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a tendon-sheath as a path for the transferred tendon, and since the transferred tendon must be sutured to another tendon instead of being attached to the bone. In other respects, however, they conform to the principles of the physiological method.
The operation for the severed flexor tendons consists in transplanting the sublimis tendon of the adjacent finger and suturing it to the distal end of the injured flexor profundus tendon; that is, two adjacent fingers are supplied with two profundi tendons, since the one sublimis tendon is converted by the operation into a deep flexor. The steps of the operation, which is best performed under local anæsthesia, are as follows. For purpose of illustration I assume that both flexor tendons of the middle finger have been severed and that a mass of scar tissue the size of a fifty-cent piece occupies the mid-palmar region and is densely adherent to the bone. The first incision runs from a point 2 inches distal to the annular ligament in a line with the tendons of the index-finger to the proximal phalanx of this finger (see Fig. 123). The incision is deepened through the palmar fascia, until the sublimis tendon is visible throughout its course. The second incision is made distal to the scar tissue over the severed flexor tendons of the middle finger; it is about 112 inches long, slightly bowed, with the convexity toward the little finger, and extends to the base of the middle finger. The flexor tendons are then dissected free from the adhesions which usually bind them down. The operator must pay particular attention to this step since adhesive bands frequently extend well into the sheath. When properly freed, gentle traction on the flexor profundus tendon should produce complete flexion of the finger. The flexor profundus should be freed from the sublimis tendon, and about 1 inch of the latter excised. This is necessary because of the tendency to adhesions between the flexor profundus and flexor sublimis, which interfere with the action of the deep flexor. A subcutaneous channel is then bored with a dressing forceps from the proximal end of the first incision to the second incision. This step of the operation is usually rather difficult owing to the presence of scar tissue. It is better to give the channel a slightly curved direction, since a straight course would necessitate boring between scar tissue and bone; the slight curve tends to be obliterated by the action of the tendon as soon as active motion has begun, whereas boring between scar tissue and bone tends to produce adhesions which nullify the effect of the operation. When a channel sufficiently roomy to accommodate the tendon has been bored, the sub
Fig. 123.—The incisions for transplantation of the flexor sublimis tendon of the index finger for the severed flexors of the middle finger. 1, First incision; 2, second incision.
limis tendon of the index-finger is divided at the metacarpophalangeal joint, dissected away from the deep tendon and as rapidly as possible, so as to avoid drying, is drawn through the subcutaneous channel.
The final step of the operation consists in suturing the transplanted tendon to the flexor profundus tendon of the third finger. The suture may be performed in two ways. The usual technic is that already described on page 171: a buttonhole opening is made in the tendon of the injured finger about a quarter of an inch from its severed end, the sublimis tendon is threaded through this opening; and the two tendons are united by fine interrupted chromic gut sutures. Another method of tendon suture is indicated if the tendons are friable
C Fig. 124.–Suture of tendon to tendon, when overlapping is impossible. The suture is reinforced by a free transplantation of fascia from the calf. A, longitudinal diagrammatic sketch showing the Lembert sulture in process of application which closes the tube of fascia overlapping the tendons; a, Lembert suture; b, tendon; c, transplanted fascia; d, Lange suture. B. Diagrammatic cross-section of the tendon and transplanted fascia indicating the manner of inserting the Lembert suture; a, suture; b, fascia (superficial surface turned toward the tendon); c, fascia (deep surface turned outward); d, tendon. C. Diagrammatic cross-section of the tendon and transplanted fascia after the Lembert stitch has been drawn taut. Note that the smooth deep surface of the fascia adapted to the gliding function is turned outward: a, suture; b, fascia (superficial surface); c, fascia (deep surface); d, tendon.
or cannot be made to overlap. Under this condition I have found that the first suture method does not give sufficient security. Therefore, after uniting the tendons by means of the stitch, shown in Fig. 124, the suture is reinforced by transplanting a piece of fascia from the calf. The technic of this procedure requires practice. A 3-inch incision is made, a hands-breadth above the annular ligament of the ankle, and a strip of fascia 2 inches long and 1 inch wide is dissected away from the muscles. Particular care is taken to handle only the corners of the fascia, so as not to injure the loose fatty tissue (paratenon) which at this point covers the deep surface of the fascia and is of particular importance in facilitating the normal
Fig. 125.—The degree of flexion secured by transferring the flexor sublimis tendon of the index finger for the severed flexor tendons of the middle finger; above, fingers extended; below, fingers flexed.
gliding mechanism of the muscles and tendons. At each corner of the fascial flap a suture is taken to permit more ready handling. The assistant grasps two of these sutures, the operator the other two, and in this way the fascia is transferred from the calf to the hand. The sutured tendons are then lifted out of their bed so as to pars two of these fixation sutures
beneath them. By means of a continuous Lembert suture the fascia is made to form a tube closely surrounding the sutured tendons. The fascia is so placed as to turn its glistening deep surface outward, and if the Lembert suture has been properly inserted the point of union of the two tendons is completely hidden by a smooth strong envelope well adapted to a gliding function. The operation is concluded by continuous skin sutures.
Fig. 126.—The incisions for transplantation of the index finger tendon of the extensor communis digitorum to replace the severed extensor of the ring finger. A, Incision over the index finger tendon; B, convex incision over the severed extensor tendon.
A similar operation can be performed for the divided extensor tendon provided the tendon of the extensor indicis proprius has not been injured. It consists in transplanting the tendon of the extensor communis digitorum which runs