The effect of real-time aging on the oxidation and wear of highly cross-linked UHMWPE acetabular liners.
Irradiation decreases the wear of ultra-high molecular weight polyethylene (UHMWPE) but generates residual free radicals, precursors to long-term oxidation. Melting or annealing is used in quenching free radicals. We hypothesized that irradiated and once-annealed UHMWPE would oxidize while irradiated and melted UHMWPE would not, and that the oxidation in the former would increase wear. Acetabular liners were real-time aged by immersion in an aqueous environment that closely mimicked the temperature and oxygen concentration of synovial fluid. After 95 weeks of real-time aging, once-annealed components were oxidized; the melted components were not. The wear rate of the real-time aged irradiated and once-annealed components was higher than the literature reported values of other contemporary highly cross-linked UHMWPEs. Single annealing after irradiation used with terminal gamma sterilization may adversely affect the long-term oxidative stability of UHMWPE components.
Wannomae
Keith K
KK
Orthopaedic Biomechanics and Biomaterials Laboratory, Massachusetts General Hospital, 55 Fruit Street, GRJ-1206, Boston, MA 02114, USA.
Christensen
Steven D
SD
Freiberg
Andrew A
AA
Bhattacharyya
Shayan
S
Harris
William H
WH
Muratoglu
Orhun Kamil
OK
D000077:Acetabulum / Q000033:anatomy & histology; D001672:Biocompatible Materials / Q000737:chemistry* / Q000528:radiation effects*; D001673:Biodegradation, Environmental; D006622:Hip Prosthesis; D006801:Humans; D008422:Materials Testing; D010084:Oxidation-Reduction; D011095:Polyethylenes / Q000737:chemistry* / Q000528:radiation effects*; D013997:Time Factors; D014965:X-Rays
D001672:Biocompatible Materials; D011095:Polyethylenes; C111601:ultra-high molecular weight polyethylene