Second-generation Highly Cross-linked X3™ Polyethylene Wear: A Preliminary Radiostereometric Analysis Study

Abstract

Background First-generation highly cross-linked polyethylene liners have reduced the incidence of wear particleinduced osteolysis. However, failed acetabular liners have shown evidence of surface cracking, mechanical failure, and oxidative damage. This has led to the development of second-generation highly cross-linked polyethylene, which has improved wear and mechanical properties and resistance to oxidation in vitro. Owing to its recent introduction, there are no publications describing its clinical performance. Questions/purposes We assessed early clinical wear of a second-generation highly cross-linked polyethylene liner and compared its clinical performance with the published results of hip simulator tests and with first-generation highly cross-linked polyethylene annealed liners. Patients and Methods Twenty-one patients were enrolled in a prospective cohort study. Clinical outcome and femoral head penetration were measured for 19 patients at 6 months and 1 and 2 years postoperatively. Results The median proximal head penetration was 0.009 mm and 0.024 mm at 1 and 2 years, respectively. The median two-dimensional (2-D) head penetration was 0.083 mm and 0.060 mm at 1 and 2 years, respectively. The median proximal wear rate between 1 and 2 years was 0.015 mm/year. Conclusions The wear rate calculated was similar to the in vitro wear rate reported for this material; however, it was less than the detection threshold for this technique. Although longer followup is required for wear to reach a clinically quantifiable level, this low level of wear is encouraging for the future clinical performance of this material.

Short-term Wear Evaluation of Thin Acetabular Liners on 36-mm Femoral Heads

“…Larger reductions in wear could be expected if the comparison were to 36-mm-diameter conventional polyethylene. Additionally, when the wear rates observed in this study were converted to linear penetration values (taking into account the effect of bearing size and clearance), the values were comparable to clinically reported yearly linear penetration values for sequentially crosslinked polyethylene [8].…”

Low Wear of a Second-generation Highly Crosslinked Polyethylene Liner: A 5-year Radiostereometric Analysis Study

“…In 2005, we started a prospective study in which we used radiostereometric analysis (RSA) to measure the wear of this second-generation XLPE liner. At 2 years, we found that the mean proximal wear rate was 0.015 mm/year [5]. There is currently only one other published study describing the clinical performance of the second-generation XLPE liner [6].…”

Evidence Linking Elevated Oxidative Stress and Aseptic Loosening of Hip Arthroplasty

“…In the 1990s, radiation crosslinking combined with thermal treatment has emerged as a technology to improve the wear and oxidation resistance of UHMWPE acetabular components (McKellop et al, 1999, Muratoglu et al, 2001). The new bearing showed reduced wear rate in numerous in vitro and clinical studies (McKellop et al, 1999, Muratoglu et al, 2001, Campbell et al, 2010, Kurtz et al, 2010. The wear rate of the alternative bearing of highly cross-linked polyethylene and CoCr was significantly lower compared to conventional articulation (UHMWPE/CoCr) (McKellop et al, 1999).…”