title: Biotribology of a vitamin E-stabilized polyethylene for hip arthroplasty - Influence of artificial ageing and third-body particles on wear.
abstract: The objective of our study was to evaluate the influence of prolonged artificial ageing on oxidation resistance and the subsequent wear behaviour of vitamin E-stabilized, in comparison to standard and highly cross-linked remelted polyethylene (XLPE), and the degradation effect of third-body particles on highly cross-linked remelted polyethylene inlays in total hip arthroplasty. Hip wear simulation was performed with three different polyethylene inlay materials (standard: γ-irradiation 30 kGy, N2; highly cross-linked and remelted: γ-irradiation 75 kGy, EO; highly cross-linked and vitamin E (0.1%) blended: electron beam 80 kGy, EO) machined from GUR 1020 in articulation with ceramic and cobalt-chromium heads. All polyethylene inserts beneath the virgin references were subjected to prolonged artificial ageing (70°C, pure oxygen at 5 bar) with a duration of 2, 4, 5 or 6 weeks. In conclusion, after 2 weeks of artificial ageing, standard polyethylene shows substantially increased wear due to oxidative degradation, whereas highly cross-linked remelted polyethylene has a higher oxidation resistance. However, after enhanced artificial ageing for 5 weeks, remelted XLPE also starts oxidate, in correlation with increased wear. Vitamin E-stabilized polyethylene is effective in preventing oxidation after irradiation cross-linking even under prolonged artificial ageing for up to 6 weeks, resulting in a constant wear behaviour.
authors.affiliation: Aesculap AG Research & Development,Tuttlingen, Germany; Ludwig Maximilians University Clinic for Orthopaedic Surgery, Campus Grosshadern, Munich, Germany. Electronic address: thomas.grupp@aesculap.de.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Grupp
authors.affiliation: Aesculap AG Research & Development,Tuttlingen, Germany.
authors.forename: Melanie
authors.initials: M
authors.lastname: Holderied
authors.affiliation: Aesculap AG Research & Development,Tuttlingen, Germany.
authors.forename: Marie Anne
authors.initials: MA
authors.lastname: Mulliez
authors.affiliation: Aesculap AG Research & Development,Tuttlingen, Germany.
authors.forename: Rouven
authors.initials: R
authors.lastname: Streller
authors.affiliation: Clinic for Orthopaedic Surgery, University of Essen, Germany.
authors.forename: Marcus
authors.initials: M
authors.lastname: Jäger
authors.affiliation: Aesculap AG Research & Development,Tuttlingen, Germany.
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Blömer
authors.affiliation: Ludwig Maximilians University Clinic for Orthopaedic Surgery, Campus Grosshadern, Munich, Germany.
authors.forename: Sandra
authors.initials: S
authors.lastname: Utzschneider
mesh_terms: D019644:Arthroplasty, Replacement, Hip; D019544:Equipment Failure Analysis; D066298:In Vitro Techniques; D008422:Materials Testing; D018384:Oxidative Stress; D020959:Polyethylene / Q000008:administration & dosage* / Q000737:chemistry; D014810:Vitamin E / Q000008:administration & dosage* / Q000737:chemistry
chemical_list: D014810:Vitamin E; D020959:Polyethylene
keywords: Hip wear simulation; Oxidative degradation; Third-body contamination; Vitamin E stabilization; XLPE remelted