title: A New Zealand national joint registry review of 202 total ankle replacements followed for up to 6 years.
abstract: OBJECTIVE
  There have been few reports of large series of ankle replacements. The aim of this study was to document and evaluate the early results of a nationwide series of total ankle replacements (TARs) performed using second- and third-generation implants.
  
  
  METHODS
  Records of total ankle replacements performed between February 2000 and November 2005 were retrieved from the New Zealand National Joint Registry and retrospectively reviewed at a mean of 28 months after the primary procedure. At 6 months post surgery, patient scores were generated from questionnaires. Comparisons between patient scores and categorical variables were made using ANOVA. Regression analyses using Cox proportional-hazards modeling were performed to determine predictors of failure. A Kaplan-Meier survivorship curve was used to describe the rate of prosthetic survival.
  
  
  RESULTS
  202 total ankle replacements were performed in 183 patients. 14 prostheses (7%) failed. The overall cumulative 5-year failure-free rate was 86%. An unfavorable patient score at 6 months after the initial procedure turned out to be a good predictor of subsequent failure. The cumulative 5-year failure-free rate was 65% at 5 years for patients with an unfavorable score, and 95% for those who had a favorable patient score. Each 1-point increase in the patient score (i.e. poorer outcome) corresponded to a 5% relative increase in the risk of failure (p < 0.05). In addition, longer operative time for the primary procedure was found in the group of TARs that subsequently failed (p < 0.05).
  
  
  CONCLUSIONS
  The National Joint Registry appears to be a useful tool for monitoring the trends in TAR surgery.
authors.affiliation: Department of Orthopedic Surgery and Musculoskeletal Medicine, Christchurch School of Medicine and Health Sciences, University of Otago, Christchurch, New Zealand. antonhosman@gmail.com
authors.forename: Anton H
authors.initials: AH
authors.lastname: Hosman
authors.forename: Rhett B
authors.initials: RB
authors.lastname: Mason
authors.forename: Toni
authors.initials: T
authors.lastname: Hobbs
authors.forename: Alastair G
authors.initials: AG
authors.lastname: Rothwell
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000843:Ankle Joint / Q000601:surgery*; D001168:Arthritis / Q000601:surgery*; D019643:Arthroplasty, Replacement / Q000009:adverse effects / Q000379:methods / Q000592:standards; D002983:Clinical Competence; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007595:Joint Prosthesis; D008297:Male; D008875:Middle Aged; D009520:New Zealand; D010003:Osteoarthritis / Q000601:surgery; D011475:Prosthesis Failure; D012042:Registries; D012086:Reoperation