Abstract
Introduction and purpose: Different bearing surfaces have been used to prevent osteolysis, such as alumina-alumina. We present here an analysis of the results of a prospective multi-center study of complications related to the use of alumina-alumina bearings.
Materials and methods: In 4 hospitals 319 cups with hydroxyapatite stems and alumina-alumina bearing surfaces were implanted with a mean follow-up of 5.6 years (range: 3–8). The mean age of the patients was 52.7 (range: 14–70). Alumina wear was calculated by means of a special program.
Results: Revision was performed of 5 cups and 2 stems. In one hip with a horizontal acetabular angle (35°) and a thin alumina liner (size 50/32), an acetabular liner fracture occurred 36 months after surgery. The probability of not undergoing revision due to any cause was 96.9% (CI 95%:94.7–99.1%). None of the patients reported any type of noise. All the non-revised cases showed good results both on clinical and X-ray exam at the end of the follow-up. The difference between the center of the head of the femur and the center of the head of the cup at 6 weeks after surgery was −2.45+0.53 mm, with no further changes seen during the follow-up.
Conclusions: These data suggest that the prosthetic alumina-alumina bearing surface has excellent results over 5 years and that alumina fractures are infrequent. No changes were seen in terms of the penetration of the femoral head in any case. Longer follow-ups are necessary to determine if the reduction of wear translates into less osteolysis and loosening.
The abstracts were prepared by E. Carlos Rodríguez-Merchán, Editor-in-Chief of the Spanish Journal of Orthopaedic Surgery and Traumatology (Revista de Ortopedia y Traumatología). Correspondence should be addressed to him at: Sociedad Española de Cirugía Ortopédica y Traumatología, calle Fernández de los Ríos 108, 28015-Madrid, Spain
