COMPONENT WEAR OF TOTAL KNEE PROSTHESES USING TI-6AL-4V, TITANIUM NITRIDE COATED TI-6AL-4V, AND COBALT-CHROMIUM-MOLYBDENUM FEMORAL COMPONENTS

A knee simulator was used to study the wear of carbon fiber reinforced UHMWPE (Poly Two) tibial and patellar components against Ti-6Al-4V, titanium nitride (TiN)-coated Ti-6Al-4V, and cobalt-chromium-molybdenum femoral components. The prostheses tested were regular sized Miller-Galante total knees mounted on 316L stainless steel fixtures using bone cement. The wear mechanisms found on the tibial components were scratching, carbon-fiber associated damage, surface deformation, pitting, minor abrasion, and delamination. Three forms of carbon fiber associated damage were identified; fibers pulled from the surface, broken fibers, and UHMWPE removed from the surface fibers. The SEM evaluation revealed a pit forming mechanism. Additional study results are discussed.