FIVE- TO TEN-YEAR RESULTS OF THE BIRMINGHAM HIP RESURFACING

Abstract

Introduction: Excellent early and medium term results have been reported for hip resurfacing. This is a minimum 5 year clinical outcome review of the resurfacings performed by a single surgeon in an independent series.

Methods: There were 329 resurfacings (302 patients). The mean follow-up is 6.6 years (5 to 9.2). 2 patients were lost to follow-up and 6 have died due to unrelated causes. The mean age at the time of surgery was 56.0 years (28.2 to 75.5). Mann-Whitney U-test was used to analyse change in hip scores, and survival analysis was performed using the Kaplan-Meier analysis using SPSS statistical software package.

Results: The mean Harris Hip Score was 51.3 (7 to 91) pre-operatively and 94.3 (24 to 100) postoperatively (p< 0.001). The mean Oxford hip scores was 38.3 (16 to 60) pre-operatively and 15.9 (12 to 46) postoperatively (p< 0.001). The mean Western Ontario and McMaster Universities Osteoarthritis Index score was 47.9 (5 to 96) pre-operatively and 6.9 (0 to 58) postoperatively (p< 0.001). The University of California Los Angeles activity scale was 4.7 (1 to 9) pre-operatively and 7.5 (3 to 10) post-operatively (p< 0.001). Mean satisfaction at the latest follow up was 9.3 (3–10) out of 10.

There were ten revisions. Kaplan-Meier analysis showed survival of 96.5% (95% confidence interval 94.7 to 98.4) at 7 years taking revision for any cause as the end-point. There was a 3.9 times higher failure rate in women compared to men.

Discussion: Medium term results of hip resurfacing in this independent series are excellent and are comparable to those from the pioneering centre. Failure rates are significantly higher in women compared to men. Long term follow up results are still awaited, however careful consideration should be made when selecting patients for hip resurfacing particularly in women.