Footprint as an alternative to X-ray in hallux valgus angle measurement

Background: X- ray images provide accurate and reliable data in different foot pathologies. However, the accompanied complications will limit its use for epidemiological studies and research purposes, especially in children. Therefore, simple, accessible, and cost- effective methods such as footprint, with a good correlation with x-ray images, are needed to help diagnose different foot pathologies. In the present study, the accuracy of footprint technique in assessing hallux valgus angle (HVA) was evaluated based on x-ray images through measuring the angle between the medial border protrusion of the foot and the hallux. Methods: In this cross-sectional study, 42 participants with symptomatic hallux valgus were recruited. HVA was measured by both x-ray imaging and footprint. The differences between the two approaches were identified by applying correlation-coefficient test and reliability, which was assessed using interclass correlation (ICC). Results: A significant correlation was found between the HVA measured by x-ray and HVA by footprints (p< 0.001), and the ICC was upper than 90%. Conclusion: Foot print is a reliable method for measuring HVA, as it was highly correlated with the HVAs obtained by x-ray imaging.