%0 Journal Article
%T Elastoplastic behavior of highly cross-linked and vitamin E-stabilized polyethylene - A biomechanical study.
%A Lu YC
%A Wu CY
%A Chang TK
%A Huang CH
%A Huang CH
%J Clin Biomech (Bristol, Avon)
%V 59
%N 0
%D 11 2018
%M 30245408
%F 2.034
%R 10.1016/j.clinbiomech.2018.09.021
%X 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.<BR>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.<BR>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.<BR>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.