CHAPTER XVI. INJURY AND REPAIR OF NERVES. (Part 1)

CHAPTER XVI. INJURY AND REPAIR OF NERVES. THE REPAIR OF DIVIDED NERVES. It is imperative to suture a divided nerve as soon as the condition is recognized. If the repair is made at once it is more casily done than the suture of tendons, for the ends are not so widely separated; but, on the other hand, it is more delicate work, for the trunks are smaller. Do not handle these tissues roughly and, above all,do not cleanse the wound with strong antiseptics, such as bichloride and carbolic acid. a Remember that the upper part of the nerve retains its sensitiveness and in it are the essentials of repair, The lower seg- ment degenerates if repair is neglected. It is usally necessary to freshen the ends, but‘one must be very sparing of the tissues, "removing less than a millimeter from each extremity, using fine sharp scissors. ‘It is better to make the section oblique (Fig. 221). Pass a silk (No. 0) suture or a small catgut with a round needle through the te eh htattica whole thickness, as in the case of around Se ouve ante, prone mare tendon (Fig. 222), draw the ends together (Yom) and complete the repair by suturing the Tips, passing the suture through the nerve sheath only (Fig. 923). Adjust the ends exactly and always where possible make the suture an end-to-ead one. Repair the various layers of fascia with great care, so that the sutured nerve may be isolated and removed from the sources of infection, Employ drainage in suturing the skin. For the rest, the treatment is the same as for any other wound, 294 -_ | sal CONTUSION AND COMPRESSION OF NERVES. 295 Secondary Suture—It may be found necessary to suture a nerve some time after the injury, and this operation will present difficulties. The ends may be separated or they may be imbedded in scar tissue. A knob often forms on the proximal stump. In such a case, freshen the ends and pass the suture in the manner pictured (Fig. 224). If the two ends are attached by a fibrous cord, split the scar tissue longitudinally (Fig, 225), and transform the longitudinal fissure into a transverse one and suture (Fig. 226). If the ends cannot be approximated or bridged they may be sutured at different levels to a neighboring nerve in the manner described under Repair of Tendons. Warn the patient that it may be a long time before function fs even partially restored. In the mean- time, muscular atrophy must be prevented by per- sistent use of electricity, and massage. Fig. sa8-—Suture CONTCSION AND COMPRESSION OP NERVES. date bo oo ‘These injuries to nerves are by no means infrequent, following blows, gun- shot wounds, machinery accidents, frac- tures, and dislocations. ‘The symptoms vary from slight ting. , ling to complete loss of function. ‘The K Joss of function is often a later develop- ment, due to a neuritis following the contusion, and is accompanied by neuralgia, muscular palsy and trophic alterations corresponding to the distri bution of the nerve, Pe nea Sealey eis, Meet Treatment.—The immediate indica- tions are to restore the parts-to ‘their normal condition as much as possible, and to relieve the pain by oe INJURY AND REPAIR OF NERVES. hypodermic injections of morphia or by phenacetine and codeine. ‘The erve must be put at rest by immobilizing the limb. Later, alteratives, eloctricty, and massage are useful. INJURIES TO INDIVIDUAL NERVES. Pactal Nerre—The facial is more frequently injured than any eabor commial nerve: in fracture of the base of the skull; in the mastoid operation as it passes through the temporal bone; by shots and blows at its exit from the styloid foramen. Depending upon the distance of the lesion fram the central origin of the nerwe, there occur paralysis of the muscles of expression, dis- turbance of salivary secretion and the sense of taste, amd paralysis of the palatal mus- cles. Injury to the facial nerve is often accompanied by injury to the abducens and auditory nerves, To Expose the Facial Nerve.—The incision begins behind the external auditory meatus and extends down- ward and forward to the angle of the lower jaw. Divide the integument, superficial fascia and the first layer of the deep fuscia, “This exposes the parotid gland, the sterno-cleido-mastoid and the mastoid process. The posterior auricular nerves and the vessels are to be avoided. Carefully dissect and draw forward the part of the gland exposed tnd the posterior of the digastric appears, just above which the ipirve lies upon the styloid process Optic Nerve.