Abstract
Aims: The aim of this open prospective study was to evaluate the minimum 2-year follow-up outcome of a consecutive series of low friction total hip arthroplasties combining zirconia on polyethylene. Methods: Between January 1997 and June 1999 fifty-five total hip arthroplasties were performed in 51 patients. The mean age was 52.2 ± 12 years. The 22.2-mm femoral head made of zirconia ceramic was secured to the femoral component through a Morse taper that had an angle of 11°25 for 27 hips and 5°40 for 33 hips. All prostheses were of Charnley-Kerboull design. Clinical results were evaluated according to the Merle d’Aubigné hip score. Wear of the acetabular component and periprosthetic osteolysis was measured on serial radiographs of the pelvis. Results: The mean follow-up of the series was 32 months (24 to 48 months). No patient was lost to follow-up. The mean functional hip score significantly increased from 12.2 ± 2.6 preoperatively to 17.8 ± 0.2 at the latest follow-up (paired Student’s t test, p < 0.0001). None of the acetabular or femoral component had migrated. Wear of the socket was always undetectable on plain radiographs. However, lytic endosteal lesions of the calcar were observed in 19 of the 55 arthroplasties (34.5%). These lytic lesions appeared between the first and second postoperative year. Conclusions: Early calcar osteolysis observed in this study can be related to either run-in wear or to preliminary severe wear. The authors do not recommend further use of zirconia ceramic until long-term follow-up studies are available.
Theses abstracts were prepared by Professor Dr. Frantz Langlais. Correspondence should be addressed to him at EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
