Smolen Chris, Quenneville Cheryl E
Department of Mechanical Engineering, McMaster University, 1280 Main Street West, Hamilton, ON, L8S 4L7, Canada.
School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada.
Ann Biomed Eng. 2017 Aug;45(8):1993-2008. doi: 10.1007/s10439-017-1844-2. Epub 2017 May 3.
The foot/ankle complex is frequently injured in many types of debilitating events, such as car crashes. Numerical models used to assess injury risk are typically minimally validated and do not account for ankle posture variations that frequently occur during these events. The purpose of this study was to evaluate a finite element model of the foot and ankle accounting for these positional changes. A model was constructed from computed tomography scans of a male cadaveric lower leg and was evaluated by comparing simulated bone positions and strain responses to experimental results at five postures in which fractures are commonly reported. The bone positions showed agreement typically within 6° or less in all anatomical directions, and strain matching was consistent with the range of errors observed in similar studies (typically within 50% of the average strains). Fracture thresholds and locations in each posture were also estimated to be similar to those reported in the literature (ranging from 6.3 kN in the neutral posture to 3.9 kN in combined eversion and external rotation). The least vulnerable posture was neutral, and all other postures had lower fracture thresholds, indicating that examination of the fracture threshold of the lower limb in the neutral posture alone may be an underestimation. This work presents an important step forward in the modeling of lower limb injury risk in altered ankle postures. Potential clinical applications of the model include the development of postural guidelines to minimize injury, as well as the evaluation of new protective systems.
足/踝关节复合体在许多致残事件中经常受伤，如车祸。用于评估损伤风险的数值模型通常验证不足，且未考虑这些事件中经常出现的踝关节姿势变化。本研究的目的是评估一个考虑了这些位置变化的足踝有限元模型。该模型由一名男性尸体小腿的计算机断层扫描构建而成，并通过比较模拟的骨骼位置和应变响应与实验结果进行评估，实验结果来自于五个常见骨折姿势。在所有解剖方向上，骨骼位置的一致性通常在6°或更小范围内，应变匹配与类似研究中观察到的误差范围一致（通常在平均应变的50%以内）。每个姿势下的骨折阈值和位置也估计与文献报道的相似（从中立姿势的6.3kN到外翻和外旋组合姿势的3.9kN）。最不易受伤的姿势是中立位，所有其他姿势的骨折阈值较低，这表明仅检查中立位下肢的骨折阈值可能会低估风险。这项工作在改变踝关节姿势的下肢损伤风险建模方面向前迈出了重要一步。该模型潜在的临床应用包括制定姿势指南以尽量减少损伤，以及评估新的防护系统。
