Miyamoto Takuma, Lisonbee Rich J, Kurokawa Hiroaki, Taniguchi Akira, Tanaka Yasuhito, Lenz Amy L
Department of Orthopaedics, University of Utah, Salt Lake City, Utah.
Department of Orthopaedic Surgery, Nara Medical University, Nara, Japan Nara, Japan.
JB JS Open Access. 2025 Sep 17;10(3). doi: 10.2106/JBJS.OA.24.00215. eCollection 2025 Jul-Sep.
The posterior tibialis (PT) muscle and tendon could be a contributing factor in progressive collapsing foot deformity (PCFD). Still, the extent to which the function of the PT is related to PCFD progression is debated. Recently, statistical shape models (SSM) have been shown to provide more accurate and comprehensive morphological evaluations of musculoskeletal tissue. To enhance understanding of the PT in patients with PCFD, we used a 3D SSM to test the hypothesis that both the shape of the PT and alignment of the PT relative to the hindfoot bones are different in female patients with PCFD when compared with female asymptomatic controls.
In this retrospective comparative study, 12 female patients presenting with PCFD and 19 female asymptomatic individuals were included. Computed tomography images were segmented to create 3D models of hindfoot bones and PT. We compared the shape of the PT and alignment of the PT with the hindfoot bones using SSM. The PT 3D model was also used to measure volume, tendon normalized length, and percentage fat of the PT muscle. Each measurement and SSM were compared between PCFD and asymptomatic controls.
SSM did not identify significant differences in the isolated shape of the PT between groups. However, the SSM showed significant differences in the alignment of PT tendon regarding the hindfoot bones. Tendon normalized length was significantly lower in PCFD than that in controls. Percent fat content was significantly higher in PCFD compared with controls. No significant differences were found for PT volume between both groups.
Our results indicate that in female patients with PCFD, the PT does not differ significantly in shape and volume, only in tendon alignment relative to hindfoot bones, suggesting that the PT may be not always directly involved in the progression of PCFD.
The application of SSM to assess bones and muscles simultaneously in female patients with PCFD is a new and novel approach to understanding the pathophysiology of this disease.
Level III. See Instructions for Authors for a complete description of levels of evidence.
胫后肌（PT）及其肌腱可能是导致进行性足塌陷畸形（PCFD）的一个因素。然而，PT的功能与PCFD进展之间的关联程度仍存在争议。近来，统计形状模型（SSM）已被证明能对肌肉骨骼组织进行更准确、全面的形态学评估。为了增进对PCFD患者胫后肌的了解，我们使用三维SSM来检验以下假设：与无症状女性对照组相比，患有PCFD的女性患者的胫后肌形状及其相对于后足骨的排列均存在差异。
在这项回顾性比较研究中，纳入了12例患有PCFD的女性患者和19例无症状女性个体。对计算机断层扫描图像进行分割，以创建后足骨和胫后肌的三维模型。我们使用SSM比较了胫后肌的形状以及胫后肌与后足骨的排列情况。胫后肌三维模型还用于测量胫后肌的体积、肌腱标准化长度和脂肪百分比。对PCFD组和无症状对照组的各项测量结果及SSM进行了比较。
SSM未发现两组之间胫后肌单独形状存在显著差异。然而，SSM显示胫后肌腱相对于后足骨的排列存在显著差异。PCFD组的肌腱标准化长度显著低于对照组。与对照组相比，PCFD组的脂肪含量百分比显著更高。两组之间的胫后肌体积未发现显著差异。
我们的结果表明，在患有PCFD的女性患者中，胫后肌的形状和体积无显著差异，仅在相对于后足骨的肌腱排列方面存在差异，这表明胫后肌可能并非总是直接参与PCFD的进展。
将SSM应用于同时评估患有PCFD的女性患者的骨骼和肌肉，是一种理解该疾病病理生理学的全新方法。
三级。有关证据水平的完整描述，请参阅作者须知。
