Department of Orthopaedics, University of Utah, Salt Lake City, UT, USA.
Orthopedic Sports Institute, Institute for Orthopedic Research & Innovation, Coeur d'Alene, ID, USA.
Foot Ankle Int. 2021 Aug;42(8):1040-1048. doi: 10.1177/10711007211001015. Epub 2021 Apr 23.
First metatarsal (M1) axial rotation is recognized as a clinically relevant component of hallux valgus deformity. Methods to realign the M1 in 3 dimensions have been developed. One goal of these operations is to restore normal rotation of the first ray. The aim of this study is to provide estimates for the normal distribution of M1 rotation in patients without relevant anatomic pathology.
Using stringent clinical and radiographic criteria, we evaluated a set of plain radiograph and weightbearing computed tomography (WBCT) images of 62 feet from a consecutive patient database. Subjects included had normal foot alignment without bunion symptoms. M1 rotation of each foot was measured using 2 unique methods (Saltzman et al and Kim et al methods). Measurement of rotation was performed by 2 observers from coronal WBCT images. Mean values and confidence intervals (CIs) of M1 rotation were calculated for each method. Inter- and intraobserver reliability values were also reported.
Mean M1 rotation values of 2.1 degrees (95% CI: 0.9-3.4) and 6.1 degrees (95% CI: 4.4-7.8) were identified using the Saltzman et al and Kim et al methods, respectively. Inter- and intraobserver reliability values were interpreted as excellent for both methods.
In this study, we describe the natural distribution of the M1 axial rotation in subjects without bunion or other identifiable bony foot deformities. This information should provide a normative reference for surgeons correcting rotational issues of the first metatarsal.
Level III, retrospective cohort study.
第一跖骨（M1）轴向旋转被认为是拇外翻畸形的一个临床相关组成部分。已经开发出了将 M1 重新排列到 3 维的方法。这些手术的一个目标是恢复第一跖骨的正常旋转。本研究的目的是为没有相关解剖病理学的患者提供 M1 旋转正常分布的估计值。
使用严格的临床和影像学标准，我们评估了一组来自连续患者数据库的 62 只脚的普通 X 线片和负重 CT（WBCT）图像。纳入的受试者足部排列正常，没有拇囊炎症状。使用 2 种独特的方法（Saltzman 等人和 Kim 等人的方法）测量每只脚的 M1 旋转。由 2 名观察者从冠状 WBCT 图像测量旋转。为每种方法计算 M1 旋转的平均值和置信区间（CI）。还报告了观察者间和观察者内的可靠性值。
使用 Saltzman 等人和 Kim 等人的方法，分别确定 M1 旋转的平均值为 2.1 度（95%CI：0.9-3.4）和 6.1 度（95%CI：4.4-7.8）。两种方法的观察者间和观察者内可靠性值均被解释为优秀。
在本研究中，我们描述了无拇囊炎或其他可识别的足部骨骼畸形患者 M1 轴向旋转的自然分布。这些信息应为纠正第一跖骨旋转问题的外科医生提供正常参考。
三级，回顾性队列研究。
