. The part of the rectum which occupies the space between the two fossae is supported by the levatores ani, external sphincter, and recto-vesical fascia. Its lateral wall is exposed for a distance of _ nearly 3 _ inches, its posterior wall for about 1 inch (Quain). The fossa is occupied by a mass of fat which affords to the rectum the support of 436 SUKGICAL APPLIED ANATOMY [Part IV an elastic cushion. This fatty tissue is badly supplied with blood, and this fact, in addition to the dependent situation of the part, and its exposure when the patient sits upon damp, cold seats, etc., leads to abscess being very frequent in the space (ischio-rectal abscess). These ab- scesses are hemmed in on all sides, soon fill the fossa, and then tend to discharge themselves in the two directions where the resistance is least, viz., through the skin and through the wall of the rectum. When this double discharge of the ab- scess has taken place, a complete fistula in ano is established. It is well to note that in all fistulce in ano the opening into the rectum is nearly always within \ an inch of the anus. An opening into the bowel higher up is resisted by the attach- ment of the levatores ani, by the anal fascia, and by the recto-vesical fascia. Crossing the space obliquely from its hinder part to the anus are the external hsemorrhoidal vessels and nerves (Fig. 71); crossing the an- terior and outer corner of the fossa are the perineal vessels and nerves, and about the pos- terior border of the space are the fourth sacral nerve and some branches of the small sciatic nerve. It will be readily understood, therefore, that ischio-rectal abscesses are associated usually with extreme suffering until they are relieved. The most severe pain is probably due to the stretching of the external hsemorrhoidal nerve by the abscess as it progresses towards the surface. In opening an abscess in the fossa the main structures to avoid are the rectum, the pudic and external hsemorrhoidal vessels. Anns. — (See p. 474.) The urethral triangle. — The skin of the peri- neum between the anus and the scrotum is thin, and shows very readily any extravasations of blood that may form beneath it. The superficial fascia is divided into two layers, of which the more superficial is quite unimportant, and con- tains what little subcutaneous fat exists in this part, Chap. XVIII] PELVIS AND PERINEUM 437 The deep layer, known as the perineal fascia or fascia of Colles, is attached on either side to the rami of the pubes and ischium, and behind to the base of the triangular ligament. In front it be- comes continuous with the dartos tissue. This fascia, therefore, by its attachments forms with the triangular ligament a well-isolated aponeu- rotic space, containing the bulb with all that part of the spongy urethra between the triangular ligament and the attachment of the scrotum, the penile muscles, the transverse perineal muscles, vessels, and nerves, and the perineal vessels and nerves. When extravasation of urine follows upon a rupture of tne part of the urethra above named, the course of the escaping fluid is directed by the fascia of Colles. It fills the aponeurotic space. It is unable to gain the ischio-rectal fossa on account of the attachment of the fascia to the triangular ligament. The lateral attachments of this membrane prevent the urine from passing into the thighs. It is therefore guided into the scrotum, and there finds itself beneath the dartos tissue. It distends the scrotal tissues, and then mounts up on to the abdomen through the gap left between the symphysis pubis and pubic spine. It must be remembered that the fascia of Colles, the dartos tissue, and the deeper layer of the superficial fascia of the abdomen, are continuous, and merely represent different parts of the same structure. Pus or blood within this aponeurotic space would follow the same course if the effusion were extensive enough. The pain occasioned by such effusion can be understood when it is noted that the three chief sensory nerves of this region (the three long scrotal nerves) are included within the space. The triangular ligament has a depth of about 1^ inch in the middle line, and is formed of two layers, of which the posterior is derived from the pelvic fascia. The membranous urethra, surrounded by the compressor urethrse, lies be- tween the two layers, and runs about 1 inch below 438 SUBGICAL APPLIED ANATOMY [Part IV the symphysis, and about f of an inch above the central point of the perineum (Fig. 72). The artery to the bulb passes inwards between the two layers about \ an inch above the base of the ligament and \\ inch in front of the anus. The dorsal vein and the terminal part of the pudic artery and nerve pierce the anterior layer of the ligament about \ an inch below the symphysis. In uncomplicated rupture of the membranous urethra, the urine extravasated would be limited to the space between the layers of the ligament, until subsequent suppuration had made a way for it to escape. When extravasation occurs be- hind the triangular ligament, the effusion may collect in the retropubic space if the pelvic fascia is ruptured (Deanesley), or it may pass back- wards by the side of the rectum into the cellular tissue of the pelvis. Just beyond the triangular ligament is the prostate, surrounded by its capsule, and the pros- tatic venous plexus (Fig. 72). In dissecting down from the surface to the prostate, we meet, as Cunningham has well pointed out, alternate strata of fascial and muscular tissue, forming seven layers in all, viz. (1) superficial fascia; (2) super- ficial perineal muscles; (3) triangular ligament (ant. layer) ; (4) compressor urethras muscle; (5) triangular ligament (post, layer) ; (6) levator ani muscle; (7) sheath of prostate. Stone in the bladder. — Stones of the bladder which were formerly removed by a perineal in- cision are now commonly crushed and washed out through the urethra by the operation of litho- lapaxy. This operation is carried out readily even in male children. If the stones are too large for crushing, the supra-pubic operation is performed to give sufficient room for extraction. Although the perineal operations are now but very rarely performed^ a description of the parts in- volved helps to give a proper conception of their important anatomical relationships. Lateral lithotomy. — The first incision, 2 or Chap. XVIII] PELVIS AND PERINEUM 43d Fig. 72. — A vertical anteroposterior section of the male pel is (Braune). 440 SURGICAL APPLIED ANATOMY [Part IV 3 inches in length, is commenced just to the left of the middle line and just behind the central point of the perineum, i.e. about l\ inch in front of the anus. The incision is carried down- wards and outwards into the left ischio-rectal fossa, and ends at a point between the tuber ischii and posterior part of the anus, and one-third nearer to the tuberosity than to the gut. In the early part of this incision the staff may just be touched, as it lies in the membranous urethra, the incision becoming more and more shallow as the knife is withdrawn. The parts cut in the first incision are: (1) skin and superficial fascia; (2) transverse perineal muscle, artery and nerve ; (3) the lower edge of the anterior layer of the triangular ligament; (4) the external hsemor- rhoidal vessel and nerves (Figs. 71 and 72). In the second incision the knife, guided by the fore-finger of the left hand, is passed upwards behind the triangular ligament, is engaged in the groove on the staff as it lies in the membranous urethra, and then, having its edge turned towards the left tuber ischii, is steadily carried along the groove into the bladder. In this incision the parts divided are : (1) membranous and prostatic portions of urethra; (2) posterior layer of tri- angular ligament; (3) compressor urethrse; (4) anterior fibres of levator ani and left lateral lobe of prostate. The finger is then introduced along the staff into the bladder, the staff is removed, and, the forceps being inserted, the stone is ex- tracted, traction being made in the proper axis of the pelvis. Parts that may be wounded. — (a) In the first incision : (1) the bulb, or the artery of the bulb. These parts can be avoided by commencing the incision well behind the " central point/' and by causing the holder of the staff to draw it, the scrotum, and the penis well up. The staff should be held as close up under the pubes as possible. The bulb is very small in children, large in adults, and largest in old men. (2) The rectum Chap. XVIII. PELVIS AND PERINEUM 441 may be cut if much distended, or if the incision be made too vertical or carried too far back. In all cases the gut should be well emptied by enema before the operation. (3) The pudic vessels can hardly be wounded unless the incision is very carelessly made, and the knife carried almost against the bone as it is being withdrawn, (b) In the second incision the knife may be passed beyond the prostate, and may so incise the vis- ceral layer of the pelvic fascia as to open up the pelvic cavity. It will be understood that the lateral lobe of the prostate may be cut freely without this cavity being endangered. The gland is enveloped by the pelvic fascia, but the incision made into the prostate is well below the superior reflection of the membrane. The incision in the neck of the bladder, therefore, must be strictly limited to the prostate. The prostatic plexus of veins cannot avoid being wounded. The left ejaculatory duct would be cut if the prostatic incision were carried too far backwards. In children the pelvis is relatively narrower than in the adult, the bladder is more an ab- dominal than a pelvic organ, and the neck of the bladder, therefore, is high up. The viscus, more- over, is very movable, and has less substantial attachments than has the adult's bladder. It thus happens that in forcing the finger into the bladder after the second incision, the viscus has actually been torn away from the urethra. In children the prostate is rudimentary, and thus more of the actual neck of the bladder itself has to be cut. From the small size of this gland, it hap- pens, too, that in some cases the knife has passed too far beyond the prostatic area, and has opened up the pelvic fascia. In children also the peri- toneum descends lower on the posterior surface of the bladder, and may be wounded by a careless operator. .Median lithotomy. — In this operation the knife is entered in the middle line, just in front of the anus. The staff has a central groove, and 442 SUEGICAL APPLIED ANATOMY [Part IV the point of the knife should hit the instrument as near as possible to the apex of the prostate. As the knife is withdrawn the whole of the mem- branous urethra is incised, and a wound made in the median raphe of about \\ inch in length. The incision is made by cutting upwards. i\ probe is then introduced into the bladder, and, the staff being removed, the finger is passed into that viscus by steady dilatation of the parts, with some laceration of the prostate. The object in this operation is to enter the bladder with the least amount of cutting, and by dilatation rather than incision. Farts divided. — (l) Skin and superficial fascia ; (2) sphincter ani ; (3) central point of perineum ; (4) lower border of triangular liga- ment; (5) whole length of membranous urethra; (6) compressor urethrse. Advantages. — (1) The bleeding is much less than in the lateral operation, the slight vascu- larity of the raphe being well known. (2) The pelvic fascia is much less likely to be wounded if the bladder be entered by dilation rather than by incision, as in the lateral procedure. Disadvantages. — (1) The bulb is in great risk of being wounded. It must, however, be noted that wounds of the bulb in the middle line do not bleed readily, as a rule. (2) The amount of space obtained for the removal of the stone is very slight. (3) In children the operation in its in- tegrity is scarcely possible, since the prostate is quite rudimentary, and the slight attachments of the parts are such that, in using forcible dila- tation, the bladder may readily be torn from the urethra. If the incision be made upwards, and one linger be retained in the rectum, the risk of wounding the gut is not great. In lithotomy, and in other operations for reach- ing the neck of the bladder through the perineum, it should be remembered that the bladder lies at a depth of from 2| to 3 inches from the surface when the body is in the lithotomy position (Fig. 72). Chap. XVIII] PELVIS AND PERINEUM 443 If the bladder is empty and the rectum full, the prostate, trigone and reflection of peritoneum are carried upwards and forwards; if the bladder is full and the rectum empty, the movement is in an opposite direction ; in fat people the bladder and peritoneum are carried away from the perineum. Suprapubic litliotoiny. — This operation has been revived of late years, and in cases in which litholapaxy is contraindicated has practically supplanted the two forms of lithotomy just de- scribed. In order to bring the summit of the bladder well above the symphysis, both bladder and rectum may be dilated. Into the former vis- cus, tepid water or bora^ic lotion is injected. It is found that in the adult 8 to 10 ounces is suffi- cient to ensure the desired distension. The rectum is dilated by some operators by means of a soft rubber bag. The gut, when thus distended, pushes forward the bladder, and gives it a firm basis upon which to rest. In the adult from 10 to 14 ounces are usually introduced into the bag. Distension of the rectum alone will elevate the bladder, but may have no effect upon the reflection of peritoneum. In operating upon children the rectal bag is very seldom required, and many surgeons do not employ it in any case. In the case of a male child, aged five, the injection of 3 ounces of water into the bladder caused the reflection of peritoneum to mount to more than 1 inch above the symphysis. An incision, some 3 inches in length, is made immediately above the symphysis in the median line. The bladder is exposed below the peritoneum, is drawn forwards by a hook, and opened. The bladder. — When empty the bladder is flattened and of triangular outline, and lies against the anterior wall of the pelvis. The empty bladder may be found in one of two condi- tions (as demonstrated by Dr. Hart in the adult female bladder). It may be small, oval, and firm, with its upper wall convex towards the 444 SURGICAL APPLIED ANATOMY [Part IV abdomen. In vertical anteroposterior section the urethra forms with the cavity of the bladder a curved slit (the systolic empty bladder). It may be larger, and soft, with its upper surface con- cave towards the abdomen, and fitting into the concavity of the lower wall or surface. In the section named, the urethra forms, with the blad- der cavity, a Y-shaped figure, the two diverging limbs of the Y corresponding to the concavity named (the diastolic empty bladder). When moderately distended with an opaque solution and examined by the aid of X-rays it is seen to be conical in form, with its apex behind the sym- physis and its base or upper surface indented by the pressure of the abdominal viscera (Fig. 70, p. 418). As distension of the bladder increases, the summit of the viscus is brought more and more in contact with the anterior abdominal wall, the organ becoming also more convex on its posterior than on its anterior surface. This tendency for the summit of the distended bladder to press itself against the anterior parietes is of good service in tapping the organ above the pubes, and in supra- pubic lithotomy. When greatly distended it may reach the umbilicus, and may even touch the dia- phragm. The usual capacity of the organ is about one pint, but when fully occupied it may hold some quarts. When both bladder and rec- tum are quite empty the apex of the bladder and the prevesical reflection of the peritoneum are a little below the upper margin of the symphysis pubis. As the distended bladder ascends above the pubes it dissects the serous membrane from the parietes, and the layer so lifted off forms a cul-de-sac or fold of peritoneum between the upper part of the anterior surface of the bladder and the parietes. When the apex of the bladder is 2 inches above the pubes the peritoneal reflection is probably not more than f of an inch above the same point of bone. When the apex of the bladder is midway between the umbilicus and the pubes there may be 2 inches (vertical) of the an- Chap. XVIII] PELVIS AND PERINEUM 445 terior abdominal wall in the middle line and im- mediately above the symphysis devoid of peri- toneal lining. Thus it happens that the distended viscus may be readily tapped above the pubes without the peritoneum being wounded. As the bladder becomes distended, not only does it rise into the abdomen, but it extends also towards the perineum, diminishing the length of the prostatic and membranous urethra. In suprapubic litho- tomy that tendency to extend downwards is pre- vented by the rectal bag (p. 442). Between the anterior surface of the bladder and the symphysis, and shut in by the peritoneum above, is the retropubic or prevesical space, con- taining lax connective tissue (Fig. 73). The loose- ness of this connective tissue permits the bladder to readily ascend as it fills. In injuries to the pelvis and to the front of the bladder a diffuse inflammation may be set up in this tissue and assume serious proportions. I have reported a case where an extensive suppuration in this area followed upon aspiration of the bladder above the pubes, and led to death. Like suppuration has followed suprapubic lithotomy. In rupture of the anterior wall of the viscus or of the urethra above the triangular ligament the urine escapes into this district of cellular tissue ; a limited sup- puration may follow and recovery ensue. The bladder, although fairly fixed, has been found in inguinal, femoral, and vaginal hernise. In the erect position its neck (in the male) lies on a horizontal line drawn from before backwards through a point a little below the middle of the symphysis, and is placed about 1\ inch (3 cm.) behind that articulation (Tillaux). Relations to the peritoneum. — The anterior surface is entirely devoid of peritoneum, while the superior surface is entirely covered by that membrane. At the sides there is no peritoneum in front of, or below, the obliterated hypogastric arteries. On the posterior aspect of the bladder the serous membrane extends down as far as a 446 SUKGICAL APPLIED ANATOMY [Part IV transverse line, uniting the upper parts of the two seminal vesicles, so that the upper ends of the vesicles are covered by peritoneum. This recto-vesical pouch of peritoneum in the adult ex- tends to within about 3 inches of the anus, and does not reach below a line 1 inch above the base of the prostate. Harrison Cripps gives the dis- tance of the pouch from the anus as 2| inches when the bladder and rectum are both empty, and as 3j inches when those viscera are distended. (See Bladder in the Child, p. 450.) Puncture of the bladder per rectum. — The base of the bladder is adherent to the rectum by dense areolar tissue over a triangular area the apex of which is formed by the prostate, the sides by the diverging seminal vesicles, and the base by the recto-vesical fold of peritoneum. This triangle is equilateral, and in the dissected specimen measures about l\ inch on all sides. It corresponds to the trigone on the inner surface of the viscus. It is through this triangle, and as near as possible to the prostate, that the blad- der is tapped when the operation is performed per rectum. The recto-vesical fold of peritoneum is raised, and is carried still farther from the anus when the organ is distended. Rupture of bladder.— The bladder may be ruptured by violence applied to the anterior ab- dominal wall apart from pelvic fracture or ex- ternal evidence of injury. Such a rupture can, however, hardly happen to the empty bladder ; it must be full or distended at the time of the acci- dent. It is very rare for the rupture to be on the anterior surface only. As a rule, the tear in- volves the superior or abdominal surface, and im- plicates the peritoneum. The injury, therefore, is very fatal (five recoveries out of seventy-eight cases). In some cases of vesical rupture the sur- geon has opened the abdomen and has stitched up the rent in the viscus with perfect success. The bladder may be torn by fragments of bone in fractures of the pelvis, or by violence applied Chap. XVIII] PELYIS AND PERINEUM 447 through the rectum or vagina. A case, for ex- ample, is reported (Holmes's " System of Sur- gery ") of a man who fell upon a pointed stake fixed in the earth. The stake passed through the anus, pierced the rectum, and entered the bladder near the prostate. The patient recovered, the wound having been made in the triangular area on the fundus of the bladder alluded to above, and therefore outside the peritoneum. The viscus may be ruptured by an accumulation of urine, as seen in cases of congenital closure of the urethra in some infants. In the museum of the Royal College of Surgeons is a preparation of " the bladder of a woman which burst near the entrance of the ureter in consequence of neglected reten- tion of urine. ;; In neglected cases of stricture in the male the urethra gives way rather than the bladder, and an extravasation of urine into the perineum follows. A small puncture of the bladder, as, for example, that made by a fine trochar, is at once closed by the muscular con- traction of its wall. The mucous meintoraiie of the bladder is very lax, to allow of its accommodating itself to the varying changes in the size of the viscus. Over the trigone, however, it is closely adherent, and were it not so the loose mucous membrane would be constantly so prolapsed into the urethral orifice during micturition as to block up the neck of the bladder. When examined by the cystoscope, the mucous membrane is seen to be red and con- gested when the bladder is empty, pale and ansemic when the bladder is full (Newman). The trigone is bounded by three orifices, for the ure- thra and the two ureters, and forms an equilateral triangle, measuring about lh inch on all sides. It is here that the effects of cystitis are most evi- dent, and the unvielding character of the mucous membrane over the trigone serves in part to ex- plain the severe symptoms that follow acute in- flammation of that structure. Since the orifice of the urethra forms the lowest part of the bladder 448 SUKGICAL APPLIED ANATOMY [Part IV in the erect posture, it follows that calculi gravi- tate towards the trigone, and are very apt to irritate that part of the interior. The same re- mark applies to foreign bodies in the viscus. The mucous membrane about the trigone and neck is very sensitive, whereas the interior of the re- mainder of the bladder appears to be singularly defective in common sensation. This can be well noted in using sounds and catheters. The sensory nerves for the bladder are de- rived mainly from two parts of the spinal cord, namely, the twelfth dorsal and first lumbar seg- ments, and the second, third, and fourth sacral segments. From the first source (through the hypogastric plexus) come the sensory nerves to the upper part of the bladder and the motor nerves which stimulate the internal sphincter and inhibit the expelling musculature ; from' the second source (through the nervi erigentes) the motor fibres which stimulate the expelling mus- culature and inhibit the sphincter. The trigone, having the same nerve supply as the penis and scrotum, gives rise, when injured, to pains which are referred along the perineal nerves. In the muscular coat of the bladder the fibres are collected in bundles which interlace in all directions. When the viscus becomes hyper- trophied these bundles are rendered very distinct, and produce the appearance known as " fascicu- lated bladder. " This simply means that the muscle of the bladder, having been unduly exer- cised to overcome some obstruction to the escape of urine, increases in size, as do other much- exercised muscles, and that increase serves to demonstrate the arrangement of the individual bundles. From distension the mucous membrane becomes bulged out between the unyielding muscle bundles, so that sacculi are formed, and the ap- pearance known as " sacculated bladder " is pro- duced. In some cases the parietes yield, especially at one part, and one large saccule is produced. In this way a sacculus may be formed which in Chap. XVIII] PELVIS AND PERINEUM 449 time may become almost as large as the bladder itself, and give rise to the erroneus description of " double bladder," etc. The ureters run for f of an inch in the mus- cular wall of the viscus, and their oblique course, together with the action of the muscular _ tissue about them, tends to prevent regurgitation of urine. On cystoscopic examination it is seen that once or twice a minute each ureter contracts and expels a spurt of urine into the bladder ; be- tween these spurts the ureteric orifices are closed as if by a sphincter. If the ureter becomes con- tracted, as is the case if it is the seat of a tuber- cular ulceration, the vesical orifice of the ureter is pulled outwards (Fenwick). The mucous mem- brane is laxly attached and may be prolapsed within the bladder as a pedunculated body. In cases of retention the ureters become distended ; but this is due rather to accumulation of urine within them than to its reflux from the bladder. In cases of great distension of the bladder the neck of the viscus is opened up by the pressure from within, and the patient exhibits the feature of overflow of urine. The female bladder is less capacious than that of the male. Its neck is situate a trifle nearer to the symphysis than it is in the male, and lies in a horizontal line continued back from the lower border of the symphysis. There being no prostate, the neck of the bladder is very dis- tensible, and this fact, taken in connection with the shortness and dilatability of the urethra, allows of most stones being extracted by forceps without cutting. By simple dilatation, stones of a diameter of f of an inch have been removed. Through the dilated urethra the orifices of the ureters can be seen and examined. The intimate relation of the bladder to the vagina allows it to be examined well from the latter passage, and the comparative thinness of the dividing wall serves to explain the frequency of vesico-vaginal fistulse. Strange foreign bodies have been intro- 2 D 450 SURGICAL APPLIED ANATOMY [Part IV duced into the female bladder, such as hair-pins, crochet hooks, sealing-wax, penholders, and the like. The orifice of the ureter is 3 cm. from the cervix uteri, and 4 cm. from the vesical opening of the urethra. Its close relation to the cervix renders it liable to injury in supravaginal amputation of that part, and in certain operations on the uterus. r*! The bladder in the child is egg-shaped, and its vertical axis is relatively much greater than it is in the adult. The larger end of the egg- shaped cavity is directed downwards and back- wards. The fundus is developed and the pelvic position assumed about the fourth year (Birming- ham). The viscus is situated mainly in the abdo- men, the pelvis being small and very shallow. At birth the orifice of the urethra is on a level with the upper edge of the symphysis. Although the bladder projects so freely into the abdomen, its anterior wall is still entirely uncovered by peri- toneum. On the posterior wall the serous mem- brane extends lower down than in the adult, reaching the level of the urethral orifice at the time of birth, and the level of the prostate in young male children. The prostate is exceedingly small in children. Thompson states that at the age of seven years it only weighs thirty grains, whereas in subjects between eighteen and twenty it weighs two hundred and fifty grains. The bladder wall in the child is so thin that in sound- ing for stone it is said that a " click ' ; may be elicited by striking the pelvis through the parietes of the viscus. The prostate. — The prostate is situated about I of an inch below the symphysis pubis, and rests upon the rectum above the anal canal (Fig. 72). It is, therefore, placed within 1^ to 2 inches from the anus, and can be readilv examined from the bowel. The prostate is made up of two lateral lobes which fuse together in front of the urethra by a pubic commissure (Fig. 73) and behind by Chap. XVIII) PELVIS AND PERINEUM 451 two commissures, one above the common ejacula- tory ducts — the median commissure — and one be- low these ducts — the rectal commissure {see Fig. 73, b, d). The part here named median commis- sure was formerly known as the median lobe — a name which is apt to mislead, for it is not a separate lobe, but, as already explained, merely a fusion of the two lateral lobes. Each gland Fig. 73.— A, Median section of the normal prostate ; B, similar section of enlarged prostate. a, a, Sphincter vesicae; b, median commissure; c, common ejactulatory duct ; d, rectol commissure ; e,e, constrictor urethras ; v, rectOr-urethral muscle ; u, Cow- per's gland ; n, ejaculator urinae ; I, internal sphincter of anus ; .t, external. sphincter of anus ; k, symphysis pubis ; L, retropubic space ; m, pubo- prostatic ligaments and sheath of prostate ; N, dorsal vein of penis ; o, pubic commissure ; p, corpus cavernosum ; q, urethra ; r, bulb. is made up of numerous branching tubular glands which are embedded in and surrounded by non- striated muscle and fibrous tissue. The glands end in the urethra — chiefly in the prostatic sinuses — but the use of their secretion is un- known. The secretion from the gland is discharged through the long and very narrow ducts of glands which are diffusely arranged as two lateral masses or lobes. In certain forms of prostatic irrita- tion, little white opaque threads, very much like 452 SURGICAL APPLIED ANATOMY [Part IV short pieces of cotton, are found in the urine, and are actual casts of the prostatic ducts. The sheath and capsule of the prostate. — Owing to the success which has attended enuclea- tion as a means of treatment for enlarged pros- tate, much discussion has recently taken place concerning its ensheathing structures. The term capsule is now usually applied to the superficial fibro-muscular stratum of the gland, while the term sheath is applied to the enveloping fibrous structure derived from the pelvic fascia. In enu- cleating the gland everything within the sheath is removed. At only one part is the sheath in- timately adherent to the capsule, and that is along the anterior or pubic surface ; elsewhere it is free from it. Since the base of the prostate is applied to the bladder and uncovered by the sheath, while elsewhere it is enclosed, it follows that the sheath is most easily entered and the gland enucleated from the bladder. The sheath determines the course of a prostatic abscess. The prostatic abscess usually bursts into the urethra, that being the direction in which least resistance is encountered. If it does not enter the urethra, it will probably open into the rectum, there being only one layer of the pelvic fascia, and that layer not a thick one, between the two organs. This encasement of the gland in an unyielding membrane will serve, in part, to explain the severe pain felt in acute prostatic abscess. In acute prostatitis pains are referred over the tip of the last rib (tenth dorsal nerve), over the posterior iliac spine (eleventh dorsal nerve), or even to the soles of the feet (third- sacral nerve). It derives its nerve supply from the lower three dorsal and upper three sacral segments ; hence the widely distributed character of the referred pains (Head). Hypertrophy of the prostate. — The average measurements of the normal prostate are 1^ inch across at its widest part, and 1\ inch from be- fore backwards, or from apex to base. After the Chap. XVIII] PELVIS AND PERINEUM 453 age of fifty-three the organ is very apt to become hypertrophied ; and, according to Sir Henry Thompson, this hypertrophy may be^ considered to exist when the gland measures 2 • inches from side to side, or when it weighs 1 ounce or more. The usual weight of the prostate is 6 drachms. If the enlargement mainly affect the lateral parts, it will be understood that the hypertrophy may at- tain considerable dimensions without retention of urine being produced. On the other hand, a comparatively trifling enlargement of the median commissure may almost entirely block the orifice of the urethra. As this part enlarges it pushes its way into the bladder through the urethral orifice, dilating and destroying the sphincter vesicae and forming a mechanical obstruction to the free passage of urine (Fig. 73, B). If the affection be general, the prostatic urethra is lengthened, and if one lateral lobe be more en- larged than the other, the canal deviates to one side. When the enlargement particularly affects the median commissure, the prostatic urethra, which is normally almost straight, becomes con- siderably curved, the curve being sometimes very abrupt. It is important to note that enlarge- ment of the median commissure alone can hardly be made out by rectal examination. The project- ing middle commissure, when viewed from the in- terior of the bladder, may appear as a distinct, well-rounded pedunculated or sessile growth. In the operation of prostatectomy this project- ing and most troublesome mass is removed through a suprapubic incision. Everything within the sheath of the prostrate — gland, urethra, common ejaculatory ducts — is enucleated by the surgeon's finger through the base of the bladder; the sheath then encloses a space which at first is filled witn blood and urine, but afterwards con- tracts to form a new urethra. The prostrate is a sexual organ, and its size and development de- pend on the presence and activity of the testes. Castration prevents its development or causes 454 SUKGICAL APPLIED ANATOMY [Part IV atrophy if already developed. Removal of one testicle causes a partial atrophy, but section of the vasa deferentia has usually no effect (C. Wallace). Embedded in the sheath of the pros- tate, especially over the groove between the base of the prostate and neck of the bladder, is an ex- tensive plexus of veins, the prostatic plexus, into which enters the dorsal vein of the penis (Fig. 73 A). This plexus is cut in lateral lithotomy, and it is through its vessels that septic matter is probably absorbed in cases of pyaemia following that' operation. Its lymphatics, which are numerous, pass to a group of glands on the wall of the pelvis, between the external and internal iliac arteries. The male urethra is about 8| inches in length (21 cm.), \\ inches being devoted to the prostatic urethra, f of an inch to the mem- branous, and 6^ inches to the penile or spongy portion. Between the ages of four and six years its length is 8 to 9 cm., and between ten and thir- teen years 10 to 11 cm. The canal may be divided into a fixed and movable part. The fixed part extends from the neck of the bladder to the posterior extremity of the penile urethra at the point of attachment of the suspensory ligament. The fixed part describes an even curve, fairly represented by the line of a " short curve " metal catheter. The two ends of the curve lie about in the same line, viz. one drawn across the lower end of the symphysis, and at right angles to the vertical axis of that articulation. The curve is formed around this line, its centre summit corre- sponding to a prolongation of the vertical axis of the symphysis, and to about the centre of the mem- branous urethra. This part of the tube lies about 1 inch below the pubic arch. The movable portion of the urethra forms, when the penis is dependent, a second curve in the opposite direction, so that the whole canal follows somewhat the outline of the letter S. The prostatic portion of the urethra is nearly Chap. XVIII] PELVIS AND PERINEUM 455 vertical. It" is surrounded by circular muscular fibres which may give rise to a spasmodic stricture (Fig. 73)- The sinus pocularis or uterus mascu- linus, in the floor of this part of the urethra, represents the united ends of the rudimentary Miillerian ducts. The penile or spongy portion of the urethra is surrounded by the erectile tissue of the corpus spongiosum urethrse, which is thickest on the under side of the canal. A very thin layer of erectile tissue surrounds the membranous urethra lying beneath the fibres of the compressor urethrse. In introducing a catheter it must be noted that while the instrument passes along the mov- able urethra, the canal accommodates itself to the catheter, but while traversing the fixed segment the instrument must accommodate itself to the unyielding canal. In introducing a catheter in the recumbent posture the penis is held vertically upwards, and in this way the curve formed by the movable urethra is obliterated. The instru- ment is best kept close to the surface of the groin, and over and parallel to Poupart's ligament. When the fixed urethra is reached, the handle of the catheter is brought to the middle line, and then, being kept strictly in the median plane of the body, is depressed between the legs, so that the front of the instrument may follow the natural curve of the canal. The greatest difficulty in the introduction is generally experienced at the point where the movable and fixed parts of the urethra meet; or, rather, in practice, at a spot a little behind this point, viz. at the anterior layer of the triangular ligament (Fig. 73). At this spot the tube abruptly becomes not only very fixed, but also very narrow, and a part of it is reached where muscular tissue is very abundant, and where _ resistance from muscular spasm is there- fore likely to be most marked. It thus happens that when a false passage has been made by a catheter in a case where no 456 SUEGICAL APPLIED ANATOMY [Part IV stricture exists to offer a definite obstruction, the instrument is usually found to have left the canal just in front of the triangular ligament. Some other points in connection with cathe- terisation will be noted subsequently. The urethral canal must not be regarded as forming an open tube like a gas-pipe. Except when urine or an instrument is passing along it, the tube appears on section as a transverse slit, the superior and inferior walls being in contact. This fact should be remembered in amputation of the penis by the ecraseur. In the fossa navicu- lars the tube appears as a vertical slit. The prostatic part of the canal is the widest and most dilutable portion of the whole urethra. It is widest at its centre, having here a diameter of nearly \ an inch ; at the bladder end its dia- meter is about \ of an inch, while at the anterior extremity of this part of the urethra the measure- ment is a little less than \ of an inch. When small catheters are being introduced their points may lodge in the orifice of the utricle, unless the tip of the instrument be kept well along the roof of the canal. The ejaculatory ducts open into the prostatic urethra, and thus it happens that in- flammation of this part of the canal may spread back along those ducts to the seminal vesicles, and from thence along the vas deferens to the epididy- mis (Fig. 73). It is by spreading along these parts that inflammation of the testicle is set up in gonorrhoea involving the prostatic urethra, and it will be understood that a like inflammation may follow lateral lithotomy, impacted stone in the prostatic urethra, prostatic abscess, and the like. Stricture never occurs in this part. The membra?wus urethra is, with the exception of the meatus, the narrowest part of the entire tube. Its diameter is about | of an inch. It is fixed between the two layers of the triangular ligament, and is the most muscular part of the canal. It is at this spot, therefore, that what is known as " spasmodic stricture " usually occurs. Chap. XVIII] PELVIS AND PERINEUM 457 In any case, the contraction of the constrictor urethra? often offers an appreciable amount of re- sistance to the passage of a catheter or sound (Fig. 73). The penile urethra is clilaed at either end, viz. at the parts occupying the bulb and the glans penis respectively. The diameter of the bulbous urethra is midway between that of the prostatic and membranous segments of the canal, while that of the greater part of the penile urethra is mid- way between that of the bulbous and membran- ous portions. It is in the bulbous urethra that organic stricture is the most commonly met with. The meatus measures from \ to \ of an inch, and therefore if a catheter will pass the meatus it will pass along an3^ part of the normal canal. Its aperture is very resisting, and has often to be incised to allow the larger instruments to pass. The narrowest parts of the urethra, therefore, are (1) at the meatus, and (2) in the membranous segment, especially at its anterior end. It is at these points that calculi passed from the blad- der are most apt to lodge. The widest portions of the canal, on the other hand, are at (1) the fossa navicularis, (2) the bulbous part of the urethra, and (3) the centre of the prostatic portion. Keegan has shown that the urethra of a male child two or three years of age will take a No. 9 catheter. In boys between eight and ten years a No. 11 lithotrite may be passed. It will be obvious, therefore, that the operation of lithotrity may be performed upon quite young male children, and that fragments of crushed calculus of no small dimensions may be removed from the bladders of such patients by washing. The mucous membrane presents, in addition to many mucous glands, several lacunae, the ori- fices of which for the most part open towards the meatus. These lacunae are most numerous in the bulbous urethra, and occupy the floor rather 458 SUKGICAL APPLIED ANATOMY [Part IV than the roof of the canal. In passing small catheters, therefore, the point of the instrument should be kept along the upper surface of the tube, so that it may not become engaged in any of these spaces. The largest lacuna, the lacuna magna, is situate in the roof of the fossa navicu- lars, and may readily engage the point of a small instrument. The urethra may be ruptured by the patient falling astride of some hard substance. In such an injury it is crushed between the hard substance and the pubic arch. The part of the canal, there- fore, that is most often damaged is the mem- branous segment, and the posterior part of the penile division. The more the body is bent for- wards at the time the perineum is struck, the greater is the length of penile urethra that may be crushed against the pubes. The female urethra is about \\ inch in length, and has a diameter of from \ to \ of an inch. It is capable, however, of great distension. In the erect position the canal is nearly vertical, and in the recumbent posture almost horizontal. Pewis. — The skin covering the bulk of the organ is thin and fine, and the subcutaneous tissue is scanty and lax. It follows, from the looseness of this tissue, that the skin is very distensible and movable. The latter fact should be borne in mind in circumcision, for in performing that operation the skin of the penis can be so readily drawn forwards over and beyond the glans, that if it is excised as far back as possible the greater part of the organ may be left bare. This applies, of course, mainly to children. The laxity of the submucous tissue permits the organ to be- come enormously swollen when cedematous, or when extravasated urine finds its way into the part. Over the glans penis the mucous mem- brane is so adherent that there is practically no subcutaneous tissue. It happens, therefore, that when Hunterian chancres appear on this part they can never be associated with other than the Chap. XVIII] PELVIS AND PERINEUM 459 most trifling induration, there being no tissue in which the thickening can develop. At the corona, on the other hand, the submucous tissue is lax and plentiful, so that the induration can readily form, and it is about this spot, therefore, that the syphilitic sore often attains its most characteristic development. The vascularity of the penis, and the rapid engorgement that ensues when the re- turn of its venous blood is impeded, serve to ex- plain the ready and extensive swelling of the organ that follows when any constricting band is placed about it. This should be borne in mind in tying in a catheter by securing it by tapes around Prepuc Corp.Caver/mos Q LA/IS Lacuna AIaqna Fossa AIaviculari Permanent AIea Primitive All Fig. 74. — Section of a penis showing a common form of hypospadias. The cross marks the point" where the tissue breaks down between the cloacal urethra and meatal ingrowth. the penis. The blood spaces in the corpus spongi- osum may be rendered indistensible from gonor- rhoeal inflammation w T hile those of the corpora cavernosa remain free. The corpus spongiosum then acts like the string of a bow during the erec- tion of the penis. Through the superficial lym- phatics disease may spread from the skin and meatal region of the penis to the inner of the in- guinal glands. Deeper vessels pass with the pros- tatic veins to the internal iliac group of glands on the lateral wall of the pelvis. Some vessels pass directly to the external iliac glands through the crural ring. The penis is often the seat of arrests of development, presenting a variety of appearances. Among them may be mentioned hypospadias, where the inferior wall of the 460 SURGICAL APPLIED ANATOMY [Part IV urethra and corresponding part of the corpus spongiosum are wanting, and epispadias, where the superior wall of the canal and corresponding parts of the corpora cavernosa are more or less entirely deficient. In the condition of hypo- spadias two meati are present — one situated on the glans opening into a cul-de-sac which repre- sents the fossa navicularis, and another just behind leading into the urethra (Fig. 74). Here is seen the double origin of the male urethra — the part within the glans is formed by an ingrowth of epithelium from the surface of the glans, while the rest of th,e penile urethra is derived from the cloaca. At first the cloacal urethra opens by its own orifice (primitive meatus, Fig. 74), but in the course of development the ingrowth from the glans takes place to form the permanent meatus and fossa navicularis ; when this ingrowth opens into tne cloacal urethra the primitive meatus becomes closed. The frenum preputii is formed over it. The condition thus represented is one of ar- rested development. On the prepuce of such cases sebaceous glands are arranged in two pigmented oval groups — preputial ocelli (Shillitoe). Scrotum. —The skin of the scrotum is thin and transparent, so that in bruising of the parts the discoloration due to the extravasation of blood beneath the surface is readily and distinctly seen. It is also very elastic, and allows of great distension, as is seen in large scrotal hernise and testicular tumours. The integument of the part is indeed redundant, and the excision of a portion of it will hardly be missed. Even in gangrene of the scrotum, when both testicles have been exposed, the parts have been entirely restored without any inconvenient shrinking or contraction. The rugce on the surface of the scro- tum favour the accumulation of dirt, and the irritation set up by such accumulation may be the exciting cause of the epitheliomata that are not uncommon in this part. When the surface is sweating, the rugse tend to favour a retention of Chap. XVIII] PELVIS AND PERINEUM 461 the moisture between their folds ; from this and other circumstances it happens that the scrotum is liable to eczema and to those syphilitic skin disorders that are often localised by irritation. The rugse are a sign of health, since they depend upon the vigorous contraction of the muscle fibres in the dartos tissue. In the enfeebled, or under the relaxing effects of heat, the scrotum becomes smooth and pendulous. In a simple incised wound, as in castration, the dartos is apt to turn in the edges of the skin and cause some difficulty in applying the sutures. This difficulty may be avoided by relaxing that tissue for a while by the application of a warm sponge to the wound. The subcutaneous tissue is lax and very ex- tensive, and permits of considerable extravasa- tions of blood forming beneath the surface. It is unadvisable, therefore, to apply leeches to the scrotum itself, since they may lead to an unde- sirable outpouring of blood beneath the skin, and to the appearance of a considerable ecchymosis. Leeches in testicular affections had better be ap- plied over the region of the cord. The scrotum, from its dependent position, and from the looseness and extent of its cellular tissue, is often the first part of the body to become cedematous in dropsy, and is apt to show that oedema in a marked degree. The scrotum also is the part most frequently the seat of elephantiasis, which is due essentially to a distension of the lym- phatic vessels and spaces of the connective tissue. The vitality of the scrotum is not considerable, and it therefore not unfrequently sloughs in parts when severely inflamed. For' this reason strapping should be applied with some care over the enlarged testis, for against the hard mass of the affected gland the integument of the scrotum can be subjected to considerable pressure when the strapping is tightly applied. _ In such a case I have seen the whole of one side of the scrotum slough from an indiscreet use of this familiar method of treatment. 