Biomedical Engineering Graduate Program, 2500 University Drive NW, University of Calgary, Calgary, AB T2N 1N4, Canada; Human Performance Laboratory, Faculty of Kinesiology, 2500 University Drive NW, University of Calgary, Calgary, AB T2N 1N4, Canada; McCaig Institute for Bone and Joint Health, 3280 Hospital Dr NW, University of Calgary, Calgary, AB T2N 4Z6, Canada.
Human Performance Laboratory, Faculty of Kinesiology, 2500 University Drive NW, University of Calgary, Calgary, AB T2N 1N4, Canada; McCaig Institute for Bone and Joint Health, 3280 Hospital Dr NW, University of Calgary, Calgary, AB T2N 4Z6, Canada.
Bone. 2022 Aug;161:116443. doi: 10.1016/j.bone.2022.116443. Epub 2022 May 16.
Tibial stress fracture is a common injury in runners and military personnel. Elevated bone strain is believed to be associated with the development of stress fractures and is influenced by bone geometry and density. The purpose of this study was to characterize tibial-fibular geometry and density variations in young active adults, and to quantify the influence of these variations on finite element-predicted bone strain. A statistical appearance model characterising tibial-fibular geometry and density was developed from computed tomography scans of 48 young physically active adults. The model was perturbed ±1 and 2 standard deviations along each of the first five principal components to create finite element models. Average male and female finite element models, controlled for scale, were also generated. Muscle and joint forces in running, calculated using inverse dynamics-based static optimization, were applied to the finite element models. The resulting 95th percentile pressure-modified von Mises strain (peak strain) and strained volume (volume of elements above 4000 με) were quantified. Geometry and density variations described by principal components resulted in up to 12.0% differences in peak strain and 95.4% differences in strained volume when compared to the average tibia-fibula model. The average female illustrated 5.5% and 41.3% larger peak strain and strained volume, respectively, when compared to the average male, suggesting that sexual dimorphism in bone geometry may indeed contribute to greater stress fracture risk in females. Our findings identified important features in subject-specific geometry and density associated with elevated bone strain that may have implications for stress fracture risk.
胫骨应力性骨折是跑步者和军人常见的损伤。骨应变增加被认为与应力性骨折的发展有关，并且受骨几何形状和密度的影响。本研究的目的是描述年轻活跃成年人的胫骨腓骨几何形状和密度变化，并定量分析这些变化对有限元预测骨应变的影响。使用来自 48 名年轻身体活跃成年人的计算机断层扫描，开发了一种描述胫骨腓骨几何形状和密度的统计外观模型。该模型沿着前五个主成分的每个成分 ±1 和 2 个标准差进行了扰动，以创建有限元模型。还创建了控制比例的平均男性和女性有限元模型。使用基于逆动力学的静态优化计算跑步时的肌肉和关节力，并将其应用于有限元模型。量化了 95%的压力修正 von Mises 应变（峰值应变）和应变体积（应变元素体积超过 4000 με）。主成分描述的几何形状和密度变化与平均胫骨腓骨模型相比，峰值应变最大相差 12.0%，应变体积最大相差 95.4%。与平均男性相比，平均女性的峰值应变和应变体积分别大 5.5%和 41.3%，这表明骨骼几何形状的性别二态性确实可能导致女性的骨折风险更高。我们的研究结果确定了与高骨应变相关的个体特异性几何形状和密度的重要特征，这可能对骨折风险有影响。
