Oxidation and oxidation potential in contemporary packaging for polyethylene total joint replacement components

The packaging and chemical stability of both conventional and highly crosslinked polyethylene (PE) components available for clinical use in Italy were analyzed. A total of 100 sterilized PE components were entered by 18 orthopedic manufacturers into the study. Six of the manufacturers were Italian and the remaining were based in Europe or America. Hydroperoxide, oxidation, and trans-vinylene levels within the PE components were characterized using Fourier-transform infrared spectroscopy (FTIR). None of the 31 gas-sterilized components had detectable free radicals, hydroperoxide content, or oxidation. Among radiation-sterilized inserts, the highest oxidation and hydroperoxide levels were associated with gas-permeable and polymer-barrier packaging. To the authors' knowledge, this is the first study that relates elevated oxidation and hydroperoxide content in gamma-sterilized PE components to certain types of contemporary, polymeric barrier packaging.