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Journal of Bone and Joint Surgery - British Volume, Vol 89-B, Issue 9,
1158-1164.
doi: 10.1302/0301-620X.89B9.19282 Copyright © 2007 by British Editorial Society of Bone and Joint Surgery Orientation and wear of the acetabular component in third generation alumina-on-alumina ceramic bearingsAN ANALYSIS OF 33 RETRIEVALSP. J. Lusty, FRCS(Tr & Orth), Arthroplasty Fellow1; A. Watson, FRCS(Tr & Orth), Arthroplasty Fellow1; M. A. Tuke, HNC, ME2; W. L. Walter, FRACS, FAOrthA, PhD, Consultant Orthopaedic Surgeon3; W. K. Walter, FRACS, FAOrthA, Consultant Orthopaedic Surgeon3; and B. Zicat, FRACS, FAOrthA, Consultant Orthopaedic Surgeon3
1 Australian Institute of Musculo-Skeletal Research, Unit 2/12, Fredrick Street, St. Leonards, New South Wales, Australia Correspondence should be sent to Dr W. L. Walter; e-mail: bill.walter{at}hipknee.com.au
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 mm3/yr for the femoral heads, and 0.04 mm3/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° (seven femoral heads) had a median femoral head wear rate of 1.2 mm3/yr, compared with 0 mm3/yr for those with an anteversion of
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15° (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. 