462 SURGICAL APPLIED ANATOMY [Part IV The laxity of the subcutaneous scrotal tissues is an essential feature in those operations for the radical cure of inguinal hernia where the fundus of the sac is invaginated, through an incision in the scrotum into the orifice of the inguinal canal. Lastly, the great mobility of the scrotum affords an admirable source of protection to the testicle ; for when the part is struck or squeezed the testis can slip about within the scrotum, as a smooth ball would within a loose indiarubber bag, and so very often eludes all injury. , The testicle may be retained within the ab- dominal cavity, or may lodge for varying periods of time, or for life, in the inguinal canal. It may, on the other hand, pass beyond the scrotum into the perineum, or may miss the inguinal canal altogether and escape through the femoral canal and saphenous opening on to the thigh. The testis proper is entirely invested by the visceral layer of the tunica vaginalis, except over a small part of its posterior border where the vessels enter. The epididymis is entirely covered by the serous membrane at its sides, is more or less so covered in front, but is free or uncovered along the greater part of its posterior border. It. is about the posterior border of the epididymis that the visceral layer of the tunica vaginalis joins the parietal layer. The posterior border of the testicle and of the epididymis — from globus major to globus minor— is bound by a reflection of serous membrane — the mesentery of the testicle. Instead of binding the whole of the posterior border, the mesentery may be attached merely to the lower pole of the testicle and globus minor ; on such a pedunculated attachment the testicle is apt to become strangulated by a twisting of its narrow mesentery. The more intimate and exten- sive connection of the serous tunic with the testis or gland proper serves in part to explain the greater frequency with which hydrocele appears in inflammation of this part of the organ, as compared with its occurrence when the epididy- Chap. XVIII] PELVIS AND PERINEUM 463 mis is alone inflamed. It is owing to the reflec- tions of the tunica vaginalis that in cases of common hydrocele the testicle remains firmly set at the lower and posterior part of the swelling, and yet so extensively is the organ surrounded by that membrane that the position of the gland in the larger hydroceles is often difficult to deter- mine. In some cases the testicle occupies the front of the scrotum, the epididymis being placed an- teriorly, and the body of the gland being located behind it. The vas deferens descends also along the front of the cord. In these cases the testicle is just in the position it would occupy if it had been turned round upon its vertical axis. The condition is known as inversion of the testicle, and should be sought for in cases of hydrocele, as in several instances the testis has ^been pierced by the trochar when tapping collections in cases where the inversion existed. The proper gland tissue is invested by a very dense membrane, the tunica albuginea. The epi- didymis, on the other hand, lacks any such firm fibrous investment. The unyielding character of the tunica albuginea serves in great part to_ ex- plain the intense pain felt in acute affections of the testis proper, a degree of pain which is not reached when the less tightly girt epididymis is alone involved. It willbe understood also that in inflammation of the epididymis the part swells rapidly and extensively, while in a like affection of the body of the gland the swelling is compara- tively slow to appear. It should be borne in mind that the lymphatics of the scrotum go to the inguinal glands, those of the testicle to the lumbar. The testicle is de- veloped in front of the tenth dorsal vertebra, and receives its nerve supply from the tenth dorsal segment. Its nerves pass by the small splanchnics, solar and aortic plexuses, to the spermatic artery, on which they reach the gland. The epididymis receives its nerve supply from the pelvic plexus, along the vas deferens. 464 SUKGICAL APPLIED ANATOMY [Part IV The spermatic cord, — The structures in the cord are (l) the vas deferens, (2) the cremaster muscle, (3) the spermatic and (4) cremasteric arteries, (5) the artery to the vas deferens, (6) the pampiniform plexus of veins, (7) the genito-crural nerve, (8) sympathetic nerve fibres, and (9) lymphatics. The vas deferens lies along the posterior aspect of the cord (Fig. ?5), and can be detected by the firm, cord-like sensation which it gives when pinched between the thumb and finger. Mr. Birkett (Holmes's "System") gives three cases of rupture of the vas deferens EE— Fig. 75. — Section of the left spermatic cord of an adult, at the level of the external abdominal ring, viewed from above. (From a specimen prepared by Mr. W. G. Spencer.) vd, vas deferens ; da, deferential artery ; dv, deferential veins ; sa, spermatic artery ; ca, cremasteric artery ; cm, cremaster muscle ; pp, pampiniform plexus. during severe and sudden exertion. The duct ap- pears to have in each case given way within the abdomen at some point between the internal ring and the spot where it approaches the ureter. Re- section of part of the vas has been practised to bring about atrophv of enlarged prostate, but has not proved successful. The size of the cremaster muscle depends mainly upon the weighty it has to suspend. In atrophy of the testicle it almost entirely disappears, while in cases of large slow- growing tumours of the gland it attains consider- able proportions. If in children or young adults the skin over the middle of the thigh just below Poupart's ligament be tickled the testicle of the Chap. XVIIIj PELVIS AND PERINEUM 465 same side will usually be seen to be suddenly drawn upwards. The tickling concerns the crural branch of the genito-crural, while the motor nerve of the cremaster is the genital division of the same trunk. The interval of time that elapses between the irritation of the skin and the movement of the testicle has been appealed to as affording evi- dence of the state of nerve health and of the readiness with which nerve impulses are con- ducted. Of the arteries, the spermatic comes from the aorta and lies in front of the vas, the cre- masteric arises from the deep epigastric and lies among the superficial layers of the cord in its outer segment, while the deferential artery from the superior or inferior vesical lies by the side of the vas (Fig. 75). The first-named vessel is the size of the posterior auricular, and the two latter the size of the supraorbital. The spermatic artery divides into a number of branches as it reaches the testicle ; these branches pass to the inner side of the epididymis, which may be removed without interfering with the blood supply of the testicle. The three arteries of the cord are divided in castration, and may all require ligature. It is advisable to secure the vessels in sections, rather than adopt the clumsy plan of involving the whole cord in one common ligature. The veins are divided roughly into two sets. The anterior is by far the larger set, runs with the spermatic artery, and forms the pampiniform plexus. The posterior set is small and surrounds the vas, run- ning with the deferential artery. The veins of the spermatic and pampiniform plexus are very frequently varicose, and then constitute the affec- tion known as varicocele. Many anatomical causes render these veins liable to this affection : they occupy a dependent position, and the main vein is of considerable length, and follows a nearly vertical course ; the vessels are very large when compared with the corresponding artery, and so the vis a tergo must be reduced to a mini- mum : they occupy a loose tissue, and are lacking 2e 466 SURGICAL APPLIED ANATOMY [Part IV in support and in the aid afforded to other veins (as in the limbs) by muscular contraction; they are very tortuous, form many anastomoses, and have few and imperfect valves; they are exposed to pressure in their passage through the inguinal canal. The left veins are more frequently affected than the right. Mr. Spencer has shown that the veins in the left cord are always much larger than those of the right. It may also be pointed out that the left testicle hangs lower than the right ; that the left spermatic vein enters the left renal at a right angle, while the right spermatic vein passes Obliquely into the vena cava ; and that the left vein passes beneath the sigmoid flexure, and is thus exposed to pressure from the contents of that bowel. The congenital origin of vari- cocele is now very generally allowed. When the varicose veins are exposed by opera- tion it is impossible to isolate or even recognise the arteries. The female generative organs require but little notice in the present volume. The labia majora have the same pathological tenden- cies as has the scrotum, to which, indeed, they anatomically correspond. They are liable to present large extravasations of blood, are greatly swollen when cedematous, are prone to slough when acutely inflamed, and are the usual seats of elephantiasis in the female. A hernia may pre- sent in one or other labium (pudendal hernia), the neck of the sac being between the vagina and the pubic ramus. " On everting one of the labia minora and pressing the hymen inwards, a small red de- pression may generally be seen on the vulva, somewhat posteriorly. It leads to the orifice for Bartholin's gland ;; (Doran). This gland, an oval body about \ an inch in length, lies against the posterior part of the vaginal orifice, under the superficial perineal fascia, and covered by the fibres of the sphincter vaginae. It wastes after thirty. It corresponds to the gland of Cowper Chap. XVIIIJ PELVIS AND PERINEUM 467 in the male (Fig. 73, p. 451). Both are apt to become the sites of chronic gonorrhoea! inflamma- tion. Abscess of the gland and cystic dilatation of its duct are not uncommon. The vagina is lodged between the bladder and rectum, while the upper fourth of its posterior surface is covered with peritoneum, and is there- fore in relation to the abdominal cavity. Thus it happens that the bladder, the rectum, or the small intestines may protrude into the vagina by a yielding of some parts of its walls and thus pro- duce a vaginal cystocele, rectocele, or entero- cele. The anterior wall of the vagina measures a little over 2 inches, the posterior wall about 3 inches. The long axis of the canal forms an angle of 60° with the horizon, and is therefore almost parallel to the pelvic brim. The loose areolar tissue at the base of the broad ligament lies on each side of the upper extremity of the vagina. The ureter terminates in the bladder, on the upper part of the vaginal roof. The abdominal cavity may be opened through a wound of the vagina. In one or two instances of such injuries several feet of intestine have pro- truded through the vulva. In one reported case an old woman, the subject of a brutal rape, walked nearly a mile with several coils of the small bowel hanging from her genitals. From the comparative thinness of the walls that separate the vagina from the bladder and rectum, it happens that vesico-vaginal and recto- vaginal fistulas are of frequent occurrence. The vagina is very vascular, and wounds of its walls have led to fatal haemorrhage. It is very dilat- able, as can be shown when the canal is plugged to arrest haemorrhage from the uterus. The uterus weighs about one ounce. The uterine cavity and the cervical canal together measure about 2^ inches. This must be borne in mind when passing a uterine sound. The blood- vessels run transversely to the length of the 468 SURGICAL APPLIED ANATOMY [Part IV uterus, so that a ligature may be placed com- pletely around the organ without affecting the circulation above or below. Ligature of the uterine artery has been practised to arrest the growth of uterine tumours. The artery rises from the in- ternal iliac \ an inch below the pelvic brim and passes to the neck of the uterus in the broad liga- ment. It is 2\ inches long and loops over the ureter midway in its course. It is reached by incising the broad ligament between the Fallopian tube behind and the round ligament in front. It is found in the loose areolar tissue under the wound. The lymphatics from the fundus of the uterus and appendages pass to the lumbar glands, a few also pass along the round ligament to the in- guinal glands. The lymphatics of the cervix, which is frequently the seat of cancer, pass to the internal iliac glands on the lateral wall of the pelvis. The unimpregnated uterus is very rarely wounded, owing its immunity to the denseness of its walls, to its small size, to its great mobility, and to its position within the bony pelvis. The ovary is so placed that the outer part of the Fallopian tube turns downwards externally to it. The more common position of the ovary may be indicated on the surface of the body by the line employed to mark out the course of the common and external iliac arteries — a line drawn from the aortic bifurcation to the, femoral point (Fig. 57, p. 340). The ovary lies internally to the mid point of this line (Fig. 70, p. 418). It lies in the angle between the external and internal iliac arteries and may be indistinctly palpated through the vagina. Its nerves come from the tenth dorsal segment of the cord. The sensory nerves for the cervix are derived from the lower sacral segments. The lymphatics of the ovary pass to the lumbar glands. The ovaries exert a very marked trophic influence on the breast; the hypertrophy of the mammae at puberty and in Chap. XVIII] PELVIS AND PERINEUM 469 pregnancy depends on an internal secretion of the ovary (Starling). By their removal it was hoped that cancer of the breast might be arrested, but the procedure has not been followed by much success. At the brim of the pelvis the ovarian vessels lie within a fold of peritoneum, named the ovario- or infundibulo-pelvic ligament, for it is attached both to the ovary and to the infundi- bulum of the Fallopian tube. This ligament forms the outer part of the pedicle in ovariotomy. The rectum in the adult is situated entirely within the true pelvis, and presents three marked curves, one in the lateral and two in the antero- posterior direction (see p. 390). In the infant, however, a good deal of the rectum is in the abdominal rather than the pelvic cavity, the gut is nearly straight, and occupies a more or less vertical position. For these reasons, _ together with the fact that the sacrum is straight, the prostate small, and the connections of the bowel loose, prolapsus ani is much more common in children than in adults. Children are, besides, especially liable to such exciting causes of pro- lapse as worms and rectal polypi. The rectum commences in front of the third sacral vertebra and is about 5 inches in length. It is continuous with the pelvic colon, which is invested by peritoneum and supported by a mesentery. The serous membrane gradually leaves its posterior surface, then its sides, and lastly its anterior surface. Anteriorly, the peri- toneum, in the form of the recto-vesical pouch, extends in the male to within 3 inches of the anus, while on the posterior aspect of the gut there is no peritoneum below a spot 5 inches from the anus. Thus, in excision of the rectum, more of the bowel can be removed on the posterior than on the anterior part of the tube without opening the peritoneal cavity. It will be seen, also, that carcinomatous and other spreading ulcers are more apt to invade the peritoneal cavity when they are situated in the anterior wall of the 4?0 StJEGtCAL APPLIED ANATOMY [Part IV intestine. The lower part of the rectum, distin- guished as the anal canal, is surrounded by the internal sphincter — an involuntary muscle con- tinuous with the circular coat. In the condition of rest the anal canal, which is directed down- wards and backwards, measures l\ inch, but during defsecation and when the patient bears down, it assumes a shallow annular form. The canal is firmly fixed to the levatores ani ; hence in prolapse it is the rectum above the canal which is extruded through the anus. Mr. Cripps has shown that the posterior edge of the levator ani forms a distinctly felt free border, which crosses the rectum, nearly at a right angle at a point from 1^ to 2 inches from the anus. By inserting the finger into the rectum the prostate and seminal vesicles can be readily felt and examined, and that triangular surface of the bladder explored through which puncture per rectum is made (p. 446). It will be understood that the prostate, when enlarged, may encroach upon the cavity of the rectum and greatly narrow its lumen (Fig. 73). The position of the seminal vesicles with regard to the bowel is such that in violent attempts at defsecation they may be pressed upon by the rectal contents, and so in part emptied, producing a kind of spermatorrhoea. Defsecation also often causes much pain in inflammatory affections of the prostate and adjacent parts. The anterior surface of the rectum in the female is in relation, so far as the finger can reach, with the vagina, and in examining the lower part of the rectum, it is convenient to pro- trude its mucous membrane through the anus by means of the finger introduced into the genital passage. The rectum is dilated, and is very distensible just above the anus. In faecal accumulations it may be distended to a considerable size, and strange foreign bodies of large dimensions have been found in the ampulla. Among the latter Chap. XVIII] PELVIS AND PERINEUM 471 may be mentioned a bullock's horn, an iron match - box, and a glass tumbler. By anti- peristaltic movements of the colon, such bodies may be carried towards the caecum. Thus a case is recently reported by Alexander in which the handle of an umbrella, accidentally lodged in the rectum, was removed by the surgeon two weeks later from the hepatic flexure of the colon. Ex- periment has shown that when the rectum is dis- tended in the male, the recto-vesical fold of peri- toneum is raised, and the bladder is elevated and pushed forwards. In the female the fundus uteri is raised and pushed towards the symphysis. The rectum is artificially distended in suprapubic lithotomy, in order to bring the bladder into better position (p. 443). Normally the rectum is empty except during defalcation. Advantage of this circumstance is taken in operations for the cure of ectopia vesicae where the ureters are re- moved from the exposed bladder and implanted in the rectum. If the sphincter be very gradually dilated, the entire hand, if small, may be introduced into the rectum in both males and females. The circum- ference of the hand should not exceed 8 inches. By a semi-rotary movement, and by alternately flexing and extending the fingers, the hand can be insinuated into the commencement of the sigmoid flexure. Owing to the mobility of this part of the bowel a large extent of the abdomen may be explored through the bowel wall. The structures that can be readily felt are the kidneys, the aorta, the iliac vessels, the uterus and ovaries, the bladder and its surroundings, the pelvic brim, the sacro-sciatic foramina, the ischial spine, the sacrum, etc. In some subjects even a small hand cannot be passed beyond the reflection of the peri- toneum over the second part of the gut. In such instances the peritoneum offers a resistance like a tight garter, and prevents the farther advance of the hand without great risk of laceration of the parts (Walsham). 472 SUEGICAL APPLIED ANATOMY [Part IV Owing to the constrained position of the hand and the cramping of the fingers, this method of examination has proved to be of but limited ser- vice. The attachments of the rectum by means of the pelvic fascia are not very firm; since, in some severe and rare cases of prolapse, all the walls of the gut may be protruded at the anus {see p. 431). In excision of the rectum, also, advantage is taken of this mobility. The mucous membrane is thick, vascular, and but loosely attached to the muscular coat be- neath. This laxity, which is more marked in children, favours prolapse, an affection in which the mucous membrane of the lower part of the rectum 'is protruded at the anus. The mucous membrane presents three prominent semilunar folds, about \ an inch in depth, which are placed more or less transversely to the long axis of the bowel. The first projects backwards from the fore -part of the rectum opposite the prostate, the second projects inwards from the left side of the tube opposite the middle of the sacrum, the third is near the commencement of the bowel on the right side. These rectal folds, especially when the gut is empty, may offer considerable resist- ance to the introduction of a bougie or long enema tube, and their position should be there- fore borne in mind. The vessels, and especially the veins, at the lower part of the rectum, are apt to become vari- cose and dilated, and form piles. The tendency to piles can in part be explained by the dependent position of the rectum, by the pressure effects of hardened faeces upon the returning veins, and by the fact that part of the venous blood returns through the systemic system (internal iliac vein) and part through the portal system (inferior mesenteric vein). This connection with the portal trunk causes the rectum to participate in the many forms of congestion incident to that vein. The veins of the rectum, also, can be affected by Char. XVIII] PELYIS AND PERINEUM 473 violent expiratory efforts. For the last 4 inches of the bowel, moreover, the arrangement of the vessels is peculiar, and is such as to favour vari- cosity. The arteries, " having penetrated the muscular coats at different heights, assume a longitudinal direction, passing in parallel lines towards the edge of the bowel. In their progress downwards they communicate with one another at intervals, and they are very freely connected near the orifice, where all the arteries join, by trans- verse branches of considerable size ;; (Quain). The veins form a plexus with a precisely similar arrangement. The veins beneath the mucous mem- brane of the anal canal perforate the muscular coat of the rectum about 1 inch above the anal canal. At the point of perforation they are liable to be compressed. The lymphatics of the rectum pass to the in- ternal iiiac group of lymphatic glands on the lateral wall of the pelvis. Hence in cancer of the lower part of the rectum these glands and the vessels leading to them are the earliest seats of secondary infections. The lymphatics of the pel- vic colon pass to the glands in front of the sacrum and to others between the layers of the meso- rectum. The rectum may be most freely exposed from behind (Fig;. 71, p. 434). In Kraske's operation for the extirpation of cancer of the rectum an incision is made along the sacrum in the middle line, from the level of the posterior inferior iliac spine to the anus. A flap is turned out on the left side, including the skin and origin of the gluteus maximus. The attachments of the left sacro-sciatic ligaments, coccygeus, and levator ani, to the sacrum and coccyx are divided and turned outwards. The lateral and median sacral arteries and a plexus of veins are raised with the fibrous tissue from the anterior surface of the sacrum by a peri- osteal elevator. The left halves of the fourth and fifth sacral vertebrae, with the left half of the coccyx, are removed. The fourth, fifth sacral and 4?4 SURGICAL APPLIED ANATOMY [Part IV coccygeal nerves are necessarily cut, but an at- tempt should be made to save the third sacral nerve, owing to the importance of its function. The rectum is then exposed, with the hsemor' rhoidal vessels and reflection of peritoneum. By opening the peritoneal cavity part of the pelvic colon may be brought into the wound. After the diseased part is removed, with the presacral and internal iliac lymphatic glands, the upper end of the rectum is brought down and sutured to the anal part. An attempt should be made to save the levator ani and third sacral nerve, in order that the integrity of the pelvic diaphragm may be maintained. The rectum is supplied with sensory and motor nerves from the second, third, and fourth sacral segments through the corre- sponding nerves. Some motor nerves are also derived from the lower two dorsal and upper lumbar segments. These nerves reach the rectum through the hypogastric and pelvic plexuses. Anus. — The skin about the anus is thrown into numerous folds, and it is in these that the ulcer or fissure of the anus forms. When the anal canal is closed the vertical columns of Morgagni meet. At their upper and at their lower ends they are united by small valvular folds of mem- brane, which prevent the escape of liquid contents. The lower valves may be torn by the passing scybalous masses, and from the rent thus caused a fissure of the anus may be produced (Ball). The extreme painfulness of these ulcers is due to the exposure of a nerve-fibre at their base, and to the constant contraction of the sphincter muscle that they excite. Relief is given by excising the base of the ulcer, so as to divide some part of the sphincter ; or by violently dilating the anus, so as to tear up the base of the ulcer and paralyse for a while the action of the disturbing muscle. Below the columns of Morgagni a fine white line surrounds the anus at the junction of the skin and mucous membrane, and indicates the interval between the external and internal sphincters (Hilton). Chap. XVIII] PELVIS AND PERINEUM 4?5 The anus may be torn during defsecation, when the stools are hard. A case is reported of a woman who, during violent efforts at defsecation, felt something give way, and discovered faeces in her vagina. The recto-vaginal wall had ruptured 2 inches from the anus. During labour the child's head has passed into the rectum, and has been delivered per anum. An imperforate anus is the most common congenital defect of the rectum. This condition represents an arrest of development. The forma- tion of the anus is a double process; first there is an ingrowth from the perineum, and secondly a downgrowth from the bowel, these two elements meeting and communicating near the upper end of the anal canal. In many cases of imperforate anus, only a thin anal membrane requires to be broken down to allow the free passage of faeces, but in other cases the defect is much greater, the anal canal, and even the rectum, being completely wanting. NTot unfrequently in such cases the rec- tum may communicate with the urethra in the male or with the vulval cleft in the female. This communication is due to the persistence of an embryonic condition. Nerves of pelvis and perineum. — The pelvic viscera are supplied by the pelvic plexus of the sympathetic. This plexus is joined by at least three spinal nerves, the second, third, and fourth sacral. It is well known that in certain affections of the bladder, rectum, prostate, etc., pain is felt along the perineum, in the penis, over the but- tock, and down the thigh. These parts are sup- plied by the pudic and small sciatic nerves, and the reason for the pain is explained by the origin of the sensory nerves for those organs from the same and adjoining segments of the spinal cord. The upper part of the rectum is provided with but_ little sensation, as illustrated by the passage of instruments, by the comparative painlessness of malignant and other growths high up in the 476 SURGICAL APPLIED ANATOMY [Part IV bowel, and by the little inconvenience felt when the gut is distended with hardened faeces. From this apathy it has probably happened that, in the self-administration of enemata, patients have thrust the tube through the rectum into the peri- toneal cavity. The anal canal, on the other hand, is extremely sensitive. The nerve relations between the anus and the neck of the bladder are very intimate. Painful affections of the anus often cause bladder troubles, and retention of urine is very common after operations upon piles. Maladies, on the other hand, that involve the bladder neck are often associated with tenesmus and anal discomfort. This relation is maintained by the pelvic plexus, but mainly by the fourth sacral nerve. This nerve gives special branches direct to the neck of the bladder, and then goes to supply the muscles of the anus (the sphincter and levator) and the integument between the anus and the coccyx. The mucous membrane of the urethra, the mus- cles of the penis, and the greater part of the skin of the penis, scrotum, perineum, and anus, are supplied, from the second, third, and fourth sacral segments, by the pudic nerve. Thus, it will be understood that irritation applied to the urethra may cause erection of the penis (as illus- trated by chordee in gonorrhoea), or may produce contraction of the urethral muscles (as seen in some forms of spasmodic stricture). The disturb- ance caused by accumulated secretion beneath the prepuce in young children may provoke great irritability of the organ, and it is well known that painful affections of the perineum and anus may be associated with priapism. The distribu- tion of the third sacral segment in the perineum by means of the long pudendal nerve will explain the pain about the buttock and down the back of the thigh that is often complained of during the growth of perineal abscess and in painful affec- tions of the scrotum. This nerve crosses just in front of the tuber ischii, and may be so pressed Chap. XVIII] PELVIS AND PERINEUM 477 upon by using a hard seat as to cause one-sided neuralgia of the penis and scrotum. It is also in close connection with the ischial bursa, and neuralgia of the same parts has been met with in cases of inflammation involving that structure. The testicle is supplied mainly from the tenth dorsal segment by the spermatic plexus. The kid- ney is also partly supplied from the same segment. This is illustrated by the pain felt in the renal region during neuralgia of the testicle, and by the pain felt in the testicle, the vigorous retraction of that organ observed in certain affections of the kidney, such as in acute nephritis, and in the passage of renal calculi. By means of the renal plexus the testicle is brought into direct com- munication with the semilunar ganglia and solar plexus, which receives some of the terminal fibres of the vagus. This communication serves to ex- plain_ the great collapse often noticed in sudden injuries to the testicle, and especially the marked tendency to vomit, _ so often observed in such lesions. _ So far as its nerves are concerned, the testicle is nearly in as intimate relation with the great nerve-centre of the abdomen as is a great part of the small intestine, and one would expect a sudden crush of the testis to be associated with as severe general symptoms as would accompany a sudden nipping of the ileum in a rupture. Such a resemblance in symptoms is actually to be observed in practice. PART V.-THE LOWER EXTREMITY CHAPTER XIX, , THE REGION OF THE HIP This region will be considered under the follow- ing heads : 1. The buttocks. 2. The region of Scarpa's triangle. 3. The hip-joint. 4. The upper third of the femur. 1, The buttocks. — Surface anatomy. — The bony points about the gluteal region can be well made out. The crest of the ilium is distinct, as is also the anterior superior spine. The posterior superior spine is less evident, but can be readily felt by following the crest to its posterior termina- tion. This spine is on a level with the second sacral spine, and is placed just behind the centre of the sacro-iliac articulation. The great trochanter is a conspicuous landmark. It is covered by the fascial insertion of the gluteus maximus. Its upper border is on a level with the centre of the hip-joint, and is somewhat obscured by the tendon of the gluteus medius which passes over it. The comparatively slight prominence of the trochanter in the living subject, as compared with the great projection it forms in the skeleton, depends upon the completeness with which the gluteus medius and minimus fill up the hollow between the tro- chanter and the ilium. When these muscles are atrophied the process becomes very conspicuous. In fat individuals its position is indicated by a slight but distinct depression over the hip. If a line be drawn from the anterior superior 478 Chap. XIX1 REGION OF THE HIP 479 spine to the most prominent part of the tuber ischii, it will cross the centre of the acetabulum, and will hit the top of the trochanter. This line, known as Nelaton's line, is frequently made use of in the diagnosis of certain injuries about the hip. McCurdy prefers a line drawn from the pubic spine ait a right angle to the median line of the body ; if the femur is normal in position the pubic line should cross at or just above the great trochanter. The mid-point of this line lies over the head of the femur. The anterior superior spine or crest of the ilium may be used as fixed points from which to estimate the degree of dis- placement of the great trochanter. The tubera ischii are readily felt. They are covered by the fleshy fibres of the gluteus maximus when the hip is extended. But when the hip is flexed, the processes become to a great extent un- covered by that muscle. The muscular mass of the buttock is formed by the gluteus maximus be- hind and by the gluteus medius and minimus and tensor vaginae femoris in front. The last-named muscle can be seen when in action, i.e. when the thigh is abducted and rotated in. The fold of the buttock crosses the obliquely placed lower border of the gluteus maximus. When the hip is fully extended, as in the erect posture, the buttocks are round and prominent, the gluteal fold is transverse and very distinct. When the hip is a little flexed, the buttocks be- come flattened, the gluteal fold becomes oblique and then disappears. Among the early symptoms of hip disease are flattening of the buttock and loss of the gluteal fold. These symptoms depend upon the flexion of the hip, which is practically constant in every case of the malady before treat- ment. It is incorrect to say, as some books still assert, that these changes are due to wasting of the gluteal muscles, since they appear at too early a period for any considerable muscular atrophy to have taken place. It is true that these symp- toms are much exaggerated by the wasting of the 480 SUEGICAL APPLIED ANATOMY [Part V muscle that occurs later on in the course of the hip affection. With regard to the vessels and nerves of the buttock, if a line be drawn from the posterior superior spine to the top of the great trochanter when the thigh is rotated in, a point at the junc- tion of the inner with the middle third of that line will correspond to the gluteal artery as it emerges from the sciatic notch. A line drawn from the posterior superior spine to the outer part of the tuber ischii crosses both the posterior inferior and ischial spines. The former is about 2 inches and the latter about 4 inches below the posterior superior process. The sciatic artery reaches the gluteal region at a spot corresponding to the junction of the middle with the lower third of this line. The position of the pudic artery as regards the buttock is not difficult to indicate, since it crosses over the ischial spine in passing from the great to the small sacro- sciatic foramen. The sciatic nerve is most easily found as it escapes from beneath the gluteus maxi- mus. When the thigh is rotated outwards, so that the great trochanter approaches the ischial tuber- osity, the nerve lies midway between these two bony points, but in the unrotated position it is found at the junction of the inner and middle thirds of a line joining them. The skin over the buttock is thick and coarse, and is frequently the seat of boils. From the appearance it presents in very fully injected speci- mens, it would appear that the blood supply is not quite so free as it is in many other parts of the surface. The subcutaneous fascia is lax, and contains a large quantity of fat. It is to this fat rather than to muscular development that the buttock owes its roundness and prominence. The enor- mous buttocks of the so-called " Hottentot Venus," whose model is in many museums, depend for their unusual dimensions upon the greatly in- creased subcutaneous fat. The amount of adipose Chap. XIX] REGION OF THE HIP 481 tissue normally in the part renders the buttock a favourite place for lipomata. The laxity of the superficial fascia permits large effusions, both of blood and pus, to take place in the gluteal region, and ecchymoses of the buttock can probably reach a greater magnitude than is possible elsewhere. The deep fascia of the buttock, a part of the fascia lata of the thigh, is a structure of much importance. This dense membrane is attached above to the iliac crest, and to the sacrum and coccyx. Descending in front over the gluteus medius, it splits on reaching the anterior edge of the gluteus maximus into two layers, one of which passes in front of the muscle and the other behind. The gluteus maximus is thus enclosed, like the meat in a sandwich, between two layers of fascia, and the two lesser gluteal muscles are bound down within an osseo-aponeurotic space, which is firmly closed above, and only open^ below towards the thigh and internally at the sciatic foramina. Ex- travasations of blood may take place beneath this fascia without any discoloration of the skin to in- dicate the fact, the blood being unable to reach the surface through the dense membrane. Such extravasations may be long pent up, and, as they fluctuate^ may be mistaken for abscess. Deep inflammations beneath this fascia, and especially when beneath the gluteus medius, may be associated with much pain, owing to the cir- cumstance that the inflammatory effusions^ will be pent up between a wall of bone on one side and a wall of dense fascia and stout muscle on the other. Abscesses so pent up may travel for a con- siderable distance down the thigh before they reach the surface, and Farabeuf relates a case where a gluteal abscess travelled to the ankle before it broke. Under other circumstances the gluteal abscess may make its way into the pelvis through the sciatic foramina, or a pelvic abscess may escape through one of these foramina and appear as a deep abscess of the buttock. 2F 482 SUEGICAL APPLIED ANATOMY [Part V The thickened part of the fascia lata that runs down on the outer side of the limb between the crest of the ileum above and the outer tuberosity of the tibia and head of the fibula below, is known as the ilio-tibial band. This band is tightly stretched across the gap between the iliac crest and the great trochanter, and if pressure be made with the fingers between these two points, the re- sistance of this part of the fascia can be appreci- ated. It is obvious that in fracture of the neck of the femur, when the great trochanter is made to approach nearer to the crest, this band will become relaxed, and Dr. Allis (Agnew's " Sur- gery/' vol. i.) has drawn attention to this fascial relaxation as of value in the diagnosis of frac- tures of the femoral neck. The lower free edge of the gluteus inaximus is oblique, and ends some way below the transverse line of the fold of the buttock. It would appear that even this great muscle may be ruptured by violence. Thus Dr. Mac- Donnell (Brit. Med. Journ.,^ 1878) reports the case of a robust man, aged sixty-three who, while trying to lift a heavy cart when in a crouching position, felt something give way in his buttock, and heard a snap. He fell, and was carried home, when it was found that the great gluteal muscle was ruptured near the junction of the muscle with its tendon. At least three bursae exist over the great trochanter, separating that process from the three gluteal muscles respectively. The most extensive is that between the insertion of the gluteus maxi- mus to the ilio-tibial band and outer surface of the great trochanter. The bursa allows the great trochanter to move freely beneath the muscle during rotation of the thigh. When this sac is inflamed much difficulty is experienced in moving the limb, and the thigh is generally kept flexed and adducted. This position means absolute rest from movement on the part of the gluteal muscles, which, when acting, would extend and abduct Chap. XIX] REGION OF THE HIP 483 the limb, and bring pressure to bear upon the tender bursa. There is a bursa over the ischial tuberosity that is often inflamed in those whose employments involve much sitting, the bursa being directly pressed upon in that position. This sac is the anatomical basis of the disease known in older text-books as "weaver's bottom" or "lighter- man's bottom." When enlarged this bursa may press upon the inferior pudendal nerve. The arteries and nerves of the buttock. — The gluteal artery is about the same size as the ulnar, and the sciatic as the lingual. The former vessel may sometimes be of much greater magnitude, and has led, when wounded, to rapid death from haemorrhage. Wounds of the gluteal vessels will probablv involve only the branches of the artery, since # the greater part of the main trunk is situate within the pelvis. Gluteal aneur- isms are not very uncommon, and with regard to the treatment of these tumours it may be noted that the gluteal artery, or, better, the internal iliac trunk, can be compressed through the rectum. Compression so applied has been adopted for the treatment of gluteal aneurism by Dr. Sands, of New York (Amer. Journ. Med. Sc, 1881), but without much effect. Aneurism of the commence- ment of the gluteal artery could hardly fail to provoke nerve symptoms, since the vessel runs be- tween the lumbo-sacral cord and first sacral nerve. Both the gluteal and sciatic arteries have been ligatured in the buttock, through incisions made directly over the course of the vessels. Henle has collected six cases where the femoral artery ran down along the back of the thigh to the "Dopliteal snace in company with the great sciatic nerve. The abnormal vessel was in each case formed by an enlargement of the comes nervi ischiadici, a branch of the sciatic artery. The great sciatic nerve is a continuation downwards of the main part of the sacral plexus. It is in this nerve that the form of neuralgia 484 SUEGICAL APPLIED ANATOMY [Part V known as sciatica is located. A reference to the immediate relations of this nerve will show that it may readily be exposed to many external in- fluences. Thus, in the pelvis it may be pressed upon by various forms of pelvic tumour, and sciatica be produced in consequence. Its anterior surface is in close relation with some of the princi- pal pelvic veins, and according to Erb one form of sciatica may be traced to an engorged condi- tion of these vessels. Aneurism of certain branches of the internal iliac artery within the pelvis, sciatic hernia, and accumulation of faeces within the rectum, may all cause neuralgia ' of this im- portant trunk. It is said to have been injured also by the pressure of the foetal head during tedious labours, and to be affected by violent movements of the hip, a circumstance readily understood if the close relation of the nerve to the hip-joint be borne in mind. The nerve is also near enough to the surface to be influenced by external cold, and to this influence many forms of sciatica are. ascribed. At the lower edge of the great gluteal muscle the trunk is still nearer to the surface, and this fact receives illustration in a case reported in Ziemssen's Cyclopaedia, where paralysis of the nerve followed its com- pression by the contracting scar of a bed : sore. Nerve stretching - . — The great sciatic nerve has been frequently cut down upon and stretched for the relief of certain nervous affections of the limb (see rj. 480). In connection with this pro- cedure it is important to know how great an amount of traction may be brought to bear upon this and other nerves without the cord giving way. Trombetta, who has paid much attention to this matter, gives the following weights as those re- quired fa> ^ break the undermentioned nerves : great sciatic, 183 pounds; internal popliteal, 114 pounds ; anterior crural, 83 pounds ; median, 83 pounds; ulnar and radial, 59 pounds; brachial plexus in the neck. 48 to 63 pounds; and brachial plexus in the axilla, 35 to 81 pounds. (In each Ohap. XIX] REGION OF THE HIP 485 instance fractions have been omitted.) It must be borne in mind, however, as pointed out by Mr. Symington {Lancet, 1S78), that in forcibly stretch- ing the great sciatic nerve the trunk may be torn away from its attachments to the soft spinal cord before a sufficient force has been applied to rup- ture the nerve at the point stretched. The same observation applies to other large nerve-cords, such as those of the brachial plexus, that are stretched at a spot not far from their spinal con- nections. The great sciatic nerve may be stretched by flexing the extended lower extremity on the belly. This measure "has served to cure certain cases of sciatica. The skin of the buttock is well supplied with nerves, and tactile sensibility is almost as acute in this part as it is over the back of the hand, while it is more acute than is like sensibility in such parts as the back of the neck, the middle of the thigh, and the middle of the back. The sensation of the gluteal integument is derived from a number of different nerves, and it may possibly interest a school-boy who has been^ re- cently birched to know that the painful sensations reached his sensorium through some or all of the following nerves : offsets of the posterior branches of the lumbar nerves, some branches of the sacral nerves, the lateral cutaneous branch of the last dorsal nerve, the iliac branch of the ilio-hypo- gastric nerve, offsets of the external cutaneous nerve, and large branches of the small sciatic. These nerves are derived from four spinal seg- ments — the twelfth dorsal, first lumbar, second and third sacral (Fig. 105, p. 597). The second and third sacral also supply the sexual organs, hence the physiological effects which may follow application of punishment to this part, as in the celebrated case of J. J. Rousseau. It should be remembered that the pelvic vis- cera can be readily reached through the sciatic foramina from the buttock. I once saw a case at the London Hospital of a man who was admitted 486 SUEGICAL APPLIED ANATOMY [Part V with an apparently insignificant stab of the but- tock. He died in a few days, of acute peritonitis; and the autopsy showed that the dagger had passed througn the great sacro-sciatic foramen, had entered the bladder and allowed urine to escape into the peritoneal cavity. The rectum has also been damaged in injuries to the buttock, and Anger records a case of an artificial anus situate upon the buttock, that had followed a gun- shot wound, which, after involving the buttock, had opened up the csecum. It is by this route that Kraske's operation for resection of the rectum is performed and Rigby's operation on the ureter. 