title: A Prospective Study of Four Total Ankle Arthroplasty Implants by Non-Designer Investigators.
abstract: BACKGROUND
  There are several types of prostheses available to surgeons when performing a total ankle arthroplasty (TAA). The main objective of this study was to summarize the clinical and functional outcomes of 4 TAA prostheses: the Hintegra implant (Integra LifeSciences), the Agility implant (DePuy), the Mobility implant (DePuy), and the Scandinavian Total Ankle Replacement (STAR) implant (Small Bone Innovations [SBi]).
  
  
  METHODS
  Patients were prospectively recruited. A total of 451 TAAs with a mean follow-up (and standard deviation) of 4.5 ± 2.0 years were included. Patients were assessed annually and completed self-reported outcome measures at these visits. Complications and revisions were reported at the time of incident. Mean improvements are reported by prosthesis. Linear mixed-effects models were used to obtain adjusted comparisons of scores across prostheses. Survivorship curves were generated by prosthesis and type of complication.
  
  
  RESULTS
  Mean improvement in the Ankle Osteoarthritis Scale (AOS) total score was less among patients with the Mobility implant (19.5; 95% confidence interval [CI], 15 to 24) than it was among patients with the Agility implant (29.1; 95% CI, 24 to 34), Hintegra implant (29.7; 95% CI, 27 to 33), and STAR implant (28.5; 95% CI, 23 to 34). Patients in the Mobility group also had less mean improvement in the AOS pain score (21.3; 95% CI, 17 to 26) compared with patients in the Hintegra (29.0; 95% CI, 26 to 32), Agility (29.8; 95% CI, 25 to 35), and STAR (29.1; 95% CI, 23 to 35) groups. The Mobility group also had less mean improvement in the AOS disability score (17.3; 95% CI, 12 to 23) compared with the Hintegra (30.4; 95% CI, 27 to 34), Agility (28.8; 95% CI, 23 to 34), and STAR (27.8; 95% CI, 21 to 34) groups. Survival results among the 4 prostheses are reported.
  
  
  CONCLUSIONS
  This study demonstrated acceptable outcomes of 4 modern TAA prostheses. Outcome results from patient-reported scores were comparable between at least 3 of the 4 prostheses (the Hintegra, STAR, and Agility implants). The rates of complications and revisions found in this study are within the limits reported in the literature for similar prostheses and methods of reporting.
  
  
  METHODS
  Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.
authors.affiliation: 1Thunder Bay Regional Health Sciences Centre, Thunder Bay, Ontario, Canada 2Departments of Orthopaedics (A.Y., K.W., and M.J.P.) and Statistics (H.W.) and School of Population and Public Health (H.W.), University of British Columbia, Vancouver, British Columbia, Canada 3Department of Orthopaedics, Vancouver Coastal Health Authority and Providence Health Care, Vancouver, British Columbia, Canada 4Vancouver Island Health Authority, Victoria, British Columbia, Canada 5CIHR Canadian HIV Trials Network, St. Paul's Hospital, Vancouver, British Columbia, Canada 6Centre for Health Evaluation and Outcomes Sciences, St. Paul's Hospital, Vancouver, British Columbia, Canada 7Department of Orthopaedic Surgery, St. Michael's Hospital, Toronto, Ontario, Canada 8Dalhousie University, Queen Elizabeth II Health Sciences Center Halifax Infirmary, Halifax, Nova Scotia, Canada.
authors.forename: Tina
authors.initials: T
authors.lastname: Lefrancois
authors.forename: Alastair
authors.initials: A
authors.lastname: Younger
authors.forename: Kevin
authors.initials: K
authors.lastname: Wing
authors.forename: Murray J
authors.initials: MJ
authors.lastname: Penner
authors.forename: Peter
authors.initials: P
authors.lastname: Dryden
authors.forename: Hubert
authors.initials: H
authors.lastname: Wong
authors.forename: Timothy
authors.initials: T
authors.lastname: Daniels
authors.forename: Mark
authors.initials: M
authors.lastname: Glazebrook
mesh_terms: D000328:Adult; D000368:Aged; D000843:Ankle Joint / Q000601:surgery*; D058737:Arthroplasty, Replacement, Ankle / Q000379:methods*; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D007595:Joint Prosthesis; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D011446:Prospective Studies; D011474:Prosthesis Design; D016059:Range of Motion, Articular / Q000502:physiology; D012720:Severity of Illness Index