Departments of Foot and Ankle Surgery (A.M.H., J.T.D., and S.J.E.), Radiology and Imaging (H.P., E.B., and C.S.), Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021. E-mail address for A.M. Haleem:
J Bone Joint Surg Am. 2014 Apr 16;96(8):e63. doi: 10.2106/JBJS.L.01205.
Posterior tibial tendon dysfunction varies in location and severity. Weight-bearing radiographs have been validated to assess posterior tibial tendon dysfunction, yet their two-dimensional nature and the inability of the patients to achieve full weight-bearing during acquisition are limitations. Multiplanar modified sectional weight-bearing imaging is a novel modality, yielding computed tomography-like images compared with radiographs, yet with true weight-bearing, shorter acquisition time, and lower radiation. The aim of this study was to test two hypotheses: first, multiplanar weight-bearing imaging would localize deformity with respect to the talus in patients with posterior tibial dysfunction compared with controls, and second, multiplanar weight-bearing imaging would correlate with specific radiographic parameters of posterior tibial tendon dysfunction on weight-bearing radiographs.
Weight-bearing radiographs and multiplanar modified sectional weight-bearing images of the foot and ankle were made for twenty-three patients with flexible posterior tibial tendon dysfunction. Ten patients with imaging for unrelated pathological conditions served as controls. Thirteen radiographic parameters on the transverse, sagittal, and coronal views of multiplanar weight-bearing imaging in the study group were evaluated and compared with those in the control group. The same parameters on standing weight-bearing radiographs of patients in the study group were compared with those in the control group.
Significant differences between study and control groups were found on multiplanar weight-bearing imaging for six of thirteen radiographic parameters (p < 0.05), notably the sagittal talonavicular angle as well as sagittal and transverse talar-first metatarsal angles (p = 0.027, p = 0.003, and p = 0.004, respectively). However, only one parameter on weight-bearing radiographs (lateral talar-first metatarsal angle) reached significance (p < 0.05). Correlation showed excellent, very good, and good agreement between both imaging modalities for three, two, and five parameters, respectively.
Deformity with respect to the talus in posterior tibial tendon dysfunction is multifactorial, but was notably seen at the talonavicular joint in the sagittal plane with both modalities. Good to excellent agreement was found between weight-bearing radiographs and multiplanar weight-bearing images for many parameters; however, a greater number of significant differences was found between the flatfoot and control groups for multiplanar weight-bearing images. This implies a potential role for multiplanar modified sectional weight-bearing imaging as a more informative tool to assess posterior tibial tendon dysfunction in the physiological, full weight-bearing position.
胫骨后肌腱功能障碍的位置和严重程度各不相同。负重位 X 线片已被证实可用于评估胫骨后肌腱功能障碍，但由于其二维性质以及患者在采集时无法完全负重，存在一定的局限性。多平面改良节段负重成像为一种新的成像方式，与 X 线片相比可生成类似 CT 的图像，但具有真正的负重、更短的采集时间和更低的辐射。本研究旨在验证两个假设：首先，与对照组相比，多平面负重成像能够定位胫骨后肌腱功能障碍患者中跟骨的畸形；其次，多平面负重成像与负重位 X 线片中胫骨后肌腱功能障碍的特定放射学参数相关。
对 23 例柔韧性胫骨后肌腱功能障碍患者进行足部和踝关节负重 X 线片和多平面改良节段负重成像检查。10 例因其他病理状况进行影像学检查的患者作为对照组。研究组在多平面负重成像的横断位、矢状位和冠状位上评估并比较了 13 项放射学参数，并与对照组进行比较。研究组患者的站立负重 X 线片上的相同参数也与对照组进行了比较。
在多平面负重成像上，研究组与对照组之间有 6 项（p < 0.05）放射学参数存在显著差异，特别是矢状位距下关节角以及矢状位和横断位跟骨-第一跖骨角（p = 0.027、p = 0.003 和 p = 0.004）。然而，只有 1 项负重位 X 线片上的参数（外侧跟骨-第一跖骨角）具有统计学意义（p < 0.05）。两种成像方式之间的相关性显示，在 3 项、2 项和 5 项参数上的一致性分别为极好、非常好和良好。
胫骨后肌腱功能障碍患者跟骨的畸形是多因素的，但两种成像方式均主要在矢状位距下关节上显示。负重位 X 线片与多平面负重成像之间在许多参数上具有良好到极好的一致性；然而，多平面负重成像显示扁平足与对照组之间有更多的显著差异。这意味着多平面改良节段负重成像作为一种更具信息量的工具，可在生理、完全负重的状态下评估胫骨后肌腱功能障碍。