2. The region of Scarpa's triangle. — Surface anatomy. The most important land- marks in the region of the groin, the anterior superior iliac spine, the spine of the pubes, and Poupart's ligament, are readily made out. To the two spines reference has already been made (p. 322). Poupart's ligament follows a curved line, with its convexity downwards, drawn be- tween these two projections. It can be felt in even stout persons, its inner half more distinctly than its outer, and even in very fat individualsits position is indicated by a slight furrow. Owing to its attachment to the fascia lata the ligament is relaxed, and rendered less distinct when the thigh is flexed and adducted, or when it is rotated in. The mid-point of a line joining the pubic with the anterior superior spine lies over the head of the femur and hip joint. In this position a crease is often to be seen crossing the groin (Holden). The sartorius muscle is brought into view when the leg is raised across the opposite knee, and the adductor longus is rendered distinct when the thigh is abducted, and the individual's attempts to adduct the limb are resisted. Even in the obese the edge of this muscle can be felt when it is in vigorous action, and the fingers can follow its border up to the very origin of the muscle, just below the pubic spine. Chap. XIX] EEGION OF THE HIP 48? The lymphatic glands in this region can some- times be felt beneath the skin, especially in thin children. The femoral ring lies behind Poupart's ligament 1 inch externally to the pubic spine (Fig. 57, p. 340). The position of the saphenous open- ing is sometimes indicated by a slight depression in the integuments. It lies just below Poupart's ligament, and its centre is about li inch below and external to the pubic spine. In thin sub- jects the long saphenous vein can be often made out, passing to the saphenous opening. If a line be drawn from the femoral point (Fig. 57, p. 340) to the tubercle for the adductor magnus, on the inner condyle of the femur, when the thigh is slightly flexed and abducted, it will correspond in the upper two-thirds of its extent to the position of the femoral artery. Just below Poupart's ligament the femoral vein lies to the inner side of the artery, while the anterior crural nerve runs about \ of an inch to its outer side. The profunda femoris arises about li inch below Poupart's ligament, and the internal and ex- ternal circumflex vessels come off about 2 inches below that structure. The skin over Scarpa's triangle is, unlike that of the buttock, comparatively thin and fine. The looseness of its attachment, also., to the parts im- mediately beneath, permits it to be greatly stretched, as is seen in cases of large femoral hernise, and in certain inguinal tumours of large size. It may even give way under severe traction, as occurred in a case reported by Berne. The patient in this case was a child aged 11, the sub- ject of hip disease. The thighs were flexed upon the abdomen, and, forcible extension being ap- plied to relieve the deformity, the skin gave way just below the groin, and separated to the extent of some 2^ inches. Contracting scars in the region of the groin may produce a permanent flexing of the hip, and this result is not uncommon after deep and severe burns in this neighbourhood. It may at the same time be noted that horizontal 488 SUEGICAL APPLIED ANATOMY [Part V wounds about the groin can be well adjusted by a slight flexion of the thigh. Instances are recorded where a supernumerary mammary gland, provided with a proper nipple, has been found located in the groin. Jessieu relates the case of a female who had a breast so placed, and who suckled her child from this part (see p. 205). In a few cases the testicle, in- stead of descending into the scrotum, has escaped through the crural canal, and made its appear- ance in Scarpa's triangle. It has even mounted up over Poupart's ligament after the manner of a femoral hernia, being probably urged in that direction by the movements of the limb. > The superficial fascia in this region is not very dense, and has little or no influence upon the progress of a superficial abscess. This fact receives extensive illustration, since the glands in Scarpa's triangle frequently suppurate, and yet the pus in the great majority of cases readily reaches the surface in spite of the circumstance that the denser layer of the superficial fascia (for in this region it is divided into two layers) covers in those glands, and should hinder the progress of pus towards the surface. Although the sub- cutaneous fat is not peculiarly plentiful in this region, yet Scarpa's triangle is a favourite spot for lipomata. It is in this place that the fatty tumour often exhibits its disposition to travel, and several cases are reported where such a tumour has started at the groin and travelled some way down the thigh. The journey is always in the direction of gravity, and rendered possible by the lax capsule of the tumour, by the loose- ness of the tissue in which it is embedded, and by the fluidity of fat at the normal temperature of the body. The fascia lata completely invests the limb, being, so far as the front of the thigh is con- cerned, attached above to Poupart's ligament, to the body and ramus of the pubes, and the ramus of the ischium. Its integrity is interrupted only Chap. XIX] REGION OF THE HIP 489 by the saphenous opening. This fascia exercises some influence upon deep abscesses and deep growths. Thus a psoas abscess reaches the thigh by following the substance of the psoas muscle, and finds itself, when it arrives at Scarpa's tri- angle, under the fascia lata. In a great number of cases it points where the psoas muscle ends, but in other and less frequent instances its pro- gress is decidedly influenced by the fascia lata, and it moves down the limb. Thus guided, a psoas abscess has pointed low down in the thigh, and even at the knee, and Erichsen reports a case where such an abscess (commencing, as it did, in the dorsal spine) was ultimately opened by the side of tne tendo Achillis. The ilio-psoas muscle, being stretched, as it were, over the front of the hip-joint, and partici- pating in many of the movements of that joint, is peculiarly liable to be sprained in violent exer- cises. Between this muscle and the thinnest part of the hip capsule is a bursa, which not unfre- quently communicates with the joint. When chronically inflamed, this bursa may form a large tumour on the front of the thigh that may, ac- cording to Nancrede, attain the size of a child's head. To relieve this bursa from pressure when inflamed, the thigh always becomes flexed, and a train of symptoms is produced that are not unlike those of hip disease. The deep origins of the ilio- psoas lie behind the caecum and kidney, and may elicit symptoms from those organs when con- tracted. The sartorius is a muscle that, from its length, peculiar action, etc., one would hardly expect to find ruptured from violence, yet in the Musee Dupuytren there is a specimen of such a rupture about the middle of the muscle united by fibrous tissue. The adductor muscles, and especially the adductor longus, are frequently sprained, or even partially ruptured, during horse exercise, the grip of the saddle being for the most part maintained by them. " Rider's sprains," as such accidents 490 SURGICAL APPLIED ANATOMY [Part V are called, usually involve the muscles close to their pelvic attachments. Much blood is often effused when the fibres are ruptured, and such effusion may become so dense and fibrinous as to form a mass that has been mistaken for a detached piece of the pubes (Henry Morris). The term '' rider ; s bone ;; refers to an ossification of the upper tendon of the adductor longus or magnus, following a sprain or partial rupture. Cases are reported where the piece of bone in the tendon was \ an inch, 2 inches, and even 3 inches long. Blood-vessels. — The femoral artery occupies so superficial a position in Scarpa's triangle that it is not unfrequently wounded. The vessel also has been opened up by cancerous and phagedenic ulcerations of this part, the occurrence leading to fatal haemorrhage. Pressure is most conveniently applied to the artery at a spot immediately below Poupart's ligament, and should be directed back- wards, so as to compress the vessel against the pubes and adjacent parts of the hip capsule. Lower down, compression should be applied in a direction backwards and outwards, so as to bring the artery against the shaft of the femur, which lies at some distance to its outer side. Pressure rudely applied by a tourniquet may cause phle- bitis by damaging the vein, or neuralgia by con- tusing the anterior crural nerve. From the proximity of the artery and vein, it happens that arterio-venous aneurisms follow- ing wounds have been met with in this situa- tion. Aneurism is frequent in the common femoral, and many reasons can be given why that vessel should be attacked. It is just about to bifurcate into two large trunks, its superficial position exposes it to injury, it is greatly influ- enced by the movements of the hip, and its coat may, if diseased, be damaged by those movements, if excessive. Phlebitis of the femoral vein has in many cases followed contusion of the vessel in its upper or more superficial part, and a like result has even Chap. XIX] REGION OF THE HIP 491 followed from violent flexion of the thigh. The long saphenous vein is often varicose, and one form of the varicosity is said to depend upon con- striction of the vein by an unduly narrow saphen- ous opening. That varicose veins are, m the majority o± cases, of congenital origin is now very generally allowed. The anterior crural nerve lies on the ilio- psoas muscle, and it is said that neuralgia, and even paralysis of the nerve, may follow upon in- flammation of that muscle and upon psoas abscess. The superficial position of the trunk exposes it to injury. The genito-crural nerve (the nerve that supplies the cremaster muscle) gives a sensory fila- ment to the integument of the thigh in Scarpa's triangle. Irritation of the skin over the seatof this nerve, which is placed just to the outer side of the femoral artery, will cause, in children, a sudden retraction of the testicle. The same result is often seen in adults, also, on more severe stimu- lation. In this manner the condition of the second lumbar segment of the cord may be tested. The lymphatic glands in this region are numerous, and as they are frequently the seat of abscess, it is important to know from whence they derive their afferent vessels. They are divided into a superficial and a deep set. The superficial set, averaging from ten to fifteen glands, is ar- ranged in two groups, one parallel and close to Poupart's ligament (the horizontal series), the other parallel and close to the long saphenous vein (the vertical series). The deep set, about four in number, are placed along the femoral vein, and reach the crural canal. The inguinal glands receive the following lym- phatics : Superficial vessels of lower limb = vertical set of superficial glands. Superficial vessels of lower half of abdomen = middle glands of horizontal set. Superficial vessels from outer surface of but- tock = external glands of horizontal set. 492 SUEGICAL APPLIED ANATOMY [Part V From inner surface of buttock = internal glands of horizontal set. (A few of these vessels go to the vertical glands.) Superficial vessels from external genitals = horizontal glands, some few going to vertical set. Superficial vessels of perineum and anus = vertical set. Deep lymphatics of lower limb = deep set of glands. The lymphatics that accompany the obturator, gluteal, and sciatic arteries, and the deep vessels of the penis, pass to the pelvis and have no con- nection with the inguinal glands. The only super- ficial lymphatics of the lower extremity which do not pass direct to the inguinal glands are those which drain the outer side of the ankle and pos- terior aspect of the leg. The vessels from these areas accompany the short saphenous vein and end in the popliteal glands ; the efferent vessels from these glands pass to the deep inguinal set. One of the deep glands lies in the crural canal and upon the septum crurale. Being surrounded by dense structures, it is apt to cause great dis- tress when inflamed and great pain when the hip is moved. In some cases, by reflex disturbance, it has produced symptoms akin to those of strangulated hernia. Some branches of the an- terior crural nerve lie over the inguinal lymph glands, and Sir B. Brodie reports a case in which these branches were stretched over two enlarged glands, like strings of a violin over its bridge, so that violent pain and convulsive movements were set up in the limb. The efferent vessels from the inguinal glands Dass through a chain of lymphatic glands stretch- ing along the course of the external and common iliac vessels. Three of these glands lie imme- diately above Poupart's ligament. The efferent vessels of the internal iliac group of glands, into which the pelvic lymphatics drain, join the chain along the common iliac vessels. The lumbar glands receive the lymph from the iliac groups Chap. XIX] EEGION OF THE HIP 493 and pass it on by the right and left lumbar trunks to the receptaculum chyli. Elephantiasis Arabum is more common in the Fig. 76. — Vertical section of the upper third of the thigh showing the structures in relationship with the hip-joint. {After Braune.) " Muscles.— 1, psoas ; 2, iliaeus ; 3, gluteus medius ; 4, glutens minimus ; 5, obturator interims ; 6, obturator externus ; 7, ilio-psoas ; 8, pectineus ; 9, adductor magnus ; 10, adductor brevis ; 11, gracilis ; 12. adductor tongus ; 13, vastus intemus ; 14, vastus externus. a, anterior crural nerve ; b, external iliac, artery; c. external iliac vein; d, obturator nerve; e, obturator artery; /, branches of obturator vessels to hip-joint ; g, internal circumflex vessels ; '/(, deep femoral vessels: i, branch of external circumflex ; j, bursa over sreat i rochanter ; k, reflections of capsule to neck of femur ; m, asc. ramus of pubes ; v, peritoneum ; o, iliac fascia. lower limb than in any other part, and leads to an enormous increase in the size of the extremity (Cochin or Barbadoes leg). Its pathology is in- timately concerned with the crural lymphatics. The lymphatics are obstructed by a small thread- 494 SUEGICAL APPLIED ANATOMY [Part V worm, Filaria sanguinis hominis. The lymph ves- sels and lymph spaces in the connective tissue be- come greatly distended, and the elements of the connective tissue hypertrophied. The hip-joint.— The hip-joint is an articula- tion of considerable strength (Fig. 76). This strength depends not only upon the shape of the articulating bones, which permits of a good ball- and-socket joint being formed, but also upon the powerful ligaments that connect them and the muscular bands that directly support the capsule. These advantages, however, are to some extent counterbalanced by the immense leverage that can be brought to bear upon the femur, and the numerous strains and injuries to which the joint is subjected, as the sole connecting link between the trunk and the lower limb. The acetabulum is divided into an articular and a non-articular part. The former is of horse-shoe shape, and varies from 1 inch to \ an inch in width. The bone immediately above the articular area is very dense, and through it is transmitted the superincumbent weight of the trunk. The non-articular part corresponds to the area enclosed by the horse-shoe, and is made up of very thin bone. In spite of its thinness it is very rarely fractured by any violence that may drive the femur up against the pelvic bones, since no ordinary force can bring the head of the thigh- bone in contact with this segment of the os in- nominatum. Pelvic abscesses sometimes make their way into the hip-joint through the non-articular part of the acetabulum, and an abscess in the hip-joint may reach the pelvis by the same route. But both such circumstances are rare. In some cases of destructive hip disease the acetabulum may separ- ate into its three component parts. Up to the age of puberty these three bones are separated by the Y-shaped cartilage. At puberty the cartilage be- gins to ossify, and by the eighteenth year the acetabulum is one continuous mass of bone. The Chap. XIX] REGION OF THE HIP 495 breaking up of the acetabulum by disease, there- fore, is only possible before that year. The manner in which the various movements at the hip are limited may be briefly expressed as follows. Flexion, when the knee is bent, is limited by the contact of the soft parts of the groin, and by some part of the ischio-femoral ligament; when the knee is extended the movement is limited by the hamstring muscles. Extension is limited by the ilio-femoral or Y ligament. Abduction, by the pubo-femoral ligament. Adduction of the flexed limb is limited by the ligamentum teres and ischio- femoral ligament, and of the extended limb by the outer fibres of the ilio-femoral ligament and upper part of the capsule. Rotation outwards is resisted by the ilio-femoral ligament, and especi- ally by its inner part, during extension, and by the outer limb of that ligament and the liga- mentum teres during flexion. Rotation inwards is limited during extension by the ilio-femoral ligament, and during flexion by the ischio-femoral ligament and inner part of the capsule. The structures which take the chief part in maintain- ing the integrity of the joint, however, are not the ligaments but the strong muscles which sur- round and act on the joint. Atmospheric pres- sure takes no part, for the fat at the transverse notch is readily drawn into the acetabulum to make good any space vacated by the femoral head in all normal movements of the hip-joint. Hip-joint disease—Owing to its deep posi- tion and its thick covering of soft parts (Fig. 76), this articulation is able to escape, to a great ex- tent, those severer injuries that are capable of producing aciite^ inflammation in other joints. Acute synovitis is indeed auite rare in the hip, and the ordinary disease of the part is of a dis- tinctlv chronic character. It follows, also, from the deep^ position of the articulation that pus, when it is formed in connection with disease, re- mains pent up, and is long before it reaches the surface. Suppuration in this region, therefore, 496 SUEGICAL APPLIED ANATOMY [Part V is often very destructive. When effusion takes place into the joint, the swelling incident thereto will first show itself in those parts where the hip capsule is the most thin. The thinnest parts of the capsule are in front and behind; in front, in the triangular interval between the inner edge of the Y ligament and the pubo-femoral ligament, and behind at the posterior and lower part of the capsule. It is over these two districts that the swelling first declares itself in cases of effusion into the joint, and as these parts are readily ac- cessible to pressure, it follows that they corre- spond also to the regions where tenderness is most marked and is earliest detected. In chronic hip disease, certain false positions are assumed by the affected limb, the meaning of which it is important to appreciate. These posi- tions may be arranged as follows, according, as nearly as possible, to their order of appearing : (1) The thigh is flexed, abducted, and a little everted ; and associated with this there is (2) apparent lengthening of the limb and (3) lordosis of the spine ; (4) the thigh is adducted and in- verted, and incident to this there is (5) apparent shortening of the limb ; (6) there is real shorten- ing of the limb. (1). The first position is simply the posture of greatest ease. It depends^ mainly upon the ef- fusion into the joint. If fluid be forcibly injected into a hip-joint the thigh becomes flexed, abducted, and a little everted. In other words, the articula- tion holds the most fluid when the limb is in this position, and the patient places it there to relieve pain by reducing the tension within the capsule to a minimum. Flexion is the most marked fea- ture in this position. Its effect is pronounced. It relaxes the main part of the Y ligament, which, when the limb is straight, is drawn as an unyield- ing band across the front of the joint. Abduc- tion relaxes the outer limb of this ligament and the upper part of the capsule. Eversion slightly relaxes the inner limb of the Y ligament and the Chap. XIXj REGION OF THE HIP 497 ischio-femoral ligament. The latter movement is the least marked, since eversion, even in the flexed position of the joint, is resisted by the outer part of the Y ligament. Any but a moderate degree of abduction would be limited by the pubo-femoral ligament, especially as that band is rendered most tense when abduction is combined with flexion and rotation out- wards. The attach- ments of the psoas muscle are approxi- mated and its pres- sure over the joint relaxed. (2). The apparent lengthening is due to the tilting down of the pelvis on the dis- eased side, and is the result of the pa- tient's attempts to overcome the effects of the position just described. The limb is shortened by flexion and abduc- tion, and to bring A the foot again to the pi ground and to re store the parallelism of the limbs, the pelvis has to be tilted down on the affected side. Thus, an apparent lengthening is produced, which is seen when the patient lies upon a bed and the abduction is made to disappear. Real lengthening of the limb can scarcely be produced by the effusion into the joint. By forcible injection into the joint Braune could only separate the arti- culating surfaces about -,th of an inch. (3). The lordosis, or curving forwards, of the spine occurs in the dorso-lumbar region. It 2g 7,. — Diagram to show the mode of production of lordosis in hip disease. natural A - Femur flexed at hip, pelvis (represented by the dotted line) straight, and spine normal, b, The flexion concealed or over- come by lordosis of the spine; the pelvis rendered oblique. 498 SUKGICAL APPLIED ANATOMY [Part V depends upon the flexion of the limb, and is the result of an attempt to conceal that false position, or at least to minimise its inconveniences (Fig. 77). When the thigh is flexed at the hip by- disease, the lower limb can be made to appear straight by simply bending the spine forwards in the dorso-lumbar region without effecting the least movement at the disordered joint. Indeed, the movement proper to the hip is in this case trans- ferred to the spine. A patient with a flexed hip as the result of disease can lie on his back in bed, with both limbs apparently perfectly straight, he having concealed the flexion, as it were, by pro- ducing a lordosis of the spine. If the lordosis be corrected and the spine be made straight again, then the flexion of the hip reappears, although all the time the hip-joint has been absolutely rigid. This lordosis generally appears a little late in the disease, and after the limb has become more or less fixed in the false positions by con- traction of the surrounding muscles. (4). Sooner or later, in hip disease, the thigh becomes adducted and inverted, while it still remains flexed. The head of the femur then rests on the upper and posterior part of the acetabu- lum, quite half of it being outside the socket. This position has been variously accounted for. According to one theory, it is due to softening and yielding of some parts of the inflamed capsule. It is more probable that this false position, and especially the adduction, depends upon muscular action. The muscles about the joint are in a state of irritability. They are contracted by a reflex action that starts from the inflamed articu- lation, and since the adductor muscles are sup- plied almost solely by the obturator nerve, it is not unreasonable to expect them to be especially disturbed if_ the large share tfrat the obturator nerve takes in the supply of the hip be borne in mind. The whole matter, however, requires further investigation. (5). Apparent shortening of the limb is due to Chap. XIX] REGION OF THE HIP 499 tilting up of the pelvis on the diseased side, and bears the same relation to adduction that ap- parent lengthening bears to abduction. To over- come the adduction, and to restore the natural parallelism of the limbs, the patient tilts up one side of his pelvis (Fig. 78). It thus happens that a patient with his femur flexed and adducted by disease may lie in bed with both limbs quite straight and parallel, but with one limb obviously B B B Fig. 7S. — A, Parts in normal position. B, The adduction corrected by tilting up tlie pelvis. C, Femur adducted. AC, Line of pelvis ; ab, limb on diseased side : CD, limb on sound side ; E, the spine. It will be found that in Figs. B and C the angle at A is the same in the two cases. shorter than the other. The flexion in such a case is concealed by lordosis, and the adduction by the tilting of the pelvis. In some cases of simul- taneous disease in both hip-joints that has been indifferently treated, both thighs may remain ad- ducted. The limbs are unable, of course, to remedy their position by the usual means, when the disease is double, and consequently one limb is crossed in front of the other, and the peculiar mode of progression known as " cross-legged pro- gression ; ' is produced. 500 SURGICAL APPLIED ANATOMY [Part V (6). The real shortening depends upon destruc- tive changes in the head of the bone, or upon dislocation of the partly disintegrated head on to the dorsum ilii, through yielding of the softened capsule and the crumbling away of the upper and posterior margin of the acetabulum. When hip disease commences in the bone it usually involves the epiphyseal line that unites the head of the femur to the neck. This line is wholly within the joint, and the epiphysis that forms the head unites with the rest of the bone about the eighteenth or nineteenth year (Fig. 76). When the bone is primarily involved the posi- tion of flexion and abduction with eversion may not be observed at all, there being no effusion at first into the joint. In such cases the limb be- comes at once flexed and adducted, and this pos- ture is probably due solely to muscular spasm, and to an attempt to prevent the head of the femur from pressing against the acetabulum, and so causing pain. It is well known that patients with hip disease often complain of pain in the knee. This referred pain may be so marked as to entirely withdraw attention from the true seat of disease. Thus I once had a child sent to the hospital with a sound knee carefully secured in splints, but without any appliance to the hip, which was the seat of a somewhat active inflammation. This referred pain is easy to understand, since the two joints are supplied from the same segments of the spinal cord. In the hip, branches from (1) the anterior crural enter at the front of the capsule ; (2) branches from the obturator at the lower and inner part of the capsule : and (3) branches from the sacral plexus and sciatic nerve at the pos- terior part of the joint. In the knee, branches from (1) the anterior crural (nerves to vasti) enter at the front of the capsule ; (2) branches from the obturator at the posterior part of the capsule ; and (3) branches from the internal and external popliteal divisions of the great sciatic Chap. XIX] REGION OF THE HIP 50l nerve at the lateral and hinder aspects of the joint. Pain, therefore, in the front of the knee, on one or both sides of the patella, has probably been referred along the anterior crural curve, and pain at the back of the joint along the obturator or sciatic nerves. In hysterical individuals joint disease may be imitated by certain local nervous phenomena, the articulation itself being quite free from struc- tural change. This affection most commonly shows itself in the hip or knee, and the " hys- terical hip," or " hysterical knee, ; ' takes a prom- inent place in the symptomatology of hysteria. It is not quite easy to understand why these two large joints should be so frequently selected for the mimicry of disease. Hilton has endeavoured to explain the fact upon anatomical grounds, having reference to the nerve supply of these joints in relation to the nerve supply of the uterus. The uterus is mainly supplied by an offshoot from the hypogastric plexus, and by the third and fourth sacral nerves. Now, the hypo- gastric plexus contains filaments derived from the lower lumbar nerves; and from the same trunks two nerves to the hip and knee (the anterior crural and obturator) are in great part derived. The great sciatic also contains a large portion of the third sacral nerve. The common origin of the joint and uterine nerves forms the basis of Hilton's explanation of the relative frequency of hysterical disease in the large articulations of the lower limb. The explanation, however, is un- satisfactory, since the uterus receives many of its nerves from the ovarian plexus, and the theory is founded upon the unwarranted supposition that all hysterical disorders are associated with some affection of the uterus or its appendages. More recently Head has revived a modified form of Hilton's theory. He explains the connection not through an anatomical association of nerves, but through an association of the centres from which 502 SUEGICAL APPLIED ANATOMY [Part V nerves arise in the spinal cord. The spinal seg- ments from which the obturator nerve arises, the second, third, and fourth, contain no visceral nerves, and, therefore, cannot be associated with visceral conditions. On the other hand, the sacral segments from which the great sciatic nerve arises are those which supply the pelvic viscera. Fractures of the upper end of the femur may be divided into (1) fractures of the neck wholly within the capsule ; (2) fractures of the base of the neck not wholly within the capsule ; (3) fractures of the base of the neck involving the great trochanter ; (4) separations of epiphyses. It can be scarcely possible, apart from gunshot in- juries, to fracture the neck of the femur by direct violence, owing to the depth at which the bone is placed, and the manner in which it is protected by the surrounding muscles. The violence, there- fore, that causes the lesion is nearly always sup- plied indirectly to the bone, as by a fall upon the feet or great trochanter, or by a sudden wrench of the lower limb. (1). The true intercapsular fracture may involve any part of the cervix within the joint, but is most usually found near the line of junction of the head with the neck. This fracture is most common in the old, in whom it may be produced by very slight degrees of violence. The liability of the aged to this lesion is explained upon the following grounds : The angle between the neck and shaft of the femur, which is about 130° in a child, tends to diminish as age advances, so that in the old it is commonly about 125°. In certain aged subjects, as a result probably of gross degenerative changes, this angle may be reduced to a right angle. This diminution of the angle certainly increases the risk of fracture of the neck of the bone. There is often, also, in ad- vanced life, much fatty degeneration of the can- cellous tissue of the cervix with thinning of the compact layer. Dr. Merkel (Amer. Journ. Med. Sc, 1874) also asserts that in old persons there is Chap. XIX] REGION OF THE HIP 503 an absorption of that process of the cortical sub- stance which runs on the anterior part of the neck between the lesser trochanter and the under part of the head. This process he calls the " calcar femorale," and maintains that it occupies the situation at which the greatest pressure falls when the body is erect. These fractures are but rarely impacted ; but when impacted, the lower frag- ment, represented by the relatively small and compact neck, is driven into the larger and more cancellous fragment made up of the head of the bone. The fracture may be subperiosteal, or the fragments may be held together by the reflected portion of the capsule. These reflected fibres pass along the neck of the bone from the attachment of the capsule at the femur to a point on the cervix much nearer to the head. " These reflected fibres occur at three places, one corresponding in position to the middle of the ilio-femoral liga- ment, another to the pectineo-femoral, and the third on the upper and back part of the neck " (Henry Morris). Fractures of this part very rarely indeed unite by bone. Blood is brought to the head of the femur by vessels in the neck of the bone, in the reflected parts of the capsule, and in the ligamentum teres. When the first two sources of blood supply are cut off by the fracture, the third does not appear to be sufficient to allow of great reparative changes taking place in the upper fragment. The fractures that heal by bone are probably either impacted, or subperiosteal, or not wholly intracapsular. (2). With regard to fractures at the base of the neck, it must be remembered that a wholly extra- capsular fracture of the neck of the femur is an anatomical impossibility. If the fracture is wholly without the capsule, then it must involve a part of the femoral shaft, and cannot be entirely through the cervix. In the front of the bone the capsule is attached to the femur along the intertrochanteric line, and strictly follows the line of junction between the cervix and the shaft. 504 SURGICAL APPLIED ANATOMY [Part V Behind, the capsule is inserted into the neck about ^ an inch above the posterior intertrochanteric line. It is therefore possible for a fracture of the neck to be extracapsular behind, but not in front, and many of these lesions at the base of the neck have this relation to the capsule. The Y liga- ment is so thick, being in one place about \ of an inch in thickness, that a fracture involving the base of the cervix may run between its fibres at their attachment, and be neither extra- nor intra- capsular. When fractures at the junction of the neck and shaft are impacted, the upper fragment, represented by the compact and relatively small cervix, is driven into the cancellous tissue about the great trochanter and upper end of the shaft. As a result of this impaction the tro- chanter may be split up, and the bones may be- come free again through the extent of this splintering. With regard to the symptoms of a fracture of the neck of the feimir, the following may be noticed : (a) The swelling often observed in the front of the limb, just below Poupart's liga- ment, is due either to effusion of blood into the joint or to projection of the fragments against the front of the capsule ; (b) the shortening is brought about by the glutei, the hamstrings, the tensor vaginae femoris, the rectus, sartorius, and ilio-psoas, the adductors, gracilis and pectineus ; (c) the eversion, or rotation outwards of the limb, is mainly due to two causes : (i.) the weight of the limb, which causes it to roll outwards, as is seen in persons insensible or asleep, the line of gravity passing through the outer part of the thigh; (ii.) the fact that the compact tissue on the posterior aspect of the neck is much more fragile than that on the anterior aspect. Thus the cervix is often more extensively fractured behind than in front, or the fracture may be impacted behind but not in front, and in either case the limb will tend to become everted. As a third cause may be mentioned the action of the ilio-psoas, the Chap. XIX] REGION OF THE HIP 505 adductor and pectineus muscles, and of the small rotator muscles, all of which will tend to roll the femur outwards. (3). Fracture of the base of the neck, involving the great trochanter. In this lesion the head, the cervix, and a part of the great trochanter are separated from the shaft and rest of the tro- chanter. (4). Separation of epiphyses. There are three epiphyses in the upper end of the femur : one for the head, which unites between eighteen and nine- teen ; one for the lesser trochanter, which unites Fig. 79. — Illustrating the ossification of the upper extremity of the femur and the condition of coxa vara. {After Elmslie.) a, The upper extremity at birth. b, ,, „ „ „ 2nd year. c, „ „ „ „ 4th year. jj, „ ,, „ of a femur from ' a subject of coxa vara. about seventeen ; and one for the greater tro- chanter, which unites about eighteen. The neck is formed by an extension of ossification from the shaft (Fig.' 79). The epiphysis for the head is secured against separation by being shaped like a cap, by its epiphyseal line being arranged trans- versely to the axis of the femur, and also by its intracapsular position. The epiphysis, however, is subject to a peculiar form of dislocation which gives rise to the condition of coxa vara. The epiphysis gradually tilts downwards so that the neck of the femur appears to sink under the weight of the body, coming to form an angle of 90° or less with the shaft of the femur. It occurs in adolescents. Owing to the prominence of the 506 SURGICAL APPLIED ANATOMY [Part V trochanter and shortening of the limb which necessarily result, the condition may be mistaken for a fracture of the neck of the femur or a con- genital dislocation of the hip-joint. The great trochanter may be separated. The epiphyseal lines of the head and great trochanter are continuous until the neck is ossified (see Fig. 79). Dislocations of the hip. — These injuries are comparatively rare, on account of the great strength of the articulation, and when they occur in a healthy joint are always the result of a con- siderable degree of violence. A dislocation of the y- 5/iaped Cartilage ACETABULUM PuBES 5yMPnysis C.RT TROCrtArtTER ,2LyL-PECTIMEU3 Adductor lohCus Capsulc Psoas Fig 80.— Congenital dislocation of the hip. From a specimen presented to the London Hospital Medical College Museum by Mr. Openshaw. It was obtained from a child aged 4 years. hip may be congenital, or may be spontaneously produced by muscular efforts, as shown in a few rare cases, or may be the result of disease of the articulation. Congenital dislocation of the hip- joint is due- in most instances to a failure in the development of the acetabulum. In such cases the acetabulum retains the shallow character seen during the second month of foetal life. The out- growth of the acetabular rim fails, especially in the iliac part. The acetabular cavity becomes filled up by the duplication of the capsule, which is unduly lax (Fig. 80). The round ligament may be intact or deficient. The head of the femur be- comes flat and the neck short, and the bone slips backwards on the dorsum ilii when the child Chap. XIX] REGION OF THE HIP S07 learns to walk. The weight of the body is sup- ported by the muscles and ligaments round the hip-joint. If replaced the head again slips from the shallow cavity. In time osteophytic out- growths from the ilium lead to the formation of a new cavity. The deformity is evidently corre- lated with the development of the female sexual organs, for it is practically unknown in male children. In dislocations due to violence the head of the bone may be found displaced in four directions, producing the four regular dislocations of the hip. In two the head of the femur is posterior to a line drawn vertically through the acetabulum, and in the other two it is found anterior to that line. (1) Backwards and upwards. Head rests upon ilium, just above and behind acetabulum. The " dislocation upon the dorsum ilii." (2) Back- wards. Head rests upon ischium, and, as a rule, about on a level with the ischial spine. The " dis- location into the sciatic notch." (3) Forwards and downwards. Head rests on thyroid foramen. The " obturator or thyroid dislocation" (4) For- wards and upwards. Head rests upon the body of the pubes, close to its junction with the ilium. The ''''dislocation upon the pubes." The above arrangement represents also the order of frequency of these luxations, No. 1 being the most common dislocation of this part, and No. 4 the most rare. General facts. — In all these dislocations of the hip, (a) the luxation occurs when the limb is in the position of abduction ; (b) the rent in the capsule is always at its posterior and lower part; (c) the head of the bone always passes at first more or less directly downwards ; (a) the Y ligament is untorn, while the ligamentum teres is ruptured. (a) It is maintained that in all luxations at the hip, the pelvis_ and femur are in the mutual position of abduction of the latter at the time of the accident. The direction of the neck of the 508 SURGICAL APPLIED ANATOMY [Part V femur and of the acetabulum, and the position of the cotyloid notch, all favour dislocation in the abducted posture. The lower and inner part of the acetabulum is very shallow, and the lower and posterior part of the capsule is very thin. In abduction, the head of the bone is brought to the shallow part of the acetabulum; it moves more than half out of that cavity ; it is supported only by the thin weak part of the capsule, and its further movement in the direction of abduction is limited only by the pubo-femoral ligament, a somewhat feeble band. In abduction the round ligament is slack, and in abduction with flexion both the Y ligament and the ischio-femoral liga- ments are also relaxed. In the position of abduc- tion, therefore, no great degree of force may be required to thrust the head of the bone through the lower and posterior part of the capsule and displace it downwards. (6) The above being allowed, it will be under- stood that the rent in the capsule is always at its posterior and lower parts. " Generally the rup- ture is jagged and irregular, but will be found to extend more or less directly from near the shallow rim of the acetabulum, across the thin portion of the capsule to the femur near the small trochanter, and then to run along the back of the ligament close to its attachment to the neck of the bone " (Henry Morris). (c) If the position of the limb at the time of the accident be considered, it will be seen that the femur will in every case be displaced downwards. There is, indeed, but one primary dislocation of the hip — a luxation downwards. The four forms given above are all secondary, the bone having in each instance first passed downwards before it moved to any of the positions indicated. This point has been ably demonstrated by Mr. Henry Morris, whose account of the anatomy of hip dis- locations is most valuable. The head having left the acetabulum, its ultimate destination will de- pend upon the character of the dislocating force. Chap. XIX] REGION OF THE HIP 509 " If the limb be flexed on the pelvis, and rotated inwards, or the pelvis be correspondingly moved on the thigh at the moment of displacement, the head of the femur will take a backward course and rest on the dorsum ilii or some part of the ischium. On the other hand, extension and out- ward rotation will cause the head of the bone to travel upwards and forwards, and what is called a dislocation on to the pubis will occur. _ . . . If the dislocation is neither accompanied nor followed by rota- tion or fixed flexion or exten- sion, the head of the femur will remain below the acetabulum, and will occupy the foramen ovale if it takes a slightly forward direction in its descent, or some position near the tuber- osity of the ischi- um if it leaves its socket in a back- ward and down- ward direction J ' (Henry Morris). (d) The Y liga- ment is never torn in any regu- lar dislocation. It is saved by its great density and the circumstance that it is probably more or less relaxed at the time of the luxation. The method of reducing these dislocations by manipu- lation > depends for its success mainly upon the integrity of the Y ligament, which acts as the fulcrum to a lever of which the shaft of the femur is the long arm and the neck the short. In the backward luxations the head is behind the Fig. 81. — Dislocation upon the dorsum ilii. (Bigeloiv.) 