Vitamin E-stabilized UHMWPE for total joint implants: a review.
BACKGROUND
Osteolysis due to wear of UHMWPE limits the longevity of joint arthroplasty. Oxidative degradation of UHMWPE gamma-sterilized in air increases its wear while decreasing mechanical strength. Vitamin E stabilization of UHMWPE was proposed to improve oxidation resistance while maintaining wear resistance and fatigue strength.


OBJECTIVE
We reviewed the preclinical research on the development and testing of vitamin E-stabilized UHMWPE with the following questions in mind: (1) What is the rationale behind protecting irradiated UHMWPE against oxidation by vitamin E? (2) What are the effects of vitamin E on the microstructure, tribologic, and mechanical properties of irradiated UHMWPE? (3) Is vitamin E expected to affect the periprosthetic tissue negatively?


METHODS
We performed searches in PubMed, Scopus, and Science Citation Index to review the development of vitamin E-stabilized UHMWPEs and their feasibility as clinical implants.


RESULTS
The rationale for using vitamin E in UHMWPE was twofold: improving oxidation resistance of irradiated UHMWPEs and fatigue strength of irradiated UHMWPEs with an alternative to postirradiation melting. Vitamin E-stabilized UHMWPE showed oxidation resistance superior to that of irradiated UHMWPEs with detectable residual free radicals. It showed equivalent wear and improved mechanical strength compared to irradiated and melted UHMWPE. The biocompatibility was confirmed by simulating elution, if any, of the antioxidant from implants.


CONCLUSIONS
Vitamin E-stabilized UHMWPE offers a joint arthroplasty technology with good mechanical, wear, and oxidation properties.


CONCLUSIONS
Vitamin E-stabilized, irradiated UHMWPEs were recently introduced clinically. The rationale behind using vitamin E and in vitro tests comparing its performance to older materials are of great interest for improving longevity of joint arthroplasties.
Dipartimento di Chimica IFM and NIS Centre of Excellence, Università di Torino, Via Pietro Guria, 7, 10125, Torino, Italy. pierangiola.bracco@unito.it
Pierangiola
P
Bracco
Ebru
E
Oral
D005720:Gamma Rays; D006801:Humans; D007595:Joint Prosthesis; D008422:Materials Testing; D010084:Oxidation-Reduction; D011095:Polyethylenes; D011474:Prosthesis Design; D013314:Stress, Mechanical; D014810:Vitamin E / Q000737:chemistry / Q000494:pharmacology*
D011095:Polyethylenes; C111601:ultra-high molecular weight polyethylene; D014810:Vitamin E