Good validity and reliability of forgotten joint score-12 in total knee arthroplasty in Hindi language for Indian population

Purpose Commonly used patient-reported outcome measurement (PROM) tools for knee joint have a ceiling effect and may not be able to differentiate between patients achieving outcomes better than the upper limit of the score. Forgotten joint score-12 (FJS-12) is said to be free of this limitation. FJS-12 has been translated and validated in different languages. This study aims to translate and validate FJS-12 in Hindi (Hindi FJS-12). Methods Hindi FJS-12 was tested for comprehensibility in a pilot study in 20 patients. This was followed by a prospective cohort study including 140 patients of bilateral total knee arthroplasty, with a minimum follow-up of 12 months. The mean age of the patients was 62.0 +/- 14.5 years. There were 77 (55.2%) males and remaining were females. All patients were asked to fill up questionnaires of Hindi FJS-12, WOMAC, KSS and OKS. Hindi FJS-12 was tested for validity, reliability, responsiveness, floor effect and ceiling effect. Construct validity was expressed as the Pearson correlation coefficient. Internal consistency was expressed as Cronbach's alpha and test-retest reliability as the intra-class correlation coefficient (ICC). Results In the pilot study, it was seen that all the questions were well answered by most of the participants. The main study showed good construct validity with Hindi FJS-12 showing moderate correlation with WOMAC, KSS and OKS (Pearson coefficients 0.45, 0.32, 0.37, respectively). Hindi FJS-12 had excellent internal consistency with Cronbach's alpha of 0.93 (95% CI 0.90, 0.97). ICC was 0.95 (95% CI 0.90, 0.99). No floor or ceiling effect was observed. Conclusion Hindi FJS-12 has high validity, reliability and reproducibility for knee function after TKA. It is devoid of floor or ceiling effect. Thus, it can be successfully used for studying knee function in the Indian population.