Biotribological behaviour of ultra-high molecular weight polyethylene composites containing Ti in a hip joint simulator

Abstract

The wear of ultra high-molecular weight polyethylene (UHMWPE) has been implicated as the major cause of osteolysis, implant loosening, and late aseptic failure in total hip arthroplasties in vivo, so increasing its wear resistance will be beneficial to obtain high-quality artificial joints. In this paper, the artificial joint acetabular materials of UHMWPE composites reinforced with titanium powders were prepared by the hot pressing formation method. A hip joint wear simulator was run to investigate the biotribological behaviours of these composites against 316L stainless steel in simulated body fluids (SBF-9) lubrication at 35 ± 1°C. The experimental results indicate that the addition of titanium particles in UHMWPE is beneficial for increasing wear resistance of UHMWPE. Under SBF-9 lubrication, the addition of titanium particles into UHMWPE has effect to decrease the wear rates of UHMWPE/Ti composites cups against 316L steel ball heads. The Maximum reduction in wear rates is 50 per cent for the UHMWPE/Ti composite cups with 20 (W) content of titanium particles. Abrasive wear and fatigue wear are found to be the main wear mechanisms of UHMWPE or UHMWPE/Ti composites in hip joint simulator wear under SBF-9 lubrication. The addition of titanium particles in UHMWPE will increase the wear debris size when the content of titanium particles is over 12 wt%.