Surface engineering of prosthetic knee components

Conventional total and uni-compartmental knee replacement designs usually incorporate metal femoral and tibial components with an ultra high molecular weight polyethylene (UHMWPE) bearing surface. The tibial components can be modular or monobloc and are of the fixed bearing type in the majority of cases. Mobile bearings are also in common use with a modular meniscal insert with either rotation only or a combination of rotation and translation. Wear of the UHMWPE components remains of primary concern in these prosthetic devices. Catastrophic wear and delamination has been largely addressed by improvements in UHMWPE quality and manufacturing methods, however, abrasive and adhesive wear of the UHMWPE components remains a concern for long-term survivorship of total knee replacement. This review very briefly covers published long-term survivorship of primary knee arthroplasties, primary wear mechanisms present in knee replacements and the potential for wear reduction by surface engineering of the metal wear counterfaces. There are several methods and materials available, which offer the potential for significantly reduced wear.