title: Wear of highly cross-linked polyethylene acetabular cup in Japan.
abstract: The wear characteristics of ultra-high-molecular-weight polyethylene acetabular cups irradiated with 6.0 to 7.5 Gy of gamma-irradiation were studied in a hip simulator and in vivo in 70 hips for 6 to 39 months. The linear wear was 2.5% to 4.5% of the wear seen in conventional polyethylene cups. A biphasic wear pattern was observed over time with a relatively large wear in the first year and a subsequent leveling of the wear rate curve. The linear wear rate in the second phase (steady state) was 0.006 mm/y. The extent of decrease in clinical wear of 6.0-Mrad polyethylene (Aeonian, Kyocera Corp, Kyoto, Japan) cups is comparable with the decrease of the in vitro wear measured by the hip simulation test.
authors.affiliation: H Oonishi Memorial Joint Replacement Institute, Tominaga Hospital, Osaka-City, Japan.
authors.forename: Hironobu
authors.initials: H
authors.lastname: Oonishi
authors.forename: Sok Chol
authors.initials: SC
authors.lastname: Kim
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Takao
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kyomoto
authors.forename: Mikio
authors.initials: M
authors.lastname: Iwamoto
authors.forename: Masaru
authors.initials: M
authors.lastname: Ueno
mesh_terms: D000077:Acetabulum; D006622:Hip Prosthesis; D006801:Humans; D007564:Japan; D008953:Models, Anatomic; D020959:Polyethylene / Q000737:chemistry / Q000528:radiation effects; D011475:Prosthesis Failure
chemical_list: D020959:Polyethylene