Obturator-nerve palsy resulting from intrapelvic extrusion of cement during total hip replacement. Report of four cases.

Obturator neuropathy is an infrequently identified complication of total hip replacement that may cause debilitating pain. There have been isolated reports of this complication in the literature, but only one case has been published in which intrapelvic cement was the causative agent. We are describing the cases of four patients with obturator neuropathy after total hip replacement, documented by electromyography and attributed to intrapelvic extension of cement. In each patient the source of the symptoms was not initially apparent. In three of the patients the extruded cement and obturator nerve were explored surgically. One of the three patients was improved by obturator neurectomy. Of the other two patients, both treated by excision of cement, only one was improved. The fourth patient was not treated. Persistent pain in the groin and thigh, intrapelvic cement visible on plain roentgenograms, and adductor weakness after total hip replacement suggest that this complication has occurred. Electromyography can confirm the presence of obturator neuropathy. Based on this limited series, excision of the extruded cement and preservation of the nerve should be attempted only when the nerve is grossly normal and functional as determined by electrical stimulation at the time of surgical exploration; otherwise, obturator neurectomy should be considered.