Cross-cultural translation of the Lysholm knee score in Chinese and its validation in patients with anterior cruciate ligament injury

BACKGROUND The Lysholm Knee Score (LKS) is widely used and is one of the most effective questionnaires employed to assess knee injuries. Although LKS has been translated into multiple languages, there is no Chinese version even though China has the largest population of patients with knee-joint injuries. The objective of our study was to develop the Chinese version of LKS (C-LKS) and assess its reliability, validity and responsiveness in Chinese patients with anterior cruciate ligament (ACL) injuries. METHODS Study participants were mainly recruited among patients with ACL injuries scheduled for arthroscopic ACL reconstruction at our hospital. First, we developed the C-LKS in a five-step translation and cross-cultural adaptation procedure. Next, we calculated the Cronbach's alpha, intraclass correlation coefficient (ICC), Pearson's correlation coefficient (r), effect size (ES), and standardized response mean (SRM) to evaluate the reliability, validity, and responsiveness of C-LKS respectively. RESULTS Overall, 126 patients with ACL injuries successfully completed the questionnaires. Acceptable internal consistency (Cronbach's alpha = 0.726) as well as excellent test-retest reliability (ICC = 0.935) was found for C-LKS. Good or moderate correlation (r = 0.514-0.837) was determined among C-LKS and International Knee Documentation Committee Subjective Knee Form (IKDC), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), physical subscales of SF-36; C-LKS also had fair or moderate correlation (r = 0.207-0.462) with the other subscales of SF-36, which adequately illustrated that good validity was included in C-LKS. In addition, good responsiveness was also observed in C-LKS (ES = 1.36,SRM = 1.26). CONCLUSIONS We have shown that our developed C-LKS questionnaire is reliable, valid and responsible for the evaluation of Chinese-speaking patients with ACL injuries and it would be an effective instrument.