A comparison of the effect of large and small metal-on-metal bearings in total hip arthroplasty on metal ion levels and the incidence of pseudotumour

This report has been verified by one or more authors of the original publication.

185 patients scheduled for metal-on-metal (MoM) total hip arthroplasty (THA) were randomized to either large-head or small-head articulation. Main outcomes of concern in this study included whole blood cobalt and chromium ion concentrations and the incidence of pseudotumor development on MRI over a 5-year follow-up. Cobalt levels were significantly lower in the large-head group compared to the small-head group at 36, 48, and 60 months postoperatively, while chromium levels were significantly lower in the large-head group compared to the small-head group at 12 and 48 months postoperatively. The incidence of moderate pseudotumor development was significantly lower in the large-head group compared to the small-head group.