510 SURGICAL APPLIED ANATOMY [Part V Y ligament, and in the forward displacements in front of it. The anatomy of each form. — Nos. 1 and 2. The dislocations backwards (Fig. 81). The femoral head, having been displaced in the way; indicated, is carried towards the dorsum or sciatic notch by the glutei, hamstring, and adductor^ muscles. The bone having taken a general direction back- wards, the height to which it ascends • depends mainly upon the nature of the dislocating force, and also upon the extent of the rupture in the capsule and the laceration of the obturator internus tendon and other small external ro- tators. The dorsal dislocation is, therefore, a more advanced grade of the sciatic. The more extreme the flexion and inward rotation at the time of the accident, the more likely is the dislocation to be sciatic. More moderate flexion and inward rota- tion will produce a luxation upon the dorsum. In the dorsal luxation the head is above the obturator internus tendon, while in the sciatic form it is below it (Bigelow). Morris has been able to find but one case of direct dislocation of the femur backwards on to the ischium. In every instance it passes first in a downward direction, and then backwards. Bigelow states that there is no evidence to show Pig. 82. -Obturator or thyroid dislocation. {Bigelow.) Chap. XIX] REGION OF THE HIP 511 that the head of the femur has even been actually displaced into the sciatic notch. In these backward dislocations the ilio-psoas muscle is greatly stretched. The quadratics femoris, the obturators, the gemelli, and the pyri- formis are more or less lacerated. The pecti- neus is often torn, and the glutei muscles even may be rupture d_ in part. The great sciatic nerve may be compressed between the femoral neck and the rotator muscles, or between the head of the bone and the tuber ischii. In both of the backward luxa- tions there is shorten- ing, due to the circum- stance that the line between the anterior superior spine and the femoral condyles is les- sened by the displace- ment backwards of the bone, with the additional shortening in the dorsal dislocation brought about by the passing of the femoral head above the level of the acetabulum. The adduction and inversion in the main depend upon the position of the head and cervix, which must follow the plane of the bone upon which they lie. This position is maintained by the tense Y ligament. The damage done to the chief external rotators places them also hors de combat. The flexion is due to the tension of the Y ligament and of the ilio-psoas muscle. Nos. 3 and 4. The dislocation forwards. If the head after leaving the acetabulum simply moves a little forwards along the inner edge of the Fig. S3. -Dislocation upon the pubes (Bigelow.) 512 SUKGICAL APPLIED ANATOMY [Part V socket, the thyroid luxation is produced (Fig. 82). If it goes farther and moves upwards, the pubic displacement will result (Fig. 83). The latter dis- location is therefore but an advanced form of the former. Whether the head will remain in the thy- roid foramen or ascend on to the pubes depends on whether extension and rotation outwards accom- pany the displacement. If these occur the pubic form is produced. In these injuries the pectineus, gracilis, and adductors will be more or less torn, while the ilio-psoas, glutei, and pyriform muscles are much stretched. The obturator nerve may be stretched or torn, and in the pubic luxation the anterior crural nerve may be involved. The ab- duction and eversion of the limb noticed in these luxations depend partly upon the position of the head of the bone, fixed more or less by the Y liga- ment, and partly upon the action of the gluteal muscles and some of the small external rotators, which are tightly stretched. The flexion of the limb is mainly due to the stretching of the ilio- psoas muscle. In the thyroid luxation the extremity is said to be lengthened. This lengthening is, however, only apparent, and is due to the tilting down of the pelvis on the injured side. In the pubic dislocation there is shortening, the head being carried above the acetabular level. Of the modes of reducing these dislocations by manipulation little can be said here. The more usual proceedings may be briefly summarised as follows : First. — Flex the thigh in the ad- \ ducted position in luxa- tions Nos. 1 and 2. To relax the Flex the thigh in the ab- f Y ligament, ducted position in luxa- tions Nos. 3 and 4. Secondly. — Circumduct out in^jTo bring back the Nos. 1 and 2. head to the rent c in the capsule by Circumduct in in the same route that JSTos. 3 and 1. ) it has escaped. Chap. XIX] REGION OF THE HIP 513 Thirdly. — Extend in all cases. To induce the head to enter the acetabulum again. In reducing dislocations of the hip it may be noted that the internal condyle of the femur faces in nearly the same direction as the head of the bone. In amputation of the thigli at the hip- joint many methods may be employed. A com- mon procedure consists of a circular incision which divides the soft parts to the bone at the junction of the upper with the middle thirds of the thigh, and is combined with a vertical incision over the great trochanter, through which the upper extremity of the femur is exposed and the joint disarticulated. (See section, Fig. 76, p. 493.) Haemorrhage from the femoral, gluteal, and sciatic vessels is prevented either by compressing the termination of the abdominal aorta a little below and to the left of the umbilicus, or by en- circling the junction of the thigh and body with a loop of elastic bandage. The bandage must pass inside the ischial tuberosity to compress the con- tents of the sacro-sciatic foramen, over the groin to compress the femoral vessels, and above the iliac crest to prevent it from slipping downwards. In the circular incision the vessels divided are : the superficial and deep femoral, the second per- forating artery, descending branches of the ex- ternal circumflex arid sciatic vessels, and long saphenous vein ; the nerves divided are : the external, middle and internal cutaneous, the in- ternal saphenous, the deep muscular branches of the anterior crural, the obturator, the great and small sciatic ; the muscles divided are : the sar- torius, quadriceps extensor cruris, adductors magnus and longus, gracilis, and hamstrings. In the vertical incision (Fig. 76, p. 493) the ilio-tibial band and the insertions of all the gluteal muscles are divided to the bone. Communicating branches between the ascending and transverse branches of the external circumflex artery in front with the gluteal, sciatic and first perforating behind are 2 H 514 SURGICAL APPLIED ANATOMY [Part V cut. The capsule of the joint is divided, the head of the femur thrust from its socket, and the liga- mentum teres cut. The attachments of the follow- ing structures to the upper third of the femur have to be separated : the gluteus maximus, medius, minimus, pyriformis, gemelli, obturator internus and externus, quadratus femoris, ad- ductor magnus, brevis, pectineus, psoas and ilia- cus, with the capsular ligament. By the method of disarticulation at the hip- joint known as the anterior racket, no elastic tourniquet and no compression of the iliac vessels are needed. The vertical part of the racket-shaped incision is placed over the femoral vessels, and those ves- sels are secured by two ligatures each and are then severed between the ligatures. The circum- flex arteries are in the same way secured before division. If carefully performed, very little blood is lost in the anterior racket amputation. CHAPTER XX THE THIGH Under the term " the thigh ' ; it will be convenient to describe that part of the lower limb that ex- tends between the regions just described and the districts of the knee and popliteal space. Surface anatomy. — In muscular subjects the outline of the thigh is irregular, but in the less muscularly developed, who are provided with a good share of subcutaneous fat, the limb, in this section of it, is more or less evenly rounded. The prominence of the rectus muscle is noticeable on the front of the thigh, especially when the muscle is in action. To the inner side of this structure, and conspicuous along the lower half of the thigh, is the eminence formed by the vastus internus. The mass to the outer side of the rectus is com- posed of the external vastus muscle, and occupies the greater part of the limb in this region, being, however, more conspicuous below. Running down the anterior and inner aspect of the thigh, from the apex of Scarpa's triangle, is a depression which indicates the interval be- tween the quadriceps muscle and the adductors. Along this groove the sartorius lies. Over the surface of the vastus externus a longitudinal de- pression is often to be observed, formed by the pressure exercised bv the superimposed ilio-tibial band of the fascia lata. The hamstring muscles cannot usually be distinguished the one from the other above the popliteal space, nor is their 515 516 SURGICAL APPLIED ANATOMY [Part V separation from the adductors indicated. The separation, however, between them and the vastus externus is distinct, and corresponds to the posi- tion of the external intermuscular septum. The line of the femoral vessels has already been given (p. 487). The long saphenous vein follows in the thigh the course of the sartorius muscle, and may be represented on the surface by a line drawn from the region of the saphenous opening (p. 487) to the posterior border of the sartorius muscle at the level of the inner condyle of the femur. The long saphenous nerve follows the course of the femoral artery, lying first to the outer side of that vessel and then gradually crossing it. In the lower fourth of the thigh the nerve passes under cover of the sartorius muscle to the inner side of the knee, and is accompanied by the superficial branch of the anastomotic artery. A line drawn down the back of the limb from a point midway between the great trochanter and tuber ischii to the middle of the ham will correspond to the great sciatic nerve and one of its continuations, the internal popliteal (see p. 480). The great trunk usually bifurcates a little below the middle of the thigh. The skin of the thigh is coarse on the outer side of the limb, but internally it is thin and fine, and is apt to be readily excoriated by ill-applied bandages or splints. It is but loosely attached to the subjacent parts, a circumstance that greatly favours the performance of circular amputations . in this region. At one place, however, it is a little more adherent, viz. along the groove that separates the vastus externus from the hamstring muscles, and that corresponds to the outer inter- muscular septum. The laxity of the subcutaneous tissue favours extensive extravasations beneath the skin, and permits of large flaps of integu- ment being torn up in cases of injury to this part of the extremity. The fascia lata invests the limb at all parts like a tightly fitting sleeve. It is thickest at its Chap. XX] THE THIGH 517 outer side, where it forms the dense ilio-tibial band. It is thinnest at the upper and inner as- pect of the thigh, where it covers the adductor muscles. It increases considerably in strength as it approaches the front of the knee, and attaches itself to the tibia and lateral margins of the patella. This fascia resists, especially at its outer part, the growth of tumours and abscesses, and limits deep extravasations of blood. It has occa- sionally been ruptured in part by violence, and through the rent so formed the subjacent muscle has bulged, forming what is known as a hernia of the muscle. This condition has been met with in the case of the quadriceps muscle, and also of the adductor longus. Such " hernise ,; are probably associated with some rupture of the fibres of the muscles implicated. Two deep processes of the fascia are attached to the femur, and form the outer and inner intermuscular septa. The outer septum separates the vastus externus from the biceps, and the inner the vastus internus from the adductors. Together with the fascia lata, these septa divide the thigh into two apo- neurotic spaces, which can be displayed in a transverse section of the limb. These divisions, however, are of little surgical moment, and the inner septum is often so thin and feeble that it could have but little effect in directing the course of an abscess. In circular amputations of the thigh the muscles are apt to retract a little unevenly, since some are attached to the femoral shaft while others are free. The muscles so attached are the adductors, vasti and crureus, while the free mus- cles are the sartorius, rectus, hamstrings, and gracilis. In spite of its great strength the tendon of the quadriceps may be ruptured by muscular violence. A good example of such an accident is recorded by Mr. Bryant (Med. Times, 1878). A man aged forty-two stumbled in the dark, and fell down a pit ten feet deep. On examination the tendon 518 SURGICAL APPLIED ANATOMY [Part V was found to be torn across, and the gap above the patella produced by the rupture occupied no less extent than the lower third of the thigh. A some- what more remarkable accident is reported to have happened to the sartorius muscle. This muscle, just before its insertion into the tibia, gjives oft' an aponeurotic expansion from its anterior bor- der to the capsule of the knee-joint. In the case alluded to (Lancet, 1873), this expansion is said to have been ruptured, and the muscle itself to have been found dislocated backwards in conse- quence. The accident befell a man aged forty, who was squatting, in the position assumed by tailors, upon the floor of a waggon, when his com- panion tripped over him and fell across his bent knees. Something was felt to have given way near the ham, and on examination the above lesion was diagnosed. The femoral artery may be ligatured at any part of its course in the thigh, and the com- paratively superficial position of the vessel ren- ders it very liable to be injured. In the middle third of the thigh it lies beneath the sartorius in Hunter's canal. The thigh affords many instances of the remarkable way in which isolated branches of a main artery are often alone damaged. Thus, Langier relates the case of a man-cook, who, in running round a table, struck the upper and outer side of his thigh against the corner of it. This led to a subcutaneous rupture of the external circumflex artery. Unfortunately the extravasa- tion was cut into, and the patient, after being subjected to many modes of treatment, died from the effects of repeated haemorrhage. Dr. Butcher (Dub. Joum. Med. Sc, 1874) gives the case of a man who was stabbed in the thigh over the femoral vessels during a scuffle. Profuse bleeding fol- lowed, and it was found that the only vessel wounded was the internal circumflex artery, just at its point of origin from the profunda. The case was treated promptly and the man did well. Fractures of the femur. — The shaft of the Chap. XX] THE THIGH 519 femur may be broken at any part, but the lesion is most common at the middle third of the bone, and least frequent at its upper third. If broken by direct violence the fracture is usually trans- verse, and if by indirect violence it is usually oblique. The probability of a fracture being due to direct violence diminishes in the bone from below upwards, while the probability of a lesion from indirect violence increases in the same direc- tion. Thus it happens that the fractures of the upper third of the bone are usually oblique, while those of the lower third are more commonly trans- verse. In the middle third the numbers of the transverse and oblique fractures are more nearly balanced. The femur has < often been broken by muscular violence, but it is doubtful if this has ever occurred in other than a diseased bone. In many of these cases the amount of force that breaks the bone is most insignificant. Thus Val- lin reports the case of a girl aged eighteen, de- scribed as robust, who broke the femur about its middle while in the act of mounting a table for the purpose of undergoing a vaginal examination. In oblique fractures in the upper third of the bone the line of fracture usually runs downwards and inwards, while in oblique fractures of the middle third the direction is more commonly downwards and forwards^ with a slight lateral inclination that is sometimes inwards and sometimes out- wards. Fractures of the lower third of the bone are discussed in connection with the region of the knee (chap. xxi.). _ With regard to fractures of the upper and middle thirds, the displacements of the fragments depend greatly upon the obliquity of the fracture. As a rule the lower fragment is drawn up behind the upper one by the hamstrings, aided by the rectus, gracilis, sartorius, tensor vaginae, and adductors, and is carried a little to its inner side under the influence of the last-named muscles. The^ lower end of the upper fragment usually projects forwards and a little backwards. This 520 SURGICAL APPLIED ANATOMY [Part V is produced by the agency of the lower fragment, which tilts the upper piece of bone in the^ direction named. In the fracture of the upper third of the shaft the projection forwards of the upper frag- ment is aided by the ilio-psoas muscle. Thus the deformity produced in fractures of the femoral shaft is usually angular in character. The ever- sion of the foot noted in fractures of the femur is due to the weight of the limb, which causes the helpless member to roll out, aided probably by the action of the external rotator muscles. Certain spiral fractures (helicoidal fractures of Leriche) may be produced in the lower part of the shaft as the result of torsion. M. Fere finds by experiment that if the limb be carried forwards in front of the opposite knee, and the foot rotated outwards, a spiral fracture can be produced at the junction of the lower and middle thirds of the femur. A like fracture at the same level, but with the direction of the spiral reversed, can be produced by carrying the limb outwards and then rotating it inwards. Shortening of the limb after fracture.— It is doubtful if a fracture of the shaft of the femur can, after any treatment, become united without some shortening resulting, save in a few exceptional cases. It is important, in connection with this subject, to remember that the lower limbs may be normally of unequal length. Dr. Wight, of Brooklyn, has fully investigated this matter, and has arrived at the following con- clusions : (1) The greater number of normal lower limbs are of unequal length ; (2) the left limb is often longer than the right ; (3) the average in- equality of normal lower limbs is probably about \ of an inch ; (4) the average amount of shortening after a fracture of the femur that has been well treated is about f of an inch ; (5) in about one case in ten or eleven the two limbs will be found to be of equal length after the union of the fracture ; (6) one limb can never be a certain standard of length for the opposite limb. Dr. Garson, as a Chap. XX] THE THIGH 521 result of the careful examination of some seventy skeletons, states that both the lower limbs are of equal length in only about 10 per cent, of all cases. He also found that the femur was more frequently the seat of variation than the tibia. Amputation of the tliigli. — In a circular amputation of the thigh about its middle the fol- 2 $ Fig. S4. — Transverse section through the middle of the thigh. (Brawne.) «, Rectus fenioris; l>. vastus extemus; c, crureus; d, vastus internus; e, short head i if biceps; /. long head of biceps ; (i. seinitendinosus ; h, semimembra- nosus ; i, adductor niaguus ; j, gracilis ; k, adductor longus ; I, sartorius. 1, femoral artery : i', great sciatic nerve ; 3, great saphenous veiu : 4, middle cutaneous nerve: 5, external cutaneous nerve; 6, perforating branches from profunda ; 7, small sciatic nerve. lowing parts would be divided (Fig. 84) : the quadriceps, sartorius, gracilis, long and great ad- ductors, and the three hamstring muscles; the superficial and deep femoral vessels, the descend- ing branches of the external circumflex artery, the lower perforating vessels, and the long saphenous vein ; the main branches of the anterior crural nerve (middle cutaneous, internal cutaneous, and muscular, together with the long saphenous nerve), the anterior branch of the external cutaneous 522 SURGICAL APPLIED ANATOMY [Part V nerve, the obturator, and the great and small sciatic nerves. Owing to the unequal manner in which the divided muscles retract, a simple cir- cular amputation is not well adapted for the thigh. A more convenient method of amputation is represented bv the elliptical method, the lower extremity of the ellipse being on that side of the limb on which muscular retraction is the more marked, i.e. on the posterior side of the thigh. & CHAPTER XXI THE REGION OF THE KNEE In this chapter will be considered the articulation of the knee, the soft parts about the joint, the popliteal space, the lower end of the femur, the patella, and the upper ends of the tibia and fibula. Surface anatomy. — In the front of the knee the patella can be distinctly felt and seen. Its inner border is a little more prominent than the outer. When the limb lies in the extended pos- ture, with the quadriceps relaxed, the patella can be moved to and fro, and appears to be but loosely attached. When the quadriceps is contracted the bone is drawn upwards, and becomes firmly fixed against the femur. In flexion of the joint the patella sinks into the hollow between the tibia and the intercondyloid notch, and is very firmly fixed. In this position some part of the trochlear surface of the femur can be made out above the patella. On each side of the knee-cap a hollow exists which may be completely filled up with fat in the obese. When the limb lies in the extended posture the ligamentum patellae is not to be very distinctly made out. It becomes a little more conspicuous in the flexed position, and is most prominent when the quadriceps muscle is vigorously contracted. The subpatellar pad of fat bulges outwards on each side of the ligament and may be mistaken by the inexperienced for fluid in the joint. On the inner side of the knee the following parts can be felt from above downwards : the 523 524 SURGICAL APPLIED ANATOMY [Part V • tubercle for the adductor magnus, and the tendon of insertion of that muscle; the inner condyle of the femur, which is very prominent, and forms the chief part of the rounded eminence on this aspect of the joint; and below this the inner tuberosity of the tibia. Between the two latter processes of bone, the interarticular line and semilunar cartilage are easily felt. On the outer side of the joint is the external condyle of the femur, which is much less conspicuous than its fellow of the opposite side, and below it is the corresponding tuberosity of the tibia, forming a marked prominence. Immediately in front of the biceps tendon the upper part of the external lateral ligament can be felt when the joint is a little flexed. Between the tendon and the patella, the lower part of the ilio-tibial process of the fascia lata can be detected as a prominent rounded band, descending to the external tuberosity of the tibia. It is most distinct when the knee-joint is forcibly extended by muscular action, and often stands out conspicuously beneath the skin. The- tubercle of the tibia and the head of the fibula are- both readily felt, and are nearly on the same level. The popliteal space only appears as a hollow when the knee is bent. In the extended limb the hollow is replaced by an evenly rounded eminence. The crease in the skin that passes transversely across the ham is some way above the line of the knee-joint. On the outer side of the space the biceps tendon can be very readily felt, especially when the muscle is in action. Just behind it, and along its inner border, lies the peroneal nerve. It can be rolled under the finger as it crosses the head of the fibula to pass beneath the peroneus longus muscle. On the inner side of the ham three tendons can be felt. Nearest to the middle of the space is the long prominent tendon of the semitendinosus. Internal to it is the larger and less distinct semimembranosus tendon, and still more to the inner side the gracilis may be made out. The popliteal vessels enter the ham obliquely Chap. XXI] EEGION OF THE KNEE 525 at its upper and inner part, and under cover of the semimembranosus muscle. The outer border of this muscle is the guide to the upper portion of the artery. The vessels in their descent reach a point behind the middle of the knee-joint, and then pass vertically downwards. The termination of the popliteal artery is on a level with the lower part of the tubercle of the tibia. When the limb is flexed, the pulsations of the artery can be felt and the vessel compressed against the femur a little below its point of entry into the popliteal space. The upper articular arteries run trans- versely inwards and outwards just above the femoral condyles. The lower articular arteries are also placed transversely, the inner vessels run- ning just below the internal tuberosity of the tibia, and the outer just above the head of the fibula. The deep branch of the anastomotica magna descends to the inner condyle of the femur in the substance of the vastus, internus, and along the front of the adductor magnus tendon. The internal saphenous vein passes up along the back part of the internal condyle of the femur, and then follows the sartorius muscle to the thigh. It is just below the interarticular line that the long saphenous nerve usually joins the vein. The short saphenous vein follows the middle line of the calf just below the ham, and pierces the deep fascia at the lower part of the popliteal space. Tnis vessel is much less conspicuous than is the long saphenous vein, and is, indeed, not often to be seen unless varicose. _ The internal popliteal nerve descends in the middle line, and continues the line that marks the course of the great sciatic trunk. In their normal condition the popliteal glands are not to be felt. The limits of the synovial membrane of the knee-joint, and the position of the various bursa? about this articulation, will be dealt with in some of the subsequent paragraphs. The front of the "knee.— The skin over the 526 SUKGICAL APPLIED ANATOMY [Part V front of the knee is dense and very movable. This mobility affords considerable protection to the knee-Joint, especially in stabs with bluntish in- struments, and in any injury where the gliding movement of the skin may direct the violence away from the articulation. The comparative looseness of the integument is sometimes utilised in the operation of removing so-called " loose cartilages ' ; from the knee-joint. It permits the incision into the joint to be very indirect, and, the skin being dragged out of place during the operation, it follows that, when the procedure is complete, the surface wound and that in the knee capsule no longer correspond. In flexion, the skin is drawn tightly over the patella, and, as is the case else- where, where the integument lies more or less directly upon the bone, a contusion over the knee- cap may produce a lesion precisely like an in- cised wound. In the Lancet for. 1877 is recorded the case of a very stout woman, aged fifty-seven, who, 'stum- bling on a hard road, fell upon her bent knee. The skin was burst across the front of the knee, and a wound was produced that was 7 inches in length, and was as cleanly cut as if made by a. scalpel. There is but little subcutaneous fat in front of the articulation, and thus it happens that in am- putations through the knee-joint the anterior flap is very thin, and is composed of little other than the simple integument. As blisters, and various forms of counter- irritant, are often applied to the front of the knee in cases of disease, it may be well to take note of the blood-supply of this part, and of the relations between the surface vessels and nerves and those of the joint. The vessels that give branches to the front of the knee, and are concerned in the suppjy of the part to which blisters are usually applied, are the anastomotic, the four articular branches of the ponliteal, and the anterior tibial recurrent. Now of these arteries, and especially Chap. XXI] REGION OF THE KNEE 527 of the anastomotica magna and superior articular, it may be said that, shortly after their origin, they divide into two branches, or two sets of branches, one going to the surface and the other to the articulation of the knee and deeper parts about it. It may be supposed, therefore, that, in applying a counter-irritant in front of the knee for the relief of a joint affection, a greatly in- creased quantity of blood is drawn into the super- ficial divisions of the above-named vessels, and less blood is thereby left to flow by their deeper branches to the seat of disease. The skin over the front of the knee, the anterior parts of the joint, and the quadriceps is supplied from the third and fourth lumbar segments through branches of the anterior crural and obturator nerves. The superficial lymphatics in the region of the knee lie for the most part on the inner aspect of the joint, and follow the course of the long saphenous vein. Ulcers, and other inflammatory affections of the skin over the articulation, are more apt to be associated with lymphangitis and with enlargement of the inguinal glands when situate on the inner aspect of the joint than when placed in front or to the outer side of it. The bursae over the front of the knee. — (1) The patellar bursa is a large sac placed in front of the patella and upper part of the patellar liga- ment, and separates those structures from the skin. It is frequently divided by septa into superficial and deep compartments. It is very often found enlarged in those who kneel much, in housemaids, stonemasons, religieuses, etc. The parts about are well supplied with nerves, and hence much pain is usually associated with acute inflammation of this sac. It is in close contact with the patella, and, in one case reported by Erichsen, suppuration of the bursa led to caries of that bone (Figs. 85, 86, and 90). (2) There is a bursa between the patellar ligament and the tubercle of the tibia (Figc. 86). When inflamed, it causes more pain than is observed in affections 528 SURGICAL APPLIED ANATOMY [Part V of the previous bursa, since it is firmly compressed between two rigid structures, the ligament and the bone. It is separated from the synovial cavity by the pad of fat that lies behind the patella. (3) The bursa between the quadriceps tendon and the femur will be considered in connection with the synovial cavity. The popliteal space. — The skin over the space is not so movable as is that over the front of the knee. When destroyed by injury, by burns, or by extensive ulceration, the contraction of the resulting cicatrix may lead to a rigidly bent knee. The skin in this place has also been rup- tured by forcible extension applied to the limb in cases of contracted knee. Beneath the skin and superficial tissue is the popliteal fascia, a dense membrane that covers in the space. It is but a continuation of the fascia lata of the thigh, and is continuous below with the fascia of the leg. It passes without bony attachment over the ham 1 string muscles that bound the ham. This fascia limits, often in a very marked manner, the pro- gress of popliteal abscesses and growths towards the surface. Its unyielding character is fa prime cause in the production of the severe pain with which such collections and tumours are often associated. The popliteal abscess, unable to reach the surface, is encouraged to extend either up into the thigh or down the leg. The ham may hold a very considerable quantity of pus. Vel- peau has seen a case where a litre (1 pint, 15 oz.) of pus was evacuated from this region in a patient who presented before the operation but an insignificant swelling in the site of the collection. Duplay records two cases of ulceration of an ab- scess into the popliteal artery, and Ollivier an instance where the abscess, unable to find a way to escape, ultimately entered the knee-joint. Pus may reach the ham from the buttock or pelvis bv following the great sciatic nerve, or may extend from the thigh through the opening in the great adductor for the femoral vessels. Chap. XXI] REGION OF THE KNEE 529 The Ii a in string muscles are frequently found contracted in neglected cases of knee-joint disease, and produce thereby more or less rigid flexion of the leg upon the thigh. Irritation from disease of the knee-joint may lead to contracture of the hamstring muscles. These muscles are sup- plied through the great sciatic nerve from the fifth lumbar segment, from which the knee-joint derives in part its nerve supply. Muscles on the flexor aspect of a bent joint undergo a permanent shortening if the position be maintained for a con- siderable space of time. Contraction of these muscles in knee-joint dis- ease tends not only to flex the knee but also to draw the tibia backwards, and produce in some cases a partial luxation. The hamstring tendons may be ruptured by violence, the tendon most frequently torn being that of the biceps. The muscles < are greatly stretched when the trunk is bent forcibly forwards at the hip-joint, the knee remaining extended. Extreme movement in this position has ruptured some of the fibres of this muscle. The difficulty experienced in touching the toes with the fingers while the knees are kept stiff depends upon the resistance offered by the stretched hamstrings. In tenotomy of the biceps tendon the peroneal nerve is in great risk of being wounded. It may be noted that contraction of the muscle tends to in- crease the distance between the tendon and the nerve, and to render the former more superficial. The peroneal nerve may be compressed by band- ages or garters applied too tightly over the head or neck of the fibula. The vessels of the ham.-— The popliteal ves- sels are, from their depth, but seldom wounded. It must be borne in mind that the lower part of the artery may be reached from the anterior aspect of the leg by an instrument passing between the tibia and fibula. Thus Spence reports the case of a farmer who received a wound in front of the leg, just below the knee, from the slipping 2 i 530 SURGICAL APPLIED ANATOMY [Part V of his knife while cutting a stick. It was dis- covered subsequently that the knife had entered the interosseous space and had wounded the pop- liteal artery at its bifurcation. It had indeed nearly severed the anterior tibial artery from the main trunk. The popliteal artery has been ruptured by ex- ternal violence, as when a wheel has passed over the region of the vessel. This artery is more fre- quently the seat of aneurism than is any other artery in the body, save only the thoracic aorta. In 551 cases of spontaneous aneurism, collected by Crisp, the popliteal vessel was the seat of the disease in 137 instances, the thoracic aorta having been affected in 175 of the cases. This marked disposition to aneurism depends upon many factors. The vessel is subjected to a great deal of movement, and often to very violent movement. Experiments upon the dead body show that the inner and middle coats of the vessel may be rup- tured by extreme flexion of the knee, and that a like rupture may in a smaller percentage of cases be brought about by forcible extension. More- over, except when the limb is in the position of extension, the popliteal artery is, like the thoracic aorta, much curved. Then, again, the vessel breaks up into two large vessels, and it is well known that the point of bifurcation of an artery is a favourite spot for aneurism. Lastly, the artery is supported only by the lax tissue of the popliteal space, and the support of strong muscles given elsewhere to so many large vessels is practic- ally absent. Some popliteal aneurisms have been successfully treated by flexing the knee and retain- ing the limb for some time in that position. That flexion can have a direct effect upon the lumen of the vessel is shown by the diminished pulse at the inner ankle produced by forcibly bending the leg upon the thigh. The artery and vein are so adherent that it is difficult to separate the two when applying a ligature to the arterial trunk. This adhesion must have been appreciated by any Chap. XXI] REGION OF THE KNEE 531 who have taken pains to " clean " the artery in a dissection of the ham. The popliteal vein is a remarkably substantial vessel, and has walls so dense and thick that on section they often look more like the tunics of an artery. On the ground of this peculiarity, and of its close adhesion to its companion vessel, Tillaux asserts that " it is unlike any other vein in the economy/' It is worthy of note that the vein, although more superficial than the artery, is very rarely ruptured by violence. As a rule, the artery alone is torn. In a few cases both the vessels may suffer; but I can find no instance recorded of rupture of the popliteal vein alone. From the relations of the artery to the vein and nerve it will be understood that a popliteal aneurism may soon lead to oedema of the leg and to nerve symptoms depending upon pressure on the internal popliteal trunk. It has more than once also made its way into the knee-joint, with the posterior ligament of which the artery is in such close relation. The short saphenous vein lies almost in the middle line, and, not being usually apparent through the skin, may be divided in an incision made into the lower part of the popliteal space. The lymphatic glands in the ham are from four to five in number and are deeply placed about the great vessels. When enlarged they have been mistaken for aneurism and other popliteal tumours. They receive the deep lymphatics of the leg. A small gland is often met with beneath the fascia, close to the point of entry of the short saphenous vein. It receives some lymphatics that follow that vessel. The bmsae about the ham are usually seven in number, four on the inner side of the space and three on the outer. Inner side. — (1) A large bursa between the internal condyle of the femur and the inner head of the gastrocnemius and the semimembranosus. This is the largest bursa in the space, and after adult life it usually communi- 532 SURGICAL APPLIED ANATOMY [Part V cates with the joint. It is, of all the bursas in this region, the one most often enlarged, and when affected may attain great size. In one re- ported case the sac measured 5 by 3.5 inches. In the extended position of the limb the enlarged bursa feels firm and resistant, but on flexion it becomes flaccid and can often be made to entirely disappear. Probably the slit-like communication between the bursa and the joint is closed when the posterior ligament is tightened by extension, and is opened when it is relaxed on bending the knee. In the latter posture the contents of the bursa can be reduced into the cavity of the knee- joint, and so the tumour disappears. (2) A little bursa between the semimembranosus tendon and the tuberosity of the tibia. Rather below the level of the knee there are two further bursas — (3) one beneath the insertion of the sartor ius, and (4) another beneath the insertions of the gracilis and semitendinosus. Outer side. — (l) A large diverticulum of the synovial membrane of the joint between the popliteus tendon and the ex- ternal tuberosity of the tibia. This diverticulum serves the purpose of a bursa, and may open into the tibio-fibular articulation, and so bring that cavity into connection with the knee-joint. (2) A bursa between the outer head of the gastrocnemius and the femoral condyle. It is not constant and is not connected with the articulation. (3) A bursa between the biceps tendon and the external lateral ligament. The peroneal nerve runs across this sac, a circumstance that may explain some of the pain experienced when the bursa is enlarged. It is not improbable that wounds in this region of bursae containing fluid have been mistaken for wounds of the joint, and the escaping serum for synovia. The kiico-joint. — This articulation is the largest in the body. The joint owes its great strength to the powerful ligaments that unite the two component bones, and especially to the muscles and fasciae that surround it. It derives no Chap. XXI] REGION OF THE KNEE 533 strength from the shape of the articular surfaces, since they are merely placed in contact with one another. In spite of its frequent exposure to in- jury, dislocations at the knee are extremely rare. The lateral ligaments are comparatively feeble, are tense in extension and relaxed in flexion. The laxity of these ligaments is such that partial Fig. 85. — Vertical section of normal knee-joint. (Braune.) a, Quadriceps; l>, semimembranosus: c, gastrocnemius; d. posterior crucial liga- ment ; c, ligamentum patellae ; /, bursa between quadriceps and femur. luxations of the tibia are possible without rup- ture of these bands, especially in cases where the joint is found slightly flexed after the accident. The crucial ligaments are very powerful, and are more or less tense in all positions of the joint. The anterior of these ligaments especially resists extension, forward displacement of the tibia, and rotation inwards of the leg. The posterior band resists flexion and displacement backwards of the 534 SURGICAL APPLIED ANATOMY [fart V tibia. In the movement of extension the tibia slides a little forwards and is rotated a little out- wards. In flexion that bone glides backwards and rolls a little inwards. Extension generally is limited by the crucial and posterior ligaments; flexion by the ligamentum patellae and anterior part of the capsule, in addition to the crucial ligaments. Rotation is possible only in the flexed position. The thinnest part of the posterior liga- ment is the portion below the oblique fibres de- rived from the semimembranosus. If pus finds its way from the joint into the ham,_ it will probably escape through this part of the ligament. In the contracted knee associated with fibrous ankylosis, the chief contraction, so far as the joint tissues are concerned, is in the posterior ligament, in the lateral ligaments, and in the fibrous and fatty tissue between the former liga- ment and the posterior crucial band. The synovial membrane of the knee-joint ex- tends upwards as a large cul-de-sac above the patella and beneath the extensor tendon. This cul-de-sac reaches a point an inch or more above the upper margin of the trochlear surface on the femur, and is rendered very distinct when the joint is distended with fluid (Fig. 86). When the knee is bent the cul-de-sac is drawn down, and therefore this position of the limb is advised when operations are about to be performed upon the lower end of the femur. Above the synovial pouch is a bursa that separates the quadriceps tendon from the femur, and is usually over an inch in its vertical measurement (Fig. 86). From the examination of two hundred and sixty knee- joints in both infants and adults, Schwartz found that this bursa communicated with the synovial cavity in seven cases out of ten in young children, and in eight cases out of ten in adults. It will thus be seen that when this communica- tion exists, a stab over the femur, about 2 inches above the trochlear surface of the bone, or about the same distance above the top of the patella, Chap. XXI] REGION OF THE KNEE 535 when the limb is extended, will practically open the knee-joint. Cases are reported of extravasation of blood into this bursa that, although at first limited to I ill M mm m Fig. S6. — Vertical section of knee-joint distended with fluid. (Braunc.) a, Vastus externus ; b, crureus ; c, short head, ami d, long head, of biceps ; e, plan- taris ; /, gastrocnemius ; c ii ii- valgum, or knock-knee. — The appear- ances produced by this affection are familiar. When a person stands erect with the feet together, the tibiae are practically vertical, and the femora meet them at a certain angle. The degree of this angle depends, in normal subjects, to a great extent upon the relative width of the pelvis. In genu-valgum the tibiae cease to be vertical in the erect position ; their lower ends deviate more and more from the middle line, until the distance be- tween the two malleoli becomes considerable when the individual stands upright and when he is not concealing any of the deformity by rotating the limb. The progress of the genu-valgum may be di- vided into three stages. In the first stage there is a yielding or elongation of the internal lateral ligament, and of the fascial structures on the inner side of the joint. That the yielding of this ligament alone will permit of a lateral movement at the articulation being accomplished is illus- 540 SURGICAL APPLIED ANATOMY [Part V trated by cases of sprains of the knee, where the ligament has been torn, and where much lateral bending has been in consequence permitted. It is probable that the crucial ligaments yield also a little, and it is upon the posterior band at- tached to the internal condyle that the strain possibly first comes. In the second stage there is a contraction of the tissues on the outer side of the joint that have been relaxed by the new posi- tion of the limb. These structures are the ilio- tibial band of the fascia lata, the external lateral ligament, and the biceps tendon. This contrac- Fig. 88. — a, Normal femur ; b, femur in an advanced state of knock-knee, showing the enlargement of the internal condyle. The dotted line in each case represents the line of the epiphysis. tion tends to give permanency to the deformity. In the third stage the bones become changed. On the outer side of the joint the external con- dyle and the outer tuberosity of the tibia are pressed together, and through these bones the greater part of the weight of the body will be transmitted. As a result of the continual pres- sure the parts waste a little, and by their atrophy contribute not only to the extent of the deformity but also to its permanency. On the inner side the internal condyle tends to become separated from the tibia, and an interval to develop be- tween the two bones as the deformity advances. This interval is prevented from actually existing Chap. XXI] REGION OF THE KNEE. 541 «&-«$ by the development of the condyle, which enlarges, and so still maintains its contact with the tibia. Mikulicz has pointed out that " the alteration in length on the inner side of the femur arises not from alteration of the epiphysis, but is confined to the lowest part of the diaphysis." This state- ment also holds true for the tibia. This is shown in the diagram (Fig. 88), where it will be seen that the enlargement of the internal condyle is due almost entirely to increased growth in the diaphysis. The increased growth does not affect the antero-posterior diameter of the condyles. Hence, when the knee is flexed, all trace of the deformity disappears. The patella.