title: The postoperative COFAS end-stage ankle arthritis classification system: interobserver and intraobserver reliability.
abstract: End-stage ankle arthritis is operatively treated with numerous designs of total ankle replacement and different techniques for ankle fusion. For superior comparison of these procedures, outcome research requires a classification system to stratify patients appropriately. A postoperative 4-type classification system was designed by 6 fellowship-trained foot and ankle surgeons. Four surgeons reviewed blinded patient profiles and radiographs on 2 occasions to determine the interobserver and intraobserver reliability of the classification. Excellent interobserver reliability (κ = .89) and intraobserver reproducibility (κ = .87) were demonstrated for the postoperative classification system. In conclusion, the postoperative Canadian Orthopaedic Foot and Ankle Society (COFAS) end-stage ankle arthritis classification system appears to be a valid tool to evaluate the outcome of patients operated for end-stage ankle arthritis.
authors.affiliation: Department of Orthopaedic Surgery, University of Berne, Berne, Switzerland.
authors.forename: Fabian G
authors.initials: FG
authors.lastname: Krause
authors.forename: Matthew
authors.initials: M
authors.lastname: Di Silvestro
authors.forename: Murray J
authors.initials: MJ
authors.lastname: Penner
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Wing
authors.forename: Mark A
authors.initials: MA
authors.lastname: Glazebrook
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Daniels
authors.forename: Johnny T C
authors.initials: JT
authors.lastname: Lau
authors.forename: Alastair S E
authors.initials: AS
authors.lastname: Younger
mesh_terms: D000368:Aged; D000843:Ankle Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D001174:Arthrodesis / Q000009:adverse effects / Q000379:methods*; D019643:Arthroplasty, Replacement / Q000009:adverse effects / Q000379:methods*; D002170:Canada; D002965:Classification / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D009985:Orthopedics / Q000145:classification; D010003:Osteoarthritis / Q000145:classification* / Q000000981:diagnostic imaging / Q000601:surgery*; D011182:Postoperative Care / Q000379:methods; D011183:Postoperative Complications / Q000145:classification* / Q000000981:diagnostic imaging; D011300:Preoperative Care / Q000379:methods; D011859:Radiography; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D012955:Societies, Medical / Q000145:classification; D016896:Treatment Outcome