Wear Characteristics of Conventional Ultrahigh-Molecular-Weight Polyethylene Versus Highly Cross-Linked Polyethylene in Total Ankle Arthroplasty:

Background:The aim of this study was to compare the polyethylene wear rate, particle size, and particle shape of primary semiconstrained, fixed-bearing, bone-sparing total ankle arthroplasty using conventional ultrahigh-molecular-weight polyethylene (CPE) versus highly cross-linked polyethylene (HXLPE) by applying a level walking input using a joint simulator.Methods:Two fixed-bearing total ankle replacement systems with different types of polyethylene liners were tested: (1) CPE sterilized in ethylene oxide, and (2) HXLPE sterilized with gas plasma after electron beam irradiation. Three implants for each design underwent wear testing using gravimetric analysis over 5 million simulated walking cycles. A fourth implant was used as a load soak control. Equivalent circle diameter (ECD) and equivalent shape ratio (ESR) were computed to determine particle size and particle shape, respectively.Results:The mean wear rate from 1.5 to 5 million cycles (MC) was 2.0 ± 0.3 mg/MC for HXLPE and 16.7 ± 1.3 mg/MC for CPE...