Hamouda, Mohammed

» Bearing materials that are used in total hip arthroplasty have undergone major developments in structure and durability since the 1960s. » Osteolysis and aseptic loosening associated with ultra-high molecular weight polyethylene had been a major concern; this led to the development of the first generation of highly cross-linked polyethylene (HXLPE), which was followed by a second generation of HXLPE. » The second generation of HXLPE was introduced with the aim of providing oxidative stability while maintaining high wear resistance. » Oxidative stabilization methods include mechanical deformation and annealing, incorporation of antioxidant-containing materials, high-pressure crystallization after melting, and polyethylene surface-grafting with a biocompatible polymer. » Results of clinical studies with ≤5 years of follow-up have shown that second-generation HXLPE acetabular liners are superior to any of the previous generation with regard to wear rates; however, additional studies are needed to compare second-generation materials among each other.