92 patients scheduled for total hip arthroplasty were randomized to one of 4 bearing surfaces: cobalt-chromium on ultra-high-molecular-weight polyethylene, oxidized zirconium on ultra-high-molecular-weight polyethylene, cobalt-chromium on highly crosslinked polyethylene, or oxidized zirconium on highly crosslinked polyethylene. Patients were assessed for wear rate over 10-year follow-up. Both raw wear rate and wear rate adjusted for "bedding in" within the first 6-12 weeks were reported. In both cases, rates were lower in the groups which received the XLPE liner compared to the UHMWPE liner. Of note, >50% of the total 10-year wear observed in the XLPE liner groups occurred within the first 6-12 weeks.