Simple foot an ankle value: a simple evaluation correlated to the existing PROMs

Abstract

Purpose: The SFAV (Simple Foot and Ankle Value) consists in asking patients how they rate their joint function on the day of the examination, as a percentage of that of a normal joint (0-100% scale with 100% being normal). The main objective was to validate the SFAV by determining its correlation with validated foot and ankle function scores.

Methods: This was a prospective study. 90 patients were included in three groups: patients 16 to 54 years old with an acute or subacute ankle pathology (foot/ankle trauma patient group), patients more than 55 years old with ankle or foot osteoarthritis (foot/ankle degeneration patient group), and adults of any age without foot or ankle pathology (control group). A self-administered questionnaire with the American Orthopedic Foot and Ankle Society, The European Foot and Ankle Society, the Foot and Ankle Outcome Score, the Visual Analogic Scale, and the SFAV was given at three different timepoints (enrollment, preoperative visit, and 6-month postoperative visit) to the patients. The validity of the SFAV was investigated by determining its correlation with the existing foot and ankle PROMs using Spearman's correlation; test-retest reliability, the responsiveness to change, and the discriminative ability of the SFAV were also analyzed. The significance threshold was set at 0.05.

Results: The SFAV was significantly correlated with the AOFAS, EFAS, and FAOS at all tested time points, with all p values below 0.033. SFAV scoring was reliable over time, as p values resulting from the comparison between initial and preoperative SFAV were all above the significance threshold. SFAV scoring was responsive to change, based on the comparison between pre- and postoperative SFAV (p < 0.05). Like for the AOFAS, EFAS, and FAOS, SFAV provides good discrimination between a healthy subject and a patient. The control group scores and initial consultation scores of the pooled patient's groups were statistically correlated (p < 0.05).

Conclusion: The SFAV is a valid outcome measure correlated with the AOFAS, EFAS, FAOS, and VAS.

Level of evidence: Level of evidence III.

Keywords: American orthopedic foot; Ankle society; European foot and ankle society; Foot and ankle outcome score; Patient-reported outcomes measures; SFAV.