Birmingham Hip Metal-on-Metal Resurfacing – 94.5% Ten-Year Survival

Results from an independent centre

November 1, 2011

Abstract

We report the findings of an independent review of 230 consecutive
Birmingham hip resurfacings (BHRs) in 213 patients (230 hips) at a
mean follow-up of 10.4 years (9.6 to 11.7). A total of 11 hips
underwent revision; six patients (six hips) died from unrelated
causes; and 13 patients (16 hips) were lost to follow-up. The
survival rate for the whole cohort was 94.5% (95% confidence
interval (CI) 90.1 to 96.9). The survival rate in women was 89.1%
(95% CI 79.2 to 94.4) and in men was 97.5% (95% CI 92.4 to 99.2).
Women were 1.4 times more likely to suffer failure than men. For
each millimetre increase in component size there was a 19% lower
chance of a failure. The mean Oxford hip score was 45.0 (median
47.0, 28 to 48); mean University of California, Los Angeles activity
score was 7.4 (median 8.0, 3 to 9); mean patient satisfaction score
was 1.4 (median 1.0, 0 to 9). A total of eight hips had lysis in the
femoral neck and two hips had acetabular lysis. One hip had
progressive radiological changes around the peg of the femoral
component. There was no evidence of progressive neck narrowing
between five and ten years.

Our results confirm that BHR provides good functional outcome and
durability for men, at a mean follow-up of ten years. We are now
reluctant to undertake hip resurfacing in women with this implant.