title: Wear and acetabular component orientation in third generation alumina-on-alumina ceramic bearings: an analysis of 33 retrievals [corrected].
abstract: We studied 33 third generation, alumina ceramic-on-ceramic bearings retrieved from cementless total hip replacements after more than six months in situ. Wear volume was measured with a Roundtest machine, and acetabular orientation from the anteroposterior pelvic radiograph. The overall median early wear rate was 0.1 mm(3)/yr for the femoral heads, and 0.04 mm(3)/yr for the acetabular liners. We then excluded hips where the components had migrated. In this stable subgroup of 22 bearings, those with an acetabular anteversion of < 15 degrees (seven femoral heads) had a median femoral head wear rate of 1.2 mm(3)/yr, compared with 0 mm(3)/yr for those with an anteversion of > or =15 degrees (15 femoral heads, p < 0.001). Even under edge loading, wear volumes with ceramic-on-ceramic bearings are small in comparison to other bearing materials. Low acetabular anteversion is associated with greater wear.
authors: Australian Institute of Musculo-Skeletal Research, Unit 2/12, Fredrick Street, St. Leonards, New South Wales, Australia.
authors: P J
authors: PJ
authors: Lusty
authors: A
authors: A
authors: Watson
authors: M A
authors: MA
authors: Tuke
authors: W L
authors: WL
authors: Walter
authors: W K
authors: WK
authors: Walter
authors: B
authors: B
authors: Zicat
mesh_terms: D000077:Acetabulum / Q000601:surgery; D000537:Aluminum Oxide; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D002516:Ceramics; D019544:Equipment Failure Analysis / Q000379:methods; D006622:Hip Prosthesis; D006801:Humans; D009949:Orientation; D011475:Prosthesis Failure
chemical_list: D000537:Aluminum Oxide