Knee Injury and Osteoarthritis Outcome Score in patients with isolated meniscus injury; Validity and reliability

BACKGROUND: The aim of this study is evaluation of the validity and reliability of the Persian version of Knee Injury and Osteoarthritis Outcome Score (KOOS) in patients with isolated meniscus injury. MATERIALS AND METHODS: One hundred people with isolated meniscal injury (29 females and 71 males with a mean age ± standard deviation [SD] = 32.37 ± 9.97 years) and fifty normal people with no knee problems (34 females and 16 males with a mean age ± SD = 28.42 ± 8.84 years) participated in this study. In patients, the duration of meniscus injury ranged from 1 month to 4 years. For evaluation of discriminate validity, we compared scores of KOOS questionnaire between patients and healthy people, and for concurrent validity, in addition to filling KOOS questionnaire, patients completed Short Form (SF-36) questionnaire, test–retest reliability with intraclass correlation coefficient) ICC), and internal consistency with Cronbach's alpha was calculated. RESULTS: Mean scores of patients (49.51 ± 17.13) and healthy people (86.01 ± 13.44) were different significantly (P < 0.001). The correlation between total score of SF-36 and KOOS was significant (r = 0.77, P < 0.001). ICC was 0.80 (ranged from 0.64–0.75) and Cronbach's alpha was 0.96 (ranged from 0.72 to 0.94). CONCLUSION: The Iranian version of KOOS is a reliable and valid tool for patients with isolated meniscus injury, so the clinicians and investigators may use this questionnaire in clinical settings and their researches.