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through bone or cartilage, ligament, and fascia. The fixation must be mechanically fast. When properly executed it can withstand a traction of 20 to 30 pounds.
This mechanical fixation does not, however, meet the physiological demand, for firm though the suture is at the time of the operation, experimental work has shown that such a suture produces a necrosis of the tendon, and therefore there is a possibility that subsequently the tendon may slip from its moorings. This slipping, however, is prevented by suturing the paralyzed tibialis tendon over the extensor hallucis (Figs. 103 and 109). In this way the living tendon-cells of the extensor proprius hallucis above the fixation suture are brought
FIG. 109.-Diagram illustrating the principle of the physioloical tendon fixation. The fixation suture gives the mechanical stability; the adhesion of the tendon to the traumatised periosteum and to the superimposed tibialis tendon gives the physiological security. TS, Tendon sutures; TA, paralyzed tibialis anticus; FS, fixation suture; IC, internal cuneiform; TP, traumatized periosteum; EPH, tendon of the extensor propius hallucis.
into direct contact with the periosteum and with the tendon of the tibialis anticus. Thus the fixation is rendered physiological as well as mechanical, for in the healing process, even though the tendon distal to the fixation suture necroses, an intimate union above this point is bound to occur between the tendon and the traumatized periosteum.
7. The distal stump of the extensor tendon is fastened to the adjacent tendon of the extensor longus digitorum, the fascia is closed, and thus the normal ligaments of the foot are restored. The skin incisions are closed without drainage.
Conversion of the Tibialis Anticus into an Abductor and Pronator. This operation is indicated in cases of paralytic
FIG. 110.-Transplantation of the tibialis anticus for the paralyzed everters of the foot. (From Biesalski and Mayer: "Physiological Method of Tendon Transplantation.") The longitudinal incision in the course of the tibialis anticus tendon exposes it from the upper pole of its sheath to its point of insertion.
clubfoot, due to an inoperable lesion of the musculocutaneous nerve. Occasionally it can be employed in the spastic talipes
varus associated with a hemiplegia produced by an injury to the cerebral cortex. It should be performed only when a marked degree of correction is required, for the action of the muscle is so powerful as easily to produce an overcorrection. When slighter grades of varus are present, the extensor proprius hallucis should be used instead of the tibialis anticus. The two operations are so nearly alike that the description of the one suffices.
1. A 2-inch curved incision is made over the insertion of the peroneus tertius (see Fig. 111). Skin, fascia and subcutane
ous tissue are retracted to form a flap.
2. The tendon of the peroneus tertius, which is almost always present, is then slit for several centimeters as in Fig. 103 and the metatarsal bones grooved for the reception of the tibialis anticus.
3. An incision is made in the course of the tibialis tendon from the upper pole of its sheath, 11⁄2 to 2 inches above the malleolus, to its insertion (Fig. 110). The sheath is opened near its upper pole. Here again the exact knowledge of the sheath, its limits and inner architecture is necessary for the neat execution of the operation.
4. It will be remembered that in describing the first operation attention was called to the fascial relations of the three anterior muscles of the foot: the tendons above the upper pole of the tibialis sheath lie in the same fascial compartment, then for about an inch the extensor proprius hallucis and the extensor longus digitorum lie in the same fascial compartment separated from the tibialis anticus by a fascial septum. From the level of the malleolus downward there are three such compartments, one for each of the three anterior muscles (Fig. 112). The transfer of the tibialis tendon is best made above the fascial septum separating it from the extensors, since in this way danger of adhesions is entirely avoided.
The lateral margin of the divided fascia just proximal to the upper pole of the tibialis sheath is retracted until the extensor longus digitorum is visible (Fig. 111). This level lies above the upper pole of the extensor sheath. To enter the sheath the loose connective tissue surrounding the extensor tendons-the paratenon-is incised until the bare
Tibialis anticus tendon
Extensor proprius hallucis
Probe emerging overthe insertion of the peroneus tertius
Probe passing through the common
FIG. 111. Transplantation of the tibialis anticus for the paralyzed everters of the foot. (From Biesalski and Mayer: "Physiological Method of Tendon Transplantation.") A convex incision is made over the insertion of the peroneus tertius. A probe is passed downward through the sheath of the extensor longus digitorum and made to emerge over the insertion of the peroneus tertius. By means of the probe the tibialis anticus tendon, which has been cut off at its insertion, preferably with a bit of the bone attached to it, is drawn downward through the common extensor sheath and fastened to the slit peroneal tendon by the technic shown in Fig. 103.
tendons cells are reached. A probe passed along the tendon is then certain to enter the sheath. Passing the probe through the sheath again calls for a knowledge of its inner architecture. All five tendons, the four extensors and the peroneus tertius are connected with one another by means of a common mesotenon. The operator must be careful to pass the probe superficial to the tendons; otherwise he will draw the tibialis
FIG. 112.-Semi-diagrammatic cross-section of the calf, through the tips of the malleoli, about 2 inch lower than the section shown in Fig. 104. Note that the three extensor muscles are divided from one another by dense fascial septa. (From Biesalski and Mayer: "Physiological Method of Tendon
anticus between the extensor tendons and thus tend to interfere with their function as well as its own. The probe is guided in the direction of the peroneus tertius, made to puncture the lower pole of the sheath, and to appear between the fascia and the tendon near its insertion.
5. The sheath of the tibialis anticus is now slit open its entire length and the fascia below the sheath incised until the insertion of the tendon is visible (Fig. 110). The tendon must