Interference screw fixation of tendontransfers in the foot and ankle.

Abstract

Tendon transfers pptay an important role in reconstructive foot and ankle surgery. Multiple methods for fixation of tendon to bone are used including suture of tendon to periosteum, suture into bone troughs, suture anchors, and passage through bone tunnels. With the increasing populatity of hamstring tendon anterior cruciate ligament reconstructions has come new fixation technology. Soft-tissue interference screws have been introduced that allow fixation of tendons into bone tunnels without the need for bone blocks.' Bioabsorbable versions of these screws have been shown to have equivalent or areater initial fixation than their titanium count em art^.^,^ We have recently begun using soft-tissue inierference screw fixation for tendon transfer in the foot. Our initial biomechanical studies in a foot and ankle model suggest its efficacy. Our originaf indication for use of an interference screw was graft length limitation. As part of our reconstruction for posterior tibial tendon insufficiency, we commonly transfer the flexor digitorum longus through a bone tunnef in the navicular, and suture the tendon back to itself. fn a case where sufficient length was not available, rather than rely on the tendon sewn to periosteum, we achieved fixation with a biodegradable interference screw. Since that time, we have confirmed the strength of this fixation method with a biomechanicai study? Several additional tendon transfers have been fixed with this technique without complication. Transfer of the posterior tibial tendon through the interosseus membrane for drop foot and split anterior tibial tendon transfer are also potential indications for interference screw fixation of the tendon transfer in the bony tunnef, Commonly, fixation for these transfers involves the use of felt and a button on the plantar aspect of the foot.5 The tension required can result in