Foot and Ankle Unit, Royal National Orthopaedic Hospital, Stanmore, United Kingdom; Department of Public Health, Trauma and Orthopaedics, University of Naples Federico II, Naples, Italy.
Foot and Ankle Unit, Royal National Orthopaedic Hospital, Stanmore, United Kingdom.
Foot Ankle Surg. 2020 Jul;26(5):564-572. doi: 10.1016/j.fas.2019.07.005. Epub 2019 Jul 26.
Pes cavovarus is a three-dimensional (3D) foot deformity. New 3D semi-automatic measurements utilising weightbearing computerised topography (WBCT) images have recently been proposed to assess hindfoot alignment, but reliability in pes cavovarus has never been investigated. The aim of this study was to assess intraobserver and interobserver reliability of the foot ankle offset (FAO), calcaneal offset (CO) and hindfoot alignment angle (HAA) in pes cavovarus.
Anonymised WBCT datasets from 51 feet (17 Charcot-Marie-Tooth related cavovarus, 17 idiopathic cavovarus and 17 controls) were retrospectively reviewed. Three observers (two senior foot and ankle fellows and one orthopaedic resident) independently measured FAO, CO and HAA using dedicated software, with measurements repeated two weeks apart. Subgroup analysis was performed to assess whether aetiology or severity of varus deformity and level of seniority affected reliability.
Mean values for intra and interobserver reliability for FAO (r=0.98; ICC: 0.99), CO (r=0.97; ICC: 0.98) and HAA measurements (r=0.97; ICC: 0.98) were excellent. Subgroup analyses showed that FAO, CO and HAA's intra (r/ρ range, 0.77-0.95) and interobserver (ICC range, 0.88-0.98) reliability remained excellent in patients with Charcot-Marie-Tooth related cavovarus, idiopathic pes cavovarus and normal feet, regardless of the severity of deformity. No difference was found in FAO, CO and HAA mean values from three observers (p>0.05 in all cases).
This study demonstrates that 3D semi-automatic measurements of WBCT images have excellent intra and interobserver reliability in the assessment of hindfoot alignment in pes cavovarus. Aetiology and severity of deformity, and level of seniority do not affect reliability of these measurements.
Level III, retrospective comparative study.
马蹄内翻足是一种三维（3D）足部畸形。最近提出了新的 3D 半自动测量方法，利用负重计算机断层扫描（WBCT）图像评估后足对线，但在马蹄内翻足中从未进行过可靠性研究。本研究旨在评估 3D 半自动测量马蹄内翻足的足踝偏移（FAO）、跟骨偏移（CO）和后足对线角（HAA）的观察者内和观察者间可靠性。
回顾性分析 51 足（17 例 Charcot-Marie-Tooth 相关马蹄内翻足、17 例特发性马蹄内翻足和 17 例对照组）的匿名化 WBCT 数据集。三名观察者（两名高级足踝研究员和一名骨科住院医师）分别使用专用软件独立测量 FAO、CO 和 HAA，两周后重复测量。进行亚组分析以评估病因或内翻畸形的严重程度以及观察者的级别是否影响可靠性。
FAO（r=0.98；ICC：0.99）、CO（r=0.97；ICC：0.98）和 HAA 测量的观察者内和观察者间可靠性的平均值均为优秀。亚组分析表明，在 Charcot-Marie-Tooth 相关马蹄内翻足、特发性马蹄内翻足和正常足患者中，FAO、CO 和 HAA 的观察者内（r/ρ 范围为 0.77-0.95）和观察者间（ICC 范围为 0.88-0.98）可靠性均为优秀，无论畸形的严重程度如何。三名观察者的 FAO、CO 和 HAA 平均值无差异（所有情况下 p>0.05）。
本研究表明，3D 半自动测量 WBCT 图像在后足对线的评估中具有优秀的观察者内和观察者间可靠性。病因和畸形的严重程度以及观察者的级别不会影响这些测量的可靠性。
三级，回顾性比较研究。
