Purpose: To perform a cross-cultural adaptation and to test the measurement properties of the Korean version of International Knee Documentation Committee (K-IKDC) Subjective Knee Form.
Materials and methods: According to the guidelines for cross-cultural adaptation, translation and backward translation of the English version of the IKDC Subjective Knee Form were performed. After translation into the Korean version, 150 patients who had knee-related problems were asked to complete the K-IKDC, Lysholm score, and Short Form-36 (SF-36). Of these patients, 126 were retested 2 weeks later to evaluate test-retest reliability, and 104 were recruited 3 months later to evaluate responsiveness. Construct validity was analyzed by investigating the correlation with Lysholm score and SF-36; content validity was also evaluated. Standardized mean response was calculated for evaluating responsiveness.
Results: The test-retest reliability proved excellent with a high value for the intraclass correlation coefficient (r=0.94). The internal consistency was strong (Cronbach's α=0.91). Good content validity with absence of floor not ceiling effects and good convergent and divergent validity were observed. Moderate responsiveness was shown (standardized mean response=0.689).
Conclusions: The K-IKDC demonstrated good measurement properties. We suggest that this instrument is an excellent evaluation instrument that can be used for Korean patients with knee-related injuries.
Keywords: Cross-cultural adaptation; International Knee Documentation Committee; Knee; Korean version; Outcome measures.