Akgun Ulas, Ozkan Deniz, Gultac Emre, Canbek Umut, Aydogan Nevres Hurriyet
Department of Orthopaedics and Traumatology, Faculty of Medicine, Mugla Sitki Kocman University, Mugla, Turkey.
Department of Radiology, Faculty of Medicine, Aksaray University, Aksaray, Turkey.
Medicine (Baltimore). 2025 Jul 18;104(29):e43203. doi: 10.1097/MD.0000000000043203.
Hallux valgus is a triplanar deformity with rotation being a significant contributing factor. Several methods exist for evaluating rotational deformity of the first ray, one of which involves assessing the shape of the lateral edge of the first metatarsal head. This study aimed to investigate the interobserver and intraobserver reliabilities of circle measurements on weight-bearing anteroposterior radiographs to categorize the shape of the lateral edge of the first metatarsal head. A power analysis determined that a minimum of 128 radiographs was required to assess observer agreement for categorical data (alpha = 0.05, beta = 0.2, power = 80%). Patients diagnosed with hallux valgus at our institution between January 2015 and December 2019 were retrospectively reviewed and 128 radiographs were randomly selected. Two foot and ankle surgeons and 2 radiologists evaluated the radiographs on 2 separate occasions, classifying the first metatarsal head shape into 3 categories (angular, intermediate, and round) using circular measurements. Interobserver reliability was assessed using Fleiss' kappa, whereas intraobserver reliability was evaluated using Cohen kappa. Interobserver reliability for classifying the shape of the lateral edge of the first metatarsal head was found to be very good in both assessments (Fleiss' kappa = 0.83 and 0.84, respectively). The subcategory analysis revealed the highest agreement for the angular type, followed by the round type, with the lowest agreement observed for the intermediate type. The intraobserver Cohen kappa values ranged from 0.78 to 0.91. The level of interobserver agreement was found to be very good for the classification of the shape of the first metatarsal, and the intraobserver agreements were substantial to very good. In our opinion, this method is reliable and may be useful in determining the necessity for rotation-correcting surgery and advanced imaging with weight-bearing computed tomography.
拇外翻是一种三维畸形，旋转是一个重要的促成因素。存在多种评估第一跖骨旋转畸形的方法，其中一种方法涉及评估第一跖骨头外侧边缘的形状。本研究旨在探讨在负重前后位X线片上进行圆形测量以对第一跖骨头外侧边缘形状进行分类时，观察者间和观察者内的可靠性。一项功效分析确定，至少需要128张X线片来评估分类数据的观察者一致性（α = 0.05，β = 0.2，功效 = 80%）。对2015年1月至2019年12月期间在本机构被诊断为拇外翻的患者进行回顾性研究，并随机选择128张X线片。两名足踝外科医生和两名放射科医生在两个不同的时间点对X线片进行评估，使用圆形测量将第一跖骨头形状分为3类（角形、中间形和圆形）。观察者间可靠性使用Fleiss' kappa进行评估，而观察者内可靠性使用Cohen kappa进行评估。在两项评估中，对第一跖骨头外侧边缘形状分类的观察者间可靠性均非常好（Fleiss' kappa分别为0.83和0.84）。亚组分析显示，角形类型的一致性最高，其次是圆形类型，中间形类型的一致性最低。观察者内Cohen kappa值范围为0.78至0.91。发现观察者间对第一跖骨形状分类的一致性非常好，观察者内一致性为实质性到非常好。我们认为，这种方法可靠，可能有助于确定旋转矫正手术的必要性以及负重计算机断层扫描的高级成像。
