NERVE INJURY AFTER POSTERIOR AND DIRECT LATERAL APPROACHES FOR HIP-REPLACEMENT - A CLINICAL AND ELECTROPHYSIOLOGICAL STUDY

Nerve injury is a rare complication of total hip replacement which may be related to the exposure used for the operation. The posterior appr oach is traditionally associated with injury to the sciatic nerve. We have compared the incidence of nerve injury after primary total hip re placement (THR) using either a posterior or a direct lateral approach. We studied 42 consecutive patients undergoing primary total hip repla cement. The surgeons used a posterior (22 patients) or direct lateral (20 patients) approach in accordance with their normal practice. The f emoral, posterior tibial and common nerves were assessed clinically an d electrophysiologically by electromyography (EMG) and measurement of the velocity of nerve conduction before operation and at four weeks af ter, All patients were free from symptoms of nerve injury after operat ion but five lesions were identified in four patients by the electroph ysiological studies; the obturator nerve was involved in two, the femo ral in one, the common peroneal in one and the posterior tibial in one . All these injuries occurred using the lateral approach. Clinical ass essment alone underestimates the incidence of nerve injury complicatin g THR, Our study does not confirm the association of nerve injury,vith the posterior approach which had been described previously.