Graduate School of Science and Technology, Keio University, Kohoku-ku, Yokohama, Kanagawa, Japan.
Med Biol Eng Comput. 2012 Oct;50(10):1091-103. doi: 10.1007/s11517-012-0951-3. Epub 2012 Sep 5.
Trabecular bone has a complicated porous microstructure and consists of interconnected plates and rods known as trabeculae. The microarchitecture of the trabeculae contributes to load distribution capacity and, particularly, the optimal bone strength. Many previous studies have shown that morphological parameters are used to characterize the microarchitecture of trabecular bone, but little is known about the mechanical role of trabecular morphology in the context of load-bearing behavior. Therefore, this study proposes a new segmentation method for examining the morphology of trabecular structure foci of load-bearing capability. A micro-finite element model of trabecular bone was obtained from the fourth lumbar vertebra on the basis of a three-dimensionally reconstructed micro-computed tomography (CT) image. We used an asymptotic homogenization method to determine microscopic stress by applying three unidirectional compressive loads in the vertical, anteroposterior, and right-left axes of two trabecular bone volumes. We then classified the complicated trabecular microstructure into three segments: primary and secondary trabeculae and trabeculae of no contribution. Next, a dynamic analysis was conducted by applying a force impulse load. The result indicated that 1/3 of the trabecular volume functions as primary trabecula. The morphology of the trabecular network could be visualized successfully highlighting the percolation of the stress wave in the primary trabecular segment. Further, we found that the role of the plate-like structures was that of a hub in the trabecular network system.
小梁骨具有复杂的多孔微观结构，由相互连接的板和杆组成，称为小梁。小梁的微观结构有助于分配负载能力，特别是优化骨强度。许多先前的研究表明，形态参数用于描述小梁骨的微观结构，但对于小梁形态在承载行为背景下的力学作用知之甚少。因此，本研究提出了一种新的分割方法，用于检查承载能力的小梁结构焦点的形态。基于三维重建的微计算机断层扫描 (CT) 图像，从第四腰椎获得小梁骨的微有限元模型。我们使用渐近均匀化方法通过在垂直、前后和左右三个方向上施加三个单向压缩载荷来确定微观应力，用于两个小梁骨体积的两个。然后，我们将复杂的小梁微观结构分为三个部分：主小梁和次小梁以及无贡献的小梁。接下来，通过施加力脉冲载荷进行动态分析。结果表明，1/3 的小梁体积起主要小梁的作用。小梁网络的形态可以成功地可视化，突出了在主要小梁段中应力波的渗透。此外，我们发现板状结构的作用是小梁网络系统的枢纽。
