Evaluation of the rearfoot component (module 3) of the ACFAS scoring scale

The American College of Foot and Ankle Surgeons (ACFAS) scoring scale modules 3 and 4 have not been validated or tested against other validated instruments widely used in medical and surgical research and practice. The purpose of the present study was to evaluate the rearfoot component (module 3) of the ACFAS scoring system by assessing its correlation against well-established instruments. A modified ACFAS scale (mACFAS), Medical Outcomes Study 36-item short form (SF-36), version 2 (SF-36v2), and the short form of the International Physical Activity Questionnaire (IPAQ) were administered to subjects enrolled in our ongoing longitudinal cohort flatfoot study. Eighty-six patients were evaluated. The mACFAS correlated moderately to highly with the SF-36v2 physical component score and moderately with the mental component score and IPAQ. When divided into higher arched, lower arched, and rectus foot groups, the mACFAS correlated more strongly with the SF-36v2 and correlated with the IPAQ in the lower arched population. The results of the present study are promising for the rearfoot component of the ACFAS scoring scale, especially in the evaluation of the lower arched foot type. Future research should evaluate the disease- and symptom-specific validity, responsiveness, and reproducibility of the mACFAS.