title: The effect of real-time aging on the oxidation and wear of highly cross-linked UHMWPE acetabular liners.
abstract: 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.
authors.affiliation: Orthopaedic Biomechanics and Biomaterials Laboratory, Massachusetts General Hospital, 55 Fruit Street, GRJ-1206, Boston, MA 02114, USA.
authors.forename: Keith K
authors.initials: KK
authors.lastname: Wannomae
authors.forename: Steven D
authors.initials: SD
authors.lastname: Christensen
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Freiberg
authors.forename: Shayan
authors.initials: S
authors.lastname: Bhattacharyya
authors.forename: William H
authors.initials: WH
authors.lastname: Harris
authors.forename: Orhun Kamil
authors.initials: OK
authors.lastname: Muratoglu
mesh_terms: 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
chemical_list: D001672:Biocompatible Materials; D011095:Polyethylenes; C111601:ultra-high molecular weight polyethylene