title: The influence of inert packaging on the shelf ageing of gamma-irradiation sterilised ultra-high molecular weight polyethylene.
abstract: Ultra-high molecular weight polyethylene (UHMWPE) is used for wear applications in total hip prostheses and total knee prostheses. Sterilisation of these prostheses is commonly by gamma-irradiation. This process creates reactive free radicals in the UHMWPE, greatly increasing its susceptibility to oxidative degradation. This study has investigated the influence of air and vacuum packaging on the properties of gamma-irradiated UHMWPE (GUR1050) following 3 years of shelf ageing. The findings indicate that vacuum packaging minimises oxidative degradation reactions that occur for UHMWPE during shelf ageing. However, gamma-irradiation of vacuum-packaged UHMWPE promotes a degree of cross-linking. It is proposed that this may enhance the wear performance of UHMWPE. Accelerated ageing studies indicate that 3 years of shelf ageing would also seem to reduce the susceptibility of gamma-irradiated UHMWPE to oxidative degradation upon removal from its vacuum packaging.
authors.affiliation: School of Mechanical and Manufacturing Engineering, The Queen's University of Belfast, Ashby Building, Stanmillis Road, Belfast, N Ireland, BT9 5AH, UK.
authors.forename: S
authors.initials: S
authors.lastname: Lu
authors.forename: J F
authors.initials: JF
authors.lastname: Orr
authors.forename: F J
authors.initials: FJ
authors.lastname: Buchanan
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry / Q000528:radiation effects*; D004349:Drug Packaging / Q000379:methods; D004355:Drug Stability; D005720:Gamma Rays; D006622:Hip Prosthesis; D006801:Humans; D066298:In Vitro Techniques; D007720:Knee Prosthesis; D008422:Materials Testing; D010084:Oxidation-Reduction; D011095:Polyethylenes / Q000737:chemistry / Q000528:radiation effects*; D013242:Sterilization / Q000379:methods; D013718:Tensile Strength; D013997:Time Factors; D014618:Vacuum
chemical_list: D001672:Biocompatible Materials; D011095:Polyethylenes; C111601:ultra-high molecular weight polyethylene