What Symptoms Are More Important for Korean Patients in Knee Osteoarthritis? Development and Validation of the Korean Knee Score

PURPOSE The purpose of this study was to develop and validate a novel knee evaluation instrument, the Korean Knee Score (KKS), to reflect a floor life style with high knee flexion. In addition, we aimed to assess the importance of high knee flexion activity for Korean patients. MATERIALS AND METHODS The KKS was developed following the guidelines of the International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine. During development step, generated items were asked to 50 patients to determine importance and obtain an impact score for each item. A total of 634 patients were included in the validation survey. RESULTS Forty one items were generated and impact scores of each item about floor life style were higher than other items. The KKS exhibited excellent reliability (intraclass correlation coefficient=0.931) and strong internal consistency (Cronbach's α=0.973). The content validity was good, with no ceiling or floor effect. The construct, convergent, and divergent validities were good. Moderate responsiveness was evident, with a standardized response mean of 0.74. CONCLUSIONS The KKS, has good validity, reliability, and responsiveness. The KKS includes items for floor life style, which are thought more important for Korean patients. The KKS can be used as a good evaluation questionnaire for Korean knee osteoarthritis patients.