Abstract：
UNASSIGNED: Talar displacement is considered the main predictive factor for poor outcomes and the development of post-traumatic osteoarthritis after ankle fractures. Isolated lateral talar translation, as previously studied by Ramsey and Hamilton using carbon powder imprinting, does not fully replicate the multidirectional joint subluxations seen in ankle fractures. The purpose of this study was to analyze the influence of multiple uniplanar talar displacements on tibiotalar contact mechanics utilizing weightbearing computed tomography (WBCT) and finite element analysis (FEA).
UNASSIGNED: Nineteen subjects (mean age = 37.6 years) with no history of ankle surgery or injury having undergone WBCT arthrogram (n = 1) and WBCT without arthrogram (n = 18) were included. Segmentation of the WBCT images into 3D simulated models of bone and cartilage was performed. Three-dimensional (3D) multiple uniplanar talar displacements were simulated to investigate the respective influence of various uniaxial displacements (including lateral translation, anteroposterior translation, varus-valgus angulation, and external rotation) on the tibiotalar contact mechanics using FEA. Tibiotalar peak contact stress and contact area were modeled for each displacement and its gradations.
UNASSIGNED: Our modeling demonstrated that peak contact stress of the talus and tibia increased, whereas contact area decreased, with incremental displacement in all tested directions. Contact stress maps of the talus and tibia were computed for each displacement demonstrating unique patterns of pressure derangement. One millimeter of lateral translation resulted in 14% increase of peak talar contact pressure and a 3% decrease in contact area.
UNASSIGNED: Our model predicted that with lateral talar translation, there is less noticeable change in tibiotalar contact area compared with prior studies whereas external rotation greater than 12 degrees had the largest effect on peak contact stress predictions.
UNASSIGNED: Level V, computational simulation study.
UNASSIGNED: Nineteen subjects (mean age = 37.6 years) with no history of ankle surgery or injury having undergone WBCT arthrogram (n = 1) and WBCT without arthrogram (n = 18) were included. Segmentation of the WBCT images into 3D simulated models of bone and cartilage was performed. Three-dimensional (3D) multiple uniplanar talar displacements were simulated to investigate the respective influence of various uniaxial displacements (including lateral translation, anteroposterior translation, varus-valgus angulation, and external rotation) on the tibiotalar contact mechanics using FEA. Tibiotalar peak contact stress and contact area were modeled for each displacement and its gradations.
UNASSIGNED: Our modeling demonstrated that peak contact stress of the talus and tibia increased, whereas contact area decreased, with incremental displacement in all tested directions. Contact stress maps of the talus and tibia were computed for each displacement demonstrating unique patterns of pressure derangement. One millimeter of lateral translation resulted in 14% increase of peak talar contact pressure and a 3% decrease in contact area.
UNASSIGNED: Our model predicted that with lateral talar translation, there is less noticeable change in tibiotalar contact area compared with prior studies whereas external rotation greater than 12 degrees had the largest effect on peak contact stress predictions.
UNASSIGNED: Level V, computational simulation study.
摘要：
■Talar移位被认为是踝关节骨折后不良预后和创伤后骨关节炎发展的主要预测因素。孤立的侧向距骨平移，正如拉姆齐和汉密尔顿之前使用碳粉印迹研究的那样，不能完全复制踝关节骨折中的多向关节半脱位。这项研究的目的是利用负重计算机断层扫描（WBCT）和有限元分析（FEA）分析多个单平面距骨位移对胫骨接触力学的影响。
■包括19名没有踝关节手术或损伤史的受试者（平均年龄=37.6岁）接受WBCT关节造影（n=1）和WBCT无关节造影（n=18）。将WBCT图像分割为骨骼和软骨的3D模拟模型。模拟了三维（3D）多个单面距骨位移，以研究各种单轴位移的各自影响（包括横向平移，前后平移，内翻外翻角化,和外部旋转）使用FEA在胫骨接触力学上。对每个位移及其等级的Tibiotalar峰值接触应力和接触面积进行了建模。
■我们的建模表明，距骨和胫骨的峰值接触应力增加，而接触面积减少，在所有测试方向上都有增量位移。计算每个位移的距骨和胫骨的接触应力图，证明了压力紊乱的独特模式。一毫米的横向平移导致峰值距骨接触压力增加14％，接触面积减少3％。
■我们的模型预测，随着距骨横向平移，与先前的研究相比，胫骨接触面积的变化不那么明显，而大于12度的外部旋转对峰值接触应力预测的影响最大。
■V级,计算模拟研究。
■包括19名没有踝关节手术或损伤史的受试者（平均年龄=37.6岁）接受WBCT关节造影（n=1）和WBCT无关节造影（n=18）。将WBCT图像分割为骨骼和软骨的3D模拟模型。模拟了三维（3D）多个单面距骨位移，以研究各种单轴位移的各自影响（包括横向平移，前后平移，内翻外翻角化,和外部旋转）使用FEA在胫骨接触力学上。对每个位移及其等级的Tibiotalar峰值接触应力和接触面积进行了建模。
■我们的建模表明，距骨和胫骨的峰值接触应力增加，而接触面积减少，在所有测试方向上都有增量位移。计算每个位移的距骨和胫骨的接触应力图，证明了压力紊乱的独特模式。一毫米的横向平移导致峰值距骨接触压力增加14％，接触面积减少3％。
■我们的模型预测，随着距骨横向平移，与先前的研究相比，胫骨接触面积的变化不那么明显，而大于12度的外部旋转对峰值接触应力预测的影响最大。
■V级,计算模拟研究。
