Reduction of osteolysis with use of Marathon cross-linked polyethylene. A concise follow-up, at a minimum of five years, of a previous report.

We previously reported wear data at a minimum of two years following thirty-four total hip replacements with a Marathon cross-linked polyethylene liner and twenty-four replacements with a conventional (gamma-sterilized-in-air) Enduron polyethylene liner. In this current study, with sequential five-year radiographs, wear rates were determined with use of linear regression analysis. The Marathon polyethylene had average wear rates of 15.4 mm(3)/yr and 8.0 mm(3)/million cycles. The Enduron polyethylene had average wear rates of 55.5 mm(3)/yr and 29.9 mm(3)/million cycles. The adjusted volumetric wear rate of the Marathon polyethylene was 73% lower than that of the Enduron polyethylene (p = 0.001). Osteolysis developed in eight of the twenty-four hips with an Enduron liner but was not apparent in any hip with a Marathon liner.