— Fractures. This bone is more often broken by muscular violence than is any other in the body. Although the patella may be fractured by both mus- cular and direct violence, it would appear that the former is the agent that most often produces the lesion. Thus, in 127 cases of simple transverse frac- ture collected by Hamilton, he considers that muscular action was the cause of the injury in 106 instances. The Fi? S9 ._ Diagram " to show IOrm Or fracture due to mechanism of fracture of muscular violence is very *•"» patella by muscular uniform. It is nearly al- ■ • i a, Line of action of ciuadriL'eps w ay s tr an s ve rs e , simp le , muscle ; &, femur ; c, tibia. and through ^ the centre of the bone, or just above that point or just below it. Fractures due to direct violence may present the same appearance, but they are more often starred, or oblique, or even longitudinal. Experiments upon the cadaver show that a simple transverse frac- ture about the centre of the bone cannot be pro- duced with any degree of certainty by a direct blow. The position of the knee that most favours fracture by muscular action is that of flexion. 542 SURGICAL APPLIED ANATOMY [Part V When the knee is bent, the patella rests upon the femoral condyles along its transverse axis only. Nearly the whole of its upper half is unsupported behind, and the extensor muscle acts in a line nearly at right angles to the vertical axis of the bone. Thus, by violent contraction of the quadri- ceps, the patella may be snapped across the con- dyle as a stick is snapped across the knee (Fig. 89). As the fracture usually causes the patient to fall, it has been supposed that the contact with the ground, rather than any previous muscular action, may have caused the lesion. But, as Hamilton has pointed out, if a person falls upon the bent knee when the limb also is flexed upon the trunk, the part that comes in contact with the ground is not the patella, but the tubercle of the tibia. In the great majority of cases the lesion not only involves the bone but also the cartilage and fibrous structures that cover it respectively be- hind and in front; the synovial membrane also is torn, and the patella bursa opened up. Thus the synovial contents may come in actual contact with the skin. " It is anatomically possible, if the fracture involve only the lower and non- articular portion of the patella, and if the amount of the separation of fragments is slight, that the fatty tissue behind the apex of the patella, over which the synovial membrane is reflected, may save the latter from injury " (Henry Morris). In all cases where there is much separation of the fragments, the fibrous expansion attached to either side of the patella must be torn through. Indeed, none but a slight separation of the parts is possible until tnat expansion is ruptured. Braune has demonstrated this by experiment, by sawing through the patella without damage to the lateral ligamentous structures, and noting that but trifling separation of the fragments was possible until these structures had been divided. In stellate fractures, due to direct violence, these fibrous expansions from the extensor tendon may Chap. XXI] REGION OF THE KNEE 543 a be uninjured, and no separation of any magni- tude be permitted between the portions of the broken bone. The patella is more readily broken by muscular violence than is either the extensor tendon or the ligamentum patellae. In the flexed position it will be seen (Fig. 89) that the bone is placed at a considerable disadvantage when compared with the two other structures. Richet reports a case where violent contraction of the quadriceps caused the tubercle of the tibia to be torn away from the bone without any other lesion of the parts immediatelv concerned being produced. The patella may be congenitally absent. It is developed in the tendon of the quadriceps, re- maining cartilaginous until the end of the second year. Its sesa- moid nature is seen in the ten- dency to unite by fibrous rather than by bony union after frac- ture. It receives its blood supply from nearly all the art'eries round the knee- joint. Dislocation of the patella, — This bone may be dislocated out- wards or in- wards, or turned upon its edge so that its interior and posterior surfaces are placed laterally. The luxation out- wards is by far Fig. 90.— Transverse section of left knee- joint through the centre of the patella. (Braune.y a, Bursa patellae; &, internal lateral ligament and inner condyle; c, external lateral ligament and outer condyle - } d, biceps: e, semimem- branosus ; /. spmitendinosus ; f/, gracilis tendon ; h, sartorius. 1, internal popliteal nerve; 2, external popliteal nerve; 3, inter- nal saphenous vein.^ 544 SURGICAL APPLIED ANATOMY [Part V the most common. This depends upon the fact that the quadriceps, the patella, and the ligamentum patellae do not, when the muscle is contracted, follow the lines of the femur and tibia. They are more nearly in a straight line, that passes to the outer side of the angle formed by the femur with the leg at the knee- joint. Muscular contraction, therefore, tends to draw the knee-cap outwards, a tendency that^ is in all normal circumstances corrected by the in- creased prominence of the external condyle. The vastus externus also is said to be more powerful than the internus. The tensor vaginae femoris has an attachment to the patella through the ilio- tibial band. Bv the sudden action of this muscle a patient of Mr. Rigby was able to produce a voluntary outward dislocation of the patella. Dislocations usually occur^in the extended posi- tion of the joint, and are commonly due to mus- cular action. In the dislocation of the patella upon its edge, the inner border of the bone usually projects forwards, while the outer is placed between the condyles. But little is known as to the mechanism of this dislocation. In dislocations of the knees which are very rare, the tibia may be displaced outwards, in- wards, forwards, or backwards. The two lateral luxations appear to be more common than the antero-posterior. The former are nearly always partial, the latter usually complete. Consider- able violence is required to produce these luxa- tions, owing to the great strength of the liga- ments and muscles and the great width of the bones involved. Direct violence to the tibia or femur, associated often with a twisting of the former bone, is the common cause of the lesion. It is probable that in all luxations of the knee the crucial ligaments are torn. The lateral liga- ments also are usually ruptured, but in the partial luxations they may be sometimes found to be intact. The tendinous expansion of the vasti Chap. XXI] REGION OF THE KNEE 545 in front of the knee seldom escapes some lacera- tion, even in the partial dislocations. The pro- jection of the spine of the tibia between the femoral condyles offers an obstruction to lateral luxation. Dr. F. S. Mackenzie found by experiment on the dead body that division of the crucial ligaments did not materially influence the force necessary to produce a dislocation at the knee-joint. He found, too, that in seven out of eight experiments, dislocation was produced and not fracture— whereas in life fracture is by far the commoner result. He concludes, therefore, that the strength of the joint depends on the surrounding muscles rather than on the surrounding ligaments. The popliteal vessels and nerves are much compressed, and appear to be more severely injured by the femur in the forward dislocation than by the tibia in the backward displacement. The lower end of the femur. — The condylar part of the femur _is composed almost wholly of cancellous bone, with but a slight layer of com- pact tissue. It is so spongy that it may be pierced by a bullet, as pointed out by Legouest, without any splintering of the bone being pro- duced and without damage to the articulation. The fractures that may be met with in the lower end of the bone are the following : (l) a fracture of the shaft above the condyles; (2) a separation of the lower epiphysis; (3) a fracture separating either the outer or inner condvle ; (4) a T-shaped fracture, i.e. a transverse fracture above the con- dyles with a vertical one between those processes. These lesions are, as a rule, due to well localised direct violence. Fractures Nos. 1 and 4 may be produced by indirect violence, as by a fall upon the feet from a height. Henry Morris states that lateral flexion, or force applied in a lateral direc- tion, is best calculated to produce a separation of the epiphysis. Hamilton reports a strange case in a man aged 21, whose outer condyle was frac- tured by a twist of the leg, which happened while he was undressing himself to bathe. The 2 J 546 SURGICAL APPLIED ANATOMY [Part V only fracture that requires special notice in this place is the fracture of the shaft just above the condyles. The lesion is situated generally about 2 inches above the line of the epiphysis, and corre- sponds to the spot where the compact shaft joins the softer and more cancellous tissue of the lower end of the bone. It is near the place, also, where the femoral artery crosses the bone to reach the ham, and it has thus happened that the vessel has been wounded by splinters in this particular injury. The fracture is usually oblique, from be- hind downwards and forwards. The lower frag- ment will be drawn upwards by the same muscles that produce shortening in other fractures of the shaft (p. 518), and its sharp upper end is very apt to be pulled forcibly into the popliteal space by the gastrocnemius muscle. This latter displace- ment is difficult to remedy. If the limb be ex- tended, the fragment is only drawn the more into the ham, and it is therefore possible for the limb to appear straight and yet have the knee-joint much bent. In several cases of this injury I divided the tendo Achillis, and then placed the limb upon a straight splint, following a practice suggested by Mr. Bryant. The effect upon the position of the fragments was in each case very good (Brit. Med. Jour., 1883). The lower frag- ment of the femur may be replaced by completely flexing the leg on the thigh. (Hutchinson and Barnard.) The upper end of the tibia is sometimes the seat of fracture, although of all parts of this bone the upper third is the part least often broken. One or other of the tuberosities may be broken off, or there may be a transverse or oblique fracture of the upper end of the shaft associated with a vertical one running up into the joint be- tween the two tuberosities. Such accidents are the result, in nearly every instance, of great direct violence. Madame Lachapelle reports a case of separation of the upper epiphysis of the tibia caused by traction during parturition; but I am Chap. XXI] REGION OF THE KNEE 547 not aware of any reported case of separation of this epiphysis due to violence or under circum- stances other than this. Mr. Makins reports three cases of separation of the anterior tuber- osity in adolescents. It is usually ossified by an extension from the epiphyseal centre for the upper extremity of the tibia, but may have a separate centre (Schlatter). The spongy tissue in the head of this bone and in the lower end of the femur is, par excellence, the favourite seat for myeloid sarcomata. In excising the knee-joint through an in- cision commencing at the back of one condyle, and continued across the joint, just below the patella, to the back of the other condyle, the following structures are divided : Skin, fascia, patellar plexus of nerves (formed by the middle and in- ternal cutaneous and the patellar branch of the long saphenous), bur- sa patellse, anterior part of the capsule, ligamentum patellae, synovial membrane, lateral and crucial ligaments, the supe- rior and inferior arti- cular arteries, the anastomotica magna, and the anterior ti- bial recurrent ves- sels. The incision over the inner condyle need not be made so far back as to divide the internal saphen- ous vein and nerve. In sawing the femur it is most important that the exact incli- nation of the joint surface of the bone q p m I Fig. 91.— Disarticulation at the knee- joint by single anterior flap. (Agate.) a, Int. condyle; ft, ext. condyle; c, inter- condyloid fossa ; d, lig. patella? : e, sar- torius ; /; gracilis ; g, semitendinosus ; li, ext. lat. ligament; i, popliteus ; j, plantaris ; k, semimembranosus ; I and m, inner head of gastrocnemius : n, outer head of gastrocnemius; o, biceps; p, popliteal vessels ; q, int. pop. nerve. 548 SURGICAL APPLIED ANATOMY [Part V be reproduced. If improperly sawn the patient would be bow-legged or knock-kneed. The rule, therefore, is that the saw be applied parallel to the articular surface and perpendicular to the shaft. In young subjects care must be taken that the saw-cuts do not pass beyond the epiphyseal line. The upper limit of the femoral epiphysis will be represented by a horizontal line drawn across the bone at the level of the tubercle for the adductor magnus. If the whole of the trochlear surface be removed in the excision the whole of the epi- physis will have been taken away. A single nucleus appears in this epiphysis shortly before birth, and joins the -snaft about the twentieth year. The limits to the tibial epiphysis are repre- sented behind and at the sides by a horizontal line that just marks off the tuberosities. It includes, therefore, the depression for the insertion of the semimembranosus, and also the facet for the fibula. In front the epiphyseal line slopes downwards on either side to a point on the upper end of the shin, so as to enclose the whole of the tubercle of the tibia. The centre joins the main bone at the twenty-first or twenty-second year. The popli- teal artery runs some risk of being wounded in excision of the joint. The vessel is separated by some little distance from the popliteal surface of the femur (Fig. 91), but is in very close relation to the tibia, the posterior ligament alone inter- vening at the upper level of the bone. It thus happens that the risk of wounding the artery is greater when the tibia is sawn than when the lower part of the femur is being removed. Excision of the knee is, to a large extent, re- placed by arthrectomy. Indeed, excision of this joint carried out in -the complete manner just de- scribed must be classed as quite a rare operation. Amputation through the knee-joint,,— To illustrate the anatomy of the part an amputation by a single anterior flap may be selected (Fig. 91). In fashioning the anterior flap (composed Chap. XXI] REGION OF THE KNEE 549 only of integument), and in opening the joint, the patellar plexus of nerves, the superficial branches of the plexus of arteries, the ligamentum patellae, and the anterior part of the capsule will be cut. Nearer the condyles of the femur the anastomotic and the two superior articular arteries will be divided. The long saphenous vein and nerve will be divided at the inner angle of the flap. On the cut surface made by the posterior incision will be found divided the sartorius, gracilis, and semitendinosus,. the semimembran- osus, both heads of the gastrocnemius, the popli- teus, plantaris, and biceps. The popliteal vessels, the sural arteries, the short saphenous vein,, the internal and external popliteal nerves, the ex- ternal saphenous and the small sciatic nerves will also be found divided in the same incision. The most convenient amputation at the knee- joint is by equal lateral flaps (Stephen Smith's operation). This operation has been attended by excellent results, and in actual practice the method of amputation by a single anterior flap is but very rarely employed. CHAPTER XXII THE LEG Surface anatomy. — The, anterior border of the tibia can be felt in its entire length, forming, as it does, the prominence of the shin. It should be remembered that this border presents a some- what flexuous course, being curved outwards above and inwards below. The broad internal surface of the bone is subcutaneous, and the internal border can be followed from the tuberosity to the malleolus. The head of the fibula can be dis- tinctly made out, but the upper half of the shaft of the bone is lost beneath the mass of muscle on the outer side of the limb. The lower half of the fibular shaft can be felt, and the bone just above the malleolus becomes subcutaneous in the interval between the peroneus tertius and the two other peroneal tendons. The fibula is situated so far behind the line of the tibia that a knife thrust transversely through the leg from the inner side behind the tibia will appear in front of the fibula on the outer side (Fig. 93). Between the tibia and fibula the outline of the tibialis anticus muscle can be well defined when it is in action. To its outer side is the less conspicuous and narrower eminence formed by the extensor communis digi- torum. In well-developed limbs the groove that separates these two muscles is very distinct, and forms the best guide to the anterior tibial artery. In the lower third of the leg these muscles be- come tendinous, and between them the extensor 550 Chap. XXII] THE LEG 551 longus hallucis can be felt as it comes to the sur- face. The long and short peroneal muscles can be defined, and their tendons followed behind the malleolus. When in active contraction the in- terval between the two muscles is often well marked. The gastrocnemius muscle and the more superficial parts of the soleus are brought well into view when the body is raised upon the toes. The two heads of the former muscle are then quite conspicuous, and it can be seen that the inner head is the larger and descends lower in the leg. The popliteal artery bifurcates on a level with the lower part of the tubercle of the tibia. The course of the posterior tibial vessel is represented by a line drawn from the middle of the limb at the lower part of the ham to a spot midway be- tween the inner malleolus and the prominence of the heel. The artery becomes superficial in the lower fourth of the leg, where it may be felt pulsating between the tendo Achillis and the tibia. The peroneal artery arises about 3 inches below the knee, follows the posterior surface of the fibula, and ends behind the outer malleolus. The position of the anterior tibial artery may be in- dicated by a line drawn from a point midway between the outer tuberosity of the tibia and the head of the fibula to the centre of the front of the ankle-joint. Both the saphenous veins can often be made out in the leg. The inner or larger vein passes in front of the malleolus and ascends just behind the internal border of the tibia. With it runs the long saphenous nerve. The short saphen- ous vein lies behind the outer malleolus, and pass- ing up the middle of the calf ends at the ham. It is accompanied by the external saphenous nerve. The legr. — The shin is somewhat more adherent to deeper parts in the leg than it is in the thigh. The difference in the degree of this adhesion is obvious when skin-flaps are dissected up from the two parts in cases of amputation. Over the in- ternal surface of the tibia and the greater part of the shin, the integument lies directly upon the 552 SUKGICAL APPLIED ANATOMY [Part V periosteum and bone, nothing intervening save a scanty amount of subcutaneous fascia. Thus blows and kicks over these parts of the leg are apt to be associated not only with much pain but also with much bruising or tearing of the integument. A " graze on the shin " is one of the commonest of lesions, and is produced by a degree of violence that upon a well-covered part would have little or no effect. It will be understood that ulcers over these feebly protected parts may, if they spread in depth, readily expose the bone and lead to some disease of its substance, or to at least some inflam- mation of its periosteum. (Scars left by deep ulcers or burns are also often found to be quite adherent to the bone. The aponeurosis of the leg invests it like a tightly-drawn buskin, being lacking only over the subcutaneous surfaces of the bones. It is attached to the head and the anterior and inner borders of the tibia, the head of the fibula, and the two malleoli. It is continuous above with the fascia lata, and below with the fascia of the foot and the annular ligaments. It is thicker in front than behind, and is especially thick at the upper part of the leg just below the knee. Here the fascia offers great resistance to the growth of tumours springing from the head of the tibia. From the deep surface of the aponeurosis two septa pass inwards to be attached to the anterior and ex- ternal borders of the fibula. They serve to isolate the two larger peroneal muscles from the other muscles of the limb, and form a closed space which might become a definite and well localised cavity for pus. Beneath the gastrocnemius and soleus a layer of fascia extends between the two bones and covers in the deep layer of muscles. It is thin above but denser below, and would have some in- fluence in directing the progress of a deep abscess. In the upper third of the leg there is a septum between the tibialis anticus and extensor com- munis digitorum, which must be found in the operation for ligaturing the upper part of the Chap. XXII] THE LEG 553 anterior tibial artery. I have never had the good fortune to see the very distinct " white line }> that many text-books describe as indicating the posi- tion of this septum. In the substance of the soleus muscle there is a tendinous expansion connected with the border of the tibia, that runs backwards and towards the middle line. In cutting through the soleus to apply a ligature to the posterior tibial artery, this intersection may be mistaken for the aponeu- rosis on the deep surface of the muscle. Several cases are reported of rupture of some part of the gastrocnemius muscle during violent exertion. The tendo Achillis has been ruptured under like circumstances. It is said that the plan- taris tendon is also not unfrequently torn across, producing a sudden sharp pain in the calf during exertion, to which the French give the name " coup de fonet." Vessels. — The large arteries of the leg, being all in close proximity with the bones, are apt to be injured by sharp fragments in fractures of the limb. This especially applies to the peroneal artery, which runs along the fibula in a fibrous canal, and is in considerable risk of being wounded in fractures about the middle of that bone. It is at the point of bifurcation of the popliteal artery that emboli are peculiarly apt to lodge. They plug the vessel and practically block the three main arteries of the leg. Gangrene, therefore, not unfrequently follows the occurrence. Billroth states that in all the cases of gangrene of the leg due to embolism that he has met with, the plug was found situated at the bifurcation of the popliteal trunk (" Clinical Surgery," 1881). Ac- cording to some French surgeons, aneurism of the commencement of the posterior tibial artery is more often associated with gangrene of the leg than is a popliteal aneurism. The reason they assign is the following : The aneurism on the former vessel not only interferes with the passage of the blood into the posterior tibial and peroneal 554 SURGICAL APPLIED ANATOMY [fart V arteries, but also compresses the anterior tibial vessel and with it the anterior tibial recurrent, an artery that is of so great importance in establish- ing the collateral circulation. Varicose veins are more commonly met with in the leg than in any other part of the body, save, perhaps, in the hemorrhoidal and spermatic veins. This depends upon the great length of the veins of the lower limb, the large columns of blood their valves have to support, their vertical posi- tion, the liability of the great trunks (iliac), into which they ultimately enter, to be compressed, and upon the fact that the superficial veins, being outside the fascia, lose that assistance to the circulation derived from muscular contraction. From a / ' \ physical point of view the vascular ( * c system must be regarded as a vertical \ J~ ' column of fluid. The lower the level 1 1 the greater is the pressure on the con- I taining walls. The saphenous veins are ^ thin-walled, distensible tubes situated Fig. 92. outside the rigid-walled cylinder formed by the deep fascia of the leg and thigh, low in the body, where the pressure from gravity is greatest (Hill). The use of garters especially affects the long saphenous vein, which lies close to the bone at the spot about which these contracting bands are usually applied. Between the two layers of the muscles of the calf Verneuil describes a venous plexus, which he be- lieves to be more often the seat of varices than are the vessels of the surface. A varicose condition of these deeply placed veins may explain the " aching legs ;; complained of by those who stand a great deal. The intramuscular veins are very large. Callender showed that the six chief veins which pass from the soleus muscle alone to enter into the posterior tibial and peroneal trunks have a united diameter of not less than 1 inch. Varix would appear to commence most often at points where the deep veins join the superficial vessels. Chap. XXII] THE LEG 555 There is good reason for this, for at these points three forces meet, the general directions of which are shown in the annexed diagram (Fig. 92). There is the weight of the superincumbent column of blood (a) acting from above, the resistance offered by the next valve below the point of entry of the deep vein acting from below (b), and the force with which the blood is driven by the con- tracting muscles out of the deep vein into the superficial trunk acting at an angle to both these lines of force (c). Unfortunately for the subjects of varices, the two principal veins (the saphenous) are accompanied by sensory nerves, and there is no doubt that much of the pain incident to vari- cose veins in the leg depends upon pressure on these nerves. With reference to pain in the leg - , it must be remembered that the nerves that bring sensa- tion to the part arise at a considerable distance from their points of termination, and that the causes of pain in the limb may be situated far away from the seat of trouble. Thus Sir B. Brodie mentions the case of a gentleman who suf- fered from severe pain in the left leg, from the foot to the knee, in the course of the peroneal nerve. No cause could be found for it. At the patient's death, however, a large tumour was found attached to the lumbar spine, which had evidently compressed the left great sciatic nerve. It is more difficult to offer an explanation, based on anatomical grounds, for cases such as those reported by Sir William Bennett, where the re- moval of a corn from the sole of the foot in one instance, and a tumour from the leg in another, led to the disappearance of a pain which was felt in the groin. There would appear to be little connection be- tween disease in the rectum and a pain in the leg, yet in one case at least that connection was marked. " Only recently, ;; writes Mr. Hilton, " I saw a gentleman from South Wales, who was the subject of stricture of the rectum from malignant 556 SURGICAL APPLIED ANATOMY [Part V disease. He suffered pain in the knee-joint and in the back part of the leg. This led me to sus- pect, what really turned out, upon careful exam- ination, to be the case, that a large mass of cancer was involving the nerves on the anterior part of the sacrum, and also, no doubt, the obturator nerve. " Dr. Ralfe mentions cases of renal calculus attended by severe pain in the sole of the foot, and I have met with many instances of this as- sociation, the pain being most commonly in the heel. Fractures of the leg - . — Of the bones of the leg the tibia and fibula are more often broken together than singly, and of separate bones the fibula is more often fractured than is the larger bone. 1. The tibia and fibula. — As regards the re- sistance it offers to violence the fibula presents about the same degree of strength in all its parts, save at the malleolus and at its upper extremity. Its great length and the manner of its attachment to the tibia (its two ends being fixed and its main part being unsupported) render it a slender bone, and but for the efficient protection it derives from the thick pad of muscles that surrounds it, it would no doubt be very frequently broken. This is all the more likely to be the case, since the bone is placed upon the more exposed aspect of the limb. The shaft of the tibia presents various degrees of strength, according as we regard its upper, middle, or lower third. According to Dr. Leriche, the average transverse diameter of the adult tibia just below the tuberosities is a little over If inch. The transverse diameter at the base of the malleolus is a little less than if inch, and that of the narrowest part of the bone is a little more than 1 inch. This narrow part is at the junction of the lower with the middle third of the shaft, and is the weakest point in the bone. The relation of the compact to the cancellous Chap. XXII] THE LEG 557 tissue is about the same in all parts of the shaft ; but according to MM. Fayel and Duret, the spongy tissue is arranged in two independent ver- tical columns, one occupying the upper two-thirds and the other the lower third of the bone. The minimum of resistance (these authors assert) is at the point where these two systems meet. Thus it happens that the most common spot for a frac- ture of the tibia is at the junction of _ the middle with the lower third of the shaft. It is here that the bone yields when broken by indirect violence, while the lesions depending upon direct violence may be at any part of the shaft. Owing to the thin covering of soft parts, and the slight barrier interposed between the fracturing force and the bone, it comes to pass that fractures of the leg are more often compound and comminuted than are those of any other bones of the extremities. If the fracture be oblique, as is commonly the case when the violence is indirectly applied, the line of breakage usually extends from behind, down- wards, forwards, and a little inwards. The lower fragment, with the foot, is drawn up behind the rest of the bone by the muscles of the calf, and is usually displaced also outwards by the obliquity of the fracture line. Often the lower fragment is slightly rotated outwards by the rolling over of the foot, a rotation produced by the simple weight of the limb. If the fracture be transverse there may be little or no displacement, The fibula is usually broken at a higher level than the tibia, and its lower fragment follows, of course, with absolute precision the corresponding fragment of the larger bone. A remarkable spiral fracture (fracture helicoide), involving the lower third of the tibia, has been described by French surgeons. It is associated with a, more or less vertical fissure that involves the ankle-joint, and with a fracture of the fibula high up. MM. Leriche and Tillaux have shown that this injury is due to torsion, especially to some twisting of the leg while the foot is fixed. 558 SURGICAL APPLIED ANATOMY [Part V 2. The fibula alone. Fractures of this bone in its lower fourth are usually due to indirect vio- lence, and will be dealt with in connection with the ankle-joint. When it is broken in any other part the fracturing force is usually directly ap- plied, the lesion transverse, and the displacement insignificant, or scarcely obvious. The tibia acts as an efficient splint. 3. The tibia alone. The malleolus may be broken by a blow, or the lower epiphysis separ- ated. The latter comprises the whole of the inner malleolus and the facet with which the fibula articulates. It joins the shaft during the eigh- teenth or nineteenth year. Fractures of the tibia alone are nearly always due to direct violence, and whilst most common in the lower third of the bone, become more rare as the knee is approached. When transverse there may be no visible displace- ment, the fibula acting as a splint. Thus Henry Morris mentions the case of a woman who walked into and out of a hospital with a transverse frac- ture of the tibia that was not detected on examina- tion, and was not indeed discovered until two days after the accident. When the fracture is just above the ankle the lower fragment may be moved in whatever direction the foot is forced, such dis- placement being resisted and limited by the in- ferior tibio-fibular ligaments. In rickets the tibia is, of all the bones of the extremities, the one that most frequently becomes bent. It yields at its weakest part (the lower third), and there the bone will be found to have developed a curve forwards and a little outwards. Amputation of the leg- at the junction of the upper with the middle third by unequal antero-posterior flaps may be taken as an example. This is not the best method of amputation, but it serves best to illustrate the anatomy of the part. In the anterior flap the following structures would be cut : Skin, cutaneous nerves, fascia, tibialis _ anticus, extensor communis digitorum, and a little of the extensor proprius hallucis, the Chap. XXII] THE LEG 559 peroneus longus, and a small part of the upper extremity of the peroneus brevis, the anterior tibial vessels and nerve, and the musculo- cutaneous nerve. In the posterior flap the follow- Fig. 93. — Amputation of leg at junction of upper with middle third by single posterior flap. (Agatz.) c. Tibia ; b, fibula ; r. tibialis amicus ; (/. ext. com. digit. ; e, peron. long. ; f, tib. post.: <7, soleus Tvith flex. long, digit. ; h, gastrocnemius: i, anterior tibial vessels ; j, post, tibial and peroneal vessels : k, int. saplien. vein ; I, post, tibial nerve. ing would be the parts divided : Skin, external and internal saphenous veins and nerves, fascia, gastrocnemius, plantaris, soleus, tibialis posticus, flexor longus digitorum, a little of the upper end of the flexor longus hallucis, the posterior tibial vessels and- nerve, and the peroneal vessels. 560 SUEGICAL APPLIED ANATOMY [Part V Fig. 93 shows the stump leftTafter the amputa- tion through the lower part of the upper third of the leg by means of a single. flap cut from the calf. It serves to show the relations of the chief parts divided, and gives a good idea of the stump that would be left in an amputation by an anterior skin flap and a posterior transfixion flap cut from the calf. c. Lj Fig. 94. — Transverse section through the lower third of the leg. (Brav ne.) a, Tibialis anticus ; b, extensor longus hallucis; c, extensor communis digitorum; '/, peroneue brevis; e, peroneus longus;/ tibialis posticus; g, flexor Longus digitorum; /', flexor Longus hallucis; i, gastrocnemius and soleus; ./'. short saphenous nerve and vein ; /.•, anterior tibial vessels and nerve ; /, peroneal vess< Is; m, posterior tibial vessels and nerve; n, musculo-cutaneous nerve. In Fig. 94 is shown a transverse section of the leg at the lower third, from which can be gathered an idea of the number and position of the parts cut in amputations through that part. An excellent method of amputation at the upper part of the leg is by a single external flap containing the anterior tibial artery in its entire length. CHAPTER XXIII THE ANKLE AND THE FOOT Surface anatomy. — Bony points. The outlines of the two malleoli can be very distinctly denned. The external is somewhat the less prominent, descends lower, and lies farther back than the internal process. The tip of the outer malleolus is about \ an inch behind and below the tip of the corresponding bony prominence. The antero- posterior diameter, however, of the internal mal- leolus is such that its posterior border is on a level with that of the outer process behind. On the dorsum of the foot the individual tarsal bones are not to be distinguished, although the astragalus forms a distinct projection upon that surface when the foot is inverted. On the inner side of the foot the tuberosity of the os calcis may be felt most posteriorly. In front of it, and about 1 inch vertically below the inner malleolus, is the projection of the sustenta- culum tali. About \\ inch in front of the mal- leolus the tuberosity of the scaphoid can be dis- tinctly made out (Fig. 97, p. 583). In the interval between it and the last-named process lies the inferior calcaneo-scaphoid ligament, and the ten- don of the tibialis posticus. Farther towards the front of the foot can be felt the ridge formed by the base of the first metatarsal bone, and between it and the scaphoid tubercle lies the inner cunei- form bone. Lastly, the shaft of the first meta- tarsal bone, its expanded head, and the sesamoid 2 K 561 562 SURGICAL APPLIED ANATOMY [Part V bones that lie on the plantar aspect of the meta- tarsal phalangeal joint can be more or less dis- tinctly denned. On the outer side of the foot the external surface of the os calcis is subcutaneous in nearly the whole of its extent. Less than 1 inch below and in front of the malleolus is the peroneal tubercle, with the short peroneal tendon above it and the long one below it. Some 2\ inches from the outer malleolus the projection of the base of the fifth metatarsal bone is very evident, and ex- tending for an inch or so behind it lies the cuboid bone. Joint lines. — The ankle-joint lies about on a level of a point \ an inch above the tip of the inner malleolus. Immediately behind the tubercle of the scaphoid is the astragalo-scaphoid articula- tion, and a line drawn transversely across the dorsum of the foot, just behind the process, very fairly corresponds to the mid-tarsal joint (the joint compounded of the astragalo-scaphoid and calcaneo-cuboid articulations). If the latter articulation be approached from the outer side it will lie opposite a point midway between the outer malleolus and the prominent base of the fifth metatarsal bone. The lines of the articulations between the first and fifth metatarsal bones and the inner cunei- form and the cuboid respectively are easily indi- cated, being placed just behind the bases of the former bones. The metatarso-phalangeal articula- tions are situated about 1 inch behind the webs of the corresponding toes. The proximal phalanx and part of the middle are buried in the web. Tendons. — The tendo Achillis stands out very conspicuously at the back of the ankle, and be- tween it and the malleoli are two hollows which are evident in even obese individuals. Over the front of the ankle the tendons of the extensor muscles are readily to be distinguished, especially when the joint is flexed. From within outwards they are : the tendons of the tibialis anticus, ex- tensor longus hallucis, extensor longus digitorum, Chap. XXIII] ANKLE AND FOOT 563 and peroneus tertius. Beneath the tendons of the extensor of the toes, and on the outer part of the dorsum of the foot, the prominent fleshy mass formed by the extensor brevis digitorum can be felt and, when in action, seen. Above and behind the inner malleolus the tendons of the tibialis posticus and flexor longus digitorum can be dis- cerned, the former lying nearer to the bone. Nearer to the middle line runs the flexor longus hallucis. Behind the outer malleolus the long and short peroneal tendons can be felt, lying close to the edge of the fibula, the tendon of the smaller muscle being the closer to it. In the middle of the sole of the foot the resist- ing plantar fascia can be felt, and some of its processes made out when the toes are drawn up by the extensors. The fleshy mass on the inner margin of the foot is formed by the abductor and flexor brevis hallucis ; that on the outer side by the abductor and flexor brevis minimi digiti. Vessels. — The anterior tibial artery and nerve are placed opposite the ankle-joint, between the tendons of the extensor proprius hallucis and longus digitorum. The dorsal artery runs from the middle of the ankle to the interval between the bases of the first and second metatarsal bones. It may be felt pulsating against the bones along the outer side of the extensor proprius hallucis tendon, which is the readiest guide to it. The plantar arteries start from a point midway be- tween the tip of the malleolus internus and the centre of the convexity of the heel. The internal vessel follows a line drawn from this point to the middle of the under surface of the great toe. The external vessel crosses the sole obliquely to within a thumb's breadth of the base of the fifth meta- tarsal bone. From thence it turns more trans- versely across the foot, running inwards over the bases of the metatarsal bones to inosculate with the dorsalis pedis artery at the back of the first interosseous space. On the dorsum of the foot the subcutaneous veins may be seen forming an arch 564 SUEGICAL APPLIED ANATOMY [Part V convex towards the toes, and from the ends of the arch vessels may be followed into the internal and external saphenous veins. The ankle and foot.