New screening method for hallux valgus with using smartphone

Abstract

Category: Midfoot/Forefoot Introduction/Purpose: We developed a new screening method for hallux valgus during weight bearing using the photo-capturing function in cell phones. Methods: We compared apparent hallux valgus angles measured from photographs of people in a standing position during weight bearing, which were captured on a smartphone (smartphone Hallux Valgus Angle: SP-HVA) (Smartphone Method), with hallux valgus angles determined using conventional radiography in a standing posture during weight-bearing (X-ray HVA: XR-HVA). We evaluated 37 feet of 25 patients (5 men and 25 women) who visited our hospital. The mean age at the time of the visit was 73.9 years. In the Smartphone Method, subjects stood upright and the examiner used a smartphone to take photos of both feet from above while holding the phone at the level of the anterior knee. Results: The mean value was 36.2° for SP-HVA and 36.7° for XR-HVA; the two methods showed a statistically significant correlation (correlation coefficient of 0.86). Conclusion: Our smartphone-assisted screening method for hallux valgus was possible to make a diagnosis equivalent to conventional radiography method without radiation exposure.