Effects of intracortical porosity on fracture toughness in aging human bone:: A μCT-based cohesive finite element study
Effects of intracortical porosity on fracture toughness in aging human bone:: A μCT-based cohesive finite element study
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DOI：
10.1115/1.2768377
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发表时间：
2007-10-01
影响因子：
1.7
通讯作者：
Vashishth, Deepak
中科院分区：
文献类型：
--
作者：
Ural, Ani;Vashishth, Deepak
皮质内孔隙率增加对老化断裂性能的影响程度。骨质疏松症尚不清楚。在这里，我们报告了基于微计算机断层扫描的有限元方法的开发和应用，该方法可以通过阻止所有其他与年龄相关的骨骼变化来确定皮质内孔隙率对骨折的影响。使用微型计算机断层扫描技术扫描先前测试的人类胫骨的紧凑拉伸样本，并将其转换为包含裂纹生长方向的三维内聚有限元的有限元网格。进行模拟时，考虑了与年龄相关的皮质内孔隙度的增加，但保持代表其他与年龄相关的影响的内聚参数不变。使用降低的内聚参数进行了额外的模拟。结果显示，随着孔隙率增加 4%，起始韧性下降 6%，扩展韧性下降 62%。当引入除孔隙率之外的其他与年龄相关的影响时，韧性的降低变得更加明显。起始韧性和扩展韧性分别下降了 51% 和 83%，孔隙率增加 4%，内聚性能下降的综合影响反映了骨中其他与年龄相关的变化。这些结果表明皮质内孔隙度是一个重要的因素。皮质骨的断裂韧性以及计算模型与先进成像的结合改进了对老年人和骨质疏松皮质骨的骨折特性的预测。
The extent to which increased intracortical porosity affects the fracture properties of aging. and osteoporotic bone is unknown. Here, we report the development and application of a microcomputed tomography based finite element approach that allows determining the effects of intracortical porosity on bone fracture by blocking all other age-related changes in bone. Previously tested compact tension specimens from human tibiae were scanned using microcomputed tomography and converted to finite element meshes containing three-dimensional cohesive finite elements in the direction of the crack growth. Simulations were run incorporating age-related increase in intracortical porosity but keeping cohesive parameters representing other age-related effects constant. Additional simulations were performed with reduced cohesive parameters. The results showed a 6% decrease in initiation toughness and a 62% decrease in propagation toughness with a 4% increase in porosity. The reduction in toughnesses became even more pronounced when other age-related effects in addition to porosity were introduced. The initiation and propagation toughness decreased by 51% and 83%, respectively, with the combined effect of 4% increase in porosity and decrease in the cohesive properties reflecting other age-related changes in bone. these results show that intracortical porosity is a significant contributor. to the fracture toughness of the cortical bone and that the combination of computational modeling with advanced imaging improves the prediction of the fracture properties of the aged and the osteoporotic cortical bone.