title: Transcultural adaptation and validation of the "Hip and Knee" questionnaire into Spanish.
abstract: BACKGROUND
  The purpose of the present study is to translate and validate the "Hip and Knee Outcomes Questionnaire", developed in English, into Spanish. The 'Hip and Knee Outcomes Questionnaire is a questionnaire planned to evaluate the impact in quality of life of any problem related to the human musculoskeletal system. 10 scientific associations developed it.
  
  
  METHODS
  The questionnaire underwent a validated translation/retro-translation process. Patients undergoing primary knee arthroplasty, before and six months postoperative, tested the final version in Spanish. Psychometric properties of feasibility, reliability, validity and sensitivity to change were assessed. Convergent validity with SF-36 and WOMAC questionnaires was evaluated.
  
  
  RESULTS
  316 patients were included. Feasibility: a high number of missing items in questions 3, 4 and 5 were observed. The number of patients with a missing item was 171 (51.35%) in the preoperative visit and 139 (44.0%) at the postoperative. Internal validity: revision of coefficients in the item-rest correlation recommended removing question 6 during the preoperative visit (coefficient <0.20). Convergent validity: coefficients of correlation with WOMAC and SF-36 scales confirm the questionnaire's validity. Sensitivity to change: statistically significant differences were found between the mean scores of the first visit compared to the postoperative.
  
  
  CONCLUSIONS
  The proposed translation to Spanish of the 'Hip and Knee Questionnaire' is found to be reliable, valid and sensible to changes produced at the clinical practice of patients undergoing primary knee arthroplasty. However, some changes at the completion instructions are recommended.
  
  
  METHODS
  Level I. Prognostic study.
authors.affiliation: Orthopedic Department, Hospital Vall d'Hebron, Passeig de la Vall d'Hebrón, 119-129, Barcelona 08035, Spain. encastel@gmail.com.
authors.forename: Enric
authors.initials: E
authors.lastname: Castellet
authors.forename: Oscar
authors.initials: O
authors.lastname: Ares
authors.forename: Fernando
authors.initials: F
authors.lastname: Celaya
authors.forename: Andrés
authors.initials: A
authors.lastname: Valentí-Azcárate
authors.forename: Angels
authors.initials: A
authors.lastname: Salvador
authors.forename: Ana
authors.initials: A
authors.lastname: Torres
authors.forename: Pedro
authors.initials: P
authors.lastname: Sesma
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D019645:Arthroplasty, Replacement, Knee; D003431:Cross-Cultural Comparison; D006615:Hip / Q000502:physiology* / Q000601:surgery; D006801:Humans; D007717:Knee / Q000502:physiology* / Q000601:surgery; D011184:Postoperative Period; D011594:Psychometrics; D011788:Quality of Life; D015203:Reproducibility of Results; D013030:Spain; D011795:Surveys and Questionnaires; D016896:Treatment Outcome