title: Long-term survival of GSB III elbow prostheses and risk factors for revisions.
abstract: BACKGROUND
  Although replacement of the elbow joint is a complex procedure there is not much clinical evidence that contributes to surgical decision-making, mainly due to small clinical samples and short follow-up. Therefore, we performed a long-term analysis up to 30 years after implantation of a GSB III total elbow prosthesis to quantify long-term outcome and to identify possible risk factors for implant revision.
  
  
  METHODS
  All patients who received a primary GSB III total elbow prosthesis between 1978 and 1998 were included. Information about patient characteristics, the latest known implant status and possible risk factors were collected, Kaplan-Meier survival curves plotted, and 10- and 20-year survival calculated. The cohort was stratified for known risk factors such as diagnosis, age, or gender and included in a Cox regression analysis.
  
  
  RESULTS
  A total of 253 patients [mean age at operation 56.9 years (range from 17.5 to 84 years)] with 293 GSB III prostheses were included. The median follow-up was 9.1 years (0 months to 29.3 years). Whereas 81 prostheses did not need revision during the observation period, 76 had been implanted in patients who died before any revision was required, and 75 had not been revised by the last known follow-up. 61 prostheses were revised. This corresponds to a 10-year survival rate of 0.8 (95 % CI 0.74-0.85) and a 20-year rate of 0.67 (95 % CI 0.57-0.76). Prostheses in patients with post-traumatic conditions survived significantly shorter than those in patients with rheumatoid arthritis; previous operations lead to a 2.8 times greater risk of revision (p = 0.004). Neither age at implantation nor gender had a significant influence on prosthesis survival.
  
  
  CONCLUSIONS
  The results indicate a good long-term prognosis for this design. The prognosis has to be adjusted for the underlying disease. Previous operations such as joint reconstruction significantly increase the risk of revision.
authors.affiliation: Research Department of Schulthess Klinik Zurich, Zurich, Switzerland, madlaina.schoeni@gmx.ch.
authors.forename: Madlaina
authors.initials: M
authors.lastname: Schöni
authors.forename: Susann
authors.initials: S
authors.lastname: Drerup
authors.forename: Felix
authors.initials: F
authors.lastname: Angst
authors.forename: Diego
authors.initials: D
authors.lastname: Kyburz
authors.forename: Beat R
authors.initials: BR
authors.lastname: Simmen
authors.forename: Jörg
authors.initials: J
authors.lastname: Goldhahn
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000601:surgery*; D057929:Arthroplasty, Replacement, Elbow / Q000295:instrumentation* / Q000379:methods; D058569:Elbow Prosthesis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000601:surgery*; D016016:Proportional Hazards Models; D011475:Prosthesis Failure; D012086:Reoperation; D012307:Risk Factors; D016896:Treatment Outcome; D055815:Young Adult