Comparison of 10-year clinical wear of annealed and remelted highly cross-linked polyethylene: A propensity-matched cohort study. (June 2016)

• Record Type: Journal Article
• Authors: Hamai, Satoshi; Nakashima, Yasuharu; Mashima, Naohiko; Yamamoto, Takuaki; Kamada, Tomomi; Motomura, Goro; Imai, Hiroshi; Fukushi, Jun-ichi; Miura, Hiromasa; Iwamoto, Yukihide
• Is Part Of: Journal of the mechanical behavior of biomedical materials. Volume 59(2016)
• Page Start: 99
• Page End: 107
• Publication Date: 2016-06
• Subjects: THA Total hip arthroplasty -- UHMWPE ultra-high-molecular-weight polyethylene -- XLPE cross-linked UHMWPE -- PE polyethylene; Polyethylene -- Wear -- Total hip arthroplasty -- Cross-linked -- Anneal -- Remelt; Biomedical materials -- Periodicals; Biomedical materials -- Mechanical properties -- Periodicals; Biomedical materials; Biomedical materials -- Mechanical properties; Periodicals; Electronic journals; 610.28
• DOI: 10.1016/j.jmbbm.2015.12.022
• Languages: English
• ISSNs: 1751-6161

Abstract

Abstract: No previous studies comparing the clinical wear rates of the two different kinds of cross-linked ultra-high-molecular-weight polyethylene (XLPE), annealed and remelted, are available. We compared the creep and steady wear rates of 36 matched pairs (72 hips in total) adjusting for baseline characteristics with propensity score matching techniques. Zirconia femoral heads with 26-mm diameter were used in all cases. The femoral-head cup penetration was measured digitally on radiographs. Significantly greater creep ( p =0.006) was detected in the remelted (0.234 mm) than annealed (0.159 mm) XLPE. However, no significant difference ( p =0.19) was found between the steady wear rates (0.003 and 0.008 mm/year, respectively) of the annealed and remelted XLPE. Multiple regression analyses showed that remelted XLPE is significant independent variable ( p <0.001) that is positively associated with creep. However, the patient age and body weight, cup size, the liner thickness, cup inclination, follow-up periods, and postoperative Merle d'Aubigné hip score had no significant effects ( p >0.05) on the steady wear rates. No patients exhibited above the osteolysis threshold of 0.1 mm/year, progressive radiolucencies, osteolysis, or polyethylene fracture. This propensity-matched cohort study document no significant difference in wear resistant performances of annealed and remelted XLPE over an average period of 10 years. Graphical abstract: Highlights: No previous studies compared clinical wear rates of annealed and remelted XLPE. We generated 1:1 matched cohorts on the basis of the propensity score. Significantly greater creep was detected in the remelted than annealed XLPE. No significant steady wear rates were found in annealed and remelted XLPE.