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

Total hip arthroplasty (THA) bearings 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.