Department of Biomechanics, Poznan University of Physical Education, ul. Królowej Jadwigi 27/39, Poznan 61-871, Poland.
Spine J. 2020 Nov;20(11):1861-1875. doi: 10.1016/j.spinee.2020.06.013. Epub 2020 Jun 25.
Mathematical modeling for creating computer spine models is one of the basic methods underlying many scientific publications. The accuracy of strength parameters of tissues introduced into such models translates directly into the reliability of obtained results. Experimental determination of Young's modulus (E) in various areas of spongy bone tissue seems to be crucial for creating a reliable spine model without excessive simplifications in the form of a single E value for the whole vertebral body.
The aim of the study was to determine Young's modulus in different parts of the lumbar vertebral column for samples subjected to compression and bending.
Cylindrical spongy bone tissue samples were subjected to bending and compression strength tests.
The study included 975 pathologically unchanged samples of spongy bone tissue harvested from the lumbar vertebrae of 15 male donors. The samples were subjected to compression or bending strength tests and then Young's modulus was determined for each sample depending on its location in the vertebral body. The samples were tested differently between given locations within one vertebra as well as between vertebrae.
Compressed specimens are characterized by highly significantly different Young's modulus values depending on the location in the vertebral body. Samples No. 7 and No. 9 in the anterior part of the vertebral body have highly significantly higher Young's modulus values compared to those in the posterior part of the vertebral body for all lumbar vertebrae. Samples subjected to bending showed significant differences (p<.05) between samples located closer to the vertebral canal (No.16, No.17) and samples located further away (No.14, No.15) with higher values for the samples located in the posterior part of the vertebral body.
Accommodating the anisotropic structure of spongy bone in computer models and the application of different Young's module values for areas within one vertebral body will allow one to obtain realistic results of computer simulations used.
Determining the exact strength parameters of spongy bone tissue within one vertebra and changes in these properties in subsequent vertebrae will allow to create more accurate computer models of the lumbar spine and the whole spine. This, in turn, will translate into more reliable computer simulations used, among others, to determine the risk of fractures or osteoporotic changes, or simulation of the procedure of spinal fusion.
创建计算机脊柱模型的数学建模是许多科学出版物的基础方法之一。引入此类模型的组织强度参数的准确性直接转化为获得结果的可靠性。在不同的海绵骨组织区域确定杨氏模量（E）似乎对于创建没有过度简化的可靠脊柱模型至关重要，即整个椎体的单一 E 值。
本研究的目的是确定腰椎不同部位在压缩和弯曲状态下的杨氏模量。
对圆柱形海绵骨组织样本进行弯曲和压缩强度测试。
该研究包括从 15 名男性供体的腰椎中采集的 975 个病理性未改变的海绵骨组织样本。对样本进行压缩或弯曲强度测试，然后根据其在椎体中的位置确定每个样本的杨氏模量。在一个椎体的给定位置之间以及椎体之间，对样本进行不同的测试。
压缩标本的杨氏模量值取决于椎体中的位置，差异具有高度统计学意义。所有腰椎的椎体前部的样本 7 和样本 9 的杨氏模量值明显高于椎体后部的样本。弯曲样本（No.16、No.17）与远离椎骨管的样本（No.14、No.15）之间存在显著差异（p<.05），椎体后部的样本的杨氏模量值更高。
在计算机模型中考虑海绵骨的各向异性结构，并为一个椎体内的区域应用不同的杨氏模量值，将允许获得所使用的计算机模拟的真实结果。
确定一个椎体内海绵骨组织的准确强度参数以及后续椎体中这些特性的变化，将能够创建更准确的腰椎和整个脊柱的计算机模型。这反过来又会转化为更可靠的计算机模拟，例如用于确定骨折或骨质疏松变化的风险，或模拟脊柱融合过程。
