Comparison of eight published static finite element models of the intact lumbar spine: Predictive power of models improves when combined together
Comparison of eight published static finite element models of the intact lumbar spine: Predictive power of models improves when combined together
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DOI：
10.1016/j.jbiomech.2014.04.002
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发表时间：
2014-06-03
影响因子：
2.4
通讯作者：
Schmidt, H.
中科院分区：
文献类型：
--
作者：
Dreischarf, M.;Zander, T.;Schmidt, H.
有限元（FE）模型研究为我们理解腰椎功能生物力学做出了重要贡献。然而，如果使用模型来回答特定人群的临床和生物力学问题，则必须考虑其固有的较大受试者间变异性。然而，当前的有限元模型研究通常仅考虑具有一组材料特性的单一独特脊柱几何形状。这就提出了关于它们的预测能力、结果范围以及它们与体外和体内值的一致性的问题。全球不同研究中心的八个完善的腰椎（L1-5）有限元模型接受了纯加载模式和组合加载模式，并与椎间旋转、椎间盘压力和小关节力的体外和体内测量进行了比较。在纯力矩加载下，几乎所有模型的预测 L1-5 旋转都落在报告的体外范围内，并且它们的中值屈伸平均仅相差 2 度，侧向弯曲平均相差 1 度，轴向旋转平均相差 5 度。预测的中位小关节力和椎间盘压力也与已发表的中位体外值非常一致。然而，预测范围更大并超过了体外报告的范围，特别是对于小关节力。对于所有组合加载模式，除了屈曲之外，预测的中位节段椎间旋转和椎间盘压力与体内测量值非常一致。鉴于受试者间的高变异性，单一模型结果对人群的推广仍然是一个问题。这项研究表明，类似于概率方法，个体模型结果的汇总中位数可以用作改进的预测工具，以估计腰椎的反应。 (C) 2014 Elsevier Ltd. 保留所有权利。
Finite element (FE) model studies have made important contributions to our understanding of functional biomechanics of the lumbar spine. However, if a model is used to answer clinical and biomechanical questions over a certain population, their inherently large inter-subject variability has to be considered. Current FE model studies, however, generally account only for a single distinct spinal geometry with one set of material properties. This raises questions concerning their predictive power, their range of results and on their agreement with in vitro and in vivo values.Eight well-established FE models of the lumbar spine (L1-5) of different research centers around the globe were subjected to pure and combined loading modes and compared to in vitro and in vivo measurements for intervertebral rotations, disc pressures and facet joint forces.Under pure moment loading, the predicted L1-5 rotations of almost all models fell within the reported in vitro ranges, and their median values differed on average by only 2 degrees for flexion-extension, 1 degrees for lateral bending and 5 degrees for axial rotation. Predicted median facet joint forces and disc pressures were also in good agreement with published median in vitro values. However, the ranges of predictions were larger and exceeded those reported in vitro, especially for the facet joint forces. For all combined loading modes, except for flexion, predicted median segmental intervertebral rotations and disc pressures were in good agreement with measured in vivo values.In light of high inter-subject variability, the generalization of results of a single model to a population remains a concern. This study demonstrated that the pooled median of individual model results, similar to a probabilistic approach, can be used as an improved predictive tool in order to estimate the response of the lumbar spine. (C) 2014 Elsevier Ltd. All rights reserved.