In vivo wear rate of the Birmingham Hip Resurfacing arthroplasty. A review of 10 retrieved components.

Abstract The wear of 8 femoral and 2 acetabular components of the Birmingham Hip Resurfacing (Midland Medical Technologies Ltd, Birmingham, UK) was measured using a coordinate measuring machine (CMM5; SIP, Geneva, Switzerland). After a median in situ time of 13 months, measurements of the Birmingham Hip Resurfacing femoral heads revealed a median volumetric wear of 2.9 mm 3 . In one case with a cup abduction angle of 70°, a significantly higher wear of 17.8 mm 3 was found. The 2 acetabular components showed volumetric wear of 5.4 and 27.6 mm 3 after 14 and 15 months in vivo. The wear rates of the investigated femoral components were somewhat, but not significantly, higher than the previously investigated 28-mm Metasul heads (median, 0.8 mm 3 ; Zimmer GmbH, Winterthur, Switzerland).