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Journal of Bone and Joint Surgery - British Volume, Vol 84-B, Issue 5,
641-646.
doi: 10.1302/0301-620X.84B5.12384 Copyright © 2002 by British Editorial Society of Bone and Joint Surgery Failure of hydroxyapatite-coated acetabular cupsTEN-YEAR FOLLOW-UP OF 85 LANDOS ATOLL ARTHROPLASTIESK.-A. Lai, MD, Professor of Orthopaedics; and W.-J. Shen, MD, Consultant Orthopaedic SurgeonPo-Cheng Orthopaedic Institute C.-H. Chen, MD, Attendant Orthopaedic Surgeon; and C.-Y. Yang, MD, Professor and Chairman of Orthopaedic Department Department of Orthopaedics W.-P. Hu, MSc, Biomedical Engineering; and G.-L. Chang, PhD, Professor of Biomedical Engineering National Cheng Kung University Medical Centre, 138 Shen-li Road, Tainan, Taiwan. Correspondence should be sent to Professor K.-A. Lai. Between March 1990 and May 1991 we performed 85 primary total hip replacements in 74 patients using the Landos Atoll hydroxyapatite (HA)-coated cup and the Corail HA-coated stem. The patients were followed up for a mean of ten years. Of the 85 cups, 26 (31%) have already been revised and a further six are radiologically unstable and awaiting revision. Two femoral stems have been revised for infection without loosening. The retrieved acetabular cups were studied by SEM and image-processing techniques to quantify the amount of residual HA on the cup. This was correlated with the clinical variables and modes of failure. The residual HA (as a percentage of the surface) on the loose cups correlated negatively with the duration of implantation (r = –0.732, p < 0.001). Six cups were stable at revision and had more residual HA coating than those which were loose (p < 0.01). The rate of failure of the Landos Atoll HA-coated, smooth hemispherical cup with screw fixation is unacceptably high. Resorption of the HA coating is markedly increased in loose cups compared with stable cups. HA coating cannot substitute for stable mechanical fixation. This article has been cited by other articles:
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