BRIDLE TRANSFER FOR PARESIS OF THE ANTERIOR AND LATERAL COMPARTMENT MUSCULATURE

In the Riordan (bridle) transfer, the posterior tibialis muscle as mot or is routed through the interosseous membrane and anastomosed into a ''bridle'' formed by the distal tibialis anterior and peroneus longus muscles. In theory, the bridle provides inversion/eversion balance eve n if the transfer effects only tenodesis. However, the procedure has b een criticized because its insertion is not into bone. This review ana lyzes the use of bridle transfer in flaccid paresis involving musculat ure innervated by the peroneal nerve. Surgery was performed 1 to 3 yea rs after injury for patients with traumatic etiology. Ten patients are reviewed at 61 months' mean follow-up. Eight patients had traumatic p eroneal nerve loss. Two had neuromuscular etiology. Evaluation include d review of records, telephone interviews, and physical examinations. Data on functional status included walking barefoot, running, need for bracing, return to duty, and patient satisfaction. Physical examinati on recorded ankle position and motions, gait findings, and results of static electromyograms. All patients were able to walk barefoot, but 6 of 10 had a mild to moderate limp. Five patients returned to running initially; only two were able to keep running. Nine patients were brac e-free initially (polio sequela required bracing initially), and four others returned to bracing. Of these, two experienced an acute ''teari ng'' and dorsiflexion loss, one sustained a prolonged gradual loss of dorsiflexion, and one sustained a contralateral cerebrovascular accide nt. Only three of seven patients returned to active duty, and one is o n jump status. All patients were satisfied with their initial result. Only two patients had no detectable swing phase problems (both returne d to active duty). Five patients had peroneal nerve exploration with r epair or neurolysis; two of them sustained complete transections. Post operative electromyograms showed insignificant, if any, nerve return. The Riordan transfer works well for neuromuscular flaccid paresis and in patients with peroneal nerve injuries with low demands. It may stre tch out over time to the point of acute failure in patients with high demands. Concurrent peroneal nerve exploration and repair did not seem to be beneficial in this small study.