—Te optic nerves are injured most frequently in eon ha al EXAMINATION YOR BRAIN TRAUMA, 207 nection with fracture of the base of the skull involving the anterior fossa, and especially when the fissure involves the optic foramen, for there the nerve is firmly attached to the bone. As a consequence of such injuries, there may be compression, lacera- tion, of extravasation into the nerve sheath. As a result of these in~ juries, there are disturbances of vision of various degrees. Jn obscure trauma of the brain, the ophthalmoscopic examination of the fundus of the retina should never be neglected as a means of diagnosis. Motor Oculi NerveThe motor oculi nerve may be injured by wounds penetrating the orbit and by fractures of the base. Tts func- tion may be disturbed by pressure following the rupture of the middle meningeal artery and often the only indication of this disturbance is a dilated pupil and drooping of the eyelid. Patheticus and Abducens —These nerves are often injured along with the third. Fifth Nerve—The fifth nerve is rarely injured alone, but injury of single branches may occur. “The usual consequence of anesthesia of the trigcminals following cranial injury is so-called keratitis ncuroparalytica.”” Auditory Nerve-—The auditory nerve is rarely injured without other serious lesions, and since traumatic disturbances of hearing may be due to injury to the labyrinth or tympanum also, a diagnosis of in- Jury to the nerve trunk must be uncertain. The pneumogastric may be divided or contused by bullet or stab wounds in the neck. The injury is not necessarily fatal, but may be followed by difficulty in respiration and deglutition or by pneumonia. When the symptoms point to injury an effort should be made to repair ft. Itis reached by the same operation as that for ligation of the com+ mon carotid. The phrenic when divided gives rise to disturbances of the functions of the diaphragm, cough, difficult respi Petentlortayeo! sien divided gives stee' to’ hoarientes and aphonia, Tf injured, an attempt should be made at repair. Laryngeal spasm may require a tracheotomy. Median Nerve.—The median nerve is likely to be divided by stab- of gunshot wounds and may be exposed in any part of its course. and fingers and movements of the thumb. To Expose the Median Nerve.—(A) In the middle third of the right angle, the operator standing to the inner side of the arm. With the two hands define the biceps muscle. Along the inner border of the muscle, following the known line of the nerve (from the middle of the axilla to the middle of the bend of the elbow) make am Incision two or three inches long, dividing the skin and connective ussue. Divide the deep fascia over the biceps and open the sheath — 7. —Kxpowure of the median nerve im the middie third of they Rew Pe oS Nodes ores A benched erty, (ade ae of the muscle, Isolate the border of the muscle and with the retractor draw ft gently aside. Do not use force or the nerve also will be placed or the musculo-cutancous may be exposed instead of the Now incise the deep layer of the muscle sheath exactly in the that was occupied by the border of the muscle and the nerve is lying a little to the inside of the vessels. (B) At Lend of elbow (see Brachial Artery). (C) In the upper third of the forearm (Fig. 228): The incision begi a little below the bend of the elbow, is two or three Inches én len and follows the line of the nerve, which lies in the middle line INJURY TO THE ULNAR NERVE. 299 the elbow to the wrist. Divide the skin and ligate the two superficial veins. Under the deep fascia define the external border of the pro- nator radii teres and over this border incise the aponeurosis and retract the muscle. ‘The nerve is immediately exposed, together with the ulnar artery, which crosses beneath it, running obliquely toward the inner border of the forearm. (D) At the wrist (Fig. 229). Make an incision two inches in length in the middle line, the middle of the incision corresponding to the up of the median nerve just below the elbow. Th 7.) drawn anward exposing the median werve (M, ¥.), artery (0. art) being at outer side. (Schwarls.) crease of the wrist. Divide first the skin and the fascia and then, very carefully, the anterior annular ligament, guarding the synavial sheath of the flexor tendons. Retract the lips of the wound, and the nerve Is exposed, ensily distinguishable from the adjacent tendons by its fibrillated appearance. The Ulnar Nerve (Fig. 230).