The role of an effective isotropic tissue modulus in the elastic properties of cancellous bone
The role of an effective isotropic tissue modulus in the elastic properties of cancellous bone
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DOI：
10.1016/s0021-9290(99)00045-7
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发表时间：
1999-07-01
影响因子：
2.4
通讯作者：
Huiskes, R
中科院分区：
文献类型：
--
作者：
Kabel, J;van Rietbergen, B;Huiskes, R
从概念上讲，松质骨的弹性特征可以直接从骨小梁形态或结构以及组织本身的弹性特性来预测。虽然几乎没有任何实验证据存在，它往往是隐含的假设，组织各向异性对松质骨的表观弹性性能的影响可以忽略不计。本文要讨论的问题是，这是否真的是这样。如果是，那么微机械有限元分析（mu-FEA）模型，代表小梁结构，使用“有效各向同性组织模量”应该能够预测松质骨的表观弹性特性。为了测试这一点，29个鲸骨标本的精确多轴压缩力学测试进行了模拟，从真正的三维重建，建立了特定的mu-FEA计算机模型。通过用恒定的组织模量缩放mu-FEA预测，可以解释实验确定的杨氏模量的92%的变化。当mu-FEA模量按比例缩放到单个样本的各向同性组织模量时，相关性甚至增加到95%。在弹性对称轴和各向异性比方面也有很好的一致性。当相关性为85%时，泊松比的预测精确度有所降低。结果支持了这一假设;对于实际目的，有效各向同性组织模量的概念是可行的。他们还建议，个别情况下，这种模量的值可能会从平均组织密度，因此矿化程度推断。未来的研究必须阐明，如果要以这种方式对弹性行为进行充分的预测，那么对于不同类型的骨，组织模量应该有多大的特异性。(C)1999 Elsevier Science Ltd.保留所有权利。
Conceptually, the elastic characteristics of cancellous bone could be predicted directly from the trabecular morphology - or architecture - and by the elastic properties of the tissue itself. Although hardly any experimental evidence exists, it is often implicitly assumed that tissue anisotropy has a negligible effect on the apparent elastic properties of cancellous bone. The question addressed in this paper is whether this is actually true. If it is, then micromechanical finite element analysis (mu-FEA) models, representing trabecular architecture, using an 'effective isotropic tissue modulus' should be able to predict apparent elastic properties of cancellous bone. To test this, accurate multi-axial compressive mechanical tests of 29 whale bone specimens were simulated with specimen-specific mu-FEA computer models built from true three-dimensional reconstructions. By scaling the mu-FEA predictions by a constant tissue modulus, 92% of the variation of Young's moduli determined experimentally could be explained. The correlation even increased to 95% when the mu-FEA moduli were scaled to the isotropic tissue moduli of individual specimens. Excellent agreement was also found in the elastic symmetry axes and anisotropy ratios. The prediction of Poisson's ratios was somewhat less precise at 85% correlation. The results support the hypothesis; for practical purposes, the concept of an;effective isotropic tissue modulus' concept is a viable one. They also suggest that the value of such a modulus for individual cases might be inferred from the average tissue density, hence the degree of mineralization. Future studies must clarify how specific the tissue modulus should be for different types of bone if adequate predictions of elastic behavior are to be made in this way. (C) 1999 Elsevier Science Ltd. All rights reserved.