Abstract
Purpose: Alumina is a bioinert ceramic used for total hip arthroplasty as an alternative to metal-on-polyethylene bearings which can wear producing massive osteolysis and loosening. The purpose of this retrospective analysis was to examine the Ceraver combination implant which uses a cemented smooth titanium femoral stem, a 32 mm alumina head, and a cemented alumina cup.
Material and methods: Between December 1979 and February 1983. 104 total hip arthroplasties were performed in 81 patients, mean age 57.8 years (2.1–70.9). The main indication was primary degenerative disease (71 hips). The Postel Merle d’Aubigné score was used for clinical assessment. Plain x-rays were used to establish the actuarial survival curves using the Harris criteria for radiological loosening for the cup and the Massin criteria for the femoral piece. Periprosthetic femoral and acetabular osteolysis were noted. Histological samples taken during revision procedures were analysed.
Results: Six hips with suppuration were not retained for analysis. The clinical scores for the other 98 hips were, at last follow-up: excellent in 34, very good in 21, good in 16, fair in 21, and poor in 6. Mean follow-up was eleven years and reached 18 years for 38 hips. Fracture of the alumina head (n=1), aseptic certain radiographic loosening of the cup (n=24), probable radiolographic loosening of the cup (n=12), and certain radiographic loosening of the femoral piece (n=3) were noted. Revision was required for 23 hips for replacement of the cup (n=23), the head (n=12), or the femoral stem (n=1). There were no cases of massive radiographic osteolysis. The histological examination of surgical specimens obtained at revision were normal in all cases (very moderate aseptic foreign body reaction). Excepting the cases of suppuration, the estimated actuarial survival without revision at 20 years was 61.4% (57.1% for he radiographic cup loosening criteria and 95.2% for the radiographic femoral implant criteria).
Discussion: This analysis confirms the long-term biotolerance of the alumina-alumina bearing despite the poor maintenance of the cemented alumina cup. It also confirms the good maintenance of the cemented smooth titanium femoral stem.
Conclusion: Cup anchorage must be improved to use the alumina-alumina bearing which does not cause osteolysis nor histological reactions.
Correspondence should be addressed to SOFCOT, 56 rue Boissonade, 75014 Paris, France.
