[Effects of different sterilization procedures on degree of oxidation of ultra-high molecular weight polyethylene]

We investigated the influence of different sterilization techniques on the degree of oxidation of UHMWPE. Oxidation effects were documented by infrared spectroscopy. The UHMWPE was sterilized with the aid of gamma radiation (2.5 Mrad) in air, gamma radiation in argon, ethylene oxide and autoclaving. Non-sterilized UHMWPE served as control material. The results showed significant differences for the various sterilization techniques employed. The highest degree of oxidation was seen after autoclaving, but gamma radiation was also associated with a significant degree of oxidation. Using gamma radiation in argon, the degree of oxidation was significantly reduced. Following sterilization with ethylene oxide, no oxidation was to be found. In view of these facts, UHMWPE should be sterilized only with ethylene oxide or with gamma radiation in argon.