A Clinical Evaluation of Tendon Transplantation in the Paralytic Foot

The method of implantation of the tendon into bone has been studied. The outcome did not seem to be appreciably affected by any of the three methods used. The degree

of tension under which a tendon was attached was found to be impossible of evaluation; however, it is our impression that a maximum degree of tension is desirable for the best result. Some transfers failed when they had to function against a fixed deformity of bone. In only one instance did a transfer produce an opposite deformity. In certain feet, especially in club feet, we were impressed by the strength of those tendons which had been passed subcutaneously rather than beneath the inferior extensor retinaculum.

Correlation of the ages of the patients at the time of operation with the operative results shows no great difference in the results of the operations done in the first decade as compared with those done in the second decade of life. Too few operations were performed in the third decade to provide figures of any value.

It is noted that the benefits derived from tendon transfer arise from the removal of a deforming factor almost as often as from the application of a positive force in a new site. Stabilization of the foot by triple arthrodesis in a good weight-bearing position has again been shown to be of considerable importance in the outcome of the average tendon transfer. Our impression is that the tibialis anterior, when normal, provides a more functional transfer than other muscles about the ankle. This was most noticeable in the patients with club-foot but was also true of the small group with residua of poliomyelitis. Transfers to the heel for calcaneus deformity resulting from poliomyelitis have proved worth while. For the most part, a satisfactory result requires osseous stabilization.

We have felt that many instances of transfer failure were due to tendon laxity at the time of the operation or to the pulling-out of the tendon attachment in the postoperative period. In the operations for club-foot, however, ten feet had excellent results from tendon transplants when the attachment was by intra-osseous suture. This is not a particularly strong suture method, and yet the outcome was good. Is there perhaps some change in tendon structure in paralytic conditions, especially in poliomyelitis, that allows for stretching in the tendon or the muscle belly?

Rating of the tibialis anterior tendon in patients with club-foot dropped only 0.6 of one grade after transfer. Is the tibialis anterior in the club-foot a better than normal muscle, or are the peroneals subnormal in their function? Both factors may be true. We have found in this very small series that the tibialis anterior function after transfer backward through the interosseous membrane was better than that of the tibialis posterior when it was transferred forward. The reason for this is not apparent.

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