-^The skin about the ankle and over the dorsum of the foot is thin and but loosely attached to the subjacent parts. It be- comes readily excoriated, as is often the case where splints or instruments have been improperly applied. Since the skin over the malleoli lies directly upon the bone, while that covering the dorsum of the foot is but slightly separated from the bones of the tarsus, it follows that the integu- ments in this region are readily contused, and may suffer gangrene from an amount of pressure that would cause but little trouble in other parts. Over the sole the integument is dense and thick in all those parts that come in contact with the ground. In the normal foot, the heel, the outer margin of the foot, and the line of metatarso- phalangeal joints are in contact with the ground when the sole is placed flat upon it (Fig. 98, p. 585). The subcutaneous tissue about the ankle and foot varies greatly both in quantity and charac- ter. Over the front of the ankle and dorsum of the foot it is very lax, free from fat, and is the first part to be infiltrated in general dropsy of the body. On the sole the subcutaneous tissue is dense, firm, and studded with pellets of fat. It is | of an inch thick over the heel. The integuments of the foot are well supplied with nerves, being furnished with branches from no less than six nerve trunks, the musculo-cutane- ous, the anterior tibial, the two saphenous, and the external and internal plantar. Many Paci- nian bodies are found upon these cutaneous branches, and end-bulbs are met with in the skin on the sole. The integuments of the foot respond acutely to sensations of pain, of pressure, of tem- perature, and to certain unwonted forms of tac- tile impression, such as tickling. Tactile sensi- bility, however, as measured by the sesthesio meter, Chap. XXIII] ANKLE AND FOOT 565 is not acute, the dorsum of the foot showing, in regard to this matter, no more sensitiveness than does the skin of the buttock. Over the " tread of the foot," and especially under the ball of the great toe, the peculiar affection known as " perforating ulcer " is most commonly met with. This ulcer occurs as an occasional symptom in certain nerve maladies, and particularly in locomotor ataxy. The fascia; of the foot and the tendons about the ankle. — The fasciae on the dorsum occur in two layers, a superficial one that is con- tinued from the anterior annular ligament, and a deeper placed over the extensor brevis and inter- ossei muscles. These membranes are both thin and insignificant, and exercise no influence from a surgical point of view. The plantar fascia is divided into three parts, a central or main por- tion which is extremely dense and powerful, and two lateral expansions which are thin and surgi- cally insignificant. The outer of the two lateral portions is, however, of some substance, and forms a very thick band between the os calcis and fifth metatarsal bone, that may become rigidly con- tracted in some forms of talipes. The central ex- pansion assists greatly in supporting the antero- posterior arch of the foot, which it tends to main- tain in the manner that the bowstring maintains the arch of the bow. The sinking of the arch that occurs in " flat foot ;; is associated with marked yielding of this fascia. The plantar fascia is often found much contracted (as a rule, secondarily) in certain forms of club-foot, such as talipes equinus and congenital varus. The term " talipes cavus ;; is applied to a deformity that depends mainly or entirely upon a contraction of the plantar fascia. The best place in which to divide this membrane is at a spot about 1 inch in front of its attachment to the os calcis. This is its narrowest part, and the knife (which should be introduced from the inner side) will be behind the external plantar 566 SURGICAL APPLIED ANATOMY [Part t artery which runs beneath the expansion. An abscess situated beneath the membrane will be very closely bound down, and will advance in any direction other than through the membrane itself so as to point in the centre of the sole. Such deep collections cause intense pain, and often much destruction, before they are discharged. They may open upon the dorsum, or may extend up along the tendons to the region of the ankle. There are certain foramina or spaces in the sub- stance of this layer occupied usually by fat. Through one or more of these an abscess will, in exceptional cases extend, and then spread out be- neath the integuments. Such an abscess will have, therefore, two cavities united by a small hole, and will form the abces en bissac or en bouton^ de chemise of the French. The plantar fascia divides into slips near the roots of the toes, and forms a series of arches, beneath which pass the tendons, vessels, and nerves bound for the digits. Two intermuscular septa connected with the membrane separate the flexor brevis digitorum from the ab- ductor hallucis on the one side and the abductor minimi digiti on the other. They are, however, membranes of too feeble a structure to affect much the progress of a deep plantar abscess. The anterior annular ligament is divided into two parts ; an upper band in front of the tibia and fibula, and a lower band in front of the upper limits of the tarsus. Beneath the former there is only one synovial sheath, that for the tibialis anticus ; beneath the latter are three sheaths : one for the peroneus tertius and extensor communis, one for the extensor proprius pollicis, and a third for the tibialis anticus. According to Holden, there is often a large irregular bursa between the tendons of the ex- tensor longus digitorum and the projecting end of the astragalus. This bursa sometimes communi- cates with the joint at the head of the astragalus. Beneath the internal annular ligament are three synovial sheaths for the tendons of the Chap. XXIII] ANKLE AND FOOT 60? tibialis posticus, flexor longus digitorum, and flexor longus hallucis. Inflammation involving the sheath for the tibialis posticus may spread to the ankle-joint, with which the tendon is in close relation. Beneath the outer annular ligament is the single synovial sheath for the long and short peroneal tendons. In severe sprains of the ankle not only are the ligaments about the joint more or less ruptured, but the various synovial sheaths just named are apt to be torn and filled with blood. The long abiding trouble in the part that often follows severe sprains depends to a great extent upon damage to these sheaths, and to extravasations of blood, and subsequently of inflammatory material, within them. These sheaths are more extensive than-is usually supposed; those at the inner side of the ankle commence from one to two inches above the malleolus, and extend into the sole of the foot to a point opposite the tuberosity of the scaphoid. Those at the outer side of the ankle are even more extensive, that round the peroneus longus extending to the base of the first meta- tarsal, although occasionally the plantar and mal- leolar parts may be found completely separated from each other at the outer border of the cuboid. From the length of the sheaths it can be readily understood that the adhesions which follow sprains and fractures at the ankle are very ex- tensive, unless passive movements be carried out to prevent their formation. There are few bursae of any magnitude about the foot, save one between the tendo Achillis and os calcis, and another over the metatarso-phalan- geal joint of the great toe. The first-named bursa rises up about ^ an inch above the os calcis, and bulges out on either side of the tendon. When in- flamed it may produce symptoms like those of ankle-joint disease, and when suppurating may lead to caries of the os calcis. The enlargement of the bursa over the metatarso-phalangeal joint of the great toe constitutes a bunion. It lies in the 568 SURGICAL APPLIED ANATOMY [Part V subcutaneous tissue between the internal sesamoid and the skin, and is not present at birth. This condition is generally brought about by impro- perly shaped boots, which force the great toe out- wards, place it obliquely to the long axis of the foot, and render the metatarsal joint very promi- nent. The cartilage over the inner part of the head of the metatarsal bone disappears, and a communication between the bursa and joint may be set up. The result of this deformity is a great weakening of the toe and adjacent part of the foot, a lengthening of the internal lateral liga- ment of the joint, and a displacement outwards of the tendon of the extensor proprius hallucis. Bursse are often developed over the malleoli in tailors, and especially over the external process, the part most pressed upon when sitting cross- legged. In club-foot, bursse are found over any points that are exposed to undue pressure. The tendons about the ankle are not unfre- quently ruptured by violence. Those that most often are so injured are the tendo Achillis and the tendons of the tibialis posticus, and long and short peroneal muscles. The tendo Achillis usually breaks at a point about l\ inch above its inser- tion, where it becomes narrowed and its fibres collected into a very definite bundle. In some forms of violence the synovial and fibrous sheaths that bind down a tendon may be ruptured and it may be allowed to become dis- placed. This has happened to the tibialis posticus and peroneal muscles. In each instance the dis- located structure comes forward upon or in front of the malleolus. No tendon in the body is so frequently displaced as is that of the peroneus longus. The tendons about the ankle are frequently divided by operation. The tendo Achillis is usually cut about 1 inch above its insertion, the knife being entered from the inner side to avoid the posterior tibial vessels. The tibialis posticus tendon is, as a rule, divided just above the base of Chap. XXIII] ANKLE AND FOOT 569 the inner malleolus. There is, however, enough room between the annular ligament and the sca- phoid bone to cut it on the side of the foot (Fig. 97, p. 583). The anterior tibial tendon may be divided readily either in front of the ankle or at its insertion into the internal cuneiform bone. On section of a tendon a gap is felt, owing to retrac- tion by the muscle. The cut ends are still united by the fibrous tissue in which they lie, and from which they derive their blood supply. If cut within a sheath the synovial membrane forms a loose binding between the cut ends. A fibrous band between the cut ends is ultimately formed from the effusion which fills the gap. The new band is firmly adherent to the sheath in which it lies, and at first will limit the movements of the tendon. Part of the tendon of a sound muscle may be yoked to that of one which has become paralysed, thus restoring certain movements to the foot. Blood-vessels. — The lines of the various arteries have been already indicated. Wounds of the plantar arch are serious, on account of the depth at which the external plantar artery lies, and the impossibility of reaching the vessel with- out making a large wound in the sole that would open up important districts of connective tissue and do damage to tendons and nerves. The arch is formed by the junction of the external plantar artery with the dorsal artery of the foot, a con- tinuation of the anterior tibial vessel. In cases, however, of bleeding from the arch, ligature of both the posterior and anterior tibial vessels at or just above the ankle would not necessarily arrest the haemorrhage. After ligature of these vessels blood would still be brought indirectly to the arch by means of the peroneal artery. By its anterior peroneal branch this vessel communicates with the external malleolar branch of the anterior tibial artery, and with the tarsal branch of the dorsalis pedis. By its terminal branch it communicates with the two last-named vessels, and also with the 570 SURGICAL APPLIED ANATOMY [Part V internal calcaneal branches of the external plan- tar artery. As a matter of practice, however, elevation of the limb, together with pressure upon the wounded point and compression of the main artery, are sufficient to check most haemorrhages from the plantar arch. The dorsalis pedis artery, from its superficial position and its close contact with the bones of the foot, is frequently divided in wounds and rup- tured in severe contusions. The posterior tibial artery at the ankle is well protected by the pro- jecting malleolus, the dense annular ligament, and the tendons that run by its side. The superficial veins of the foot, like those of the hand, are found mainly upon the dorsum of the member. The sole, as a part exposed to pres- sure, is singularly free from them. About the malleoli, and especially about the inner process, these veins form a considerable plexus. Hence it is that appliances that fit tightly around the ankle are apt to produce oedema and pain in the parts beyond. The dull pain in the feet that is often caused by tight elastic-side boots is probably due to the same cause. The lymphatics form a very fine and elabo- rate plexus in the coverings of the sole, from which vessels arise that reach the borders and dor- sum of the foot, and principally the inner border. The main lymph vessels of the part are found upon the dorsum, about the radicles of the two saphenous veins. Those on the inner side of the foot are by far the more numerous ; they follow pretty generally the course of the internal saphe- nous vein, and end in the inguinal glands. The external vessels pass up along the outer ankle and outer side of the leg. The bulk of them pass obliquely across the ham to join the inner set above the knee ; others reach the inner set by cross- ing the front of the tibia, while a few follow the short saphenous vein and end in th«3 popliteal glands (see p. 531). The ankle-joint is a very powerful articula- OKap. XXIII] ANKLE AND FOOT 571 tion, its strength being derived not only from the shape of its component bones, but also from the unyielding ligaments and many tendons that are bound about it like straps. Of the ligaments, the two lateral are very strong, and have an extensive hold upon the foot. The anterior and posterior are extremely thin and insignificant, although the latter is supported by the tendon of the flexor longus hallucis, which crosses it. When effusion takes place into the joint, it first shows itself in front, beneath the extensor tendons, and just in front of the lateral ligaments. This is due to the feebleness of the anterior ligament and the extent and looseness of the synovial sac in relation with that structure. More extensive effusions cause a bulging behind through yielding of the thin pos- terior part of the capsule, and fluctuation can then be obtained on either side of the tendo Achillis. In no ordinary case can fluctuation be detected distinctly beneath the unyielding lateral ligaments. Moreover, the loose synovial sac of the ankle-joint extends both in front and behind be- yond the limits of the articulation, while, at the sides, it is strictly limited to the joint surfaces. The ankle is a perfect hinge-joint, and permits only of flexion and extension. The very slightest amount of lateral movement is allowed in extreme extension, when the narrower, or hinder, part of the astragalus is brought into contact with tne widest, or anterior, part of the tibio-fibular arch. When obvious lateral movement exists at the ankle, the joint must be the seat of either injury or disease; and it is important not to mistake the lateral movements permitted between certain of the tarsal bones for movements at the ankle-joint. Dorsi-flexion is limited by the posterior and middle parts of the internal ligament, by the pos- terior part of the external ligament, by the pos- terior ligament, and by the contact of the astra- galus with the tibia. Plantar flexion is limited by the anterior fibres of the inner ligament, the anterior and middle parts of the outer ligament, 572 SURGICAL APPLIED ANATOMY [Part V by the anterior part of the capsule, and the con- tact of the astragalus with the tibia. Owing to its exposed position, this joint is very liable to become inflamed from injury or other external causes. When inflamed, no dis- tortion is, as a rule, produced, the foot remaining at right angles with the leg. It would appear that this position is due to the circumstances that the flexor and extensor muscles about balance one another, and it does not seem that the capacity of the joint is affected by the posture of the foot. The synovial cavity of the ankle is in communica- tion with the inferior tibio-fibular articulation. In connection with the subject of " referred pains," it should be remembered that the nerves supplying the ankle-joint bring that articulation into relation with the lumbar segments of the spinal cord through the internal saphenous, and the sacral segments through the anterior tibial nerve. Dislocations at the ankle-joint. — The foot may be dislocated at the ankle in five directions, which, placed in order of frequency, are, out- wards, inwards, backwards, forwards, and up- wards between the tibia and fibula. These dis- locations_ are nearly always associated with frac- ture of either the tibia or fibula or of both bones. 1. The lateral dislocations: Outwards, in- wards. These luxations differ somewhat from those met with in other joints. In the great majority of cases they consist of a lateral twisting of the foot, of such a kind that the astragalus is rotated beneath the tibio-fibular arch. There is no great removal of the upper surface of the astra- galus from that of the tibia, one or other edge of the former bone being brought in contact with the horizontal articular surface of the latter. Although much deformity is produced, the actual separation of the foot from the leg is not con- siderable. In some rare cases a true lateral dis- location in the horizontal direction has been met with. Chap. XXIII] ANKLE AND FOOT 573 These injuries are due to sudden and violent twistings of the foot, and are in nearly every in- stance associated with fractures of the tibia or fibula. The luxation outwards is due to forcible eversion of the foot, the luxation inwards to vio- lent inversion. Fig. 95. — Diagrams to illustrate the mechanism involved in fractures of the lower end of the fibula. A, Parts in normal position; a, tibio-fibular ligaments; b, external lateral liga- ment ; c, internal lateral ligament. B, fracture of fibula due to eversion of foot. C, fracture of fibula due to inversion of foot. It is of interest, in the first place, to note the relation of the fibula to injuries at the ankle- joint, especially as a fracture of the lower end of the shaft of that bone may follow alike upon both inversion and eversion of the foot. The lower 3 or 4 inches of the fibula may be considered to form a lever of the first kind (Fig. 95, a). The fulcrum is at the inferior tibio-fibular articulation, one 574 SUKGICAL APPLIED ANATOMY [Part V arm of the lever is the malleolus below that joint, while the other arm may be regarded as formed by the lower 2 or 3 inches of the shaft of the bone. Now the lower ends of the tibia and fibula are bound together by very powerful ligaments, viz., the anterior and posterior tibio-fibular, the trans- verse, and the inferior interosseous. I would ven- ture to insist particularly that in no ordinary lesion about the ankle, whether fracture or dis- location, do these ligaments give way. If they should yield, then an anomalous form of fracture or luxation will be produced. In forcible eversion of the foot, the internal lateral ligament becomes stretched and tears, the astragalus is rotated laterally beneath the tibio-fibular arch and is brought into violent contact with the end of the outer malleolus. This process is pushed outwards, and acts as one end of a lever. The fulcrum is secured by the unyielding tibio-fibular ligaments, and the fibula breaks at the other end of the lever, a point some 2 or 3 inches above the end of the bone (Fig. 95, b). In forcible inversion of the foot, the astragalus undergoes a little lateral rota- tion in the opposite direction ; the external lateral ligament is greatly stretched, and tends to drag the end of the outer malleolus inwards. If the ligament yields, the case will probably end as a sprained ankle, or pass on to a dislocation in- wards of the foot. But if it remains firm, the end of the fibular lever (the tip of the malleolus) is drawn towards the middle line, the fulcrum is secured by the fcibio-fibular ligaments, and the shaft breaks at the other end of the lever, some few inches above the end of the bone (Fig. 95, c). It will be seen that in the fracture due to eversion the upper end of the lower fragment is displaced towards the tibia, while in the lesion due to in- version it is displaced from that bone. From a careful examination of all the cases of fracture of the lower end of the fibula admitted into the London Hospital during the time I held the post of surgical registrar there, I convinced myself that Chap. XXIII] ANKLE AND FOOT 575 the lesion is much more frequently due to eversion than to. inversion of the foot. I think it may be said that a fracture of the lower end of the fibula due to simple inversion of the foot is not possible unless the external lateral ligament remains entire. In the outward luxation, better known as Pott's fracture, the condition is such as has just been described in connection with the effects of eversion of the foot upon the fibula. That bone is always broken some 2 or 3 inches above the malle- olus, the deltoid ligament is torn, or the tip of the inner malleolus wrenched off. The astragalus is so rotated laterally that the foot is much everted, its outer edge raised, while its inner edge rests upon the ground. The inferior tibio- fibular ligaments remain intact. If they yield, an unusual form of fracture or dislocation is pro- duced, as already stated. Boyer relates a case, considered to be unique, where the foot was lux- ated outwards, but without any fracture of the fibula. That bone, however, had been forced up- wards entire, and its head dislocated from the articular facet of the tibia. A horizontal disloca- tion outwards, without rotation of the foot and without fracture of the fibula, is possible if the inferior tibio-fibular ligaments are entirely torn. In Dupuytren's fracture (a rare injury) the fibula is fractured from 1 to 3 inches above the malleolus, the inferior tibio-fibular ligaments are entirely lacerated, or the portion of the tibia to which they are attached is torn away, and remains connected with the lower fragments of the fibula. The foot is dislocated horizontally outwards, and is drawn upwards, the extent of the upward dis- placement depending upon the height at which the fibula breaks. In the_ inward luxation the external lateral ligament is torn or the tip of the outer malleolus dragged away, the deltoid ligament is intact, but the internal malleolus is commonly broken by the violence with which the astragalus is brought into 576 SUKGICAL APPLIED ANATOMY [Part V contact with it. That bone itself may be broken, and is in any case rotated laterally, so that the foot is inverted and its inner border much raised. In all forms of this dislocation, whether simple or complicated, the inferior tibio-fibular ligament remains intact. 2. The antero-posterior dislocations : Back- wards; forwards. These injuries are brought about by great force applied to the foot while the leg is fixed, or more commonly by sudden^ arrest of the foot during some violent impulse given to the body, as on jumping from a carriage when in motion. In the luxation backwards the astra- galus is displaced behind the tibia, while the articular surface of the latter bone rests upon the scaphoid and cuneiform bones. The anterior and posterior ligaments are entirely torn, and a great part also of the two lateral bands. The fibula is broken some 2 or 3 inches above the mal- leolus, and there is usually a fracture also of the inner malleolus. The luxation forwards is of extreme rarity. In the few reported cases one or both malleoli were broken. R. W. Smith believes that the dis- location is never complete. 3. The dislocation upwards. In this rare acci- dent the inferior tibio-fibular ligaments are rup- tured, the two bones are widely separated at their lower ends, and the astragalus is driven up be- tween them. The anterior and posterior ligaments are entirely ruptured, but the lateral ligaments usually escape with but some slight laceration. The accident appears to be generally caused by a fall, the patient alighting flat upon the soles of the feet. Mr. Bryant records a case in which both feet were similarly dislocated upwards. The foot. — There are two arches in the foot, an antero-posterior and a transverse. 1. The antero-posterior arch has its summit at the astragalus. It may be considered as composed of two piers. The hinder pior consists of the os calcis, the anterior pier of the scaphoid, cunei- Ohap. XXIII] ANKLE AND FOOT 577 form and metatarsal bones. The astragalus forms the keystone of the arch, the head of the bone especially performing that function (Fig. 96). The foot rests upon the heel, the heads of the metatarsal bones, and the outer margin of the foot (Fig. 98). The hinder pier is solid, is made up of a strong bone, and contains only one joint. It serves to support the main part of the weight of the body, and gives a firm basis of attachment Fig. 96. — Antero- posterior section of the foot. (Rudihger.) 1. Tibia ; 2, astragalus ; 3, os calcis ; 4, scaphoid ; 5, int. cuneiform ; h, first meta- tarsal bone; 7 and 8; phalanges of great too. to the muscles of the calf. The anterior part of the arch, on the other hand, contains many small bones and a number of complicated joints. It serves to give elasticity to the foot, and to diminish the effect of shocks received upon the sole of the foot. The comparative value of the two piers of the arch in this latter respect can be estimated by jumping from a height and alight- ing first upon the heels and then upon the balls of the toes. The inner part of the arch is much more curved than the outer, and forms the in- step. % L 578 SUEGICAL APPLIED ANATOMY [Part V 2. The transverse arch is most marked across the cuneiform bones. It gives much elasticity to the foot and affords protection to the vessels of the sole. These two arches result from the shape of the component bones, and are maintained by the vari- ous ligaments and muscles of the sole. The peron- eus longus tendon, and nearly all the ligaments which connect the first and second rows of tarsal bones on both the plantar and dorsal aspects, are inclined forwards and inwards, and by this ar- rangement are well adapted to maintain the in- tegrity of the transverse as well as of the antero- posterior arch. The movements of inversion and eversion, whereby the foot is adapted to the ground on which it treads, occur at the subastragaloid joints. These are two in number : (1) the anterior subastragaloid joint between the head of the astra- galus and three other parts, (a) sustentaculum tali; (6) inferior calcaneo-scaphoid ligament; (c) scaphoid (Fig. 96) ; (2) posterior subastra- galoid between the body of the astragalus and os calcis. The posterior is separated from the an- terior joint by the interosseous ligament. A third joint is also concerned in these important move- ments, viz. that between theos calcis and cuboid. The muscles which produce inversion are (l) tibi- alis posticus, (2) tibialis anticus. The first pro- duces inversion with plantar flexion, the second with dorsal flexion. The flexor muscles of the toes assist the first, the extensor of the great toe the second. Eversion is produced by (1) peroneus longus, (2) peroneus brevis, (3) peroneus tertius, (4) the extensor longus digitorum. The first pro- duces eversion with plantar flexion, the others with dorsal flexion. Thus there are four groups of muscles acting on the subastragaloid articula- tions which balance and determine the movements of the foot, and four positions in which they may fix the foot : (1) inversion with plantar flexion (talipes equino-varus) ; (2) eversion with plantar Chap. XXIII] ANKLE AND FOOT 579 flexion (talipes equino-valgus) ; (3) inversion with dorsi-flexion (talipes calcaneo-varus) ; (4) eversion with dorsi-flexion (talipes calcaneo-valgus). The position assumed will depend on the group or groups of muscles which are paralysed or weak- ened. Eversion is limited by the inferior calcaneo- scaphoid ligament and the structures along the inner side of the sole of the foot— the abductor hallucis, plantar fascia, and the tibial muscles. Inversion is limited by the tuberosity of the scaphoid coming in contact with the sustenta- culum tali, the peroneal muscles, and ligaments along the outer border of the foot. The move- ments of inversion and eversion correspond to supination and pronation, but in the upper ex- tremity these are produced between radius and ulna, whereas in the lower extremity they occur almost entirely between the astragalus and the rest of the foot. Dislocation of the astragalus. — This bone is sometimes luxated alone, being separated from its connections with the os calcis, the tibia, the fibula, and the scaphoid bone* The displacement may be either forwards, backwards, or laterally. The luxation forwards is by far the most common lesion, the next in frequency being a luxation outwards and forwards. In these injuries the interosseous ligament between the os calcis and astragalus is entirely torn, as are also the greater part of the lateral ligaments of the ankle, and the various bands that connect the astragalus with the os calcis and scaphoid. In all instances the malleoli are brought nearer to the sole. Dislocation of the os calcis. — This bone, although often fractured, is very rarely luxated. When displaced, however, it^is usually displaced outwards, and is torn away from its attachments to the astragalus and cuboid, or from the former bone alone. Subastragaloid dislocations of the foot.— — In these lesions, which are not very uncommon, the astragalus remains in position between the 580 SUKGICAL APPLIED ANATOMY [Part V tibia and fibula, while the rest of the foot is dis- located below that bone. The luxation, therefore, concerns the anterior and posterior subastraga- loid joints. The foot may be displaced either forwards, backwards, or laterally. The forward dislocation is extremely rare, and the lateral luxa- tions are nearly always oblique. In the most usual displacements the foot is dislocated outwards or inwards, and is at the same time carried back- wards. These luxations are often compound, especially when lateral. They are, as a rule, incomplete as regards the anterior subastragaloid joint, while, on the other hand, the displacement of the astragalus from the scaphoid is in nearly every instance complete. In all cases the inter- osseous ligament between the os calcis and astraga- lus must be torn, and there will also be more or less laceration of the ligaments joining the astragalus to the scaphoid and to the malleoli. The malleoli are very often fractured. It is only necessary to notice in any detail the two lateral luxations, as being the only common forms. In the inward dislocation the foot is in- verted, its inner border is raised, is shortened, and rendered concave, while its outer border is lengthened and made convex. The deformity much resembles that of talipes varus. The head of the astragalus with the outer malleolus forms a projection at the outer aspect of the foot, while below them a deep hollow exists. The inner border of the os calcis is very prominent at the internal side of the limb, while the inner malleolus is buried in the hollow left by the displacement of that bone. The calcaneum and scaphoid are ap- proximated. In the outward luxation the foot is abducted, its outer border is raised, and the deformity produced is not unlike that of talipes valgus. The outer malleolus is lost in the hollow caused by the eversion of the foot, while the tibial malleolus and head of the astragalus form a pro- jection on the inner aspect of the limb. The inediotarsal joint is situated between Chap. XXIII] ANKLE AND FOOtf 58l the head of the astragalus and scaphoid on the inner side of the foot, and os calcis and cuboid on the outer. The inner is part of the anterior sub- astragaloid joint (see p. 578), while the outer has a separate synovial cavity. It should be noted that the movements of turning the toes either in or out take place mainly at the hip-joint; while the turning of one edge of the foot either up or down is a movement that mostly concerns the subastragaloid joints. Club-foot. — It is usual to divide the various forms of talipes, or club-foot, into four main divisions, viz. (1) T. equinus; (2) T. calcaneus; (3) T. varus; and (4) T. valgus. Four secondary forms result from combinations of these principal varieties, viz. T. equino-varus, T. equino-valgus, T. calcaneo-varus, and T. calcaneo-valgus, corre- sponding to the four positions assumed by the foot at the subastragaloid articulations (see p. 578). 1. Talipes equinus. In this deformity the heel is drawn up, and the patient walks upon the balls of the toes. The contracting muscles are those of the calf attached to the tendo Achillis. There is flexion of the ankle and marked inversion of the foot. In a well-marked case the os calcis is much raised, and may even be brought in contact with the tibia. The astragalus is displaced down- wards, and projects upon the dorsum. The foot tends to become more and more inverted, until at last the scaphoid may even touch the sustenta- culum. The ligaments of the sole are usually much contracted. 2. Talipes calcaneus. In this form of club-foot the toes are drawn up, and the patient walks upon the heel. The contracting muscles are the ex- tensors on the anterior aspect of the limb. The os calcis is rendered more vertical, and the astragalus becomes so obliquely placed that part of its upper articular surface may project beyond the tibia in a backward direction. 3. Talipes varus. This is the commonest form. Certain features of the fcetal foot are retained 532 SURGICAL APPLIED ANATOMY [Part V in an exaggerated degree. In a well-marked con- genital case there is a threefold deformity : (1) The heel is drawn up by the muscles attached to the tendo Achillis ; (2) the foot is inverted by the contraction of the tibialis anticus and posticus; (3) the sole is contracted by the flexor longus digitorum muscle and the shrinking of the plantar fascia and ligaments. The neck of the astragalus is elongated and deflected downwards and inwards to a greater extent than in the normal foot. In the adult the neck of the astragalus is deflected inwards to the axis of its body at an angle of 10° ; in the newly born at an angle of 25° ;> and jn talipes varus at an angle of 50°. The scaphoid is displaced upwards and inwards, until its inner border often touches the internal malleolus. The three cuneiform bones follow the scaphoid, and the cuboid becomes the lowest bone in the tarsus. The outer border of the cuboid forms an angle with the os calcis, and the tendons of the peroneus longus slip backwards from the groove in the cuboid to lie on the os calcis. The anterior border of the internal lateral ligament is con- tracted and unduly prominent. There is thus a marked degree of inversion. 4. In talipes valgus the foot assumes perma- nently the position of eversion. The contracting muscles are the two peronei. In a well-marked congenital case the os calcis is found a little raised and the astragalus is displaced forwards and downwards. The scaphoid is so rotated that its inner part is depressed and its outer raised. The internal portion of the bone forms one of the two projections obvious on the inner side of the foot, the other prominence being formed by the head of the astragalus. The cuboid is found to be a little rotated outwards. The arch of the foot is lost, and all those ligaments are stretched that serve to support and maintain that arch. Of the mixed, or secondary, forms of talipes nothing need be said. They are the results merely of a combination of the primary varieties. Chap. XXIII] ANKLE AND FOOT 583 As trouble is often caused in talipes by pres- sure being brought to bear upon an unusual part of the foot, it is well to note upon what portion of the member the patient treads in the different varieties of the deformity. In varus the "tread " is mainly upon the outer side of the fifth meta- tarsal bone ; in valgus upon the internal malleolus and scaphoid ; in equinus upon the bases of all the toes; in equino-varus upon the base of the little toe ; in equino-valgus upon the base of the great toe; in all forms of calcaneus upon the heel. In cases of extreme and obstinate club-foot wedges of bone are sometimes removed bv the operation known as tarsectomy. Thus in talipes equino-varus the base of the wedge will be on the outer side of the foot, and will be mainly repre- sented by the cuboid; the apex will be at the scaphoid. Flat - foot and splay - foot are the names given to a deformity due probably to the yield- ing of certain ligaments, whereby the arch of the /lEAD OpASTRACALUS Inf. CALCA/ieo-ScAP/1 Liq. Tuberosity ofScap/ioid Fig. 97. — Dissection of a flat-foot from the inner side. DO ACrtlLLl s .L.Dicitorum t. Malleolus ibialis Post. SuSTEflT.TALI foot is lost and the sole becomes more or less perfectly flat. The foot, at the same time, is ab- ducted, and the outer border is often a little raised, so that the patient walks mainly upon 584 SUEGICAL APPLIED ANATOMY [Part V the inner side of the foot. This deformity is met with in those who stand a great deal, and is the direct result of yielding of the muscles which maintain the foot in a position of inversion — especially the tibialis anticus and posticus. It is only when these muscles become exhausted and yield that the ligaments are strained and elon- gated, for it may be accepted as a lav/ that the normal strain at a joint falls on the muscles, the ligaments only coming into action in limiting the extent of movements. The inferior calcaneo- scaphoid ligament is lax in the standing posture ; the weight of the head of the astragalus is then supported by the tibialis posticus (Fig. 97). As is well known, the muscles of the leg and foot become more quickly exhausted when stand- ing than when walking, for in the standing posture the muscles which invert the foot are maintained in a condition of tonus, whereas in walking they have alternate periods of action and rest. Hence in those whose occupations entail prolonged periods of standing, the muscles which maintain the inversion of the foot become ex- hausted — especially the tibialis posticus; they gradually yield, and the superincumbent weight of the body then falls on the structures which limit eversion of the foot, especially the inferior calcaneo-scaphoid ligament, on which the head of the astragalus then comes to rest (Fig. 97). When the weight falls on this ligament it begins to yield; the head of the astragalus is pressed for- wards, downwards, and inwards by the superin- cumbent weight, and the foot beyond becomes, as a consequence, over-extended and turned out (Fig. 97). The os calcis slants inwards, and its anterior end is depressed. The sustentaculum tali, the head of the astragalus, and the scaphoid tubercle form prominences on the inner^ side of the foot, and may rest on the ground (Fig. 97). The long and short plantar ligaments also, which contribute so much to the maintenance of the arch of the foot, in time yield, and allow of a still greater Chap. XXIII] ANKLE AND FOOT 595- degree of deformity. There is a stretching also of the deltoid ligament. In neglected cases the distortion is rendered more or less permanent by alterations in the shape of the tarsal bones, and by a contraction of such ligaments as have been re- laxed by the deformity. The scaphoid and inter- nal cuneiform become markedly wedge-shaped, with the apices directed on the dorsum of the foot Fig. 98. — Various forms of foot-prints. A, Of normal foot with high arch ; c, Hat foot. also with high arch with low arch : ; (Fig. 97). The foot being abducted, and its outer border a little raised, the peronei muscles become relaxed, shortened, and contribute to the perma- nency of the disorder. It will be understood that the abnormal pressure brought to bear upon the, various tarsal bones and articulations will cause severe pain to be often associated with this affec- tion. The calf muscles waste, owing to the arch of the foot having lost its rigidity and being no longer able to support the weight of the body. Imprints of normal feet vary much in form 586 SURGICAL APPLIED ANATOMY [Part V {see Fig. 98). Dr. Lovett, of Boston, is of opinion that the feet which come in contact with the ground at only two parts — at the heel behind and along the pad of the foot in front — are those which are most prone to break down (Fig. 98, a). In flat foot the inner border of the foot also comes in contact with the ground, so that the area be- tween the heel, the plantar pad, and the outer margin of the foot, left blank in the normal im- print, becomes partially or completely filled up (Fig. 98). It may be noted that the medio-tarsal joint, which is so conspicuously involved in the distor- tion, is supplied by the anterior tibial, musculo- cutaneous, and external plantar nerves. The tarsal bones, owing to their spongy character, are readily broken by direct violence, as in severe crushes. The soft parts that cover these bones being scanty upon the dorsal aspect of the foot, it follows that these accidents are often compound and associated with much lacera- tion of the integuments. The tarsal bone the most frequently fractured is the os calcis. This bone may be broken by a fall upon the heel, and in many instances has been the only one fractured by such an accident. A few cases have been recorded of fracture of the calcaneum by muscular violence, the muscles producing the lesion being those attached to the tendo Achillis. Thus, Sir A. Cooper reports the case of a woman, aged forty-two, in whom a large fragment of the posterior part of the os calcis was torn away by the muscles and drawn some 2\ inches away from the heel. The accident was caused by her taking a false step. Abel has collected three cases of fracture of the sustentac- ulum tali. He believes that this injury may be produced by falls upon the sole or by extreme in- version of the foot, whereby the astragalus is forced violently against the process. The astragalus alone may be broken by a fall upon the feet, and such accidents are often associ- Chap. XXtll] ANKLE AND FOOT 587 ated with fractures of both that bone and the os calcis. It must be noted, however, that in a fall, when the patient alights upon the feet, the tibia and fibula are much more likely to be broken than are the tarsal bones, since the bones of the leg transmit the weight of the body directly, whereas that weight is much diffused and broken up when passing through the foot with its many bones and joints. The metatarsal bones and phalanges are nearly always broken by direct violence. I had, how- ever, under my care at the London Hospital a man who had broken the shafts of the three outer metatarsal bones by simply slipping off the edge of the curb. Since the introduction of X-rays as a means of diagnosis, fractures of the metatarsal bones, especially of the fifth, and of the phalanges, are found to occur not infrequently, and often as the result of a movement or accident which seems totally insufficient to produce such lesions. With regard to the luxations of the foot not yet considered, it may be said that the cuboid is never dislocated alone. Walker reports a case of dislocation of the scaphoid alone, that structure being quite separated from the astragalus and cuneiform bones. The accident was brought about by alighting upon the ball of the foot when jump- ing, and the little bone was found projecting on the dorsum. Mr. Bryant has mentioned an in- stance of dislocation of the scaphoid inwards. As a rule, however, this bone when displaced is dislocated along with the astragalus. Of the cuneiform bones the one most often luxated alone is the internal. The attachments of the tendons of the tibialis anticus and peroneus longus about the internal cuneiform and first metatarsal bones render it common for the latter to follow its tarsal colleague when dislocated. Mr. Luke has recorded a case of incomplete luxa- tion of all three cuneiform bones upwards, and at least three cases have been described of disloca- tion of the internal bone upwards and backwards, 588 SURGICAL APPLIED ANATOMY [Part V together with a like displacement of all the meta- tarsals. One or more of the metatarsal bones may be luxated, or the entire series may be displaced upwards, downwards, inwards, or outwards, the first-named lesion being the most common. In rarer instances, one bone has been thrown in one direction and its fellow or fellows in another. Ossification of the tarsus. — At birth the tarsus is mainly cartilaginous. Ossification be- gins in the os calcis in the sixth month and in the astragalus in the seventh month of foetal life. The centre for the cuboid appears at birth, and in the scaphoid, the last to ossify, in the third year. It is not until puberty that the cartilage of the tarsal bones is completely ossified. Like the epiphyses of long bones the tarsal bones are en- tirely formed in cartilage, there being no peri- osteal formation. Hence it is possible, as Ogston has shown, to enucleate the ossific centres from the tarsal bones of children who are the subjects of club-foot and by remodelling the cartilaginous capsules left behind, obtain new ossifications of a more normal form. Dislocation of the proximal phalanx of the great toe is often very difficult to reduce, as is also the case in the corresponding luxation of the thumb. When the displacement is dorsal, the difficulty is probably due to the sesamoid bones, which are embedded in the glenoid ligament or fibro-cartilaginous plate. " Like the glenoid liga- ments, the sesamoid bones are much more firmly connected with the phalanx than with the meta- tarsal bone, and thus get torn away and shut back behind the head of the metatarsal bone ; or it may be that the sesamoid bones, retaining their connections with the lateral ligaments of the joint as well as with the short flexor tendons, are separated from one another, and so allow the head of the metatarsal bone to pass forwards, and thus become nipped, as it were, in a button- hole between them " (Henry Morris). A partial Chap. XXIII] ANKLE AND FOOT 589 dislocation of the proximal phalanx outwards on the head of the metatarsal bone of the great toe constitutes the con- dition known as hallux valgus. The inner lateral liga- ment of the joint is elongated, while the outer is contracted. In hallux rigidus this joint is slightly flexed and rigid, due probably to a reflex contraction of the flexor brevis hallucis. The second toe is com- monly longer than the others, and is more liable to assume the form known as " hammer toe." The proximal phalanx in such a form is ex- tended, while the middle is strongly flexed. The condition is commonly inherit- ed, and is due to a contraction of the glenoid and lateral ligaments of the proximal phalangeal joint. The extensor tendon is also con- tracted. There are six synovial cavities in the foot, excluding viz. one for the poster Fig. 99. — Oblique anteroposterior section of the foot. (Eudingcr.) ], Tibia ; 2, fibula ; 3, astragalus ; 4, os oalcis ; 5, external lateral ligament ; tj, internal lateral ligament ; 7, inter- osseous ligament between astragalus and os calcis ; 8, head of astragalus; 9, scaphoid ; 10, 11 and 12, the three cuneiform bones; 13, cuboid. that of the ankle-joint, ior subastragaloid joint. 590 SURGICAL APPLIED ANATOMY [Part V a second for the anterior subastragaloid, a third between the os calcis and cuboid, a fourth between the latter bone and the two outer metatarsals, a fifth for the joint between the inner cuneiform and first metatarsal bones, and a sixth for the remain- ing articulations (Fig. 99). These synovial cavities tend greatly to diffuse disease among the various bones of the foot when once one bone has become Fig. 100.