CEMENTED VERSUS UNCEMENTED FEMORAL STEMS IN RHEUMATOID ARTHRITIS PATIENTS IN THE NORWEGIAN ARTHROPLASTY REGISTER

Abstract

There has been no general agreement about the use of uncemented hip prostheses in patients with rheumatoid arthritis (RA). In the present study we compared the results for the cemented and uncemented stem that most commonly had been used in RA patients in the Norwegian Arthroplasty Register.

MATERIAL AND Methods: All hospitals in the country participate and report their primary and revision operations of RA patients to the register. This group constitutes 3.5% of the patients in the register. For the present study we included primary prosthesis operations in RA patients during 1987–2005, where either the Corail or the Charnley stem, the most commonly used uncemented and cemented stems, had been used. We calculated survival by the Kaplan-Meier method and by Cox multiple regression with adjustment for age and gender.

Results: The 10 years survival of the total hip prostheses were 81 % in the uncemented group and 89 % in the cemented group. However, the revisions of the uncemented prostheses were mainly performed due to cup problems. With revision of stem for any reason as end-point, the 10-year survival was 98% for the fully HA-coated uncemented Corail stem and 91% for the cemented Charnley stem. In the Cox regression, the risk for revision of the Charnley stem was 3.4 times increased compared to the Corail (95% CI: 1.43–8.06. P< 0.006). Also revision due to aseptic stem loosening was statistically significant increased for the Charnley stem, whereas there was no significant difference concerning revision due to dislocation or periprosthetic fracture.

Conclusions: Both stems had a 10-years survival better than 90%, and the uncemented stem had excellent results in RA patients. However, the uncemented total hip prostheses had inferior results compared to the cemented total hip prostheses due to problems with the uncemented cups that had been used in association with this uncemented stem.