Conclusion
ACL
SECONDARY
Overall, the bifactor model lends support to continue reporting the IKDC as a unidimensional score for young active patients with ACL tears, recognizing the presence of specific secondary factors made up of items with similar formatting/content. Clinically, it appears that the IKDC can be administered and scored as the intended unidimensional questionnaire for young active patients with ACL tears, with secondary factors available for further interpretability of outcome scores.