Translation and validation of the simplified Chinese new Knee Society Scoring System

BACKGROUND: The NKSS has recently been translated into Dutch version. The reliability and validity were also assessed. However, there is no Simplified Chinese version of New Society Knee Scoring System (SC-NKSS) for Chinese population. METHODS: The SC-NKSS was translated from the original English version following international guidelines. All patients undergoing total knee arthroplasty (TKA) between September 2012 and September 2013 were invited to participate in this study. Finally, a total of 105 did so. Patients (preoperative and postoperative) completed the Chinese version of NKSS, Oxford Knee Score (OKS), the Medical Outcomes General Health Survey (SF-36) and Visual analog scale (VAS). Psychometric testing of reliability, construct validity, content validity were conducted. RESULTS: All the 105 participants completed the questionnaires and no floor or ceiling effects were checked. Internal consistency was excellent with Cronbach’s alpha coefficient ranging from 0.71 to 0.85. Test-retest reliability was satisfactory with an intraclass correlation coefficient of 0.92 (95%confidence interval, 0.86–0.95). Construct validity was demonstrated to correlate well with the Chinese version of OKS (r =−0.78; p < 0.01), VAS (r =−0.70; p < 0.01), Physical Function (PF) (r = 0.74; p < 0.01), Body Pain (BP) (r = 0.63; p < 0.01) and General Health (GH) (r = 0.51; p < 0.01) of SF-36 domains. CONCLUSION: The SC-NKSS was well accepted and demonstrated acceptable psychometric properties in mainland China. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12891-015-0854-1) contains supplementary material, which is available to authorized users.