J Am Podiatr Med Assoc. 2021 Sep 1;111(5). doi: 10.7547/19-167.
Hallux valgus is a progressive foot deformity that commonly affects middle-aged women. The aim of this study was to develop a novel method using only top-view photographs to assess hallux valgus severity.
A top-view digital photograph was taken of each foot of 70 female participants. Two straight lines were drawn along the medial edge of the great toe and forefoot, and the included angle (termed bunion angle) was measured using a free software program. Each foot was also assessed by a clinician using the Manchester scale as no (grade 1), mild (grade 2), moderate (grade 3), or severe (grade 4) deformity.
The mean bunion angles of the 140 feet were 6.7°, 13.5°, and 16.2° for Manchester grades 1, 2, and 3, respectively (no foot was in grade 4). The reliability was excellent for both intrarater (intraclass correlation coefficient [ICC] = 0.93-0.95) and interrater (ICC = 0.90) assessments. Receiver operating characteristic curves determined the optimal bunion angle cutoff value for screening hallux valgus to be 9°, which gives 89.2% sensitivity and 74.2% specificity.
The bunion angle is a reliable, clinician-free method that can potentially be integrated into a smartphone app for easy and inexpensive self-assessment of hallux valgus.
拇外翻是一种常见于中年女性的进行性足部畸形。本研究旨在开发一种仅使用足正位照片评估拇外翻严重程度的新方法。
对 70 名女性参与者的每只脚拍摄一张足正位数码照片。在大脚趾和前足部的内侧边缘画两条直线，使用免费软件程序测量所形成的夹角（称为拇囊炎角）。每只脚还由临床医生使用曼彻斯特量表进行评估，分为无（1 级）、轻度（2 级）、中度（3 级）或重度（4 级）畸形。
140 只脚的拇囊炎角分别为曼彻斯特 1、2 和 3 级的 6.7°、13.5°和 16.2°（没有 4 级的脚）。内部观察者（组内相关系数 [ICC] = 0.93-0.95）和外部观察者（ICC = 0.90）的评估均具有极好的可靠性。受试者工作特征曲线确定了用于筛查拇外翻的最佳拇囊炎角截断值为 9°，其灵敏度为 89.2%，特异性为 74.2%。
拇囊炎角是一种可靠的、无需临床医生参与的方法，可能会整合到智能手机应用程序中，用于方便、经济地自我评估拇外翻。
