Korean version of the anterior cruciate ligament-return to sport after injury scale: Translation and cross-cultural adaptation

Background: To translate into Korean and culturally adapt the anterior cruciate ligament-return to sports after injury (ACL-RSI) scale assessing psychological readiness to return to sports after ACL reconstruction and to validate its psychometric properties. Methods: The ACL-RSI scale was forward translated into Korean and back-translated into English for cultural adaptation according to the standardized guideline. For validation, the Korean version of the ACL-RSI (ACL-RSI Kr) was administered to patients who underwent ACL reconstruction. The following subjective questionnaires were also administered: International Knee Documentation Committee Subjective Knee Evaluation Form (IKDC-SKF), Lysholm scale, Knee injury and Osteoarthritis Outcome Score (KOOS), and a Return to Sports Questionnaire. Test-retest reliability, internal consistency, content validity, construct validity, and discriminant validity of the ACL-RSI Kr were assessed. Results: A total of 129 patients (102 men and 27 women) were included in the study. Their mean age was 28.3 years. The average follow-up duration was 13.2 months. Test-retest reliability was remarkable (intraclass correlation coefficient, 0.949), internal consistency was high (Cronbach’s alpha, 0.932), and floor and ceiling effects were confirmed to be less than 10%. Construct validity assessed by correlation analysis with KOOS, IKDC-SKF, and Lysholm scale showed the correlation coefficients ranging from 0.169 to 0.679 (all p < 0.01). Compared with the Return to Sports Questionnaire, statistically significant difference was found in the ACL-RSI Kr between patients who received more than 7 points and less than 7 points (72.2 vs. 60.3, p = 0.025) for performance level scored using a 10-point Likert scale, proving its discriminative value. Conclusions: The ACL-RSI Kr demonstrated good psychometric properties. This scale can be an excellent instrument for evaluating patient’s psychological readiness to return to sports after ACL injury.