Chen Heming, Wang Dong, Li Jiayi, Yao Qingqiang, Pugno Nicola M, Li Zhiyong, Chen Qiang
School of Biological Science & Medical Engineering, Southeast University, Nanjing, 210096, People's Republic of China.
Nanjing Center for Applied Mathematics, Nanjing, 211135, People's Republic of China.
Med Biol Eng Comput. 2024 Jul 15. doi: 10.1007/s11517-024-03162-4.
The mechanics of the trabecular bone is related to its structure; this work aimed to propose a simple projection method to clarify the correlation between the principal mechanical direction (PMD) and the principal microstructural direction (PMSD) of trabecular bones from osteoporotic femoral heads. A total of 529 trabecular cubes were cropped from five osteoporotic femoral heads. The micro computed tomography (μCT) sequential images of each cube were first projected onto the three Cartesian coordinate planes to have three overlapped images, and the trabecular orientation distribution in the three images was analyzed. The PMSD corresponding to the greatest distribution frequency of the trabecular orientation in the three images was defined. Then, the voxel finite element (FE) models of the cubes were reconstructed and simulated to obtain their compliance matrices, and the matrices were subjected to transversal rotation to find their maximum elastic constants. The PMD corresponding to the maximum elastic constant was defined. Subsequently, the correlation of the defined PMSD and PMD was analyzed. The results showed that PMSD and PMD of the trabecular cubes did not show a significant difference at the xy- and yz-planes except that at the zx-plane. Despite this, the mean PMSD-PMD deviations at the three coordinate planes were close to 0°, and the PMSD-PMD fitting to the line PMSD = PMD demonstrated their high correlation. This study might be helpful to identify the loading direction of anisotropic trabecular bones in experiments by examining the PMSD and also to guide bone scaffold design for bone tissue repair.
松质骨的力学性能与其结构相关；本研究旨在提出一种简单的投影方法，以阐明骨质疏松性股骨头松质骨的主机械方向（PMD）和主微观结构方向（PMSD）之间的相关性。从五个骨质疏松性股骨头中裁剪出总共529个松质骨立方体。首先将每个立方体的微观计算机断层扫描（μCT）序列图像投影到三个笛卡尔坐标平面上，得到三个重叠图像，并分析这三个图像中的小梁方向分布。定义与三个图像中小梁方向分布频率最高相对应的PMSD。然后，重建并模拟立方体的体素有限元（FE）模型，以获得其柔顺性矩阵，并对矩阵进行横向旋转以找到其最大弹性常数。定义与最大弹性常数相对应的PMD。随后，分析所定义的PMSD和PMD之间的相关性。结果表明，除了在zx平面外，松质骨立方体的PMSD和PMD在xy平面和yz平面上没有显著差异。尽管如此，三个坐标平面上的平均PMSD - PMD偏差接近0°，并且PMSD - PMD与直线PMSD = PMD的拟合表明它们具有高度相关性。本研究可能有助于通过检查PMSD来确定实验中各向异性松质骨的加载方向，也有助于指导骨组织修复的骨支架设计。
