Ozaki Yusuke, Hara Ryota, Okamura Kensuke, Kurokawa Hiroaki, Inagaki Yusuke, Ogawa Munehiro, Taniguchi Akira, Tanaka Yasuhito
Department of Orthopaedic Surgery, Nara Medical University, Kashihara, Nara, Japan.
PLoS One. 2025 Jun 3;20(6):e0324974. doi: 10.1371/journal.pone.0324974. eCollection 2025.
In knee osteoarthritis, the subtalar joint undergoes valgus and varus contractions to compensate for deformities in the knee joint. In this cross-sectional study, we investigated the relationship between varus-type knee osteoarthritis severity and hindfoot alignment severity by concurrently assessing varus-type knee osteoarthritis severity and hindfoot alignment using radiographs in the long-leg weight-bearing anteroposterior view.
A total of 114 patients with knee osteoarthritis graded Kellgren-Lawrence II or higher (128 knees) and 30 healthy controls (31 knees) underwent long-leg weight-bearing anteroposterior imaging for 1 year. Four angles were measured on radiographs in the long-leg weight-bearing anteroposterior view: the femorotibial angle; tibial calcaneal angle; tibial anterior surface angle; and talocrural joint angle between the tibial plafond and talar dome on weight-bearing. Group comparisons were conducted for each Kellgren-Lawrence classification, which was used to classify the severity of knee osteoarthritis at each measured angle. One-way analysis of variance was used to test the results.
The mean tibial calcaneal angles were 9.7°, 11.3°, 8.8°, and 9.8° in controls and in patients with Kellgren-Lawrence grades II, III, and IV, respectively (p < 0.05). The mean femorotibial angles were 175.6°, 176.8°, 180.3°, and 186.2° in controls and in patients with Kellgren-Lawrence grades II, III, and IV, respectively (p < 0.05). On weight-bearing, the tibial anterior surface angle and the talocrural joint angle between the tibial plafond and talar dome varied according to severity level.
In varus-type knee osteoarthritis cases, defined in accordance with the Kellgren-Lawrence classification, hindfoot alignment leaned toward valgus. As the severity of knee osteoarthritis progressed, the valgus of the hindfoot alignment reduced. While future longitudinal analyses are necessary, these observations indicate both potential compensatory changes and their limitations in varus-type knee osteoarthritis.
在膝关节骨关节炎中，距下关节会发生外翻和内翻挛缩，以代偿膝关节的畸形。在这项横断面研究中，我们通过在长腿负重前后位X线片上同时评估内翻型膝关节骨关节炎的严重程度和后足对线情况，来研究内翻型膝关节骨关节炎严重程度与后足对线严重程度之间的关系。
共有114例Kellgren-Lawrence分级为II级或更高的膝关节骨关节炎患者（128个膝关节）和30例健康对照者（31个膝关节）接受了为期1年的长腿负重前后位成像检查。在长腿负重前后位X线片上测量四个角度：股胫角；胫跟角；胫骨前表面角；以及负重时胫骨平台与距骨穹窿之间的踝关节角。对每个Kellgren-Lawrence分级进行组间比较，该分级用于在每个测量角度对膝关节骨关节炎的严重程度进行分类。采用单因素方差分析来检验结果。
对照组以及Kellgren-Lawrence II级、III级和IV级患者的平均胫跟角分别为9.7°、11.3°、8.8°和9.8°（p < 0.05）。对照组以及Kellgren-Lawrence II级、III级和IV级患者的平均股胫角分别为175.6°、176.8°、180.3°和186.2°（p < 0.05）。负重时，胫骨前表面角以及胫骨平台与距骨穹窿之间的踝关节角随严重程度水平而变化。
在根据Kellgren-Lawrence分类定义的内翻型膝关节骨关节炎病例中，后足对线倾向于外翻。随着膝关节骨关节炎严重程度的进展，后足对线的外翻程度降低。虽然未来需要进行纵向分析，但这些观察结果表明了内翻型膝关节骨关节炎中潜在的代偿性变化及其局限性。
