PAPER 015: BIRMINGHAM HIP RESURFACING ARTHROPLASTY: A SERIES OF 117 CONSECUTIVE HIPS WITH A MINIMUM FIVE-YEAR FOLLOW-UP

Abstract

Purpose: We report a series of 117 consecutive metal-on-metal Birmingham Hip Resurfacings in 105 patients with a minimum of 5 year follow up.

Method: Patients were followed up both clinically and radiographically for a minimum of 5 years following implantation. Revision of either the femoral or acetabular component during the study period is defined as failure.

Results: We followed up 114 of 117 hips (97%). We had 4 failures giving us survivorship at 5 years of 97% (95% confidence interval (CI) 94–100). The mean follow up was 72 months and the mean age at implantation 54.5 years old. The mean Oxford Hip Score fell from 41.6 preoperatively to 15.3 postoperatively (p< 0.0001). The mean Harris Hip Score at 5 year follow up was 96.4. The UCLA Activity Scale rose from 3.93 preoperatively to 7.54 postoperatively (p< 0.001). Radiographic analysis revealed neck thinning in 12 patients (10%) and we define a method of measuring this. The average stem shaft angle in our cohort was 130 degrees and the average cup angle was 36 degrees. Heterotropic ossification was present in 17 hips (15%).

Conclusion: This study confirms that metal-on-metal resurfacing produces an excellent clinical and functional outcome in the younger patient who requires surgical intervention for hip disease. The results compare favourably with those from the originating centre and confirm that resurfacing is well suited for younger higher demand patients. It is the first study with a minimum 5 year follow up outside the originating centre.