Antioxidant-Loaded Highly Cross-Linked Polyethylene May Reduce Revision Risk in Total Knee Arthroplasty

Background: Although the use of highly cross-linked polyethylene (HXLPE) with antioxidants in total knee arthroplasty (TKA) has increased over time, evidence of any benefit in survivorship over HXLPE without antioxidants is lacking. We sought to compare the TKA revision risk for HXLPE with and without antioxidants. Methods: Data from the Kaiser Permanente health-care system’s total joint replacement registry were used for a cohort study. Adult patients who underwent primary fixed-bearing TKA with patellar resurfacing for osteoarthritis from 2001 to 2023 were included. The study groups were cases of TKA performed with HXLPE with and without antioxidants. The primary outcome was all-cause revision; revisions for septic reasons, any aseptic reasons, wear, and loosening were secondary outcomes. Multivariable Cox proportional-hazards regression was used to evaluate the revision risk by treatment group with an adjustment for covariates. Results: The final study sample included 92,923 TKA cases: 48,846 performed with HXLPE implants with antioxidants and 44,077 performed with HXLPE implants without antioxidants. The mean patient age was 67.7 years, and the mean patient body mass index was 31.2 kg/m 2 . Most patients were female (64.3%) and White (64.8%) and had an American Society of Anesthesiologists classification of 1 to 2 (65.2%). The 13-year crude revision incidence was 3.4% for the antioxidant group and 4.2% for the group without antioxidants. After we adjusted for confounders, we observed a lower revision risk for the antioxidant group compared with the group without antioxidants (hazard ratio [HR], 0.86 [95% confidence interval (CI), 0.79 to 0.95]). When we investigated revisions for specific reasons, we observed a lower risk for aseptic revision (HR, 0.86 [95% CI, 0.76 to 0.97]) and for wear (HR, 0.41 [95% CI, 0.21 to 0.81]) in the antioxidant group. Conclusions: We observed a lower risk of al-cause revision and a lower risk of revision specifically for wear in TKA cases performed with HXLPE with antioxidants added. Level of Evidence: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.