title: Survival of primary total hip arthroplasty in rheumatoid arthritis patients.
abstract: OBJECTIVE
  There has been a limited amount of research on survival of total hip arthroplasties (THAs) in rheumatoid arthritis (RA). We therefore performed a population-based, nationwide study to compare the survival of primary THAs in RA patients and in osteoarthritis (OA) patients. We also wanted to identify predictors of THA failure in RA patients.
  
  
  METHODS
  Using the Danish Hip Arthroplasty Registry, we identified 1,661 primary THAs in RA patients and 64,858 in OA patients, all of which were inserted between 1995 and 2008. The follow-up period was up to 14 years for both groups.
  
  
  RESULTS
  Regarding overall THA survival, the adjusted RR for RA patients compared to OA patients was 0.81 (95% CI: 0.65-1.01). We found no difference in survival of cups between primary THAs in RA and OA patients. In contrast, there was better overall survival of stems in RA patients than in OA patients, both regarding revision due to aseptic loosening (adjusted RR = 0.58; 95% CI: 0.34-0.99) and for any reason (adjusted RR = 0.63; 95% CI: 0.45-0.88). In RA patients, males had a higher risk of revision than females concerning aseptic loosening of the stem, any revision of the stem, and any revision of both components.
  
  
  CONCLUSIONS
  The overall survival of primary THAs in RA patients is similar to THA survival in OA patients. Stem survival appeared to be better in RA patients, while survival of the total THA concept did not show any statistically significant differences between the two groups. In RA patients, males appear to have a greater risk of revision than females.
authors.affiliation: Department of Orthopaedic Surgery, Odense University Hospital, and Clinical Institute, University of Southern Denmark, Odense, Denmark. christoffer.rud-soerensen@ouh.regionsyddanmark.dk
authors.forename: Christoffer
authors.initials: C
authors.lastname: Rud-Sørensen
authors.forename: Alma B
authors.initials: AB
authors.lastname: Pedersen
authors.forename: Søren Paaske
authors.initials: SP
authors.lastname: Johnsen
authors.forename: Anders Hammerich
authors.initials: AH
authors.lastname: Riis
authors.forename: Søren
authors.initials: S
authors.lastname: Overgaard
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000601:surgery*; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects; D003718:Denmark; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000601:surgery*; D011475:Prosthesis Failure; D012042:Registries; D012307:Risk Factors; D016896:Treatment Outcome