Hip Arthroplasty to alleviate pain related to arthritic degeneration has become one of the most common orthopedic procedures performed. As the elderly population expands, the number of such procedures can be expected to continue to increase. An electrodiagnostic evaluation can aid in localization, help identify the mechanism of injury, and be used as a tool to identify the nature and severity of the nerve pathology. Electrodiagnosis can also be used to generate a prognosis for recovery from nerve damage following hip surgery. © 1998 John Wiley & Sons, Inc. Muscle Nerve 21:519–527, 1998.

Hip Arthroplasty to alleviate pain related to arthritic degeneration has become one of the most common orthopedic procedures performed. As the elderly population expands, the number of such procedures can be expected to continue to increase. An electrodiagnostic evaluation can aid in localization, help identify the mechanism of injury, and be used as a tool to identify the nature and severity of the nerve pathology. Electrodiagnosis can also be used to generate a prognosis for recovery from nerve damage following hip surgery. CASE REPORTClinical History. The patient was a 59-year-old woman who underwent a revision of a right total hip prosthesis that had been originally placed for hip pain related to severe osteoarthritis. A posterolateral approach was used. Revision was required because of aseptic loosening of the femoral component. Besides the previous hip arthroplasty on the right, past medical history included hypertension, diet-controlled diabetes mellitus, and a previous total hip arthroplasty on the left side also for severe osteoarthritis. On postoperative day 1, she was noted to have weakness in dorsiflexion of the right foot and toes along with sensory loss over the dorsum of the foot. The level of injury was not clear at that time. Following transfer to the rehabilitation hospital for postarthroplasty remobilization, the patient was found to drag the right forefoot when attempting to walk. The patient was referred for needle electromyography (EMG) and nerve conduction studies (NCSs) to determine the site and severity of nerve injury and to