Evaluation of sciatic nerve compromise during total hip arthroplasty.

Sciatic nerve function was monitored intraoperatively by somatosensory evoked potentials (SEP) in 50 patients during total hip arthroplasty. There were 12 instances of temporary nerve compromise in ten patients: three during acetabular preparation due to retraction, one due to reamer contact, six during femoral reaming due to positioning, and two during trial reduction due to inadequate shortening of the femoral neck. The technique for monitoring, causes, and incidence of nerve compromise during total hip arthroplasty are discussed. SEP monitoring may be especially useful in revision surgery.