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transplanted tendon and the lowermost muscle fibres. In performing the transfer care must be taken not to produce a torsion of the muscle. The tendon is fastened to the patella by the suture illustrated in Fig. 108.
5. If possible one of the inner hamstring group-preferably the gracilis or the semitendinosus-is transplanted in a similar way. The two transplanted tendons are united above the insertion (see Fig. 119) so as to make their line of traction correspond to the long axis of the thigh.
6. Closure of Skin Wounds.
For the tendons of the hand two groups of operations are applicable: first, that for paralytic conditions; second, for traumatic injuries of the tendons.
FIG. 120. Two exposures on one plate illustrating the power of extension in a case of complete paralysis of the quadriceps femoris subsequent to transplantation of the biceps and of one of the inner ham string muscles. Extension is possible against the weight of a 5 lb. sand bag. (From Biesalski and Mayer: "Physiological Method of Tendon Transplantation.")
Operation for Musculospiral Paralysis. The method of transplantation is based upon the fact that extension of the distal phalanges is rendered possible by the action of the interossei and lumbricales. Therefore the transplanted tendons need not be utilized to extend the fingers, but can be sutured directly to the metacarpus to produce extension of the wrist.
This insertion has two advantages: (a) implantation of the tendon into bone instead of to tendon; (b) vigorous flexion of the fingers, as in making a fist, an action for which extension of the wrist is necessary, can be performed more effectively if the transplanted tendon is sutured, not to the extensor communis digitorum, as generally advised, but to the metacarpus.
Since extension of the thumb is due solely to action of muscles supplied by the musculospiral, a special tendon must be transferred to the extensor longus pollicis. I advise the flexor carpi ulnaris for this purpose, since its line of traction when transplanted corresponds closely to that of the long extensor of the thumb. To extend the wrist, the flexor carpi radialis is used.
The steps of the operation are as follows:
1. Preparation of the Implantation Site.-A 111⁄2-inch slightly curved incision exposes the insertion of the extensor carpi radialis longus and brevis. Either one of these tendons is slit longitudinally (see Fig. 103) and the periosteum at the insertion scarified.
2. Preparation of the path through the sheath of the extensor carpi radialis longus and brevis.
A 12-inch vertical incision is made over the upper pole of the sheath, the sheath opened, and an eye-probe threaded with a loop of silk passed downward through it to the insertion of the tendons. As the sheath closely invests the two tendons, leaving scant room for a third, it is advisable to withdraw one of the tendons from it. This is done by dividing a tendon 1 inch above its insertion, incising its mesotenon as far upward as possible and then withdrawing the tendon from the sheath through the lower angle of the second skin incision.
3. Exposure of the Flexor Carpi Radialis.-A 7-inch incision exposes the tendon from the middle of the forearm to the annular ligament (see Fig. 121). This must be divided and the tendon exposed where it courses through its bursa, which corresponds closely to a short tendon sheath. In so doing the operator must sever the fibres of some of the short muscles of the thumb. It is necessary to free the tendon down to a point as near its insertion as possible, otherwise it is not long enough
the tendon near its insertion, it is dissected upward until the to reach the dorsum of the metacarpal bones. After dividing
121. Transplantation of the flexor carpi radialis tendon for the paralyzed extensors of the
desired line of traction can be secured-usually about half
way to the elbow.
4. Transfer of the Tendon and Fixation.-A subcutaneous channel is bored from this point to the upper end of the sheath of the extensor carpi radialis longus and brevis, through which the tendon is drawn by means of the guide suture (see second step of operation). It is fastened to the insertion of the extensor tendon by the technic already described in the previous operations.
5. Exposure of the Tendon of the Extensor Longus Pollicis.— This is found just to the ulnar side of the upper pole of the sheath of the extensor carpi radialis longus and brevis, so that additional incisions are unnecessary. It is to be observed that its course is oblique from the ulnar side downward toward the radial side. The tendon is divided at the musculo
6. Exposure of the Flexor Carpi Ulnaris Tendon.-This tendon is freed by a 6-inch incision along the ulnar border of the arm. It is divided close to its insertion into the pisiform bone. In dissecting it upward, the operator must divide some of the muscular fibres which have their origin from the ulnar; with care this division can be made parallel to the muscular fibres, so as not to produce any ragged edges.
FIG. 122. Suture of tendon to tendon when overlapping is possible. Button-hole opening; b, flexor tendon; c, carpi ulnaris tendon of extensor longus pollicis.
7. Transfer and Fixation.-The transfer is made by the subcutaneous route. Then it is seen that the line of traction of the transplanted tendon corresponds closely to that of the extensor longus pollicis.
The fixation cannot be made to the bone, since the tendon is too short for that, but must be made to the paralyzed tendons. A button-hole opening is made in the flexor tendon about 4 of an inch from its free end (see Fig. 122) through this opening the extensor tendon is threaded, and the two tendons are firmly united by five or six fine chromic gut
stitches, so planned as to flatten the tendons against one another. To promote firm adhesion of the tendons, it is well to traumatize slightly the surfaces of the tendons which are brought into apposition.
8. Closure of all skin wounds by continuous sutures.
Operations for Median Nerve Paralysis. In my own experience I have never had occasion to perform tendon transplantation for this type of paralysis. When all hope of recovery of the median nerve has to be abandoned, the tendon transfer would however be indicated.
A. If the ulnar nerve is intact: (a) The outer tendons of the flexor profundus are inserted into the inner tendons of the same muscle. (b) The tendons of the flexor sublimis are inserted into the tendon of the flexor carpi ulnaris. The extensor carpi radialis longior is attached to the flexor longus pollicis (Jones). The technic of the suture resembles that described in the preceding operations.
B. If the ulnar nerve also is paralyzed, the extensor carpi radialis longus and brevis may be utilized to activate the paralyzed tendons.
Transplantations for Injuries to the Tendons of the Fingers. -Thus far I have described tendon operations for paralytic conditions. In the succeeding paragraphs I shall outline a number of transplantations applicable to gunshot injuries of tendons in which direct union of the retracted tendon ends is impossible. At the beginning of this chapter it was stated that one of the commonest lesions seen in military practice is a perforating wound of the hand. The wound of entrance is usually on the palmar aspect, the larger star-shaped wound of exit is on the dorsum. Almost always one or more metacarpal bones are fractured and the flexor and extensor tendons of one or more fingers are completely severed. Such an injury leaves the patient with a badly crippled hand, since one or more fingers are not merely useless but in the way. Despite the usual demands for amputation of the helpless members it is advisable to conserve wherever possible by means of tendon operations. These operations cannot be considered in the same category as the transplantations described in the preceding pages, since from the nature of the injury it is impossible to utilize