Large diameter metal on metal articulations. Comparison of total hip arthroplasty and hip resurfacing arthroplasty.

Abstract The use of large diameter metal bearing total hip arthroplasty (THA) and hip resurfacing arthroplasty (HRA) increased in popularity in the last decade. More recent literature has highlighted the effect of head size in patient outcomes. Data was obtained from the Australian Orthopaedic Association National Joint Replacement Registry (AOA-NJRR) to evaluate the Birmingham (MoM) bearing surface when used with THA and HRA. There is no difference in the overall rate of revision between the THA and HRA but head size has a significant effect on revision rate. The data show that small diameter metal bearings in HRA (below 50mm) have a higher rate of revision than large diameter metal bearings in HRA (equal to and above 50mm) ( P P =.027). The revision rate for large diameter HRA compared to small diameter THA is not significantly different P =.670. We recommend caution when choosing either a large diameter (≥50mm) metal on metal THA or small diameter (