— Syme's amputation. (Agatz.) Tibia • b, fibula ; c, tibialis anticus ; d, extensor proprius pollicis ; e, extensor communis digitorum ;/, peroneus tertius; g, flexor longus pollicis; //.tibialis posticus; i flexor longus digitorum; ;", peroneus brcvis ; 7;, peroneus longus ; I tendo Achillis : m, some muscles of the sole that are not usually left in this operation ; n, anterior tibial vessels; o, posterior tibial vessels ; p, posterior tibial nerve. Chap. XXIII] ANKLE AND FOOT 591 inflamed. The best position, therefore, for bone disease, with reference to the question of exten- sion, would be in the hinder parts of either the os calcis or astragalus, and one of the worst posi- • tions would be assumed by disease involving the scaphoid bone. Myiue's amputation at the ankle. — In the heel-flap are cut the integuments, the external saphenous nerve and vein, the peroneus longus, peroneus brevis, tibialis posticus, flexor longus digitorum, flexor longus hallucis, tendo Achillis, points of origin of the flexor brevis digitorum and of the two abductor muscles, and the internal and external plantar arteries and nerves. In the dorsal flap are cut the integuments, tibialis anticus, extensor communis digitorum, ex- tensor proprius hallucis, peroneus tertius, anterior tibial vessels and nerve, musculo-cutaneous nerve, and internal saphenous nerve and vein. The posi- tion of the principal structures divided is shown in Fig. 100. It is not usual to dissect up any of the muscular tissue of the sole, as shown in Agatz's plate. It should be noted that the integuments of the heel derive their blood supply, which is very free, mainly from the external calcaneal branch of the posterior peroneal artery, and the internal calcaneal from the external plantar. If the heel incision is carried sufficiently far back to divide the trunk of the posterior tibial artery, the heel flap is deprived of the last-named source of blood supply. The posterior tibial artery bifurcates upon a line drawn from the tip of the inner malleolus to the centre of the con- vexity of the heel. The nerves supplying the integuments of the heel are the calcaneal branch of the external saphenous and the calcaneal and plantar cutane- ous twigs from the posterior tibial. In Pirog-off's amputation the parts divided in the anterior flap are the same as in Syme's operation. In the heel or sole flap the same structures also are cut as in the corresponding 592 SURGICAL APPLIED ANATOMY [Part V flap in a Syme, with the exception that the tendo Achillis is not divided, the flexor brevis digitorum, abductor pollicis, abductor minimi digiti, and flexor accessorius are divided more ex- tensively, and the plantar vessels are cut farther from the bifurcation. Cliopart's operation is an amputation at the mediotarsal joint. In the dorsal flap are cut the integuments, the extensor communis and brevis digitorum, ex- tensor proprius hallucis, tibialis anticus, pero- neus tertius and brevis, the mus- culo - cutaneous, anterior tibial, and two saphen- ous nerves, the dorsal artery, and the dorsal plexus of veins. In the plantar flap are found divided the in- teguments, plan- tar fascia, flexor brevis digitor- um, abductors of the great and little toes, flexor accessorius, and tibialis posticus tendon. If the flap be well dis- sected up from the bones, parts of the short flexors of the great and little toes, the abductor hallucis, and trans- versus pedis will be found cut in the flap. The tendons of the long flexors of the digits and great toes, the peroneus longus, and the plantar vessels and nerves are also divided (Fig. 101). Chopart's operation. (Agatz.) Astragalus ; b, os calcis ; c, extensor proprius hallucis ; d, tibialis anticus ; e, extensor com- munis digitorum ; /, peroneus longus ; g, abduc- tor minimi digiti; h, flexor brevis digitorum •i, flexor longus dig'torum ; j, abductor hallucis ft, flexus longus hallucis ; 1, dorsalis pedis artery m, internal plantar artery ; n, external plantar artery. Chap. XXIII] ANKLE AND FOOT 593 Lisfranc's operation, or amputation through the tarso-metatarsal line of joints (Fig. 102). In the dorsal flap the same structures are divided as are cut in the corresponding flap in Chopart's amputation. In the plantar flap also the parts divided are the same as in that procedure, with the exception that the flexor accessorius and the tendon of the tibialis posticus escape section. The articulations be- tween the three outer metatarsals and the corresponding tarsal bones form a line sufficiently straight to be traversed by the knife in one cut when once the blade has been introduced. The joint also be- tween the first meta- tarsal and internal cuneiform bones is in a straight line and readily opened. The most difficult part of the disarticulation concerns the separation of the second metatarsal bone, which is deeply lodged between the tarsal segments. The chief bond of union between this bone and the tarsus is effected by a strong interosseous ligament that passes be- tween it and the internal cuneiform. In Fig. 102 the knife is placed in the position required to divide that ligament, 2 m Fig. 102. — Lisfranc's operation. (Agatz. a, b, c. Inner, middle, and outer cuneiform bones ; il, cuboid ; e, f, the metatarsal bones; g, tibialis anticus ; h, extensor proprius hallucis ; i, extensor communis djgitoruin ; j, extensor brevis digi- torum ; fc, extensor tendons; I, dorsalis pedis artery. 594 SURGICAL APPLIED ANATOMY [Part V In the subastragaloid amputations a dis- articulation is effected at the subastragaloid articulations. The astragalus is the only bone of the foot left behind, and forms the summit of the stump. Fig. 103 shows the position of the more im- portant structures that are divided in amputation of the great toe together with its metatarsal bone. The nerve supply of the lower limb.— In Fig. 104 is shown the cutaneous nerve-supply of Fig. 103. — Amputation of great toe, with its metatarsal bone. (Agatz.) a, Internal cuneiform bone ; b, adductor liallucis ; c, extensor longus hallucis ; d, flexor longus liallucis ; e, plantar branch of dorsalis pedis artery. the inferior extremities on both the anterior and the posterior aspect, and in Fig. 105 are seen the cord segments from which they are derived. Paralyses of the lower limbs are common, but are more often due to some lesion in the inferior segment of the cord than to damage received by any one individual nerve. Cases, however, are recorded where a single trunk has been injured and a limited form of paralysis has followed in consequence. Paralysis of the anterior crural nerve has been caused by injuries to the lower part of the vertebral column implicating the cauda t- 8 \ i S 1*1 8 Fig. 104. — Cutaneous uerve-supply of lower limli. 11 aspect.— 1, Ilioinguinal ; 2, genito-crural ; 3, external cutaneous : 4, middle cutaneous; •",, internal cutaneous; 6, patellar plexus: 7, branches <>f external popliteal; 8, internal saphenous; 9, tnusculo-cutaneous ; ID, external saphe- nous; 11, anterior tibial. Posterior aspect.— 1, 2, and ■"., small sciatic; 4, external cutaneous; 5, internal cutaneous; 6, internal saphenous; 7, branches of external popliteal; 8, short saphenous;!i, posterior tibial; 10, internal saphenous; 11,' internal plantar; 12, external plantar. 596 SUKGICAL APPLIED ANATOMY [Part V equina, by fractures of the pelvis, by tumours of the pelvis, by psoas abscess, by fractures and dis- locations of the femur, and by stabs in the region of the groin. In this nerve lesion the patient is unable to flex the hip or to raise the body from the recumbent position (ilio-psoas). The adductor muscles may simulate the action of the flexors of the hip, but it will be observed that they rotate and adduct the thigh as well as flex it. The power of extending the leg at the knee is lost (quadri- ceps extensor cruris) ; the function of the sar- torius is destroyed and that of the pectineus im- paired. Sensation is impaired in parts supplied by the internal and middle cutaneous nerves and the long saphenous nerve. Paralysis of the obturator nerve alone is a rare condition, although it may be found associ- ated with a like lesion of the preceding trunk. It may be brought about by the pressure exer- cised upon the nerve in cases of obturator hernia and by the foetal head during delivery. The muscles implicated are the adductors, gracilis, and external obturator. The patient is unable to press the knees together, or to cross the legs. Rotation outwards is difficult, but sensation is scarcely affected in the skin supplied. Paralysis of the internal popliteal nerve. — There is inability to flex the ankle and to flex the toes (flexor longus digitorum, flexor proprius hallucis, tibialis posticus, gastrocnemius, and soleus). The patient is unable to stand upon the toes, owing to loss of function in the two last- named muscles. The power of inverting the foot is impaired (tibialis posticus), and lateral move- ment in the toes is lost owing to paralysis of all the small muscles of the sole. Sensation is im- paired over the plantar aspect of the toes, the sole, and in part of the lower half of the back of the leg. In paralysis of the external popliteal nerve the action of the muscles on the front of the leg is lost. The foot hangs down and the toes catch the Fig. 105. — Showing the skin areas in the lower extremity supplied by the lumbar and sacral segments of the spinal cord. {After Head.) i in each area is indicated the segment of the- cord by which it is supplied Fur the nerves supplying each area see Fig. 104 598 SUKGICAL APPLIED ANATOMY [Part V ground in walking. The foot can be neither dorsi- flexed nor everted (extensor communis digitorum, extensor proprius hallucis, peroneal muscles). Adduction is imperfect, owing to paralysis of the tibialis anticus. Extension of the toes is only possible to the slight extent effected by the interossei. The arch of the foot becomes flattened owing to loss of the support furnished by the peroneus longus. Sensation is impaired over the front and outer side of the leg and on the dorsum of the foot, and also over some part of the back of the leg, owing to paralysis of the communicans peronei. The fibres destined for any particular muscle are not assorted in one fasciculus until near their point of exit from the nerve trunk ; hence a nerve trunk such as the internal popliteal may be partly divided without any apparent effect. This cir- cumstance is taken advantage of in cases of in- fantile paralysis. In a case where the external popliteal is affected, action of the extensor muscles may be restored by suturing that nerve to a slip partially separated from the internal popliteal. When the great sciatic nerve is paralysed there will be, in addition to the loss of function in the two preceding nerves, an inability to flex the knee owing to paralysis of the hamstrings, while rotation of the limb may be impaired by loss of power in the quadratus femoris and ob- turator internus. Mr. Sherren found that the knee may still be flexed in such cases through the action of the gracilis, and that sensation was com- pletely lost in only part of the sole of the foot. A knowledge of the segments of tlic cord from whicli the nerves of the lower limb arise often assists the surgeon in localising cer- tain lesions. Section of a nerve root, as may happen in fracture of the spine, or destruction of its centre in the spinal cord, gives rise to paralysis in a definite group of muscles and anaesthesia of a certain area of skin. The skin areas supplied by the lumbar and sacral segments Chap. XXIII] ANKLE AND FOOT 599 are shown in Fig. 105, and these segments, accord- ing to Kocher, innervate the following groups of muscles : Third lumbar, the psoas, iliacus, pec- tineus, sartorius and adductors; fourth lumbar, quadriceps extensor cruris; fifth lumbar, gluteus medius and minimus, tensor vaginae femoris and hamstrings; first sacral, gluteus maximus, short external rotators of hip-joint, peronei, extensors of toes and flexors of ankle ; second sacral, gastroc- nemius, soleus, long flexors of toes and extensors of the ankle-joint and muscles of the sole. Part VI— THE SPINE CHAPTER XXIV The vertebral column combines in a remarkable way many very different and complicated func- tions. It acts as the central pillar of the body, and as the column that supports the weight of the head. It connects the upper and lower seg- ments of the trunk. It gives attachments to the ribs. It has the property of mitigating the effects of shocks that are transmitted from various parts of the body. It permits, to a wonderful degree, of a number of most complicated movements; and, lastly, forms a solid tube for the reception of the spinal cord. It owes much of its elasticity, and of its power of breaking up divers forces communicated to it, to its curves. Of the four curves, two, the dorsal and sacral, are primary and are due to the forma- tion of the thoracic and pelvic cavities, depending mainly upon the shape of the bones. The other two, the cervical and lumbar, are compensatory curves, and depend mainly upon the shape of the intervertebral discs. The dorsal and sacral curves appear in foetal life ; the lumbar and cervi- cal curves appear after birth, and depend on the assumption of the erect position. The infant's spine appears straight. The only marked curve seen in the back of the young child is a general curving of the column backwards, a kyphosis. When the infant is first encouraged to sit erect, this is the outline assumed by the spine, and in 600 Chap. XXIV] THE SPINE 601 some weakly children, and especially in those afflicted with rickets, this curvature is often very pronounced. The discs are twenty-three in num- ber and make up nearly one-fourth of the entire length of the spine. If the discs be removed, and the vertebrae be articulated in the dry state, the cervical and lumbar convexities almost dis- appear, and the column tends to present one great curvature, the concavity of which is forwards, and the most marked part of which corresponds to a point just below the middle of the dorsal region. This somewhat resembles the curve seen in the spines of the aged, and in such individuals it may be to no small extent due to the shrinking of the intervertebral discs. It is by means of the discs that the movements of the spine are in the main permitted, and it will be found that they are most developed in regions where most movement is allowed. They act also as springs in giving elasticity to the column, and in economising muscular action, while at the same time they play the part of buffers in modifying the effect of shocks transmitted along the spine. Although the motion permitted between any two individual vertebrae is not extensive, yet the degree of movement capable of being exercised in the column as a whole is considerable. While lateral movements and those of flexion and ex- tension are restricted in the dorsal region, those of rotation are free ; hence scoliosis of the spine is most marked in this region. Movements from back to front and from side to side are freest in the cervical, dorso-lumbar, and lumbar regions. From a surgical point of view the weakest part of the spinal column is between the ninth dorsal and third lumbar vertebrae. Here side-to-side and back-to-front movements occur most freely ; above this region the spine is supported by the thorax ; below the intervertebral discs are larger and stronger, and the supporting ligaments and muscles better developed. It is impossible to insist too strongly on the 602 SURGICAL APPLIED ANATOMY [Part VI fact that the muscles of the back and trunk are the sole agents in maintaining the spine erect. The minute they are thrown out of action the spinal column loses its rigidity and collapses. All four groups of muscles which act on the spine are concerned : the extensors (erector spinas) ; the flexors (rectus abdominis, longus colli, psoas) ; the lateral flexors (erector spinas, quadratus lum- borum, internal and external oblique, intercos- tals, and levatores costarum); rotators (external and internal oblique, multifidus spinas, semi- spinalis, intercostals, and levatores costarum). By these muscles the vertebras are maintained balanced on their intervertebral discs, one above the other. The ligaments are slack, and the sur- faces of the articular processes are in only light contact. When the muscles approach exhaustion, owing to Drolonged maintenance of the erect pos- ture, partial relief may be obtained by allowing a certain degree of rotation and lateral flexion to take place. Thereby the articular processes are brought into firm contact, the ligaments become somewhat tightened, and a certain degree of pas- sive support is obtained. In this manner the con- dition of scoliosis is produced. Scoliosis. — In very few people do the spines of the vertebras lie in a perfectly straight line down the back. There is commonly a slight de- gree of lateral curvature. If the pelvis be tilted laterally, as when the limbs are unequal in length, a compensatory lateral curve is produced. In scoliosis, lateral curvature is combined with a rotation of the vertebras, the spinous processes turning to one side of the median line and the bodies to the opposite. It is a disease of ado- lescents, due to a weakness of the spinal muscles, which are unable to maintain the vertebras in the position necessary for the erect posture. Each vertebra is provided with three levers, a posterior (the spinous process) and two lateral (the transverse processes and attached ribs). The erector spinas acts on the lateral levers ; the mul- Chap. XXIV] THE SPINE 603 tifidus spinse and muscles for the upper ex- tremity on the posterior. It is through training these muscles by suitable exercises that the ver- tebrae can be restored to, and maintained in, their normal positions. Sprains of the vertebral column. — The many joints and ligaments of the part, and the varied and violent movements to which it may be exposed, render it very liable to be the seat of sprains. These injuries, however, cannot reach any great magnitude, for so closely are the in- dividual vertebrae articulated, that_ any force severe enough to produce other than slight tearing of the ligaments will tend to cause a fracture or dislocation of the bones. Sprains are most commonly met with in the cervical and lumbar segments of the spine. This localisation is due to the mobility of those parts, and to their tendency to diffuse any violence transmitted to them, and so to render it more general. For it is to be noted that the more localised an injury, the more likely it is to pro- duce a fracture or dislocation rather than a sprain. In the cervical region, also, the tendency to sprain is increased by the near articulation of the column with the head, and the possibility of _ any violence applied to the skull being transmitted to the spine. Sprains of the spine are not apt to be asso- ciated with the external evidences of ecchymosis, since between the skin and the column there inter- vene not only many layers of muscles, but also dense expansions of fascia. It has already been pointed out that sprains in the loin, produced by severe bending forwards of the column, may be associated with some damage to the kidney and consequent hsematuria (p. 410). A sprained back is often the seat of a con- siderable degree of pain and stiffness, that per- sists long after the immediate effects of the lesion 604 SURGICAL APPLIED ANATOMY [Part VI must have passed away. Such a condition may be understood by noticing that the column presents a vast number of separate articulations, each pro- vided with cartilage, synovial membrane, and capsular ligaments. These joints have no quali- ties that exempt them from the common evils in- cident to sprains of more superficial articula- tions; and there is little doubt that the long-felt pain and inconvenience often depend upon some synovitis of the vertebral joints. In a few cases this synovitis has gone on to suppuration, and in one instance at least the pus so formed found its' way into the spinal canal and induced some mis- chief in the cord. Fractures and dislocations of the spine.— The effects of violence applied to the column are much diminished by the general elasticity of the spine, by its curves, and by the circumstance that it is composed of a number of separate segments. Each vertebra meets the one immediately above or below it at three points of contact, the body and the two articulating processes. The bodies are separated by the inter-vertebral disc, which acts as an excellent spring or buffer in modifying the effects of violence. The articulating processes are more or less wedge-shaped, the thin edge of one being applied to the base of the other. When a force is applied to the column that tends to com- press the vertebrae together, the bases of the two wedges are brought into more and more close rela- tion, and thus an increasing resistance is offered to the compressing power. The parts of the spine most liable to injury are (1) the atlanto-axial ; (2) the cervico-dorsal ; and (3) the dorso-lumbar. In the atlanto-axial region the parts not only enjoy a very considerable degree of movement but are very directly influenced by many forms of violence applied to the head. In the two other regions it will be noted that a flexible part of the spine joins a comparatively rigid segment of it, and thus violence applied to the column in either of these districts is apt to be Chap. XXIV] THE SPINE 605 concentrated rather than diffused. The sternum and ribs act as a splint to the dorsal part of the column. The mechanism is in a way illustrated by the circumstance that a fishing-rod when it snaps commonlv breaks near a joint, that is to say, at a spot where a flexible segment of the rod meets a less elastic portion. In the dorso-lumbar region, moreover, the vertebrae, although they have to support almost as much weight as have those of the lumbar region proper, are yet dispro- portionately small in size. Being placed, also, near the middle of the column, they can be in- fluenced on all sides by a powerful amount of leverage. The gravity of all injuries to the spine depends upon the risk of damage to the cord en- closed in the column. Apart from this complica- tion, fractures and dislocations in this region are apt to do well, and if the patient survive, the former lesions nearly always heal readily. The position of the cord within the vertebral canal and the arrangement of its membranes are such that it presents many facilities for escaping injury from violence. These will be dealt with subsequently in speaking of the cord itself. < It may, however, be noted here that the construction of the vertebrae, and their relation to one another, are of a character to afford much protection to the cord, even in cases where they themselves are ex- tensively damaged. " Being lodged in the centre of the column, it . (the cord) occupies neutral ground to forces which might cause fracture. For it is a law in mechanics that when a beam, as of timber, is exposed to breakage, and the force does not exceed the limits of the strength of the material, one division resists compression, another laceration of the particles, while the third, between the two, is in a negative condi- tion." (Jacobson, Holmes's " System.") Now, it happens that fractures of the spine are most often due to violence that bends the column forwards. The anterior segment, in such a case, will be sub- ject to compression, the posterior to laceration, 606 SUEGICAL APPLIED ANATOMY [Part VI and the intermediate portion will be in a neutral condition. When the spine is examined, it will be found that its anterior part, composed of the large cancellous bodies, is excellently adapted to resist the effects of compression, while its pos- terior parts, composed of slighter and more com- pact bones and surrounded by many strong liga- ments, are well arranged to resist the effects of a tearing force. The spinal cord, situated between these two divisions, occupies the position of least danger. The vertebrae may be fractured without being dislocated, but a dislocation without a fracture is rarely possible. It would appear, indeed, that a luxation of the spine, with no fracture of the bone, cannot occur in either the dorsal or lumbar regions. Mr. Jacobson, in the essay above referred to, writes : "I believe I am correct in stating that there is no case recorded, and thoroughly verified, in recent years, of dislocation of the lumbar or dor- sal vertebrae unaccompanied with any fracture of the body, transverse or articular processes." Dis- location without fracture has been met with in the cervical spine, although even there, if we except the first two vertebrae, it is very rare. When it occurs it most often involves the fifth vertebra, which, with the rest of the column above it, is displaced forwards and downwards. Luxa- tions in other directions have been noted, but they are extremely uncommon. The possibility of luxation in the cervical region without disloca- tion is explained by the small size of the vertebral bodies, the obliquity of their articular processes, and the relatively slight opposition they offer to displacement when compared with like processes in the other parts of the column. The luxation is usually bilateral and incomplete, and the result of a forcible bending of the head and upper part of the spine forwards and downwards. When situated high up the displacement may be appre- ciated by an examination of the part through the Chap. XXIV] THE SPINE 607 pharynx. In the complete bilateral dislocation the cord is usually hopelessly crushed. These luxations have been reduced by forcible extension, although the circumstances under which such a procedure is advisable are neither frequent nor very distinctly marked. Since, in severe injuries, dislocation and frac- ture are so usually associated, it is common to deal with these lesions under the title of " frac- ture-dislocation. ' ' Fracture-dislocation may be due to (l) in- direct, or (2) direct violence. (1). The injuries from indirect violence are by far the more com- mon. They are due to a violent bending of the head, or of the spine above the seat of lesion, for- wards and downwards. Thus, the cervical spine has been more than once broken by a "header " into shallow water ; while the dorsal vertebrae have been fractured and displaced by the acute bending of the column produced by a heavy sack falling upon the back of the neck. This form of injury is most commonly met with in the cervical and upper dorsal regions. These parts of the column possess great mobility, the bodies that compose them are not large, and are influenced by violence applied to the head. In a well-marked case there is some crushing of the vertebrae involved, and the usual deformity de- pends upon the sliding of the centrum above downwards and forwards upon the centrum below. Complete displacement of any two vertebrae from one another is prevented by a locking of the pos- terior processes. In some cases the luxation is complete, a condition that is least frequently met with in the lumbar spine. In the cervical and dorsal regions, the parts, after the dislocation, may often be returned to their normal position ; but in the loins this re- placement is usually impossible, owing to the lock- ing of the large and powerful articular processes. In the neck the laminae and spines may be frac- tured, while the articulating processes, being 608 SURGICAL APPLIED ANATOMY [Part VI broad and nearly horizontal, usually escape, even when there is much displacement of the parts. In the dorsal spine the laminae and articular pro- cesses are always torn when displacement occurs. In the lumbar region the articular processes usually escape fracture, although they are vio- lently torn asunder. In all cases there is more or less laceration of the intervertebral discs, the supraspinous, interspinous, and capsular liga- ments are torn, as are also the ligamenta subflava. When the bodies are much crushed and displaced the anterior and posterior common ligaments are commonly ruptured. (2). In the fracture-dislocations due to direct violence the lesion may be at any part of the spine. Some form of direct violence is applied to the back, and the column tends to become bent backwards at the spot struck. In the previous class of injuries it will be noted that the anterior segments of the vertebras suffer compression, while the posterior suffer from the effects of laceration and a tearing asunder of their parts. In lesions due to direct violence the circumstances of the in- jury are reversed, the posterior segments tend to be crushed together, while the bodies on the front of the spine are separated. Much displacement is very rarely met with in this form of accident. To produce separation of the vertebrae the violence must be very extreme, and as a rule the force expends itself upon a crushing of the hinder portions of the spinal seg- ments. It follows from this, also, that injury to the cord is less common and less severe in lesions due to direct violence than in those due to indirect violence. In the atlanto-axial region the atlas and occipital bone have been dislocated from one another by direct violence, although the most fre- quent lesion is a dislocation of the former for- wards upon the axis, a lesion usually, if not always, associated with fracture of the odontoid process. The spinous processes may be broken off as a Chap. XXIV] THE SPINE 609 result of well-localised blows. The prominent spines in the lower cervical region and the long processes of the dorsal tract of the column are those that usually suffer. The lumbar spines are less frequently broken, being comparatively small and well protected by the great muscles of the back. The transverse processes and laminae can scarcely be fractured alone. In several instances of fracture-dislocation and of fracture alone the spine has been trephined, or rather portions of the laniinse and spinous pro- cesses have been resected {laminectomy). By this means the spinal canal has been freely opened up, effused blood has been allowed to escape, and the cord has been freed from pressure. The laminae are divided as near the transverse process as pos- sible, and the tough ligamenta subflava require careful division. The column is reached through a median in- cision, and the great muscular masses are cleared from the spinous processes and laminae on either side. The wound being nearly median, the bleed- ing is not excessive. The dorsal spinal plexus of veins lies along the spines and over the laminae. On the deep surface of the laminae lie the pos- terior longitudinal spinal veins This operation has also been carried out with success in cases of paralysis due to the pressure upon the cord by displaced bone or inflammatory exudations in caries of the spine (Pott's disease). It has to be noted, however, in the last named class of case, that the condition exhibits a ten- dencv to spontaneous cure. The spinal cord is in the adult about 18 inches in length, and extends from the lower margin of the foramen magnum to the lower edge of the body of the first lumbar vertebra. In some cases it ends at the second lumbar, and in other instances at the last dorsal vertebra. It is to be noted also that in flexion of the spine the cord is a little raised. When the body is bent and the arms 2N 610 SUEGICAL APPLIED ANATOMY [Part VI stretched out the lumbar part is raised 10 mm. In the earlier months of foetal life the medulla spinalis occupies the whole length of the vertebral canal, but after the third month the canal and lumbar and sacral nerves grow so much faster than does the cord itself, that by the time of birth it reaches no farther than the third lumbar ver- tebra. It is obviously a great advantage, in cases Spine. Fig. 106. — Section through spinal cord, membranes, and spinal canal. a.r., at origin of anterior root; p.r., at origin of posterior root; s.p., septum posticum ; p.m., pia mater ; l.d., ligamentum denticulatum. The arachnoid (arach.), dura mater (dura ru.), and subarachnoid space are shown. of injury, that the spinal cord does not occupy that part of the vertebral pillar which joins the base of the column, and which permits not only of considerable movement, but is liable also to frequent wrenches and strains. It is important to recollect that although the cord itself ends at the spot indicated, the dura mater, the arachnoid, and the collection of cerebro-spinal fluid extend as far as the third piece of the sacrum (Fig. 107). Injuries inflicted, therefore, upon the spine as Chap. XXIV] THE SPINE 611 low down as this latter point may cause death by inducing inflammation of the meninges. The cord in the dorsal region measures about 10 mm. from side to side, and 8 mm. in the antero-posterior direction. The cervical enlargement is largest opposite the fifth or sixth cervical vertebrae, where it measures about 13 mm. from side to side. The greatest part of the lumbar enlargement is op- posite the twelfth dorsal vertebra, where its lateral measurement is about 12 mm. The spinal dura mater is a strong and sub- stantial membrane, and between it and the walls of the vertebral canal a considerable space exists occupied by loose areolar tissue and a plexus of veins (Fig. 106). It is tough, and may remain undamaged when the cord is completely severed by a crushing force. It will be readily understood that injury and inflammation of the meninges, as results of lesions applied to the spine, are much less frequent than are like complications after injuries to the skull. The looseness of the spinal dura mater, its freedom from any but slight and occasional attachments to the bone, and the space around it in which effusions can extend with little possibility of becoming limited, will explain the rarity in the spine of those complications which follow upon depressed bone and extravasations of pus and blood in connection with the dura mater within the skull. The plexus of thin-walled veins that occupies the interval between the theca and the bones may prove a source of extensive haemor- rhage in cases of injury to the column. The blood so poured out tends to gravitate to the lowest part of the canal, and when sufficient in quantity may produce pressure effects upon the medulla spinalis. Over the arches at the posterior aspect of the vertebrae is situate a plexus of vessels (the dorsal spinal veins) that receives blood from the muscles and integuments of the back. These vessels com- municate through the ligamenta subflava with the venous plexuses within the spinal canal, and by 612 SURGICAL APPLIED ANATOMY [Part VI means of this communication inflammation from without may be conducted to the theca of the cord. Thus spinal meningitis has followed upon deep bed-sores, and upon suppurative affections situated in the immediate vicinity of the spinal laminae. Within the dura mater are two spaces, the sub- dural and the subarachnoid, as in the skull. The arachnoid is closely applied to the dura mater, the subdural being merely a potential space, while the subarachnoid is extensive and occupied by cerebro-spinal fluid (Fig. 106), which surrounds the cord and is continuous with the great sub- arachnoid spaces at the base of the brain (Fig. 9, p. 35). By means of this open communi- cation inflammatory affections may readily spread from the cord to the brain. Into these spaces blood may be extravasated in cases of injury. In- stances have been re- corded where the theca has been opened by a wound, and the cere- bro-spinal fluid has escaped in large quan- tities. The fluid nor- mally contains .05 per cent, of albumen, but if the membranes are inflamed the percent- age is double that amount. In certain conditions the pres- sure of the fluid may rise to such an extent as to cause death. In normal conditions the fluid is absorbed at any pressure above that of the surrounding veins (Hill). In the recumbent posture the pressure Roots Fig. 107. — Vertical section of the lower part of the spinal column to show the position and extent of the subarachnoid space. The arfowjsnows the point for lumbar puncture. Chap. XXIV] THE SPINE 613 should support a column of water 2 inches high. In disease it may rise to ten times that amount. The pressure may be relieved by a lumbar punc- ture, made by thrusting a needle 8-10 cm. long into the subarachnoid space in the lumbar region of the spine. A point is selected between the third and fourth lumbar spines, exactly in the middle line, because here the interlaminar spaces are widest and the danger of wounding blood-vessels and nerve-roots is less than if a lateral point is selected. The interlaminar space is much in- creased when the spine is bent forwards. The needle perforates the ligamentum subflavum be- tween the lamina?. Convulsions follow if the pres- sure be reduced much below the normal. At this level the cord cannot be injured, but the needle may pierce one of th'3 lower nerve-roots, giving rise to twitching in some of the. muscles of the lower extremity. The injection of stovaine or allied substances into the subarachnoid space to produce spinal analgesia is performed at the same point as lumbar puncture. The injection should not be made until the cerebro-spinal fluid escapes freely from the cannula when the needle is with- drawn, for unless this occurs the cannula is not yet within the subarachnoid space. Mr. Barker has pointed out that the lowest part of the sub- arachnoid space when the body is supine is that situated in the mid-dorsal region, and that there- fore a fluid which is of greater specific gravity than that of the cerebro-spinal fluid (1.007) will tend, if injected in the lumbar region, to gravi- tate to that part. The position of the cord is such that it is not readily reached in incised and punctured wounds. The only spots at which it is easy of access are the intervals between the atlas and occiput and the atlas and axis. Many cases have been recorded of fatal wound of the cord in these positions. Lower down in the column the medulla spinalis may be reached if the wound have a certain direction. Thus a case is reported where a pointed body 614 SURGICAL APPLIED ANATOMY [Part VI entered the canal between the ninth and tenth dorsal vertebrae, having been introduced from below upwards. Several examples of damage to the cord by sword or bayonet wounds have been put on record, but in most of these instances the wound was associated with some fracture of the protecting bone. The pia mater forms a strengthening sheath for the cord. On it the arteries ramify before entering to supply its substance. The vertebral, intercostal, lumbar, ilio-lumbar, and lateral sacral arteries send twigs along the nerve-roots to the cord. Concussion of the cord. — After certain in- juries to the back a train of symptoms, usually of a severe and complicated character, has been de- scribed, which has been assigned to a concussion or shaking of the spinal cord. In these injuries it is assumed that, as a result of a sudden shock transmitted to it, the cord undergoes certain molecular changes, which lead to a more or less severe disturbance of its func- tion. The condition has been compared to con- cussion of the brain, although it must be owned that the symptoms often accredited to concussion of the cord have a character more complex than those seen in like lesions of the more complex organ. A great many surgeons are inclined to dispute the existence of this lesion, or rather decline to recognise the connection between a certain train of symptoms and a simple molecular disturbance of the cord. _ It is very probable that in many of the reputed instances of cord-concussion the symp- toms (if we except such as are assumed and such as depend upon changes in the brain) are due to a more distinct damage to the medulla spinalis, to haemorrhages, to pressure, and to other gross changes. Without entering into any discussion upon the subject, it may be sufficient to point out some of the anatomical ^objections that appear to Chap. XXIV] THE SPINE" 615 oppose themselves to the common conception of concussion of the cord. The spinal cord is swung or suspended in its bony canal, and is separated from the walls of that canal on all sides by a con- siderable interval. It is, indeed, only lield in position by the nerve trunks that pass out from it through' the intervertebral foramina, and by its connections with the theca. Above, it is connected with that part of the brain that lies upon the largest intracranial collection of the cerebro- spinal fluid (p. 35), and it would appear that the most violent movements possible of the brain within the skull could be but very feebly communi- cated to the spinal cord. The cord, moreover, within its theca, is surrounded on all sides by a space occupied by cerebro-spinal fluid. It is diffi- cult to understand, therefore, how a structure so protected can be so violently disturbed by a shock received upon the body as to undergo a grave and progressive loss of function. The cord is, indeed, somewhat in the position _ of a caterpillar sus- pended by a thread in a phial of water. It would probablv be difficult to permanently disturb the internal economy of such an insect (even if it had a structure as elaborate as the cord) by other than violence that would be comparatively excessive. Coutusioii and crushing of the cord.— As has already been observed, the _ gravity of frac- tures and clislocations of the spine depends upon the extent of the damage received by the cord. In these accidents it is very usual for some_ part of the injured verte'brse to be projected into the spinal canal, so as to press upon or actually crush the delicate nerve centre that it contains. It is needless to observe that the cord is ex- tremelv soft, and thus it happens that it may be entirely broken up by violence without the mem- branes being perceptibly damaged. Indeed, in fracture-dislocations it is unusual for the theca to be torn, and it is possible for the cord to be quite crushed at some one spot without the corre- sponding pia mater being in any way lacerated. 