Long-term in-vitro wear performance of an innovative thermo-compressed cross-linked polyethylene

New cross-linked polyethylene acetabular cups, obtained by thermo-compression process, were compared with conventional and traditional commercially available cross-linked polyethylene in terms of wear behaviour in a hip simulator for 10 million cycles using bovine calf serum as lubricant. Gravimetric measurements revealed significant differences between the wear behaviours of the five sets of acetabular cups. In particular, this new type of thermo-compression cross-linked wore more than the traditional cross-linked polyethylene but exhibited a wear rate about four times lower than conventional ultra-high-molecular-weight-polyethylene. The FTIR analyses indicate that oxidation to various extents appears as a consequence of gamma-irradiation in presence of oxygen.