The overall mechanical behaviour of cortical bone is strongly dependant on its microstructure. X-ray computed tomography (XCT) has been widely used to identify the microstructural morphology of cortical tissue (i.e. pore network, Haversian and Volkmann's canals). However, the connection between microstructure and mechanics of cortical bone during plastic deformation is unclear. Hence, the purpose of this study is to provide an in-depth evaluation of the interplay of plastic strain building up in relation to changes in the canal network for cortical bone tissue. In situ step-wise XCT indentation was used to introduce a localised load on the surface of the tissue and digital volume correlation (DVC) was employed to assess the three-dimensional (3D) full-field plastic strain distribution in proximity of the indent. It was observed that regions adjacent to the imprint were under tensile strain, whereas the volume underneath experienced compressive strain. Canal loss and disruption was detected in regions of higher compressive strains exceeding −20000 με and crack formation occurred in specimens where Haversian canals were running parallel to the indentation tip. The results of this study outline the relationship between the micromechanical and structural behaviour of cortical bone during plastic deformation, providing information on cortical tissue fracture pathways.

皮质骨的整体机械行为在很大程度上取决于其微观结构。X射线计算机断层扫描（XCT）已被广泛用于识别皮质组织（即，孔网，Haversian和Volkmann氏管）的微观结构形态。但是，尚不清楚塑性变形过程中皮质骨的微观结构与力学之间的联系。因此，本研究的目的是对与皮质骨组织的管网变化相关的塑性应变的相互作用进行深入评估。原位逐步XCT压痕用于在组织表面上引入局部载荷，数字体积相关性（DVC）用于评估压痕附近的三维（3D）全场塑性应变分布。观察到，与压印相邻的区域处于拉伸应变下，而其下方的体积则经历了压缩应变。在高压缩应变超过-20000με的区域中检测到运河损失和破裂，并且在哈弗斯运河平行于压痕尖端延伸的标本中发生了裂纹形成。这项研究的结果概述了塑性变形过程中皮质骨的微机械和结构行为之间的关系，提供了皮质组织骨折途径的信息。