High-temperature melted, cross-linked, and stabilized ultrahigh molecular weight polyethylene

Abstract

Highly cross-linked ultrahigh molecular weight polyethylene has been one of the most popular materials for the articular surfaces of joint implants. Major challenges in clinical use include the sacrificed mechanical properties and susceptibility to in vivo oxidation due to the high dose radiation cross-linking and subsequent thermal treatments. It is desired to develop highly cross-linked UHMWPE with improved strength and toughness. This chapter introduces a method to improve the ductility of UHMWPE by melting at very high temperatures to eliminate the structural defects. Subsequently, the high-temperature melted (HTM) UHMWPE was radiation cross-linked to generate low cross-link densities in comparison to virgin UHMWPE receiving the same radiation doses. The obtained radiation cross-linked HTM UHMWPE shows low wear and high strength. This HTM method is also used to vitamin E-stabilized UHMWPE, which shows outstanding strength, oxidation stability, and wear resistance. The clinical relevance is discussed.