Common peroneal nerve palsy following total hip arthroplasty: prognostic factors for recovery.

BACKGROUND Common peroneal nerve palsy, although rare, is a serious complication of total hip arthroplasty. Although several publications have dealt with the risk factors for peroneal nerve palsy, there is little literature regarding the time it takes for the nerve to recover and the factors that influence its recovery. The purpose of this study was to elucidate the clinical course of this injury and identify prognostic factors for recovery. METHODS From January 2000 to December 2007, 7969 primary and 1601 revision total hip arthroplasties were performed at our institution. Common peroneal nerve palsy developed following thirty-one (0.32%) of these procedures. Thirty of these patients were evaluated by a neurologist at the time of diagnosis and at regular intervals thereafter. Univariate and multivariate regression analyses were performed to identify risk factors and prognostic factors for recovery. RESULTS On average, patients who developed common peroneal nerve palsy were significantly younger (fifty-six years) than those who did not develop palsy (sixty-three years, p < 0.05). Higher body mass index (BMI) was a negative prognostic factor for recovery from palsy (p < 0.05). The palsy was incomplete in twenty-five of the thirty patients, and fourteen of these recovered fully at a mean of 10.3 months (range, 1.0 to 50.0 months). Three of the five patients with complete nerve palsy recovered fully at a mean of 14.5 months (range, 8.0 to 21.0 months). CONCLUSIONS Only one-half of the patients in the study who developed common peroneal nerve palsy following total hip arthroplasty recovered fully. The mean time to recovery was approximately one year for partial peroneal palsy and one and one-half years for complete palsy. Obesity adversely influenced the nerve recovery.