Nomkhondorj Otgonsaikhan, Chun Dong-Il, Park Kwang-Rak, Cho Jaeho
Department of and Biomedical Science, Graduate School of Medicine, Hallym University, Chuncheon 24252, Republic of Korea.
Department of Orthopaedic Surgery, Chuncheon Sacred Heart Hospital, Hallym University, Chuncheon 24252, Republic of Korea.
J Clin Med. 2025 Apr 9;14(8):2587. doi: 10.3390/jcm14082587.
Hindfoot valgus malalignment, characterized by the lateral deviation of the calcaneus and medial tilting of the talus, disrupts hindfoot biomechanics and increases strain on subtalar joint. This study evaluates weightbearing and non-weightbearing imaging modalities to identify dynamic alignment changes and their diagnostic implications. This study aims to (1) quantify changes in subtalar joint parameters between non-weightbearing computed tomography (NWBCT) and weightbearing computed tomography (WBCT) in patients with hindfoot valgus; (2) evaluate correlations between WBCT and standard radiographic parameters; and (3) identify radiographic predictors of subtalar joint status during weightbearing. We reviewed 70 patients with confirmed hindfoot valgus malalignment (hindfoot valgus angle >5°), identified through radiographic measurements. Of these, 32 underwent both NWBCT and WBCT, while 38 underwent WBCT alone. Hindfoot alignment angle (HAA) and hindfoot alignment ratio (HAR) were measured on hindfoot alignment radiographs, while heel valgus angle (HVA), talocalcaneal distance (TCD), subtalar joint subluxation (SL) and calcaneofibular distance (CF) were assessed on CT. WBCT revealed significant increases in HVA and SL (both, < 0.001) and decreases in TCD and CF ( < 0.001 and = 0.002, respectively) compared to NWBCT, reflecting dynamic subtalar joint changes under weightbearing conditions. Receiver operating characteristic (ROC) analysis identified hindfoot alignment angle (HAA) as the most reliable predictor of talocalcaneal osseous contact, with a cutoff value of >9.25° based on Youden's index, yielding a sensitivity of 73% and specificity of 81.8%. Inter- and intra-observer reliabilities for all parameters were excellent (ICC > 0.81). WBCT provides critical insights into subtalar joint dynamics under physiological loads, surpassing NWBCT in assessing weightbearing-induced alignment changes. Although standard radiographic parameters, particularly HAA, can serve as reliable, cost-effective predictors of subtalar joint pathology in resource-limited settings, WBCT should still be preferred when available, especially in patients with significant malalignment or when detailed dynamic evaluation is needed to guide clinical decision-making.
后足外翻畸形排列，其特征为跟骨外侧偏斜和距骨内侧倾斜，会破坏后足生物力学并增加距下关节的应力。本研究评估负重和非负重成像方式，以识别动态排列变化及其诊断意义。本研究旨在：(1) 量化后足外翻患者非负重计算机断层扫描（NWBCT）和负重计算机断层扫描（WBCT）之间距下关节参数的变化；(2) 评估WBCT与标准放射学参数之间的相关性；(3) 识别负重期间距下关节状态的放射学预测指标。我们回顾了70例经放射学测量确诊为后足外翻畸形排列（后足外翻角>5°）的患者。其中，32例患者同时接受了NWBCT和WBCT检查，38例患者仅接受了WBCT检查。在后足排列X线片上测量后足排列角（HAA）和后足排列比（HAR），而在CT上评估足跟外翻角（HVA）、距跟距离（TCD）、距下关节半脱位（SL）和跟腓距离（CF）。与NWBCT相比，WBCT显示HVA和SL显著增加（均P<0.001），TCD和CF显著降低（分别为P<0.001和P = 0.002），反映了负重条件下距下关节的动态变化。受试者工作特征（ROC）分析确定后足排列角（HAA）是距跟骨骨性接触最可靠的预测指标，根据约登指数，截断值>9.25°，灵敏度为73%，特异度为81.8%。所有参数的观察者间和观察者内可靠性均极佳（ICC>0.81）。WBCT能提供生理负荷下距下关节动态的关键见解，在评估负重引起的排列变化方面优于NWBCT。虽然标准放射学参数，尤其是HAA，在资源有限的情况下可作为距下关节病变可靠且经济有效的预测指标，但在可行时仍应首选WBCT，尤其是在畸形排列严重的患者中，或需要详细动态评估以指导临床决策时。
