title: Wear resistance and mechanical properties of highly cross-linked, ultrahigh-molecular weight polyethylene doped with vitamin E.
abstract: Our hypothesis was that cross-linked, ultrahigh-molecular weight polyethylene (UHMWPE) stabilized with vitamin E (alpha-tocopherol) would be wear-resistant and fatigue-resistant. Acetabular liners were radiation cross-linked, doped with vitamin E, and gamma-sterilized. Hip simulator wear rate of vitamin E-stabilized UHMWPE was approximately 1 and 6 mg/million-cycles in clean serum and in serum with third-body particles, respectively, a 4-fold to 10-fold decrease from that of conventional UHMWPE. The ultimate strength, yield strength, elongation at break, and fatigue resistance of vitamin E-stabilized UHMWPE were significantly higher than that of 100 kGy-irradiated and melted UHMWPE, and were unaffected by accelerated aging. Rim impingement testing with 3.7-mm-thick acetabular liners up to 2 million-cycles showed no significant damage of the cross-linked liners compared with conventional, gamma-sterilized in inert UHMWPE, vitamin E-stabilized liners. The data indicate good in vitro wear properties and improved mechanical and fatigue properties for vitamin E-stabilized, cross-linked UHMWPE.
authors.affiliation: Department of Orthopaedic Surgery, Orthopaedic Biomechanics and Biomaterials Laboratory, Massachusetts General Hospital, Boston, Massachusetts, USA.
authors.forename: Ebru
authors.initials: E
authors.lastname: Oral
authors.forename: Steven D
authors.initials: SD
authors.lastname: Christensen
authors.forename: Arnaz S
authors.initials: AS
authors.lastname: Malhi
authors.forename: Keith K
authors.initials: KK
authors.lastname: Wannomae
authors.forename: Orhun K
authors.initials: OK
authors.lastname: Muratoglu
mesh_terms: D005221:Fatigue; D006622:Hip Prosthesis; D008422:Materials Testing; D011095:Polyethylenes / Q000737:chemistry* / Q000528:radiation effects; D011474:Prosthesis Design; D013314:Stress, Mechanical; D013718:Tensile Strength; D014810:Vitamin E
chemical_list: D011095:Polyethylenes; C111601:ultra-high molecular weight polyethylene; D014810:Vitamin E