Long-term prognosis of nerve palsy after total hip arthroplasty: results of two-year-follow-ups and long-term results after a mean time of 8 years.

INTRODUCTION: Nerve damage is a rare but serious complication after THA. There exist only little data about the outcome of these patients particularly regarding the long-term results later than 2 years postoperatively. Aim of this study is to answer the following questions: Is the recovery to be expected for light nerve lesions different from the severe ones? Is there a possibility of nerve recovery more than 2 years after THA? Is the potential of nerve recovery depending on the affected nerve?

MATERIALS AND METHODS: This study investigates 2,255 primary THA as well as revision surgeries performed from 1988 to 2003 relating to iatrogenic nerve lesion. We classified the nerve lesion according to the core muscle strength in severe (M0-M2) and light (M3-M4) nerve damage and differentiated between femoral, sciatic and superior gluteal nerve, according to the electromyography.

RESULTS: We found 34 cases of iatrogenic nerve damage representing an incidence of 1.5 %. 17 of 34 (50 %) patients showed a complete recovery after 2 years. Out of the remaining 17 patients, six out of seven patients with a final examination after a median time of 93 months achieved further improvement. The different nerves showed no significant different potential of recovery.

CONCLUSIONS: In contrast to the literature, an improvement beyond the limit of 2 years is probable and independent of the nerve affected.