Intraoperative evoked potential monitoring in acetabular surgery.

The effectiveness of intraoperative sciatic nerve monitoring was evaluated for 88 consecutive patients undergoing open reduction and internal fixation for acetabular fractures. Intervention outcomes and pre and postoperative electrophysiologic status were compared to postoperative functional findings. Only 2% of the patients demonstrated iatrogenic sciatic nerve palsies. Functional and evoked potential findings were in agreement for 89% of the patients with postoperative palsies, while 26% of the functionally normal patients showed abnormal evoked potentials. Intervention occurred in 55 surgeries; 80% of interventions involved the peroneal nerve. Forty one of the 55 patients who had interventions based on evoked potential results showed recovery of responses to baseline. Of the 14 patients with incomplete intervention recovery, 11 showed impaired postoperative responses. Patients with preoperative evoked potential abnormalities did not show increased susceptibility to iatrogenic evoked potential changes.