Department of Orthopaedic Surgery, Seoul National University Bundang Hospital, 82 Gumi-ro 173 Beon-gil, Bundang-Gu, Sungnam, Gyeonggi, 13620, South Korea.
BMC Musculoskelet Disord. 2020 Apr 16;21(1):250. doi: 10.1186/s12891-020-03285-3.
In planovalgus deformity with triceps contracture, a midfoot break happens, and ankle dorsiflexion (ADF) occurs at the mid-tarsal joint during gait. Results of standard 3D gait analysis may misinterpret the true ankle dorsiflexion because it recognizes the entire foot as a single rigid segment. We performed this study to investigate whether the severity of planovalgus deformity is associated with the discrepancy between the value of ADF evaluated by physical examination and 3-dimensional (3D) gait analysis. In addition, we aimed to identify the radiographic parameters associated with this discrepancy and their relationships.
Consecutive 40 patients with 65 limbs (mean age, 11.7 ± 5.5 years) with planovalgus foot deformity and triceps surae contracture were included. All patients underwent 3D gait analysis, and weightbearing anteroposterior (AP) and lateral (LAT) foot radiographs. ADF with knee extension was measured using a goniometer with the patient's foot in an inverted position.
Twenty-one limbs underwent operation for planovalgus foot deformity, and 56 limbs underwent operation for equinus deformity. The difference between ADF on physical examination and ADF at initial contact on gait analysis was 17.5 ± 8.4°. Differences between ADF on physical examination and ADF at initial contact on gait analysis were significantly associated with the LAT talus-first metatarsal angle (p = 0.008) and calcaneal pitch angle (p = 0.006), but not associated with the AP talus-first metatarsal angle (p = 0.113), talonavicular coverage angle (p = 0.190), talocalcaneal angle (p = 0.946), and naviculocuboid overlap (p = 0.136).
The discrepancy between ADF on physical examination and 3D gait analysis was associated with the severity of planovalgus deformity, which was evaluated on weightbearing LAT foot radiographs. Therefore, physicians should be cautious about interpreting results from 3D gait analysis and perform a careful physical examination to assess the degree of equinus deformity in patients with planovalgus foot deformity.
在伴有三头肌挛缩的足内翻畸形中，中跗关节发生断裂，在步态中踝关节背屈（ADF）发生在中跗关节。标准的 3D 步态分析结果可能会误解真正的踝关节背屈，因为它将整个脚识别为一个单一的刚性段。我们进行这项研究是为了探讨足内翻畸形的严重程度是否与体格检查评估的 ADF 值与 3 维（3D）步态分析之间的差异有关。此外，我们旨在确定与这种差异相关的影像学参数及其关系。
连续纳入 40 例 65 侧足内翻畸形伴三头肌挛缩的患者（平均年龄 11.7±5.5 岁）。所有患者均接受 3D 步态分析和负重前后位（AP）和侧位（LAT）足部 X 线检查。使用足处于倒置位置的量角器测量膝关节伸展时的 ADF。
21 侧接受足内翻畸形手术，56 侧接受马蹄内翻足畸形手术。体格检查时 ADF 与步态分析初始接触时 ADF 的差值为 17.5±8.4°。体格检查时 ADF 与步态分析初始接触时 ADF 的差值与 LAT 距骨第一跖骨角（p=0.008）和跟骨倾斜角（p=0.006）显著相关，但与 AP 距骨第一跖骨角（p=0.113）、距下关节覆盖角（p=0.190）、距跟角（p=0.946）和跗骨-舟骨重叠（p=0.136）无关。
体格检查与 3D 步态分析之间 ADF 的差异与负重 LAT 足部 X 线片上评估的足内翻畸形的严重程度有关。因此，医生在解释 3D 步态分析结果时应谨慎，并进行仔细的体格检查，以评估足内翻畸形患者的马蹄内翻畸形程度。
