Novel Hindered Phenolic Antioxidants Comparison on the Performance of Crosslinked Ultrahigh Molecular Weight Polyethylene for Use in Total Joint Replacement

Vitamin E (VE) is commercially used to stabilize highly crosslinked ultrahigh molecular weight polyethylene (UHMWPE) against oxidation in artificial joints. Despite being FDA approved, there is a discord that VE hinders the crosslinking efficiency and compromises the wear resistance of UHMWPE bearings, thereby limiting its use at high concentrations. It thus emphasizes the need for efficient antioxidants to stabilize UHMWPE liners in total joint replacements (TJRs). In this work, the oxidation resistance of highly crosslinked UHMWPE was demonstrated to improve with novel hindered phenolic antioxidants such as butylated hydroxytoluene (BHT) and Irganox 1010 (Irg) without compromising crosslinking efficiency. These antioxidants were blended with UHMWPE at 0.5% (w/w) concentration and consolidated by compression molding prior to radiation crosslinking with E‐beam radiation. Four UHMWPE blends, including control‐UHMWPE (without antioxidant), VE‐UHMWPE, BHT‐UHMWPE, and Irg‐UHMWPE, were developed and characterized with respect to crosslink density, oxidation induction time (OIT), mechanical properties, surface hydrophobicity, and biocompatibility to evaluate overall performance. Among the tested blends, Irg‐UHMWPE exhibited the highest OIT, hydrophobicity and highest biocompatibility along with the second‐highest crosslink density. Although BHT‐UHMWPE attained the highest crosslink density, it exhibited a low OIT value. Overall, Irg‐UHMWPE ranked highest in this study in fulfilling the performance criteria essential for artificial joint bearings.