Modeling deformation-induced fluid flow in cortical bone's canalicular-lacunar system
Modeling deformation-induced fluid flow in cortical bone's canalicular-lacunar system
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DOI：
10.1007/s10439-005-8959-6
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发表时间：
2005-01-01
影响因子：
3.8
通讯作者：
Lakes, RS
中科院分区：
文献类型：
--
作者：
Gururaja, S;Kim, HJ;Lakes, RS
为了探讨载荷诱导的流体流动在骨适应中作为机械传导机制的潜在作用，开发并实现了一个腔隙-小管尺度的骨孔隙弹性模型。该模型使用微观力学均匀化的pericanalicular骨基质，骨基质中的直圆柱体的系统，通过骨流体可以流动，作为一个局部各向异性的多孔弹性介质。在这项工作中，一个简化的二维模型的周期性阵列的腔隙和周围系统的小管被用来量化局部流体流动特性在附近的一个单一的腔隙。当加载皮质骨模型时，微尺度应力和应变集中发生在单个骨陷窝附近，并引起孔隙流体压力场的微尺度空间变化。此外，含有骨基质的小管的加载在所包含的流体中产生流体压力。因此，皮质骨的负荷引起泪小管中的液体流动以及泪小管和骨陷窝之间的液体交换。对于现实的骨形态参数，和一系列的加载频率，流体压力和流体-固体阻力的计算和相关的能量耗散模型相比，在人体皮质骨的体外物理实验中测得的。所提出的模型表明，变形引起的流体压力的腔隙-小管系统的松弛时间的顺序为毫秒，而不是更短的时间（百分之几毫秒）与变形引起的压力在哈弗系统。
To explore the potential role that load-induced fluid flow plays as a mechano-transduction mechanism in bone adaptation, a lacunar-canalicular scale bone poroelasticity model is developed and implemented. The model uses micromechanics to homogenize the pericanalicular bone matrix, a system of straight circular cylinders in the bone matrix through which bone fluids can flow, as a locally anisotropic poroelastic medium. In this work, a simplified two-dimensional model of a periodic array of lacunae and their surrounding systems of canaliculi is used to quantify local fluid flow characteristics in the vicinity of a single lacuna. When the cortical bone model is loaded, microscale stress, and strain concentrations occur in the vicinity of individual lacunae and give rise to microscale spatial variations in the pore fluid pressure field. Furthermore, loading of the bone matrix containing canaliculi generates fluid pressures in the contained fluids. Consequently, loading of cortical bone induces fluid flow in the canaliculi and exchange of fluid between canaliculi and lacunae. For realistic bone morphology parameters, and a range of loading frequencies, fluid pressures and fluid-solid drag forces in the canalicular bone are computed and the associated energy dissipation in the models compared to that measured in physical in vitro experiments on human cortical bone. The proposed model indicates that deformation-induced fluid pressures in the lacunar-canalicular system have relaxation times on the order of milliseconds as opposed to the much shorter times (hundredths of milliseconds) associated with deformation-induced pressures in the Haversian system.