期刊Study of fatigue resistance of chemical and radiation crosslinked medical grade ultrahigh molecular weight polyethylene.pdfVIP

Study of fatigue resistance of chemical and radiation crosslinked medical grade ultrahigh molecular weight polyethylene D. A. Baker,1 R. S. Hastings,2 L. Pruitt1,3 1Department of Mechanical Engineering, University of California, Berkeley, California 94720 2Research Division, DePuy Inc., Warsaw, Indiana 46581 3Department of Bioengineering, University of California, Berkeley, California 94720 Received 11 November 1998; accepted 26 March 1999 Abstract: The aim of this work is to understand the role of clinical relevance, the combined effects of sterilization and chemical and radiation induced crosslinking on the fatigue aging are examined in two commercially available crack propagation resistance of medical grade ultrahigh mo- crosslinked resins. Nonsterile and unaged resins serve as a lecular weight polyethylene (UHMWPE). In recent years, control. To evaluate the effect of crosslinking, a comparison the need to improve the tribological performance of UHM- is made to uncrosslinked resins. Scanning electron micros- WPE used in total joint replacements has resulted in the copy is used to provide an understanding of fatigue fracture widespread utilization of crosslinking as a method to im- mechanisms in the crosslinked polymers. The results of this prove wear resistance. Although crosslinking has been study show that the current level of crosslinking used in shown to drastically improve the wear resistance of the orthopedic resins for enhanced wear resistance is not ben- polymer, the potential trade-off in fatigue properties has yet eficial for fatigue crack propagation resistance. © 1999 John to be addressed. Fatigue crack propagation resistance is a Wiley Sons, Inc. J Biomed Mater Res, 46, 573–581, 1999. concern in tibial inserts where large cyclic stresses are suf- ficient to drive the gro