Abrasion resistance of oxidized zirconium in comparison with CoCrMo and titanium nitride coatings for artificial knee joints.

Most total knee replacement joints consist of a metal femoral component made from a cobalt-chromium- molybdenum (CoCrMo)-alloy and a tibial component with an ultrahigh molecular weight polyethylene (UHMWPE) bearing surface. Wear of the UHMWPE remains the primary disadvantage of these implants. The allergic potential ascribed to CoCrMo-alloys is a further concern. Other metallic alloys with and without ceramic coatings are clinically used to avoid these problems. This study compared the mechanical surface properties of an oxidized zirconium alloy with those of cast and wrought CoCrMo and TiAlV6-4. Additionally, the influence of a titanium nitride (TiN)-plasma coating on the surface properties was investigated. The composition of the oxidized zirconium layer was analyzed. Micro- and macrohardness tests as well as adhesion tests were used to reveal material differences in terms of their abrasive wear potential in artificial joints.