LAUSR

Background: Vitamin E‐stabilized cross‐linked polyethylene has been touted to alleviate the negative effects of oxidation. Although it has demonstrated significant improvements in wear resistance, bio‐tribology, and oxidative resistance, little is known about the effect of antioxidants and dosage of cross‐linking on the mechanical strength. This study aimed to evaluate the mechanical properties of these novel materials, which are commonly used in orthopedic implants. Methods: Samples of different polymers were prepared with various levels of cross‐linking and with or without vitamin E‐stabilization and then tested according to ASTM D695 and D638. The elastoplastic characteristics under compression and tension were compared between the groups. Findings: Vitamin E‐stabilized cross‐linked polyethylene showed a significant increase in elastic modulus over other groups, with a maximum increase of 26% in compression and 40% in tension when compared to the highly cross‐linked group without vitamin E stabilization. The elastoplastic behavior under compression differed to that in tension for all polymers, demonstrating the anisotropic characteristics of these polymers. Interpretation: The lower mechanical strength of highly cross‐linked polyethylene has been a complication with the use of this polymer in orthopedic liners. This current study suggests that vitamin E‐stabilized cross‐linked polyethylene could be a suitable alternative material for knee implants because of its improved strength in resisting external forces.