INFLUENCE OF OXIDE VERSUS NON-OXIDE FEMORAL HEADS ON THE OXIDATION OF POLYETHYLENE ACETABULAR LINERS

IntroductionThe longevity of highly cross-linked polyethylene (XLPE) bearings is primarily determined by its resistance to long-term oxidative degradation. Addition of vitamin E to XLPE is designed to extend in vivo life, although it has unintended consequences of inducing higher frictional torque and increased wear when articulating against metallic femoral heads.1–3 Conversely, lower friction was observed when oxide ceramic heads were utilized.3 Previous studies suggest that oxide ceramics may contribute to XLPE oxidation, whereas a non-oxide ceramic, silicon nitride (Si3N4), might limit XLPE's degradation.4 To corroborate this observation, an accelerated hydrothermal ageing experiment was conducted using static hydrothermal contact between XLPE and commercially-available ceramic femoral heads.Materials and MethodsTwo sets of four types of ceramic femoral heads, consisting of three oxides (Al2O3 BIOLOX®forte, and ZTA BIOLOX®delta, CeramTec, GmbH, Plochingen, Germany; and m-ZrO2 OXINIUMTM, Smith & Nephew...