Local bone-related adverse events occur more frequently following metal-on metal hip resurfacing (MOMHR) versus convention total hip arthroplasty (THA). High local tissue levels of cobalt and chromium may contribute to impaired bone health, however the systemic effects on bone of exposure to elevated metal levels after MOMHR are unknown. In this cross-sectional study we compared whole body bone mineral density (WB-BMD) and biochemical markers of bone turnover in 31 healthy male subjects at a mean of 8 years after MOMHR versus 31 individually age and time since surgery matched male subjects after conventional THA. All subjects had well-functioning prostheses and were in good self-reported health as assessed by Oxford Hip Score and EQ-5D questionnaire. WB-BMD was measured by dual energy x-ray absorptiometry and adjusted for pre-morbid osteoporosis risk factors using the FRAX tool, and for the presence of the metal prostheses using identical exclusion regions. Bone turnover markers were measured on fasting morning serum or 24hr urine collection by electro-chemiluminescent assay. Cobalt and chromium were measured by ICP-MS.Background and objectives
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