Abstract
Aims: The aim of this retrospective study is comparatively analysing cemented versus hydroxyapatite coated cementless þxation. A 10-year survival analysis of 2 patient cohorts operated by the same senior surgeons and with the same stem design was performed. Methods: Between 1990 and 2000, 1207 primary prostheses, 599 cemented and 608 cementless stems have been implanted. When mineral bone density and anatomic shape of the femur advised against inserting a cement-less stem a third generation cementing technique was chosen. In all cases an anatomic CoCr alloy stem and an alumina coupling were employed. Cementless stems were fully coated with hydroxyapatite. To provide homogeneity for preoperative diagnosis, only replacements for primary arthritis were considered. The remaining prostheses were 432 cemented and 366 cementless. The cumulative probability of revision for aseptic loosening of the stem was estimated by the Kaplan-Meier method. Results: 98.5% of the cemented stems and 96.7% of the cementless stems survived at 10 years, the difference between the 2 cohorts being statistically not signiþcant (p> 0.05). Conclusions: Using the same stem design and ceramic coupling, thus avoiding the confounding presence of polyethylene wears debris on study outcomes, allows for the reliable evaluation of stem þxation effectiveness. Noting that the evaluated survival rates are consistent with the literature, we are conþdent that at 10 years cementless stems performed as cemented.
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.
