Persistent traumatic peroneal nerve palsy - surgical treatment by neuromusculotendinous gastrocnemius muscle transfer

Aims and Objectives: Common peroneal nerve palsy is a relatively frequent complication in trauma of the knee and lower extremity. Persistent traumatic peroneal nerve palsy is usually treated by tendon transfer. A surgical concept for the treatment by neurotized lateral gastrocnemius muscle transfer is demonstrated with the aim of restoring active voluntary dorsiflexion. The indication, the surgical technique and the results obtained in two own cases with review of the literature are presented. Materials and Methods: Surgical technique: The lateral head of the gastrocnemius muscle is transferred to the tendons of the anterior tibial muscle group. The intact proximal end of the deep peroneal nerve is transpositioned to the tibial nerve of the gastrocnemius muscle by microsurgical technique. The transferred muscle is reinnervated by nerve coaptation between the undamaged proximal part of the deep peroneal nerve and the motor branch of the tibial nerve supplying the gastrocnemius muscle. The key steps of the surgical technique are described. Results: Short term results of the own cases appeared excellent. In both patients the transferred gastrocnemius muscle showed signs of reinnervation within 6 months after the operation. The patients achieved stable functional gait, voluntary movement of the transferred muscle and active range of motion of about 40 degrees. The early clinical results are compared with the clinical series in the literature since 1994. Conclusion: Early clinical results after the neuromusculotendinous gastrocnemius muscle transfer appear highly successful. They still need to be compared with conventional tendon transfer procedures. The described operative approach offers some advantages compared with other methods in the reconstruction of a drop foot secondary to traumatic common peroneal nerve palsy in a well-selected group of patients. In contrast to the commonly used treatment of tibialis posterior muscle transfer no reeducation of the transferred muscle is needed. We review the indications and limitations of this technique.