—The ulnar nerve may be divided any- where along lis course, but is more likely to be contused {n the uln: groove. There also it may be dislocated by forcible flexion of the forearm. The loss of function of this nerve results in inability to extend the distal phalanges, to adduct the fingers and to flex the little finger, geo. INJURY AND REPAIR OF NERVES. Eventually the “claw hand” appears as a resalt of atrophy of the — muscles. To Expose the Ulnar Nerveo=(A) In the arm> Make ap incision two or three inches in length along the line of the nerve, which extends from the middle of the axilla to the internal condyle. Divide the skin and superficial and deep fascia, ‘The brachial, artery is about a finger's breadth to the outside of the line of incision, Draw the Pro, 299.Expe ste mee he weist, (Semmerls basilic vein to one side. Carefully divide the subjacent tissue be neath which is the ulnar and median nerves and the brachial artery; the ulnar nerve is to the inside and in contact with the long bead of the triceps, (B) At the elbow (Fig. 231); Place the patient om the back; abduct the arm; flex the forearm at a right angle; stand to the inner side of the arm and locate the inner condyle, the olecranon and the im tervening gutter. Along the line of the gutter incise the skin and the ama - INJURY TO MUSCULO-SPIRAL NERVE, 301 fascing for two or three inches, and the nerve will be exposed, accom- panied by the posterior ulnar recurrent artery, (C) In the lower third of the forearm (Big. 232): Following the line of the nerve, from the internal condyle to the radial side of the pisiform, make an incision two inches long to the outside of the flexor carpi ulnaris, dividing the skin and superficial fascia. Retract inward the tendon of this flexor. Carefully incise the deep fascia and the nerve is exposed lying to the ulnar side of the ulnar artery. = Rou, UR, Re ptiten Bawemare 4 the lnge merge at ew. IC, Lateral conte youth aryl pinarie, U. i: Vinar nerve. Giec, Oleceunon frocks, Fok Teter tscbewrend C Muscate-spiral—The musculo-spiral, more than any other nerve of the arm, is subject to injury from stab, contused, or gunshot wounds - or to fracture of the humerus. Very characteristic, too, are the symptoms resulting from its loss of function: The wrist and fingers cannot be extended and assume the attitude well known as the “drop wrist.” In every fracture of the humerus, the stability of this nerve should be tested. The nerve may be explored in any part of its course, but is most easily reached at the outer side of the arm just above the elbow. gor To Expose the Musculo-spiral.—In the lower third of the orm INJURY AND REPAIE OF NERVES. @ line drawn along the middle of the external surface, half-way between the shoulder and elbow and extending to a one-half inch from the center of the bend of the elbow, incision two or three inches in length through the skin and fascia. Retract the cephalic vein. Divide the deep fascia border of the supinator longus and expose the muscle fully, Pos. spam Hagen ft re owe) mene it to the outside. At the bottom of the wound is the nerve lying upon the brachialis anticus, Circunglex,—In addition to such injuries as may be due to stab or gunshot wounds, the circumflex is Hable to be lacerated in wiolemt wrenching or in dislocation of the shoulder-joint “The loss of power to abduct the arm through paralysis of the deltaid - is the immediate result. The nerve may be exposed as it winds around the humerus just below its head. Operation.