Experimental and finite element analysis of the rat ulnar loading model -: correlations between strain and bone formation following fatigue loading
Experimental and finite element analysis of the rat ulnar loading model -: correlations between strain and bone formation following fatigue loading
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DOI：
10.1016/j.jbiomech.2003.08.009
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发表时间：
2004-04-01
影响因子：
2.4
通讯作者：
Silva, MJ
中科院分区：
文献类型：
--
作者：
Kotha, SP;Hsieh, YF;Silva, MJ
大鼠前肢受压模型被广泛用于研究骨对机械载荷的反应。我们使用应变计来评估成年Fisher大鼠前肢尺骨和桡骨之间的负荷分担。在体内疲劳负荷12天后，我们使用组织学和外周定量计算机断层扫描（pQCT）来量化尺骨形成。最后，我们建立了尺骨的有限元模型来预测压缩过程中表面应变的模式。我们的研究结果表明，尺骨在中轴处承受了前肢施加的65%的压缩力。我们观察到疲劳引起的骨形成在尺骨的周长上有很大的变化。骨形成在中轴远端1-2mm处最大。在中轴，我们观察到编织骨的形成在中间是最大的。有限元分析表明，其应变模式与压缩-弯曲加载模式一致，内侧表面压缩应变最大，外侧拉伸应变较小。在前肢受压13.3 N时，在中轴远端1- 2mm处出现- 5190 μ epsilon的峰值应变。纵向骨形成模式与预测的7个截面的峰值轴向压缩应变高度相关（r(2) = 0.89, p = 0.014）。面内骨形成模式与51个骨膜位置轴向应变的预测大小相关性较差（r(2) = 0.21, p < 0.001），因为在拉伸应变最高的地方观察到的骨形成最少。这些研究结果表明，在高压缩应变区域，疲劳载荷后骨形成的幅度最大。(C) 2003 Elsevier Ltd.版权所有。
The rat forelimb compression model has been used widely to study bone response to mechanical loading. We used strain gages to assess load sharing between the ulna and radius in the forelimb of adult Fisher rats. We used histology and peripheral quantitative computed tomography (pQCT) to quantify ulnar bone formation 12 days after in vivo fatigue loading. Lastly, we developed a finite element model of the ulna to predict the pattern of surface strains during compression. Our findings indicate that at the mid-shaft the ulna carries 65% of the applied compressive force on the forelimb. We observed large variations in fatigue-induced bone formation over the circumference and length of the ulna. Bone formation was greatest 1-2mm distal to the mid-shaft. At the mid-shaft, we observed woven bone formation that was greatest medially. Finite element analysis indicated a strain pattern consistent with a compression-bending loading mode, with the greatest strains occurring in compression on the medial surface and lesser tensile strains occurring laterally. A peak strain of - 5190muepsilon (for 13.3 N forelimb compression) occurred 1-2 mm distal to the mid-shaft. The pattern of bone formation in the longitudinal direction was highly correlated to the predicted peak compressive axial strains at seven cross-sections (r(2) = 0.89, p = 0.014). The in-plane pattern of bone formation was poorly correlated to the predicted magnitude of axial strain at 51 periosteal locations (r(2) = 0.21, p < 0.001), because the least bone formation was observed where tensile strains were highest. These findings indicate that the magnitude of bone formation after fatigue loading is greatest in regions of high compressive strain. (C) 2003 Elsevier Ltd. All rights reserved.