Fabrication and Testing of Silicon Nitride Bearings in Total Hip Arthroplasty Winner of the 2007 HAP PAUL Award

Total hip arthroplasty (THA) hearings were fabricated from silicon nitride (Si3N4) powder. Mechanical testing showed that Si3N4 had improved fracture toughness and fracture strength over modern alumina (Al2O3) ceramic. When tested with Si3N4 cups in a hip simulator, both cobalt-chromium (CoCr) and Si3N4 femoral heads produced low wear rates that were comparable to Al2O3-Al2O3 bearings in THA. This study offers experimental support for a novel metal-ceramic THA bearing couple that combines the reliability of CoCr femoral heads with the wear advantages of ceramic surfaces.