1 Department of Orthopedics and Rehabilitation, University of Iowa, Iowa City, IA, USA.
2 Carver College of Medicine, University of Iowa, Iowa City, IA, USA.
Foot Ankle Int. 2018 Nov;39(11):1345-1354. doi: 10.1177/1071100718786500. Epub 2018 Jul 13.
The purpose of this study was to compare mechanical behavior of conventional syndesmosis fixation devices with new anatomic repair techniques incorporating various repair augmentations to determine which approach would return rotational ankle mechanics closer to those of an intact ankle.
Ten pairs of fresh-frozen through-the-knee cadaveric lower limbs were subjected to 7.5 Nm of external rotation torque while under 750 N of axial compression. After testing specimens intact and with the deltoid and syndesmotic ligament complexes completely destabilized, specimens underwent syndesmotic fixation using a screw, a suture button construct, a prototype structurally augmented flexible trans-syndesmotic fixation device, or the prototype device plus suture repairs of the anterior-inferior tibiofibular ligament and deep deltoid ligament. Syndesmotic repair devices were exchanged between tests so that each specimen was tested with 2 different fixation techniques. Whole-foot rotation angles at 7.5 Nm of applied torque were measured for comparison of the different repair strategies, and reflective markers mounted on the tibia, fibula, and talus were used to track translations and rotations of the talus and the fibula relative to the tibia during testing.
Syndesmotic destabilization significantly ( P < .001) increased whole-foot, talus, and fibula rotation in an axial plane and posterior fibula translation under 7.5 Nm of torque. Neither the suture button nor the augmented flexible trans-syndesmotic fixation device reduced those increases. Screw fixation or addition of anatomic ligament repairs to the augmented flexible fixation device successfully reduced axial plane rotations and sagittal plane translations to near intact levels.
Flexible trans-syndesmotic fixation alone was found to be insufficient for restoring rotational stability to the ankle/talus or preventing sagittal plane displacement of the fibula.
Repairs to simulate anatomic structures disrupted during a syndesmosis injury were required to restore rotational stability to the foot when using flexible trans-syndesmotic fixation that may have clinical applicability.
本研究的目的是比较传统的下胫腓联合固定装置与新型解剖修复技术的力学行为，这些技术包括各种修复增强，以确定哪种方法能使踝关节的旋转力学更接近正常踝关节。
10 对新鲜冷冻的膝下尸体下肢在 750N 的轴向压缩下，受到 7.5N·m 的外部旋转扭矩。在测试标本完整以及三角韧带和下胫腓联合复合体完全不稳定后，标本分别采用螺钉、缝线纽扣结构、原型结构增强的柔性经下胫腓联合固定装置或原型装置加前下胫腓韧带和深层三角韧带的缝线修复进行下胫腓联合固定。在测试之间交换下胫腓联合修复装置，以使每个标本用 2 种不同的固定技术进行测试。在施加 7.5N·m 扭矩时测量整个足部的旋转角度，以比较不同的修复策略，在测试过程中，胫骨、腓骨和距骨上安装的反射标记用于跟踪距骨和腓骨相对于胫骨的平移和旋转。
下胫腓联合不稳定显著增加了整个足部、距骨和轴向平面中的腓骨旋转以及 7.5N·m 扭矩下的后腓骨平移（P<0.001）。缝线纽扣或增强的柔性经下胫腓联合固定装置都不能减少这些增加。螺钉固定或在增强的柔性固定装置中加入解剖韧带修复成功地将轴向平面旋转和矢状平面平移减少到接近正常水平。
单独使用柔性经下胫腓联合固定不足以恢复踝关节/距骨的旋转稳定性或防止腓骨矢状面位移。
在下胫腓联合损伤时，需要修复模拟解剖结构的损伤，以在使用可能具有临床适用性的柔性经下胫腓联合固定时恢复足部的旋转稳定性。
