<p>Raised levels of blood metal ions are associated with failed metal-on-metal hip resurfacings and total hip arthroplasties, according to a study published in the July 2 issue of The Journal of Bone & Joint Surgery.</p><p>The researchers found that patients with failed arthroplasty had significantly higher blood cobalt and chromium ion levels than patients with non-failed arthroplasty (P < 0.01).</p>