title: Translation and validation of the Dutch new Knee Society Scoring System ©.
abstract: BACKGROUND
  A new version of The Knee Society Knee Scoring System(©) (KSS) has recently been developed. Before this scale can be used in non-English-speaking populations, it has to be translated and validated for a particular population.
  
  
  OBJECTIVE
  We evaluated the construct and content validity, the test-retest reliability, and the internal consistency of the Dutch version of the New Knee Society KSS.
  
  
  METHODS
  A Dutch translation was performed using a forward-backward translation protocol. We tested the construct validity of the Dutch New KSS by comparing it with the Dutch versions of the WOMAC, Knee Injury and Osteoarthritis Outcome Score (KOOS), and SF-12 scores in 137 patients undergoing total knee arthroplasty (TKA). Content validity was assessed by comparing pre- and postoperative scores and by checking floor and ceiling effects. To evaluate test-retest reliability and consistency, 47 patients completed the questionnaire a second time with a mean of 8 days interval (range, 2-20 days) between tests.
  
  
  RESULTS
  Construct validity was demonstrated because the Dutch New KSS correlated well with the Dutch WOMAC (r = -0.751; p < 0.001), Dutch KOOS (r = -0.723; p < 0.001), and Dutch SF-12 (r = 0.569; p < 0.001). There was a significant difference between pre- and postoperative scores (p < 0.001) in line with the other scores. Test-retest reliability proved excellent with an intraclass correlation coefficient between 0.73 and 0.92 depending on the domain tested. Consistency as indicated by Cronbach's alpha ranging from 0.84 to 0.96 was good to excellent.
  
  
  CONCLUSIONS
  As demonstrated by the validation procedure, the Dutch New KSS is an excellent instrument to evaluate TKA outcome in Dutch-speaking patients.
authors.affiliation: Department of Orthopedic Surgery and Physical Medicine, Faculty of Medicine & Health Sciences, Ghent University, University Hospital, De Pintelaan 185, 9000, Ghent, Belgium, Catherine.VanDerStraeten@ugent.be.
authors.forename: Catherine
authors.initials: C
authors.lastname: Van Der Straeten
authors.forename: Erik
authors.initials: E
authors.lastname: Witvrouw
authors.forename: Tine
authors.initials: T
authors.lastname: Willems
authors.forename: Johan
authors.initials: J
authors.lastname: Bellemans
authors.forename: Jan
authors.initials: J
authors.lastname: Victor
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D007719:Knee Joint / Q000503:physiopathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D020370:Osteoarthritis, Knee / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D014175:Translating; D016896:Treatment Outcome