616 SURGICAL APPLIED ANATOMY [Part VI The amount of damage inflicted upon the cord will vary, of course, with the magnitude of the accident ; but, other things being equal, it will be found to be more severely injured in fracture- dislocations of the cervical and dorsal segments than in like lesions in the lumbar spine. In the atlanto-axial region the amount of displacement that follows upon luxation of the two bones from one another is such that the cord is, as a rule, severely crushed, and death ensues instantaneously, as is seen in cases of death by hanging. In the cervical and upper dorsal segments of the column the vertebral bodies are small, the spine is mobile, the fractures met with in the parts are usually due to indirect violence, and are associated with much displacement. In the lower dorsal region, again, the greater rigidity of the spine renders any dis- placement, when it does occur, likely to be con- siderable. In the lumbar region, on the other hand, it must be noted that the cord only extends to the lower border of the first vertebra. The bodies of the vertebrae, also, in this district, are very large and cancellous, and can undergo a severe amount of crushing without a correspond- ing degree of displacement being produced. The part is also well protected by the large interverte- bral discs, and by the immense masses of muscle that surround the spine in the loins. Such por- tion also of the spinal cord as extends into the lumbar region is protected by the many cords of the cauda equina, which, by their looseness and comparative toughness, tend to minimise the effects of violence. The degree of displacement of bone required to produce pressure effects upon the cord is often greater than would be supposed. At post-mortem examinations portions of injured vertebrae have been found encroaching upon the spinal canal to a considerable extent in cases where no evidences of damage to the cord existed during life. Dr. J. W. Ogle reports the case of a man who, after an injury to the neck from a fall, presented no Chap. XXIV] THE SPINE 617 spinal symptoms until three days had elapsed. He ultimately became paralysed, and died thirty- bwo days after the accident. The autopsy revealed a dislocation forwards of the sixth cervical verte- bra, of such an extent that the body below pro- jected at least i- an inch into the spinal canal. The remarkable manner in which the cord will accommodate itself to a slowly progressing pres- sure is often well seen in the results of chronic bone disease in the column. The symptoms due to injury to the cord and to the nerves contained in the spinal canal will ob- viously depend upon the situation and extent of the lesion. The diagnosis of the situation of the lesion is complicated by the relation the nerves bear to the various vertebrae, and by the fact that the majority of the great trunks arise from the cord at a spot above the point at which they issue from the vertebral canal. The two highest nerves, the first and second cervical, pursue an almost hcrizontal course in their passage from the cord to their points of exit from the canal. The re- maining nerves take a more and more oblique direction, until at last the lowest nerve trunks run nearly vertically downwards as they pass to their respective intervertebral foramina. Points of exit. — The first cervical nerve leaves the canal above the first cervical vertebra. The remaining cervical trunks escape also above the vertebrae after which they are named, the eighth cervical nerve leaving the canal between the last cervical and the first dorsal vertebras. The dorsal, lumbar, and sacral nerves have their points of exit below the vertebrae after which they are named. Thus, the first dorsal nerve will pass through the foramen between the first and second dorsal vertebrae, and so on. Points of Origin from the Corel. The first cervical nerve arises from the cord opposite the interval between the atlas and occijjut. The second and third cervical nerves arise from the cord opposite the axis. 618 SURGICAL APPLIED ANATOMY [Part VI The fourth, fifth, sixth, seventh, and eighth cervical nerves arise from the cord opposite the third, fourth, fifth, sixth, and seventh vertebrae respectively. The first four dorsal nerves arise from the cord opposite the discs below the seventh cervical and the first, second, and third dorsal vertebra? respectively. The fifth and sixth dorsal nerves arise from the cord opposite the lower borders of the fourth and fifth vertebrae. The remaining six dorsal nerves arise from the cord opposite the bodies of the sixth, seventh, eighth, ninth, tenth, and eleventh vertebrae. The first three lumbar nerves arise from the cord opposite the twelfth dorsal vertebra. The fourth lumbar nerve arises from the cord opposite the disc between the twelfth dorsal and first lumbar vertebrae. The last lumbar nerve, together with the sacral and coccygeal nerves, arises from the cord opposite the first lumbar vertebra. It will be seen, therefore, that in noting the symptoms due to crushing of the entire nerve contents of the vertebral canal at a certain spot, consideration must be taken, not only of the effects of damaging the medulla at that point, but also of the result of lacerating nerve-trunks that may issue there, although their origins are above the seat of lesion. The cord is also very often only damaged in part, or it may entirely escape, while one or more nerves are crushed by the fractured vertebrae or by fragments of bone separated by the lesion. In fracture-dislocations the upper vertebral body, as already stated, usually glides forward, with the result that the anterior and antero- lateral parts of the cord are brought into violent contact with the projecting border of the ver- tebra below the seat of lesion. It is in these parts of the cord that the main motor tracts run, and thus it happens that motion is more often lost in the parts below the site of the injury than is sensation. If there be partial motor and sensory paralysis, the disturbance of the former function is likely to be in excess of that of the latter. In no case, indeed, does there appear to have been a loss of sensation without, at the same time, some disturbance in the powers of Chap. XXIV] THE SPINE 619 movement. If the grey matter of the cord be not severely damaged, reflex movements appertaining to that segment of the cord can usually be induced in the paralysed parts by proper stimulation. If those reflex movements be lost, it may be inferred that the grey matter is broken up, and that the entire spinal medulla has been crushed at the seat of lesion. The higher up the fracture in the column the greater is the tendency for the function of respira- tion to be interfered with. If the lesion be at the upper end of the dorsal spine, then not only will all the abdominal muscles be paralysed, but also all the intercostals. A fracture associated with injury to the cord, when above the fourth cervical vertebra, is, as a rule, instantaneously fatal. The phrenic nerve comes off mainly from the fourth cervical nerve, receiving contributions also from the third and fifth. The fourth nerve issues just above the fourth cervical vertebra. If the cord be damaged immediately below this spot, the patient can breathe only by means of the dia- phragm, and if the lesion be so high as to destroy the main contribution to the phrenic, respiration of any kind becomes impossible. Certain disturbances of the act of micturition are frequent in cases of injury to the cord. The reflex centre for this act is lodged in the lumbar enlargement. The irritation of the vesical walls, produced by the increasing distension of the bladder, provides the needful sensory impulse. This impulse is reflected to the nerves controlling the bladder muscles, and especially to the detrusor urinse, and by their contraction the organ is emptied (p. 448). The action, however, can be to some extent inhibited by influences passing down from the brain to the lumbar centre, and the tendency to a frequent discharge of urine is re- sisted by contraction of the sphincter. When, therefore, any part of the cord is damaged that lies between the lumbar centre and the brain, in- hibition can have no effect. Immediately after 620 SURGICAL APPLIED ANATOMY [Part VI the accident the temporary suspension of reflex actions from shock produces some retention of urine, and after that the bladder empties itself at frequent intervals, the patient being unconscious of the act and unable to influence it. If the centre itself be damaged in the lumbar cord, the patient, after a little retention, will suffer from absolute incontinence ; and a like result will follow if the nerve connections between the cord and bladder below the spinal centre have been destroyed. The principal nerves connecting the medulla spinalis with the bladder are the third and fourth sacral. The act of defsecation also is apt to be dis- turbed in a like manner. Here there is, as in the previous case, a reflex centre in the lumbar en- largement, with motor and sensory nerves connect- ing it below with the rectum and its muscles ; and also between this centre and the brain are tracts, but little known, along which inhibitory actions can extend. When the centre itself is damaged, or the con- nection severed that unites it with the viscus, the patient will suffer from incontinence of faeces and will be unable in any way to control the act. When the cord is damaged at any spot between the centre and the brain, then the act of defsecation will be performed at regular intervals, without either the patient being conscious of the act or being capable of inhibiting it. In some injuries to the cervical cord the patient has suffered from severe vomiting for some time after the accident, or has exhibited a remark- able alteration in the action of his heart. Mr. Erichsen, for example, reports the case of a man who, after a severe blow upon the cervical spine, continued to vomit daily for several months. In the other category, instances have been recorded where the pulse has sunk as low as 48, or even as 36 or 20, after lesions to the column in the neck. These changes are supposed to be due to dis- turbance of the vagus, and it is further suggested Chap. XXIV] THE SPINE 621 that the morbid influence is conveyed to the vagus by the spinal accessory nerve with which it is so freely associated. It should be remembered that the spinal acces- sory trunk has origin from the cord as low down as the sixth or seventh cervical nerves. Some de- tails concerning the position of centres in the spinal cord, connected with areas of skin, groups of muscles and viscera, have been given already when dealing with the nerve supplies of the ex- tremities and abdomen (see pp. 337 and 594). Spina bifida, — This term refers to certain congenital malformations of the vertebral canal associated with the protrusion of some of its con- tents in the form of a fluid tumour. The mal- formation usually consists in an absence of the neural arches and spines of certain of the verte- brae, and the tumour therefore projects pos- teriorly. Spina bifida is most common in the lumbo-sacral region, the neural arches of the last lumbar and of all the sacral vertebrae being ab- sent. The neural arches close first in the dorsal and last in the lumbo-sacral region. Next in fre- quency it is found limited to the sacral region. It is rare elsewhere. (1) The membranes may protrude alone (spinal meningocele). (2) The membrane may protrude together with the spinal cord and its nerves (meningo-myelocele). (3) The membranes may protrude with the cord, the central canal of which is dilated, so as to form a sac cavity (syringo-myocele). {See Fig. 107, p. 612.) The meningo-myelocele is the most common form. The first-named variety is rare, the last- named very rare. When the cord occupies the sac it usually adheres to its posterior wall, the nerves running transversely^ across the sac to reach the intervertebral foramina. When compressed, the cerebro-spinal fluid is forced into the subarach- noid spaces at the base of the brain, which is forced upwards against the anterior fontanelle, where its impact may be felt. The tumour be- comes enlarged and tense when the child cries. 622 SURGICAL APPLIED ANATOMY [Part VI The distension of the cerebral and spinal veins forces the fluid in the direction of least resistance. As might be expected, spina bifida is very com- monly associated with some evidence of injury to the nerves arising from the lower part of the spinal cord. The defect occurs at an extremely early stage of development, and hence part of the cord or of the nerves in the region of the tumour may be absent or defectively developed. In some cases the nerve affection takes the form of club-foot of a severe grade. In other instances there is more or . less complete paralysis of the lower limbs, bladder, and rectum. Operations upon the cord. — Sir Victor Horsley and others have cut down upon the spine and removed a tumour from the spinal cord with perfect success, and with relief to the symp- toms from which the patient was suffering. The spinal canal has also been exposed in certain cases where callus in an old fracture of the spine was pressing upon the cord, or where a small osseous growth was encroaching on the canal. INDEX Abdomen, blood-vessels of, 324, 332, 421 , blows on the, 326 , congenital deformities of the, 338 , fascia of, 325 , lymphatics of the, 332 , nerves of, 333, 418 , parietes of, 321, 324, 330, 353 , skin of the, 325 , surface anatomy of the, 321 , wounds of the, 331 - Abdominal belt," 325 ■ , connective tissue and abscesses, 330 ■ rings, 338, 341 viscera, nerve supply of, 337, 418 ■ , support of, 367 ■ . surface markings of, 364 Abscess, alveolar, 136 , axillary, 234 , cervical, 167 , gluteal, 481 , hepatic, 399 , iliac, 331, 354 in antrum, 109 in mastoid cells, 87 in the abdominal parietes, 331, 353 in the scalp, 6 in the temporal fossa, 8 , intercostal, 201 . ischio-rectal, 436 , lumbar, 353, 357 , mammary, 205 , mediastinal, 167, 213 , orbital, 52 , palmar, 300 , parotid, 122 , pelvic, 428, 431 Abscess, perinephritic, 411 , perityphlitic, o85 , plantar, 566 , popliteal, 528 , post-pharyngeal, 153 , prostatic, 452 , psoas, 355, 489 , renal, 411 , retroperitoneal, 354 , thecal, 303 Acetabulum, 427, 494, , fractures of, 427 Acromio-clavicular joint, 214, 227 , dislocations of, 229 Acromio-thoracic artery, 216, 218 Acromion process, fracture of, 230 Addison's disease, 419 Adductor longus muscle, 486 ■ tubercle, 524 Adenoids, 153 Air in veins, 189, 237 ■ sac in neck, 194 " Alderman's nerve," 82 Alveolar abscess, 136 Amputation (see Arm, Leg, etc., amputation of, etc.) Anal canal, 470 triangle, 433 ■ valves, 474 Angulus Ludovici, 198 Anastomoses between tribu- taries of superior and in- ferior venae cavae, 213, 322 ■ portal and systemic veins, 360, 422 Anastomotica magna, 525 Aneurism, aortic, 188, 421 •, axillary, 237 in the neck, 188 ■ of the posterior tibial artery, 553 1 popliteal, 530 623 624 SUEGICAL APPLIED ANATOMY Ankle, 561 , fasciae of, 565. joint, 562, 570 ■ , amputation at, 591 , disease of, 5/1 ■ , dislocations at, 572 , fractures about, 572 , nerve supply, 572 , sprains of, 567 , surface anatomy of, 561 , tendons of, 562 Annular ligaments of ankle, 566 ■ of wrist, 300 Anterior crural nerve, 491, 594 Anticlinal spine, 207 Antrum of Highmore, 109 of mastoid. 87 Anus, 434, 474 imperforate, 475 Aorta, abdominal, 324, 420 thoracic, 188, 211 Aponeuroses (see Fasciae) Appendicitis, 385 Appendix vermiformis, 382, 385 , lymphatics of, 386 Aqueous humour, 69 Arachnoid, 34, 611 Arcus senilis, 58 Arm, 256 , amputation of, 261 , fascia of, 257 , lymphatics of, 269 , nerves of, 313 , skin of, 256 ■ — — , surface anatomy of, 255 Arnold's nerve, 81 Arteries (see Axillary, etc., and Blood-vessels) Arterio-venous aneurisms, 53, 268, 490 Aryteno-epiglottidean folds, 152, 173 Astragalus, dislocations of, 579 , fractures of, 587 Atlas, 152 Atlo-axial portion of spine, 604 Attic of tympanum.. 84, 87 Auditoi'y meatus, external, 79 — — , its relations, 80 Auricle (see Ear) Auricles, supernumerary, 78, 194 Axilla, 217, 233 , suspensory ligament of. 234 Axillary abscess, 234 Axillary artery, 217, 237, 250 fasciae, 167, 233 glands, 204, 217, 235 • nerves, 240 vein, 236 Axis, 152 Azygos veins, 213 Bartholin's glands, 466 Basal gangli, 42 Base of skull, fractures of, 27 Basilic vein, 264 Biceps tendon in arm, 243, 262 ■ ■ ham, 529 Bile duct, rupture of the, 401 , relationships of, 400 Bladder, 420, 443 , cystoscopic examination of, 447 development of, 329 distension of, 444 double, 449 extroversion of, 338 fasciculated, 448 female, 449 foreign bodies in, 449 found in hernias, 445 male, 443 mucous membrane of the, 447 nerves of, 448, 476 of child, 450 puncture of, above pubes, 444 , per rectum, 446 relations to the peri- toneum, 443, 444, 445 rupture of the, 446 sacculated, 448 - stabbed through but- tock, 486 , stone in the, 438 Blood-vessels of abdomen, 324, 332, 421 of abdominal walls, 332 of auditory meatus, 79 ■ of brain, 44 ■ of breast, 205 ■ of buttock, 480, 483 • of eye, 61 ■ of foot, 563, 569 of hand, 295, 304 of heel, 591 ■ of knee. 529 of leg, 553 ■ of nasal cavities, of neck, 160, 187 of orbit, 53 of palate, 151 103 INDEX 625 Blood-vessels of pelvis, 433 of perineum, 434 of pinna, 81 of rectum, 472 of retina, 62 of scalp, 13 of spinal cord, 614 of Scarpa's triangle, 490 of spermatic cord, 465 of tympanum, 92 Bones, nerve-supply of, 320 Brachial artery. 256, 258, 269 , abnormalities of, 258 in phlebotomy, 264, 267 , ligature of, 258 fascia, 256 plexus, 162, 238, 314 Brachialis anticus, 257 Brain, 33, 42, 44 ■ and skull relations, 37 , basal ganglia of, 42 , blood-vessels of the, 45 , concussion of the, 44 , convolutions of, 38 , cortex of, 42 , fissures of, 38 , injuries to, 44 , membranes of, 31 ■ , motor centres of, 38, 42 . surface relationships of, 37 Branchial fistulae, 78, 193 Brasdor's operation, 187 Breast (see Mamma), 202 Bregma, 17 Broca's convolution, 41 Bronchi, 174 , foreign bodies in, 180, 210 Bronchial lymphatic glands, 185 Bronchocele, 181 Brunner's glands, 379 Bryant's method of dividing the muscles of the palate, 151 Buccal cavity, 138 ■ in embryo, 148 nerve, 117 Bulla ethmoidalis, 101 Bunions, 568 Bursae about the elbow, 271 ~> foot, 567 hyoid, 172 • ham, 531 shoulder, 243 over the great tro- chanter, 482 2 Bursse over the ischial tuber- osity, 483 knee-joint, 527, 531 , patellar, 527 , subacromial, 243 , subpsoal, 489 Buttocks, 478 arteries and nerves of the, 480, 483 fascia of, 481 , fold of, 479 , surface anatomy of, 478 Caecum, 382, 392 , foreign bodies in, 384 , hernia of, 384 in intestinal obstruction, 384 , movements of, 384 , opening of, 394 -, position of, 382 Caesarian section, 427 Oalcaneo-astragaloid joint, 578 Oalcaneo-cuboid articulation, 580 Calcaneo-scaphoid ligament, 584 Calcar femorale, 503 Canal of Nuck, hernia in, 346 Capsule of Tenon, 50 Cardiac orifice of stomach, 368 Carotid artery, 86, 156, 160, 187, 188 , aneurism of, 187 , destroyed by abs- cess, 167 ■ •, external, 123 , ligature of, 187 , sheath of, 167 , wounds of, 170 tubercle, 158, 189 Carpo-metacarpal joints, 308 Carpus, fracture of, 310 Castration, 454, 465 Cataract, 67 Catheterism of Eustachian tube, 90 Of urethra, 455 Cavernous sinus, 33, 54 Centre of gravity of an adult body, 426 Cephalhsematomata, 7 Cephalic vein, 219, 264, 267 Cerebellum, point for trephin- ing, 11 , lesions of, 47 Cerebral circulation, 36, 44 localisation, 38, 42 626 SURGICAL APPLIED ANATOMY Cerebrospinal fluid, 29, 36, 99, 612 Cervical (see Neck) ribs, 169 sinus, 194 sympathetic, paralysis of, 55 Cervico-dorsal part of spine, 604 Check ligaments, 51 Cheloid, its frequent seat, 197 Cholecystectomy, 403 Oholecystenterostomy, 403 Cholecystotomy, 402 Chopart's operation, 592 Chorda tympani, 84, 92 Choroid, 58 Ciliary zone, 65 Circumcision, 458 Circumcorneal zone, 66 Circumflex artery, external, rupture of, 518 , internal, wound of, 518 , posterior, 218, 241 ■ nerve, 218, 241 Cirsoid aneurism, 13 Cisternal of brain, 34 Clavicle, 214, 219 , absence of, 224 , dislocations of, 226, 229 , excision of, 220 , fractures of, 220 , movements of, 228 , ossification of, 224 , relations of, 218, 223 Cleft palate, 147 Clergyman's sore throat, 175 Club-foot, 581 Coccygeus, 430 Coccygodynia, 430 Coccyx, 430 Cceliac axis, 324, 421 Colectomy, 394 Colles' fascia, 437 fracture, 308 Coloboma iridis, 61 Colon, 387 , antiperistalsis in, 471 , ascending, 388 , descending, 388, 393 •, iliac, 388 ■ , malformation of, 390, 392 — — , operations on, 394 , stricture of, 388 , transverse, 388 Colotomy, iliac, 392, 394 , lumbar, 388, 392 Compression of brain, 32 of cord, 611, 616 Concussion of brain, 44 of cord, 614 Congenital club-foot, 520 exomphalos, 328, 338 fistuhe, 78, 194 hernia, 328, 338 hydrocele, 345 malformations of anus and rectum, 475 malformations of blad- der, 329, 338 ■ malformations of colon, 391 malformations of penis, 338 tumour of sterno-mas- toid, 164 Conjunctiva, 74 Convolutions of brain, motor centres on, 42 , relations of, 37 Coraco-acromial arch, 242 Coraco-clavicular ligaments, 221, 228 Coracoid process, 216 , fracture of, 231 Cornea, 56 Coronal suture, 18 Coronoid process of ulna, 264, 279 of mandible, 140 Corpus striatum, 42 Costo-vertebral ligament, 415 Coxa vara, 505 Cowper's glands, 466 Cranial nerves, 54 Craniectomy, 30 Cranio-tabes, 18 Cranium (see Skull) Cremaster muscle, 464 ' Cremasteric artery, 464 reflex, 464 Cribriform plate, 99 Cricoid cartilage, 173 Crico-thyroid space, 177 Crucial ligaments, 536 Crural canal, 347 sheath, 353 Crutch paralysis, 259 Cuboid bone, 587 Cuneiform bone, inner, 561 , , dislocation of the, 587 , , fracture of the, 587 Cut throat, 170 Cystic duct, 400 INDEX 627 Dartos, 325 Deltoid muscle, 240, 255 region, 215, 240 tubercle, 214 Descending palatine artery, 149 Diploic veins, 14 Dislocation (see the several bones and joints) Dorsalis pedis artery, 570 Dorso-lumbar part of spine, 604 Drop-wrist, 318 Duodenal fossa, 379 Duodenum, 378 , suspensory muscle of, 379 Duchenne's palsy, 239 Dupuytren's contraction, 298 ■ fracture, 575 Dura mater, 31, 611 Ear, 78 , bleeding from, in frac- tures of base of skull, 29 , blood supplv of, 81 , coughing, 82 , external, 78 , hsematomata of, 81 , nerves" of, 81 , ossicles of, 84, 85 . watery discharge from, 29 , yawning, 82 Ectopia vesicae, 338, 471 Elbow, 262, 264 , bursas about, 271 , dislocations of the, 272 , fold of the. 262 , fractures about, 276 , gland of. 269 joint, 269 ■ , disease of, 271 , sprains of. 271, 275 , ligaments of, 271 , resection of the, 280 , surface anatomy of the, 263 . veins about, 267 Elephantiasis arabum. 493 Emissary veins of skull, 13 . Emphysema, surgical, 208 Encephalocele. 19 Encysted hydrocele of the cord, 345 Enterectomy, 381 Enteroraphy, 381 Enterotomy, 381 Epicondyles, 277 Epicritic sensibility, 117, 319 Epididymis, 463 Epiphysis, lower, of femur in excision of knee, 548 , , in knock-knee, 539 of acromion, separation of, 231 of clavicle, separation of, 224 of coracoid process, 231 of femur, separation of, 500, 505, 548 of humerus, separation of, 252, 278 of olecranon, 279 of pelvis, separation of, 427 of radius, separation of, 280, 310 tibia, separation of, 548, 558 of third phalanx in whit- low, 304 of upper limb, 320 Epipteric bone, 21 Epispadias, 459 Epistaxis, 104 Erb's palsy, 239, 314 Erector spinae, 602 Estlander's operation, 201 Ethmoidal cells, 101 Eustachian catheter, to pass, 91 tube, 89 Eversion, movements of, 578 Excision (see special parts) External auditory meatus, 78 — — , blood supply of, 81 , nerve supply of, 81 carotid, bleeding from, 189 pterygoid, action of, 132 Extravasation of urine, 324, 437 Eye-baH, 48 , blood supply of the, 61 , dangerous area of, 65 , nerves of the, 63 Eyelids, 71 Face, 111 — , development of, 114 , injuries to, 112 , nerves of, 115 , vessels of, 112 Facial artery, 113, 160 nerve, 86, 124 628 STJKGICAL APPLIED ANATOMY Fallopius, aqueduct of, 85 Fascia, abdominal, 325 , axillary, 233 , bicipital, 263, 267 , cervical, 164 , clavi-pectoral, 233 , iliac, 353 lata, 481, 488, 516 lumborum, 356 obturator, 431 of arm. 257 of buttock, 481 of Oolles, 437 of deltoid region, 240 ■ of foot. 565 of leg, 552 — of palm, 298 of scalp, 1, 6 of Scarpa's triangle, 488 ■ of tbigb, 481, 488, 516 .orbital, 50 , palmar, 298 , parotid, 122 , pectoral, 233 •, pelvic, 430 ■, perineal, 437 , popliteal, 528 , prevertebral, 166 , recto-vesical, 431 , temporal, 7 -, transversalis, 353 Femoral hernia, 347, 352 point, 340 vessels, 487, 490, 518, 525 Femur, dislocations of, 506, 544 , epiphyses of, 500, 505, 548 , fractures of, 502, 504, 518, 545 , neck of. 502 Fenestra ovalis, 85 rotunda, 85 Fergusson's method of divid- ing the muscles of the palate, 150 Fibula, 550, 556 . fractures of, 558, 573 Fifth nerve, 15, 55, 82, 95, 115, 134 , section of, 117 Finger, " snap," 301 , little, congenital con- traction of, 301 , " mallet." 508 Fissure of Rolando, 38 ■ ■ Sylvius, 40 Fissures of brain, 38 , parietal, 21 Fistula at the navel, 329 Fistula between the gall blad- der and gut, 401 , congenital, 78, 193 , gastric, 370 in ano, 436 , lachrymal, 77 , salivary, 127 , vesico-vaginal, 467 , umbilical, 329 Plat-foot, 583 Pontana, spaces of, 69 Fontanelle, sagittal, 21 , temporary occipital, 20 Fontanelles, 17 Foot, abscess of, 566 , amputations of, 591 — — , arches of, 576 , blood-vessels bf, 563, 569 , chief joints of, 578 , dislocations of, 579, 586 , fasciae of, 565 , fractures of, 586 , imprints of, 587 , integuments of. 564 , lymphatics of, 570 , movements of, 578 , nerves of, 564 , surface anatomy of, 561 , synovial membranes of, 589 , the, 517, 561, 564 Foramen caecum of tongue, 145 of Majendie, 36 of Monro, 36 Foramen ovale, surface mark- ing of. 117 Forearm, 282 , amputation of the, 288 , bones of the, 284 , fractures of the, 286 , luxations of the, 273 -. surface anatomy of the, 282 -, vessels of the, 283 Fossa duodeno-jejunalis, 379 , ischio-reetal, 435 , nasal, 100 of Rosenmuller, 91 -, subclavicular, 216 ■ in region of caecum, 386 Fracture (see the several bones) Fraenum linguae, 141 Frontal sinus, 106 . infundibulum of, 101, 107 Gall bladder, 396, 400 INDEX G29 Gall bladder, arteries of, 400 — , fundus of, 396 -, nerve supply of, 401 -, operations on, 402 -, rupture of the, 401 — obstructed by mov- able kidney, 364 -, veins of, 400 - stones, 354, 400 Gasserian ganglion affected by abscess spreading from parotid, 123 , position of, 13 , removal of, 119 Gastrectomy, 373 Gastrocnemius muscle, 551 , rupture of the, 553 Gastro-enterostomy, 374 Gastroplication, 374 Gastrostomy, 372 Gastrotomy, 372 Generative organs, female, 466 ■ , male, 458 Genito-crural nerve, 464, 491 Genu-valgum, 539 Gimbernat's ligament, 349 Gladiolus, 196 Glans penis, 459 Glaucoma, 58, 70 Glottis, 159, 174 Gluteal abscess, 481 ■ aneurisms, 483 artery, 480, 483 bursae, 482 fascia, 480 fold, 479 region, 478 Gluteus maximus, 482 ■ , rupture of, 482 Great toe, dislocation of, 588 Groin, lymphatics of, 491 , pains referred to, 420 , region of, 486 Gubernaculum testis, 343 Gullet (see Oesophagus) Gums, 140 Gustatory nerve, Moore's method of dividing the, 140 Hsematomata of scalp, 7 on septum nasi, 100 on the pinna, 81 Haemorrhage from choroid, 59 from fraenum linguae, 141 from intercostal vessels, 201 from tongue, 142 from tonsil, 156 f Haemorrhage in lithotomy, 440 I ■ into vitreous, 63 in tracheotomy, 179 , meningeal, 32 Haemorrhoidal vessels and nerves, 436, 472 Haemothorax, 208 Hallux rigidus, 589 valgus, 589 Hammer toe, 589 Hamstring muscles, 524, 529 Hand, 290 -, amputation of, 313 , blood-vessels and lym- phatics of, 295, 304 , dislocations of, 311 ■, fasciae of, 298 , surface anatomy of, 292 , synovial sheaths of, 302 Hanging, mode of death from, 616 Hard palate, 149 Hare-lip, 148 Heart, 210 , its relation to the sur- face, 210 , wounds of, 211 Heel, blood-vessels of, 591 , integuments of, 591 Helicoidal fractures of Leriche, 520, 557 Hernia, congenital, 329, 339, 342 , diaphragmatic, 351 , direct, 341 ■ , encysted, 345 , fatty, 327 , femoral, 347 , infantile, 345 , inguinal, 338, 345 into the funicular pro- cess, 345 -, ischio-rectal, 351 , lumbar, 351 , mesenteric, 380 , obturator, 350 , omental, 360 , perineal, 351 , pudendal, 351 , rare forms of, 351 , retroperitoneal, 380 , sciatic, 351 , umbilical, 329, 351 , vaginal, 467 Hernial sacs, 338, 352 Herniotomy, 347 Hesselbach's triangle, 341 Hiatus semilunaris, 101 Hip, dislocations of, 507 630 SURGICAL APPLIED ANATOMY Hip joint, 479, 494 , amputation at the, 513 ■ , congenital disloca- tions of, 506 , disease, 495, 500 ■ , fractures about, 502 , movements of, 495 , nerve supply, 500 • , region of the, 478 Holden's line, 486 Hottentot Venus, 480 Human tails, 429 Humerus, dislocations of, 215, 241 , fractures of, 251, 259, 276 ■ , of, non-union after, 260 Hunter's canal, 518 Hyaloid membrane, 70 artery, 70 Hydrencephalocele, 19 Hydrocele, 345, 462 of the neck, 194 Hydrocephalus, 17, 37 Hyoid bone, 159, 172 ■ , accessory glands about, 182 , fracture of, 172 Hypertrophy of the prostate, 451 Hypogastric line, 366 Hypoglossal nerve, 124, 143 Hypopyon, 69 Hypospadias, 459 Hypothenar eminence, 292 Hysterical hip, 501 ■ knee, 501 Ileo-csecal fossae, 386 intussusception, 386 region, 382 sphincter, 384 • valve, 386 Ileo-colic intussusception, 386 Ileum (see Intestine, small) Iliac abscess, 354 colotomy, 394 — — fascia, 353 Ilio-psoas muscle, 353, 489 Ilio-tibial band, 482, 524 Indirect hernia,. 338 Infantile hernia, 345 Inferior caval point, 211 Inferior dental nerve, dividing the, 116, 130 maxilla, deformities of, 134 , dislocations of, 132 Inferior maxilla, excision of, 133 ■ , fracture of, 129 , subluxation of the, 133 thyroid veins, 179 vena cava, 421 Infraorbital foramen, 115 artery, 115 ■ nerve, 115 Infundibulo-pelvic ligament 469 Inguinal canal, 338, 341 ■ colotomy, 392 ■ glands, 487, 491 hernia, 338, 341 Innominate artery, 187 bone, 426 Intercostal artery, 201 - spaces, 200 Intercosto-humeral nerve, 205 Internal cutaneous nerve, 268 mammary artery, 202 Interparietal bone, 21 Interscapulo-thoracic ampu- tation, 232 Intersigmoid fossa, 390 Intervertebral discs, 601 Intestine, large, 387 , operations on, 381 -, stricture of, 378 resection of, 381 small, 374 , diverticula of, 377 , injury of, 376 ■, length of, 374 , operations on, 381 , position of, 375 Intestinal anastomoses, 381 Intussusception, 386 Iridectomy, 61 Iris, 56, 58 Iritis, 60 Ischial spine as guide to ureter, 418 Ischio-rectal abscess, 436 ■ fossa, 435 hernia, 351 Isthmus of the thyroid, 182 , division of, 179, 182 Jaws (see Inferior and Superior maxilla) Jejunum (see Intestine, small) Joints, surgical classification of the, 241 Jugular vein, 86, 160, 191 INDEX 631 Keloid (see Cheloid) Kidney, 408 , abnormalities of, 413 , abscess of, 411 , hilum of, 408, 416 , borse-shoe, 413 , its relations, 408 , its support. 412 • , movable, 411 , nerve supply of, 412 •. operations on, 415 , pelvis of, 410, 417 , rupture of, 410 , vessels, point of origin of, 324 Knee, blood supply of the, 527 , bursa? about, 527, 531 , dislocations of the, 544 , fractures about, 545 , integuments of, 525 joint, 532 , amputation through, 548 , derangement of, 538 , disease of, 536 , excision of the, 547 . region of, 523 , surface anatomy of the, 523 Knock-knee, 539 Kraske's operation, 473 Kyphosis, 196, 601 Labia majora. 466 Labyrinth of ear, 92 Lachrymal abscess, 76 apparatus, 75 gland, 75 sac, 75 Lacuna magna, urethral, 458 Lambda. 17 Lambdoid suture, 17 Lamina cribrosa, 59, 71 fusca, 59 suprachoroidta, 59 Laminectomy, 609 Laryngotomy, 177 Larynx. 173 , excision of, 176 , foreign bodies in, 180 , fracture of, 173 , lymphatics of, 176 , mucous membrane of, 175 Lateral lithotomy, 435 sinus, position of, 10, 33 ventricles, 42 Leg, 550 , amputation of, 558 , fasciae of, 552 Leg, fractures of, 556 , rickets affecting bones of, 558 , skin of, 551 , surface anatomy of, 550 , vessels of, 553 Lens, 66 , artery to the, 70 Levator ani, 430, 435 , relation to fistula in ano, 436 palati, 150 palpebral, 72 Ligamentum patellae, 523, 536 pectinatum iridis, 69 Lighterman's bottom, 483 Liuea alba, 322, 327 - — - semilunaris, 322 Linsrual artery, 142, 160 nerve, 139. 140, 142 tonsil, 143 Lipomata in deltoid region, 240 in Scarpa's triangle, 488 on the buttock, 479 , rare on face, 112 Lips, 137 Lisfranc's amputation, 593 Litholapaxy. 438 Lithotomy, lateral, 438 , , in children, 441 , , parts divided in, 440 , median, 441 , suprapubic, 443 Littre's operation, 390 Liver, 395 , abscesses of, 399 , fixation of, 397 , nerve supply of, 420 , operations on, 399 in pyaemia, 399 , ptosis of, 397 , relations of, 395 , Kiedel's lobe, 397 , ruptures of, 397 , wounds of, 398 Lockjaw, 135 Longitudinal sinus, 33 Lordosis in hip disease, 497 Lower limb, length of, 520 , lymphatics of, 492 ■ , nerve supply of, 594 Lumbar colectomy, 394 colotomy, 392 fascia, 356 glands, 492 ■ hernia, 351 632 SURGICAL APPLIED ANATOMY Lumbar puncture, 613 region, 356 spine, 603 . , injuries to, 603, 616 Lung, 206 and secondary deposits, 210 cavities, drainage of, 210 hernia of, 208 in neck, 168, 206 , relations of, to surface, 206 , rupture of, 208 -, wounds of, 207, 208 Luschka's tonsil, 91, 153 Lymphangioma cavernosum, 145 Lymphatic glands and vessels (see each region) Macroglossia, 145 Malar bone, 120 , fracture of, 120 Malleoli, 561 , fractures of, in disloca- tions of the foot, 572 Mamma, 202 , arteries of, 205 , cancer of, 203 , capsule of, 203 , development of, 203 — — in groin, 488 , lymphatics of, 203, 235 , nerves of, 203 Mammary abscess, 205 Manubrium, 196 Mastication, muscles of, 135 Mastoid antrum, 87 ■ cells, 89 , perforation of, 89 Maxillae (see Inferior and Superior) Meatus, the auditory, 79 Meatuses of nose, 100 Meckel's diverticulum, 329, 377 ganglion, 115 Median basilic vein, 264, 267 Median cephalic vein, 264 Median lithotomy, 441 nerve, 281, 284, 318 Mediastina, 213 , abscess of, 167, 213 Mediotarsal joint, 580 , amputation at, 592 Meibomian glands, 73 Membrana tympani, 83 Membranous urethra. 456 Meningeal artery, 9, 32 haemorrhage, 32 Meninges of brain, 31 , spinal cord, 611 Meningitis from abscess in the ear, 80, 86, 89, 99 (spinal) from bed-sores, 612 Meningocele, 19, 96, 99, 621 Mesenteric arteries, 324, 421 hernia, 380 holes, 362 Mesentery, 360 , length of, 346, 361 , prolapse of, 361 Mesocolic hernia, 380 Mesocolon, 388 Metacarpo-phalangeal joint of thumb, dislocations at, 312 Metacarpus, fracture of, 310 Metatarsal bone of great toe, amputation of, 594 bones, fractures of the, 587 Metatarso-phalangeal articu- lations, 562 joint of great toe, dis- location at, 588 Middle meningeal artery, 32 , trephining for, 9, 10 Mid-epigastric point, 323, 365 Mid-hypogastric point, 366 Miner's elbow, 271 Monro's point, 366 Morgagni, columns of, 474 Motor centres on the cortex, 38 paralysis in injuries to cord, 618 Mouth, 138 Mucous polyp of nose, 103 Miiller's muscle, 56 Muscles, functional classifica- tion, 307 Musculo-cutaneous nerve of arm, 268 Musculo-spiral nerve, 259, 281, 318 Myxcedema, 183 Nails, 297 Nares, anterior, 96 , posterior, 97 Nasal bones, 96 -, fracture of, 96 - cavity, 96 - cavity of child, 98 - cavities, lymphatics of, 105 - , blood-vessels of, 103 INDEX 633 Nasal cavities, nerve supply of, 104 douche, 99 duct, 77, 100 . fossae, 100 mucous membrane, 102 ■ polypus, 103 sinuses, 105 Neck, 158 , abscess of, 167 , fascia? of, 164 , fistula? of, 193 , great vessels of, 160, 171 , hydrocele of, 194 — — , integuments of, 162 , lung in, 168, 206 , lymphatic glands of, 191 , middle line of, 159 , nerves of, 161 , ribs in, 169 , side of, 159 , surface anatomy of, 158 , wounds of, 170 Nelaton's line, 479 Nephrectomy, 415 Nephro-lithotomy, 415 Nephroraphy, 415 Nephrotomy. 415 Nerve stretching, 484 supply of lower limb, 594 of upper limb, 313 Nerves (see the various regions) , division of (see the various trunks) of the spinal cord, their points of exit, 616 , results of section of, 117, 318 , of anastomosis, 125, 598 to viscera, 337 Neuralgia, facial, 115 of scalp, 14 Nipple, 203 Nipples, supernumerary, 205 Nose, 94 , cartilaginous part of, 95 Obturator artery (abnormal) 349 hernia, 350 nerve, 501, 596 or thyroid dislocation, 507, 512 Occipital artery, 161 bone at birth, 19 Occipital bone, necrosis of, causing wasting of tongue, 143 glands, 191 Odontoid process, 608 CEsophagus, 184, 367 , cancer of, 186 -, foreign bodies in, 185 , malformations of, 186 , nerve supply of, 186 , relations of, 185 Olecranon, 265 , fractures of, 279 -, ossification of, 279 Omega loop of colon, 389 Omental hernia, 360 sac, 360 Omentum, great, 359 Omo-hyoid, 160 Ophthalmia, sympathetic, 66 Optic disc, 67, 71 nerve, 67 neuritis, 67 thalamus, 42 Ora serrata, 67 Orbicularis palpebrarum, 72 Orbit, 48 , abscess of, 52 -, arteries of, 53 -, dimensions of, 48 , fasciae of, 50 , fracture of, 48 , muscles of, 53 , nerves of, 53 , pulsating tumours of, 53 , relations of, 49 Os calcis, dislocations of the, 579 ■-, fractures of the, 586 epactal, 21 innominatum, 427 magnum, dislocation of, 311 Ovario-pelvic ligament, 469 Ovary, 468 , influence of, 468 , nerves of, 468 Pacinian bodies in the foot. 561 in the hand, 296 Palate, 147 , cleft, 147 , development of, 147 , hard, 149 , soft, 149 Palmar (see Hand) Palmaris longus tendon, 290 Pampiniform plexus, 465 634 SUKGICAL APPLIED ANATOMY Pancreas, 406 Pancreatic cysts, 408 ■ ducts, 406 Paracentesis of the pericar- dium, 212 of the thorax, 201 of the tympanum, 87 of the ventricles of brain, 42 Paralysis in spinal injuries, 618 of anterior crural nerve, 594 ■ of brachial plexus, 314 of cervical sympathetic, 55 ■ of Erb, 239, 314 of external popliteal nerve, 596 of facial, 125 of fourth nerve, 54 of great sciatic nerve, 598 of internal popliteal nerve, 596 of median nerve, 318 of musculo-spiral nerve, 259, 318 of obturator nerve, 596 of orbital nerves, 54 of sixth nerve, 54 of ulnar nerve, 318 Parasinoids, 33 Parietal bone, relationships of, 21, 41 fissures, 21 Parieto-occipital fissure, 41 Parathyroid bodies, 183 Parotid abscess, 122 fascia, 122, 166 ■ gland, 122 ■ lymphatic glands, 126 nerve supply, 123 region, 120 structures, 125 tumour, 126 Patella, 523, 541 , development of, 543 , dislocation of, 543 , fractures of, 541 Patellar ligament, 523, 536 ■ bursa, 527 Pectoral glands, 204 Pelvic' arch, 424 cellulitis, 431 colon, 389 fascia, 430 symphysis, 427 Pelvis, 424 Pelvis, floor of, 430 , fractures of, 426 , mechanism of, 424 , nerves of, 433, 475 , vessels of, 433 Penile urethra, 457 Penis, 458 ■ , lymphatics of, 459 , malformations of, 459 Perforating ulcer, 565 Pericardium, tapping of, 211, 212 Pericranium, 5 Perineal hernia, 351 Perinephritic abscess, 411 Perineum, depth of, 435 ■ ■, fasciae of, 437 , male, 433 , nerves of, 475 , vessels of, 434 Perirenal capsule, 411 Peritoneum, 358 , fossae of, 341, 352, 386 , watersheds of, 362 Perityphlitis, 384 Peroneal artery, 551 muscles, 562, 567, 568 nerve, 529 tubercle, 562 Petit's triangle, 323, 356 Petro-squamous suture, 86 Phantom tumour, 329 Pharyngeal pouch, 187 recess, 91 Pharynx, 151 , excision of, 154 , foreign bodies in, 151 , mucous membrane of, 91, 153 — — , relations of, 152 Phrenic nerve, 162, 420 Pigeon breast, 195 Piles, 472 Pinna (see Ear), 78 Pirogoff's amputation, 591 Plantar (see Foot) Plantaris tendon, rupture of, 553 Platysma myoides, 162 Pleura, 207 , wounds of, 207 — , to last rib, 415 Pneumatocele, 89 Pneumothorax, 207 Politzer's method of inflating the middle ear, 90 Pollock's method of dividing the muscles of the palate, 150 INDEX 635 Popliteal abscess, 528 bursas, 531 fascia, 528 glands, 531 - nerves, 480, 529, 596 space, 528 vessels, 525, 529, 548, 551 Portal vein, 360, 421 Post-nasal growths, 153 Pott's disease of spine, 196, 609 — — , operations in, 609 • fracture, 575 Poupart's ligament, 486 Preputial ocelli, 460 Processus vaginalis, 338, 343 Profunda arteries in arm, 258 • femoris, 487, 490 Prolapsus ani, 469 Pronation, movement of, 285 Prostate, 441, 450 , abscess of, 452 , capsule of, 452 , commissures of, 451 , hypertrophy of, 451 , lobes of, 451 , lymphatics of, 454 , nerves of, 452 , sheath of, 452 Prostatectomy, 452, 453 Prostatic plexus of veins, 454 Protopathic sensibility, 117, 319 Psoas abscess, 355 muscle, 353, 489 Pterion, 40 Pterygo-mandibular ligament, 140 Ptosis, 54 Pubic spine, 322 Pudendal hernia, 351, 466 Pudic artery, 480 Pulmonary artery, 209 Puncta lachrymalia, 75 Pupillary membrane, 61 Pylorus, 368, 370 , hypertrophy of, 371 , resection of the, 373 Quadriceps of thigh, 517 Radial artery, 283, 306 nerve, strength of the, 484 Radio-humeral joint, 265 Radius, dislocations of the, 274, 276 , fractures of the, 280, 286, 290 Radius, surface markings, 283 Ranula, 139 Rectocele, 467 Recto-vaginal fistula, 467 Recto-vesical pouch, 446, 469 Rectum, 389, 435, 469 , attachments of the, 472 -, effects of distension of, 470 , foreign bodies in, 470 — of infant, 390 , introduction of hand into, 471 , lymphatics of, 473 , malformations of, 391 mucous membrane of, 472 , nerves of, 474 , serous membrane of, 469 , valves of, 472 , vessels of, 472 Rectus abdominis muscle, 327, 329 Recurrent laryngeal nerve, 176, 184 Referred pain, 135, 318, 337, 420, 555 Reflex contracture, 330 Renal abscess, 411 Resection (see the various parts) Respiration in fracture of the spine, 619 Retina, 67 , central artery of, 62 Retroperitoneal hernia, 380 Retropubic space, 445 Rhinoplasty, 256 Rhinoscopy, 96, 97 Ribs, 198 , cervical, 169 , excision of, 201 , fractures of, 199 , twelfth, 323, 415 Rickets, effect of, on pelvis, 425 -, ribs, 200 skull, 18 tibia, 558 Rider's bone, 489 ■ sprains, 489 Riedel's lobe, 397 Rima glottidis, 159, 174 Rivini, notch of, 84 Rolando, fissure of, 38 Rosenmuller, fossa of, 91 Rouge's operation, 96 Sacro-coccygeal joint, 429 tumours, 429 636 SUEGICAL APPLIED ANATOMY Sacro - iliac synchondrosis, 428 Sacrum, 424 , dislocation of the, 429 Sagittal fontanelle, 21 Salivary fistuhe, 126 Santorini, duct of, 406 Saphenous opening, 347, 487 veins, 487, 491, 516, 525 Sartorius muscle, 486, 489 Scalene muscles, 160 Scalp, ahscess of, 6 , dangerous area of, 3 , fatty tissue in, 2 , hsematoma of, 7 , its mobility, 3 , lymphatics of, 16, 192 , nerves of, 13, 15, 16 , neuralgia of, 14 , sebaceous tumours of, 2 , sutures in wounds of, 3 , suppuration in the, 6 , temporal region of, 7 , vascularity of the, 4 , vessels of, 13 wounds, 4 Scaphoid bone, dislocation of the, 587 Scapula, 216, 229 , excision of, 232 , fractures of, 230, 231, 232 , " winging " of, 230 Scarpa's triangle, 486 , fascia of, 488 , glands of, 487 — — , vessels of, 487, 490 Schlemm, canal of, 69 Sciatic artery, 480, 483 dislocation, 507 nerve, great, 480, 483, 598 Sciatica, 484 Sclerotic, 58 Scoliosis, 196, 602 Scrotum, 460 ■ and oedema, 461 , application of leeches to the, 461 , lymphatics of, 463 , subcutaneous tissue of the, 461 Semilunar cartilages of knee, dislocation of the, 538 Semimembranosus tendon, 524, 529 Sensori-motor areas of brain, 38, 42 Septum of nose, 100 Sesamoids of hallux, 588 Shoulder, 214 Shoulder, bursse about, 243 , dislocation of the, 245 248, 249, 250 — — , fractures about the, 251 joint, 241 ■ , amputation at the, 253 disease of the, 244 , surface anatomy of, 214 ■ tip pain from liver ail- ments, 420 Sibson's fascia, 168 Sigaultean operation, 427 Sigmoid flexure, 389 Sinus, cervical, 194 , lateral, 10 pocularis, 455 , superior longitudinal, 33 , sphenoidal, 108 Sinuses of skull (venous), 32 (air) of skull, 105 Skull, 17 , abnormalities of, 19 , deformities of, 19, 23 , development of, 18 , emissary veins of, 13 , fractures of, 22, 26 , necrosis of, 5, 21 of infant, 17, 23, 30 , pillars of, 24 , soft parts covering, 1 , sutures of, 16, 29 , thickness of, 30 , trephining the, 9 , venous tumours of, 16 Soft palate, 149 Solar plexus, 419 Soleus, 553 Spermatic artery, 464 cord, 464 ■ plexus of veins, 465 Sphenoidal sinus, 108 Sphincter ani, 435, 471 Spina bifida, 621 [230 Spinal accessory nerve, 162, anaesthesia, 613 - cord, 545, 609 blood supply of, 614 concussion of, 614 — , contusion and crush- ing of, 615 - , loss of motion due to injury of the, 618 , sensation due to injury of the, 618 operations on, 622 - , wounds of, 612, 613 - injuries and defsecation, 620 INDEX 637 Spinal injuries and micturi- tion, 619 and respiration, 619 and vomiting, 620 meninges, 611 meningitis, 611 nerves, disti'ibution, 317, 598 , points of origin, 616 Spine, 600 , curves of, 196, 600 , fractures and disloca- tions of, 604 , how maintained erect, 602 , scoliosis of, 196 , sprains of, 603 , trephining the, 609 Spinous processes, fracture of, 608 Splay foot, 583 Spleen, 403 , capsule of the, 405 , dislocation of, 404 , enlarged, 404 , extirpation of the, 405 , injuries to the, 404 , relations of, 404 , rupture of, 404 Stenson's duct, 126 Sterno-clavicular joint, 224 , disease of, 225 , dislocations of, 226 , movements of. 224 Sterno-ensiform line, 365 — — point, 323, 365 Sterno-manubrial joint, 197 Sterno-mastoid muscle, 159, 163 Sterno-xiphoid joint, 197 Sternum, 196 , fractures of, 197 , holes in, 198 , separation of segments of, 197 , trephining the, 198 Stomach, 367 , displacement of, 366 , fistulse of, 370 , foreign bodies in, 371 . functional divisions of, 369 , lymphatics of, 372 , operations on, 373 , ptosis of, 366 , relations of, 367 , wounds of the, 370 Strabismus. 53, 54 Stylo-maxillary ligament, 166 Subacromial bursa, 240 Subarachnoid space, 34, 612 Subastragaloid amputation, 594 , dislocations of the foot, 579 joint, 578 Subclavian artery, 161, 187 vein, 161, 219 Subclavicular fossa, 216 Subclavius muscle, 219 Subdural space, 34, 612 Sublingual bursa mucosa, 139 gland, 138 papilla, 138 Submaxillary gland, 139 lymphatic glands, 144, 191 Subperitoneal connective tis- sue of the abdomen, 330 Superficial cervical glands, 191 Superior maxilla, 127 ■ -, antrum of, 109 — , cleft of, 147 excision of the, 128 fractures of, 127 necrosis of, 128 - thyroid artery, 159 vena cava, 213 Supination, movement of, 285 Supinator longus, 266 Supraclavicular nerves, 219 Supracondyloid process, 259 Suprahyoid glands, 191 Supraorbital foramen, 115 Suprapubic lithotomy, 443 Suspensory ligament of eye- ball. 51 Sustentaculum tali, 562 ■ , fracture of, 586 Sutures of skull, 17, 20, 29 , closure of, 24 , position of, 17 . relations of, to brain, 37 . relations of, to surface, 17 , separation of, 29 Sylvius, fissure of, 40 Symblepharon, 75 Syme's amputation, 591 Sympathetic ophthalmia, 66 Symphysis of pelvis, 427 Synostosis of skull, 24 Synovial cavities of the foot, 589 ■ ■ of the hand, 311 membranes, relationship to tendons, 304 63S SURGICAL APPLIED ANATOMY Synovial membranes of knee, 536 sheaths in the hand, 302 of ankle, 567 Synovitis, acute, in the hip- joint, 495 , , in the knee, 477 Tabatiere anatomique, 295 Tagliacozzi's operation, 256 Talipes calcaneus, 581 ■ cavus, 565 equinus, 581 and the plantar fascia, 565 , mixed forms of, 582 valgus, 582 varus, 581 Talma-Morrison operation, 422 Tarsal bones, fractures and dislocations of, 586 , locations of, 586 , ossification of, 588 ligaments of orbit, 76 plate, 72 Tarsectomy, 583 Tarso-metatarsal joint, 593 Tarsus (see Foot) Taxis, 349 Teeth, 135 , wisdom, 136 Tegmen tympani, position of, 11 Temporal abscess, 8 convolutions, 40, 41 • fascia, 7 fossa, 7 Temporo-maxillary articula- tion, 131 , dislocations at, 132 , movements of, 132 Tendo Achillis, 562, 568 oculi, 76 Tendon, suture and anasto- mosis of, 569 Tenon's capsule, 50 Tenotomy at ankle, 568 Tensor palati, 150 Testicle, 343, 462 , descent of, 343, 345 , inversion of, 463 , investments of, 462 — , nerves of, 463, 477 , torsion of, 462 , tunic of, 463 , vessels of, 465 Thecal abscess, 303 Thenar eminence, 292 Thigh, 515 Thigh, amputation of the, 521 , fasciae of, 516 , fractures of, 518 , integuments of, 516 , muscles of, 517 , surface anatomy of, 515 Thoracic duct, 193, 213, 220, 422 Thoracoplasty, 201 Thorax, 195 , deformities of, 196 , paracentesis of, 201 , viscera of, 206 , walls of, 195 , wounds of, 207 Thumb, amputation of the, 313 , dislocation of, 312 , movements of, 320 Thymus, 179 Thyro-glossal duct, 182 Thyroid body, 159, 181 , accessory glands of, 145, 182 , development of, 182 , excision of, 183 ■ , lymphatics of, 183 in tracheotomy, 179 cartilage, 159, 173 , nerves of, 183 Thyroidea ima artery, 158, 184 Thyrotomy, 176 Tibia and fibula, fractures of, 556 , fractures of, 546, 558 • in rickets, 558 , ossification of, 547, 548 , shaft of, its strength, 556 , upper end of, 546 Tibial vessels, 551, 553 Tibialis anticus muscle, 550 Tongue, 141 , accessory glands about, 145 •, dermoid cyst of, 145 , blood supply of, 142 , epithelium of, 142 , excision of, 146 , lymphatics of, 144 , mucous cysts of, 142 , nerve supply of, 142 Tongue-tie, 141 Tonsil, 154 , bleeding from, 156 , foreign body in, 156 , hypertrophy of, 154 ( and deafness, 154 , lingual, 143 , lymphatics, 155 , Luschka's, 91, 153 , pharyngeal, 91, 153 INDEX 639 Trachea, 159, 173, 177, 210 , foreign bodies in, 180, 210 Tracheotomy, 177 Transpyloric plane, 366 Transversalis fascia, 353 Transverse cervical artery, 161 ■ colon, 388 process of the atlas, 158 of the cervical vertebrae, 158 Trapezium, 292 Trendelenburg's operation, 429 Trephining, 9, 609 , for intracranial abscess, 10 Triangular ligament of the urethra, 386, 436 Trigone, 447 Tubera ischii, 453, 479 Tunica abdominalis, 325 albuginea, 463 vaginalis, 338, 462 Turbinate body, 103 — — processes, 102 Tympanum, 85 , blood supply of, 92 , lymphatics of, 92 Ulna, dislocation of the, 273 , fracture of the, 286 , surface markings of, 283 Ulnar artery,, 283 ■ nerve, 256, 269, 281, 319 vein in venesection, 265, 267 Umbilical fistula, 329 hernia, 310, 328 line, 366 Umbilicus, fibrous ring of, 327 , position of, 322 , vessels of, 328 Umbo of membrana tympani, 84 Urachus, 329, 341 Ureter, 416, 449 , and regurgitation of urine, 449 -, distension of, 417, 449 , resection of, 418 , relationships of, 416, 450 , radiographic examina- tion of, 417 , rupture of, 417 Urethra, female, 458 , male, 421, 454 , , curve of, 454 Urethra, male, membranous, 438, 454 , mucous membrane of, 457 , narrowest parts of, 457 , penile, 455, 457 , prostatic, 454, 456 , rupture of the, 458 Urethral triangle, 433, 436 Uterus, 467 , arteries of, 468 , lymphatics of, 468 Vagina, 467 Vaginal cystocele, 467 process of peritoneum, 338, 343 Valsalva's method of inflating the middle ear, 90 Varicocele, 465 Varicose veins, 465, 472, 491, 554 Vas aberrans, 258 ■ deferens, 464 . , section of, 454, 464 Vater, ampulla of, 401 Veins (see various parts) , air in, 189 , emissary of skull, 13 of diploe, 13 , valves in, 191 Venesection at the elbow, 267 Venous sinuses, 32 tumours of skull, 16 Ventricles of brain, 36, 42 Vermiform appendix, 382 Vertebra, caries of, 357 prominens, 158 Vertebral artery, 189 column, 600 — — , sprains of, 603 Vesico-vaginal fistula, 467 Visceral nerves, 337 supports, 367 Visceroptosis, 364 Vitello-intestinal duct, 329, 377 Vitreous humour, 69, 70 Vocal cords, 174 Volvulus of the sigmoid fiexure, 390 Vulva, 466 Wardrop's operation, 188 Weaver's bottom, 483 Wharton's duct, 139 White line at anus, 474 in the pelvic fascia, 430 Whitlow, 303 Winged scapula, 230 640 SURGICAL APPLIED ANATOMY Wirsung, duct of, 406 Wormian bones, 21 Wrist, 290 joint, 291 , amputations at, 313 , dislocations at, 311 , fractures about, 308 Wrist joint, movements at, 307 , surface anatomy of the, 290 Wry neck, 163 Zygoma, fracture of, 12 as guide to structures, 12 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DATE BORROWED DATE DUE DATE BORROWED DATE DUE C2B(23B)M100 551 T72 1907 Treves 2*3QQ0M)Q4