—The course of the nerve is in a line drawn from the inber end'of the scapular spine to the point of insertion of the deltoid. Place the patient on the sound side, exposing the shoulder well by rotating the arm inward a little and placing it in front of the trunk. mca INJURY TO THE ANTERIOR CRURAL NERVE, 393 Along the line indicated make an incision three or four inches long, corresponding at its outer end to the acramion process, but an inch or two from it. This incision divides the skin and superficial and deep fascia and exposes the posterior border of the deltoid. Bring into view and draw upward this border of the deltoid, Next locate the quadrilateral space, bounded above by the teres minor, below by teres major, posteriorly by the long head of the triceps, Fis, 9)5—Exporure of the musculo-sviral in iis lower thind, ‘The pupinavor ow Sxpoeel and the nerve found to Ite inner vide lying upon the brachialis aaticas., (Schoor's) and anteriorly by the shaft of the humerus. By locating the tendons of these muscles define this space in which lie the nerve and the posterior circumflex artery (Fig. 254). The musculo-cutancous is exposed in the same manner as the median in the upper third of the arm (Fig. 235). Anterior Crural,—The division of the anterior crural nerve means, among other things, loss of extension of the leg. ‘To outline it locate the spine of the pubes and the anterior superior iliac spine, which points are connected by Poupart’s ligament; under 304 INJURY AND REPAIR-OF NERVES, this ligament a finger’s breadth outside of its middle point the nerve passes (Fig. 236), To Expose the Anterior Craral—Make an incision from this point downward in the axis of the thigh, about three inches in length, divid- ing the skin. relia TM Teves enim arusy, GN, Cheerios At the upper end of the wound expose the bower border of Poupart's ligament. Immediately below this line, open up the sheath of the psoas magnus, pass a grooved director under the sheath, and divide it tothesameestent.as the skin incision, Separating the lips of the sheath wound, the nerve is seen lying on the fibers of the muscle and Isto be distinguished by its whiteness and its subdivisions, ) al ANTERIOR CRURAL NERVE, 305 Pro, 235. Exposure of the muteulo-cutaneous nerve in the middle third of arm). The bce (1 drawe ourwant exists he nerve (3, Cut. N) Tying ta the cuted ‘of the median nerve (Med. N.) and the brachial artery, Br. Art. | (Schwarts,) Foe. a56—Anterior cvural ard oxteranl catazeoms nerven, (Lae 20 306 INJURY AND REPAIR OF NERVES. The Odturator.—1i the obturator is divided, there follows loss of ab- duction of the thigh. To Expose the Obturator.—Abduct the thigh until the border of the ductor longus can be clearly defined, and along this line make an in- cision four or five inches long, beginning an inch below the fold of the groin, a little to the outside of the scrotal base. Divide the skin and superficial fascia, retracting to the outer side the internal saphenous = Pee. 497-—Toxtniare of the obturatny nerve: prepreting the aAdactor lougus trem ‘peetinwws (Labey,) vein, but ligating its croas branches (Fig. 237). "Divide the deep fascia in the same line. Separate the adductor longus from the pectincus by blunt dissection, A fairly well-defined gutter indicates the line of separation. Retract the two muscles and at the bottom of the upper part of the wound you will see the obturator nerve, consisting of a couple of flattened cords, Now extend the thigh to relax the abductors and separate more wilely the two muscles mentioned and the perve may be completely exposed, EXPOSURE OF THE SCIATIC NERVE. 3°07 ‘one branch lying upon the adductor brevis and the other passing under it (Fig. 238). Mio-inguinal and Genito-crural—These nerves are frequently wounded in hernia operations, and may give rise to an obstinate neu- ralgia of the testicle requiring removal of this organ. In such a case an effort should first be made to repair the nerve or resect it. The Sciatic Nerve. —The sciatic nerve may be injured in many ways and from the functional point of view, these injuries are always serious, Pio. agf—Obturator exposed. (Loley:) Tt may mean loss of extension of the thigh and complete paralysis of the leg. It may be exposed at any part of its course down the back of the thigh. Exposure in the Middle of the Thigh—Place the patient face down- ward or on the sound side. Along the line of the nerve (a straight line extending from a point midway between the ischial tuberosity and the great trochanter to the middle of the popliteal space), make an in- cision three or four inches long, dividing the tissues down to the deep . go8 INJURY AND REPAIR OF NERVES. . | fascia, Determine the interspace between the biceps and the internal | hamstring, and over it divide the deep fascia and separate by