RESULTS OF THE BIRMINGHAM HIP AT 2–5 YEARS

Abstract

We undertook this study to determine whether the concerns regarding early complications following hip resurfacing were justified. One hundred and twenty-nine consecutive resurfacing procedures (118 patients, mean age 52.3 years) utilising the Birmingham hip prosthesis were reviewed at a mean of 36.1 (range 24–62) months. Pre-operative diagnosis included osteoarthritis (94), Dysplasia (19), AVN (8), Inflammatory arthropathy (8). Immediate post-operative x-rays were analysed for prosthesis placement and interface gaps. Follow up films were assessed for lucent lines, osteolysis, bone resorption and component migration. Harris hip and UCLA activity scores were recorded pre and post operatively on all patients. Three patients were lost to follow up. Five cases were revised. Three cases due to femoral neck fracture. One patient developed late infection and subsequently fractured. All four patients underwent successful revision to an uncemented stem. One patient required revision of the acetabular component due to migration following a fall three years postop. Five cases of osteolysis were seen (Acetabulum (3), Femur (2)). Four cases of bone resorption at the femoral neck were noted. Two patients developed significant heterotopic ossification (Brooker II & III). All patients with radiological abnormalities were asymptomatic. The mean Harris hip score pre-operatively was 56.4 increasing to 97.5 post-operatively. The mean UCLA activity score pre-operatively was 3.3 increasing to 7.4 post-operatively. Kaplan-Meier survivorship was 94.7% at 5 years. Surface replacement gives excellent clinical results and offers significant advantages over conventional hip replacement. Long-term results are awaited to fully evaluate the effects of resurfacing arthroplasty.