Hoogervorst Paul, Working Zachary M, El Naga Ashraf N, Marmor Meir
Department of Orthopaedic Surgery, University of California, San Francisco, California.
Foot Ankle Spec. 2019 Jun;12(3):233-237. doi: 10.1177/1938640018782602. Epub 2018 Jun 20.
It is clear that motion at the syndesmosis occurs due to ranging of the ankle joint, but the influence of weightbearing with the foot in the plantigrade position is unclear. In vivo computed tomographic (CT) evaluation of the syndesmosis has not been previously described. The purpose of this study is to quantify physiological fibular motion at the level of the ankle syndesmosis in both weightbearing and nonweightbearing conditions with the foot in the plantigrade position. CT images were obtained from 9 normal healthy subjects using a weightbearing CT imaging system. The subjects were positioned in a nonweightbearing and weightbearing state with their foot in the plantigrade position. Fibular translation and rotation were measured from the axial CT images using previously validated techniques. Both the average lateral and anteroposterior translation of the fibula between weightbearing and nonweightbearing states was minimal (0.3 mm and 0.2 mm, respectively). The largest difference in translation observed in either direction was 0.9 mm. An average of 0.5° was found for rotational differences of the fibula between weightbearing and nonweightbearing. Neither of the translational and rotational parameters reached statistical significance. In vivo CT analysis of the distal tibiofibular joint with an intact syndesmosis did not reveal statistically significant physiological motion between weightbearing and nonweightbearing conditions with the foot in plantigrade position. Our findings suggest that weightbearing accounts for little motion at the syndesmosis and supports further investigation into the role of early protected weightbearing after syndesmosis fixation. Level III: Case-control study.
显然，下胫腓联合处的活动是由于踝关节的活动范围引起的，但足部处于跖行位时负重的影响尚不清楚。此前尚未有对下胫腓联合处进行体内计算机断层扫描（CT）评估的描述。本研究的目的是量化在足部处于跖行位的负重和非负重条件下，踝关节下胫腓联合水平的生理性腓骨活动。使用负重CT成像系统从9名正常健康受试者获取CT图像。受试者足部处于跖行位，分别处于非负重和负重状态。使用先前验证的技术从轴向CT图像测量腓骨的平移和旋转。在负重和非负重状态之间，腓骨的平均外侧和前后平移均最小（分别为0.3mm和0.2mm）。在任一方向观察到的最大平移差异为0.9mm。负重和非负重之间腓骨的旋转差异平均为0.5°。平移和旋转参数均未达到统计学显著性。对下胫腓联合完整的胫腓远端关节进行体内CT分析，未发现足部处于跖行位时负重和非负重条件之间存在具有统计学显著性的生理性活动。我们的研究结果表明，负重在下胫腓联合处引起的活动很小，并支持进一步研究下胫腓联合固定后早期保护性负重的作用。III级：病例对照研究。
