LONG-TERM FOLLOW UP OF MATCHED BIRMINGHAM HIP RESURFACING AND HYBRID TOTAL HIP REPLACEMENTS IN YOUNG PATIENTS

Abstract

Introduction: We compared the eight- to ten-year clinical and radiological results of the metal-on-metal Birmingham hip resurfacing (BHR) with a hybrid total hip arthroplasty (HYBRID) in two groups of 54 hips, previously matched for gender, age, body mass index and activity level.

Method: Patients were followed up in outpatients and function assessed by using the Oxford Hip Score, UCLA activity score and Euroqol score. Radiographs were assessed for osteolysis and wear. BHR were also assessed for the presence of a pedestal sign around the femoral component.

Results: The mean follow up of the BHR group was 9 years (8.17 to 10.33) and for hybrids 10 (7.53 to 14.5). Four patients had died in the hybrid group and one in the BHR. Four were lost to follow up in each group. The revision rate in the BHR group was 9.25% verses 18% in the Hybrid, a further eight patients in the hybrid group have evidence of wear and osteolysis and are intended for revision (p=0.008). One patient in the BHR group was explored for late onset sciatic nerve palsy. All patients in the hybrid group had evidence of polyethylene wear, mean 1.24mm (0.06–3.03). 90% of the BHR group had evidence of a pedestal sign.

Satisfactory function was shown in both groups. There was no significant difference between groups with respect to the OHS but the UCLA score was superior in the BHR group (p=0.008). There was no significant difference for Euroqol visual analogue score. 56% of hybrids were delighted with their hip replacement verses 65% of BHR patients.

Discussion: After ten years the hip resurfacing patients were still more active and had a lower revision burden than the hybrid hip replacements. Both groups showed worrying radiological evidence of change with long-term follow-up.