Authors (including presenting author) :
Lee QJ, Chang WY Esther, Yung KC, Kam WL
Affiliation :
Total Joint Replacement Centre, Yan Chai Hospital
Introduction :
Forgotten joint score (FJS) has been increasingly popular as an outcome assessment tool in total knee arthroplasty (TKA) and has been validated in multiple languages, except Cantonese. As FJS was designed as a patient-reported outcome measurement with situational questions in daily life, the accuracy of data collected depended largely on whether the setting of questions is appropriate and understandable. When applying FJS in Hong Kong, a Cantonese language dominant society with considerably different life style comparing with western countries, the subtle cultural and life style differences and the uniqueness of Cantonese expression may render potential misinterpretation and inconsistency in data collection when English or Mandarin-Chinese based FJS was used. Therefore, our institute has developed a Cantonese-Chinese version of FJS (CC-FJS) and this study is to investigate the validity and reliability of this modified FJS.
Objectives :
To develop a valid and reliable language modified version of FJS for TKA outcome measurement adapted for use in Cantonese-Chinese population.
Methodology :
A prospective cross-sectional study was conducted from July 2018 to September 2018. Patients with primary TKA done within 1 year were recruited. Patients with dementia, psychiatric illness and post-operative local complications were excluded. The CC-FJS was developed by independent forward-backward translation, pilot testing and refinement. All cases were evaluated by both WOMAC and the CC-FJS post-operatively at clinic. Validity of CC-FJS were tested against WOMAC using Pearson correlation, reliability by intraclass-correlation and internal consistency by Cronbach’s α. The ceiling, floor effects and skewness were also assessed.
Result & Outcome :
Results 163 subjects were recruited. 84(51.5%) were assessed at 3months, 56(34.4%) at 6months, and 23(14.1%) at 12months post-operation. The response rate was excellent (96.3%). CC-FJS demonstrated a moderate correlation with WOMAC (R=-0.52), good test retest reliability (r>0.9, N=42) and excellent internal consistency (α=0.96, N=126). When compared with WOMAC, a lower ceiling effect (10th percentile: 6.7% vs 13.5%), higher floor effect (90th percentile: 12.9% vs 0%) and less skewness (0.09 vs -0.56) were observed. Conclusion CC-FJS is a valid and reliable assessment tool for TKA tailored for Cantonese-Chinese population and is especially useful in assessing better outcome. However, due to its comparatively higher floor effect, it might not be an ideal tool to differentiate cases with poorer outcome at early stage.
