Neuromusculotendinous transfer: an original surgical concept for the treatment of drop foot with long-term follow-up.

BACKGROUND: An original surgical technique for the correction of drop foot is demonstrated.

METHODS: Eighteen patients with drop foot underwent transfer of the lateral, medial, or both heads of the gastrocnemius muscle to the tendons of the anterior and/or lateral muscle group of the lower leg. The transferred muscle was 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.

RESULTS: In all patients, the transferred gastrocnemius muscle showed signs of reinnervation within an average of 6 months after operation. Ten patients achieved excellent results, having regained stable, fully automatic walking without foot inversion/eversion and active range of foot movement of at least 40 degrees. Four patients achieved good results with active range of movement of less than 40 degrees but very stable functional gait. Satisfactory results were presented in three cases with stable ankle motion. Two of three cases had dual transfer of the gastrocnemius muscle and had a very stable ankle joint. In one fair case, the treatment improved stability and the patient was able to walk.

CONCLUSIONS: To compensate for the loss of function of the anterior muscle compartment, neuromusculotendinous transfer of the gastrocnemius muscle has proved to be highly successful. Voluntary movement of the transferred muscle and fully automatic walking was achieved in the majority of patients treated. In contrast to the commonly used treatment of tibialis posterior muscle transfer, no reeducation of the transferred muscle was needed.