title: Outcome after total ankle arthroplasty-results and findings from worldwide arthroplasty registers.
abstract: OBJECTIVE
  The data currently available concerning total ankle arthroplasty (TAA) does not allow valid conclusions in several clinically relevant areas. Total ankle arthroplasty imposes special requirements on the methodology of data collection, evaluation, publication and the assessment of register data.
  
  
  METHODS
  We undertook a structured and descriptive analysis of all outcome data available from high-quality national arthroplasty registers worldwide. Register data from Sweden, Finland, Norway, New Zealand and Australia were included in the analysis.
  
  
  RESULTS
  There are marked differences between Europe and Oceania with respect to indications. All data sets show revision rates of approximately 10 % at five years, of which about 40 % of cases are for aseptic loosening. Inlay fractures are relatively common, which indicates potential for the improvement of implants. The documentation of intraoperative surgical errors leading to revision surgery varies significantly among registers. A relevant number of complications are treated without an implant component being exchanged and therefore not covered by a register.
  
  
  CONCLUSIONS
  The results of TAA are promising, but the revision rate is higher than for total hip or knee arthroplasty. TAA outcome measurement by means of registers has several specific requirements necessitating additional documentation beyond the basic data set. For methodological reasons the evaluation of results is more complex than for hip or knee arthroplasty. It will therefore be essential to standardise data collection and evaluation and develop a methodology addressing the specific needs of TAA.
authors.affiliation: Department of Orthopaedic Surgery, Innsbruck Medical University, Anichstr. 35, 6020 Innsbruck, Austria. Gerold.Labek@i-med.ac.at
authors.forename: Gerold
authors.initials: G
authors.lastname: Labek
authors.forename: Svilen
authors.initials: S
authors.lastname: Todorov
authors.forename: Liviu
authors.initials: L
authors.lastname: Iovanescu
authors.forename: Christian Ioan
authors.initials: CI
authors.lastname: Stoica
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Böhler
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000842:Ankle; D001168:Arthritis / Q000453:epidemiology / Q000601:surgery*; D001172:Arthritis, Rheumatoid / Q000453:epidemiology / Q000601:surgery; D058737:Arthroplasty, Replacement, Ankle / Q000706:statistics & numerical data*; D001315:Australia / Q000453:epidemiology; D005387:Finland / Q000453:epidemiology; D006801:Humans; D008875:Middle Aged; D009520:New Zealand / Q000453:epidemiology; D009664:Norway / Q000453:epidemiology; D010003:Osteoarthritis / Q000453:epidemiology / Q000601:surgery; D012042:Registries; D012086:Reoperation / Q000706:statistics & numerical data; D013548:Sweden / Q000453:epidemiology; D016896:Treatment Outcome