Impact of material and morphological parameters on the mechanical response of the lumbar spine - A finite element sensitivity study.
Impact of material and morphological parameters on the mechanical response of the lumbar spine - A finite element sensitivity study.
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DOI：
10.1016/j.jbiomech.2016.12.014
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发表时间：
2017-02
影响因子：
2.4
通讯作者：
T. Zander;M. Dreischarf;Anne-Katrin Timm;W. Baumann;H. Schmidt
中科院分区：
文献类型：
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作者：
T. Zander;M. Dreischarf;Anne-Katrin Timm;W. Baumann;H. Schmidt
有限元模型常用于腰椎生物力学研究。确定性模型用于反映某种配置，包括几何和材料特性的平均值，而概率模型则考虑总体的固有变异性。由于模型参数通常是不确定的，其预测能力经常受到质疑。在本研究中，我们确定了脊柱力和运动对椎间盘、椎骨和韧带的材料参数以及腰椎形态的敏感性。我们进行了1200个模型模拟，使用一个通用模型的人类腰椎下加载纯力矩。确定所有参数和响应组合的决定系数和变异系数。椎骨的材料特性对结果的影响最小，而椎间盘和形态的材料特性对结果的影响最大。受影响最大的结果是屈曲时椎体和几个韧带中的轴向压缩力以及伸展时的小关节-关节力。只有当几个参数同时变化时，椎间旋转才受到相当大的影响。结果可以用来决定哪些模型参数需要在确定性模型中仔细考虑，哪些参数可以在概率研究中省略。研究结果允许定量估计模型的精度。
Finite element models are frequently used to study lumbar spinal biomechanics. Deterministic models are used to reflect a certain configuration, including the means of geometrical and material properties, while probabilistic models account for the inherent variability in the population. Because model parameters are generally uncertain, their predictive power is frequently questioned. In the present study, we determined the sensitivities of spinal forces and motions to material parameters of intervertebral discs, vertebrae, and ligaments and to lumbar morphology. We performed 1200 model simulations using a generic model of the human lumbar spine loaded under pure moments. Coefficients of determination and of variation were determined for all parameter and response combinations. Material properties of the vertebrae displayed the least impact on results, whereas those of the discs and morphology impacted most. The most affected results were the axial compression forces in the vertebral body and in several ligaments during flexion and the facet-joint forces during extension. Intervertebral rotations were considerably affected only when several parameters were varied simultaneously. Results can be used to decide which model parameters require careful consideration in deterministic models and which parameters might be omitted in probabilistic studies. Findings allow quantitative estimation of a model׳s precision.