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be divided as near the bone as possible; otherwise it would not be long enough to reach its new point of insertion. It is advisable to remove a little bone with the tendon since this renders the fixation doubly secure. The tendon is then threaded with stout chromic gut as in Fig. 108 and freed from its mesotenon until it can run a direct course into the sheath of the extensor digitorum and peroneus tertius.
6. The tendon is drawn through the sheath by means of an eye-probe, and fastened to the bone and to the peroneus tertius tendon by the technic described in the first operation. Care must be taken that the course of the tendon is straight and that the muscle is not twisted.
Transplantation of the Peroneus Longus for the Tibialis Anticus.--The operation is indicated in severe cases of spastic or paralytic talipes valgus, in which transplantation of the extensor proprius hallucis would be insufficient to restore muscular balance. When combined with transplantation of the peroneus brevis to the outer side of the dorsum of the foot (conversion of the peroneus brevis into a dorsal flexor) it can be performed to correct the foot drop subsequent to an inoperable lesion of the anterior tibial nerve involving all the extensor muscles. This operation possibly better than any other illustrates the advantages of the physiological method of tendon transplantation. The operation as usually performed does not efficiently replace the paralyzed tibialis anticus, for unless the peroneal tendon runs through the sheath of the tibialis tendon a supinating effect is impossible. This fact can readily be demonstrated by experiments on the cadaver as well as by clinical experience. The operator, however, faces a grave difficulty in running the peroneal tendon from its original site to the sheath of the tibialis anticus, for the two muscles are separated throughout their entire length by a well-developed fascial wall—the septum intermusculare anterius. To overcome this difficulty, a fascial plastic is necessary.
The steps of the operation are as follows:
1. Incision over the insertion of the tibialis anticus as in the first operation, and preparation of the implantation site by slitting the tibialis tendon and grooving the internal cuneiform.
Fig. 113.—Diagrammatic cross-sections of the calf illustrating the principle of the fascial plastic for transfer of the peroneus longus from its compartment to that of the tibialis anticus. (From Biesalski and Mayer: “Physiological Method of Tendon Transplantation.") A. The incisions over the lateral and anterior muscular compartments. B. The eversion of the fascia turning the deep surface, coated with paratenon, outward to act as a bridge over which the peroneal tendon can glide.
2. A 1 inch incision near the upper pole of the tibialis sheath enables one to open the sheath and to pass a probe threaded with a guide-suture through it to the insertion of the tendon. The probe is drawn entirely through, leaving the guide-suture in place.
3. The third skin incision is made over the peroneus longus tendon from the middle of the calf to the cuboid. This long incision is necessary, for unless the tendon is freed almost to the middle of the calf it cannot be given a proper line of traction. The upper end of the incision curves anteriorly so as to permit the execution of the fascial plastic. The skin and subcutaneous tissues above the malleolus are retracted from the underlying fascia cruris until not only the peroneal muscles, but also the muscles of the anterior group—the extensors—are visible.
4. The Fascial Plastic.-Experimentally we know that the boring of a hole through the fascial septum tends to produce adhesions, whereas it is equally evident that the deep surface of the fascia from the middle of the calf downward is unusually well adapted to the gliding of the tendon, because it is clothed with the elastic paratenon. Therefore, instead of ripping a hole through the fascia with the dressing forceps it is carefully incised first over the peroneal compartment, then over the anterior muscular compartment (see Fig. 113). This latter incision is made to outline a flap (Fig. 114), which is inverted so as to expose the paratenon clothing its deep surface, and sutured by a Lembert stitch to the edge of the inverted fascia of the lateral fascial compartment (see Fig. 114). The stitch itself is taken as near as possible to the fibula, so as to bury it in the muscular fibres of the peroneus brevis. By this simple procedure a physiological path for the peroneal tendon is constructed. The fascial incision must be somewhat longer than at first thought seems necessary, because the tendon runs not transversely but slanting from above downward.
5. An eye-probe is then passed from the upper pole of the tibialis sheath beneath the fascia cruris and made to appear in the region of the fascial plastic. The upper end of the guide suture lying in the tibialis sheath (second step of the operation) is drawn beneath the fascia by means of the probe. The
6. The perone al tendon is now freed by prolonging the fascial It serves to draw the peroneal tendon along this course. the sheath and out near the insertion of the tibialis tendon.
fascia cruris into the tibialis anticus sheath, downward through guide suture thus runs from the fascial plastic beneath the
incision already made over its upper end, downward until the sheath has been opened, usually 1 to 2 inches above the malleolus, and then along the sheath to the groove in the cuboid where the peroneal tendon passes into the sole of the foot. When the peroneal tendon is divided at this point it reaches exactly the desired insertion on the inner border of the foot. It is threaded with the fixation suture, freed from its mesotenon, and by means of the guide suture drawn over the
6 Fig. 115.—Photographs illustrating the effect of transplanting the peroneus longus tendon for spastic flatfoot. (From Biesalski and Mayer: “Physiological Method of Tendon Transplantation.”) A. Before the operation. B. Standing after the operation. C. Showing the power of voluntary inversion of the foot subsequent to operation.
fascial bridge downward through the tibialis sheath. Fixation to the internal cuneiform, as in the first operation.
The fascial incisions are closed wherever possible, not only to restore the normal anatomical relations, but also as far as possible to prevent postoperative hæmorrhage.
Transplantation of the Flexor Longus Hallucis and One of the Peronei (Either Longus or Brevis) for Paralysis of the Gastrocnemius and Soleus Muscles. Indications. In military practice this operation is indicated but seldom, since it rarely or never occurs that the nerves of these muscles are