Temporary antibiotic-loaded cement spacers are widely used for treating chronic periprosthetic hip infections. The aim of this study is to evaluate the short-term tribological performance of ultra-high-molecular-weight polyethylene (UHMWPE) and (60Co) gamma-irradiated cross-linked UHMWPE (XLPE) self-mated systems as frictional pairs for temporary total hip spacers. A three-axial hip joint simulator, FIME II, was used to test the UHMWPE and XLPE self-mated systems under variable load profiles. A fetal bovine serum solution was used as a lubricant. After simulation tests, wear measurements of damaged coupled surfaces were made with a coordinate measuring machine. Finally, surfaces were characterized with scanning electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, and nanoindentation tests. The mass loss test results for UHMWPE were 11.91 ± 3.43 mg for the cups and 4.57 ± 0.92 mg for the heads. Whereas, the results for XLPE showed a significant reduction, with mean mass loss values of 6.59 ± 0.14 mg for the cups and 2.82 ± 0.59 mg for the heads, suggesting the viability of the self-mated XLPE contact pair for a temporary total hip spacer.
Keywords: Cross-linked UHMWPE; friction pair; hip joint simulator; hip prosthesis spacer; orthopedic materials; tribology of materials.