Dong X Neil, Guo X Edward
Bone Bioengineering Laboratory, Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA.
J Biomech Eng. 2006 Jun;128(3):309-16. doi: 10.1115/1.2187039.
A two-level micromechanical model of cortical bone based on a generalized self-consistent method was developed to take into consideration the transversely isotropic elasticity of many microstructural features in cortical bone, including Haversian canals, resorption cavities, and osteonal and interstitial lamellae. In the first level, a single osteon was modeled as a two-phase composite such that Haversian canals were represented by elongated pores while the surrounding osteonal lamellae were considered as matrix. In the second level, osteons and resorption cavities were modeled as multiple inclusions while interstitial lamellae were regarded as matrix. The predictions of cortical bone elasticity from this two-level micromechanical model were mostly in agreement with experimental data for the dependence of transversely isotropic elasticity of human femoral cortical bone on porosity. However, variation in cortical bone elastic constants was greater in experimental data than in model predictions. This could be attributed to variations in the elastic properties of microstructural features in cortical bone. The present micromechanical model of cortical bone will be useful in understanding the contribution of cortical bone porosity to femoral neck fractures.
基于广义自洽方法开发了一种皮质骨的两级微观力学模型，以考虑皮质骨中许多微观结构特征的横向各向同性弹性，包括哈弗斯管、吸收腔以及骨单位和间质板层。在第一级，将单个骨单位建模为两相复合材料，使得哈弗斯管用细长孔隙表示，而周围的骨单位板层被视为基质。在第二级，骨单位和吸收腔被建模为多个夹杂物，而间质板层被视为基质。该两级微观力学模型对皮质骨弹性的预测与人体股骨皮质骨横向各向同性弹性对孔隙率依赖性的实验数据大多一致。然而，实验数据中皮质骨弹性常数的变化比模型预测中的更大。这可能归因于皮质骨微观结构特征弹性特性的变化。目前的皮质骨微观力学模型将有助于理解皮质骨孔隙率对股骨颈骨折的影响。
