Department of Orthopaedic Surgery, The Jikei University School of Medicine, Tokyo, Japan.
Institute for High Dimensional Medical Imaging, The Jikei University School of Medicine, Tokyo, Japan.
Foot Ankle Int. 2023 Jun;44(6):545-553. doi: 10.1177/10711007231161011. Epub 2023 Mar 24.
The windlass mechanism (WM) increases the longitudinal arch of the foot via tension of the plantar aponeurosis during dorsiflexion of the metatarsophalangeal (MTP) joint. The purpose of this study was to perform a 3-dimensional evaluation of the displacement of each joint and the height of the navicular during dorsiflexion of the first MTP joint by using weightbearing computed tomography (CT).
Participants were 6 men and 8 women with 23 healthy feet. CT of the foot with a load equivalent to the participant's body weight was performed. The first MTP joint was in the neutral position and dorsiflexed 30 degrees. Between the conditions, we measured the (1) rotation of each bone, (2) rotation of the distal bone with respect to the proximal bone at each joint, and (3) height of the navicular.
With respect to the tibia, the calcaneus was at 0.8 ± 0.7 degrees dorsiflexion and 1.4 ± 0.9 degrees inversion, while the talus was at 2.0 ± 1.2 degrees dorsiflexion and 0.1 ± 0.8 degrees eversion. The navicular was at 1.3 ± 1.2 degrees dorsiflexion and 3.2 ± 2.1 degrees inversion, whereas the medial cuneiform was at 0.3 ± 0.6 degrees plantarflexion and 1.3 ± 1.1 degrees inversion. At the talonavicular joint, the navicular was at 0.7 ± 1.3 degrees plantarflexion, whereas at the cuneonavicular joint, the medial cuneiform bone was at 1.4 ± 1.4 degrees plantarflexion. The height of the navicular increased by 1.1 ± 0.6 mm.
We 3-dimensionally confirmed the dynamics of WM and found that the calcaneus, navicular, and medial cuneiform moved in all 3 planes. The results suggest that the cuneonavicular joint has the greatest movement among the joints. We believe that these findings will help to elucidate the pathogenesis of WM-related diseases and lead to advances in treatments for pathologies involving the longitudinal arch.
Level IV, case series.
在跖屈第一跖趾关节（MTP）时，通过拉紧足底腱膜，卷扬机机制（WM）增加足的纵弓。本研究的目的是通过负重 CT 对每个关节的位移和第一 MTP 关节跖屈时的舟骨高度进行三维评估。
参与者为 6 名男性和 8 名女性，共 23 只健康足。对负重相当于参与者体重的足部 CT 进行检查。第一 MTP 关节处于中立位，跖屈 30 度。在这两种情况下，我们测量了（1）每个骨的旋转，（2）每个关节近端骨相对于远端骨的旋转，以及（3）舟骨的高度。
与胫骨相比，跟骨跖屈 0.8±0.7 度，内翻 1.4±0.9 度，而距骨跖屈 2.0±1.2 度，外翻 0.1±0.8 度。舟骨跖屈 1.3±1.2 度，内翻 3.2±2.1 度，而内侧楔骨跖屈 0.3±0.6 度，内翻 1.3±1.1 度。在跗舟状骨关节，舟骨跖屈 0.7±1.3 度，而在楔舟状骨关节，内侧楔骨跖屈 1.4±1.4 度。舟骨高度增加 1.1±0.6mm。
我们从三维角度证实了 WM 的动力学，并发现跟骨、舟骨和内侧楔骨在所有三个平面上都有运动。结果表明，在这些关节中，楔舟状骨关节的活动度最大。我们相信这些发现将有助于阐明 WM 相关疾病的发病机制，并促进与纵弓相关的病理治疗进展。
IV 级，病例系列。
