Relationship of Plasma Metal Ions and Clinical and Imaging Findings in Patients with ASR XL Metal-on-Metal Total Hip Replacements

Abstract

In our sample, with a threshold of 5 ppb, abnormal plasma metal ions were associated with larger sizes of pseudotumors when present, but were not predictive of patient symptoms. Abnormal plasma cobalt levels have a significant association with periprosthetic lucency and presence of pseudotumor. Plasma chromium shows a similar pattern of association with lucency and presence of pseudotumor, although the relationships were not significant. Metal ion analysis should be used in conjunction with clinical and imaging evaluation and not as a sole indirect screening test when evaluating patients following metal-on-metal hip arthroplasty.