Abstract
Materials and methods: Based on data from the Norwegian Arthroplasty Register, we reviewed the results of uncemented femoral stems in Norway in the period 1987 to 1. April 2002. We compared these results to the results of the cemented Charnley monoblock stem, which still is the most commonly used femoral stem in Norway. Only prostheses used in more than one hundred hips were included. Based on these criteria, we identified a total of 7 856 primary total hip prostheses in fifteen different uncemented stems. With the Kaplan-Meier method, the survival of the primary prostheses were calculated and compared with each other and with the Charnley stem. The endpoint was revision in which the whole prostheses or the stem alone was removed or exchanged. The Cox regression analysis was used to adjust for differences in age, gender, diagnosis, former operations and profylactic antibiotics. Separate analyses for patients younger than 60 years and for stems with follow-up less than ten years were done. Reasons for revision in the uncemented Corail stem and the cemented Charnley stem was analysed.
Results: The Corail stem, wich is the most commonly used uncemented stem in Norway (n=3590), had excellent long term results. 10 years survival in patients younger than 60 years was for the Corail 97,5% and for the Charnley 90,2% (p=0,001). Reasons for revision of the Corail were in most cases pain and repeated dislocations. Aseptic loosening was the dominant cause of failure of the Charnley stem. Several uncemented stems have results which are as good as or superior to the Charnley. The Femora, the Biofit, the Parhofer and the Harris Galante stems all had inferior results. Many uncemented stems with less than 10-years of follow-up have excellent 5 years survival.
The 10 years survival of uncemented total hip arthroplasties, however was inferior to the all-cemented Charnley. Cup revisions due to aseptic loosening, and wear and/or osteolysis were the reasons for this.
Discussion: The Corail stem has excellent long term results. Several newer stems have promising short- and medium term results. Due to inferior results of unce-mented cups, however, most Norwegian orthopaedic surgeons use cemented primary hip replacements.
Theses abstracts were prepared by Professor Roger Lemaire. Correspondence should be addressed to EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
