Hip resurfacing for rheumatoid arthritis: independent assessment of 11-year results from an international register.

Total hip replacement has shown good outcomes for patients with rheumatoid arthritis. Can hip resurfacing give similar results for patients with rheumatoid arthritis? Using an international hip resurfacing register, 47 patients with rheumatoid arthritis were identified and age and gender matched to a group of 131 randomly selected patients with osteoarthritis of the hip joint. Patients completed a questionnaire to record function and implant revision. Hierarchical regression, Cox regression and Kaplan-Meier method were used for analysis. There was a significant increase in post operative hip score in both groups (p < 0.001) with rheumatoid group scoring higher as compared to the osteoarthritis group (p = 0.23). The post operative score was not significantly influenced by pre-operative score and age (p = 0.15 and 0.84, respectively) but the pre-operative score was a predictor of implant failure (p = 0.02). Patient mobility was affected by age with younger patients scoring high on mobility as compared to older patients (p = 0.01). The Kaplan-Meier analysis showed a survival rate of 96.3% in the rheumatoid group and 97.8% in the osteoarthritis group. This difference was not significant (Log rank test, p = 0.45). Our results from an independent and international register show that hip resurfacing provides good post-operative hip function and excellent implant survival for patients with rheumatoid arthritis of the hip joint. This procedure can be considered as a viable option for management of rheumatoid arthritis of the hip joint.