Role of Trabecular Microarchitecture in Whole-Vertebral Body Biomechanical Behavior
Role of Trabecular Microarchitecture in Whole-Vertebral Body Biomechanical Behavior
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DOI：
10.1359/jbmr.090317
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发表时间：
2009-09-01
影响因子：
6.2
通讯作者：
Keaveny, Tony M.
中科院分区：
文献类型：
--
作者：
Fields, Aaron J.;Eswaran, Senthil K.;Keaveny, Tony M.
小梁微结构在整个椎体生物力学行为中的作用尚不清楚，其影响可能被整体骨量、骨几何形状和皮质壳的存在等因素所掩盖。为了解决这个问题，我们使用 mu CT 扫描了 22 个人类 T9 椎体（11 名女性；11 名男性；年龄范围：53-97 岁，81.5 +/- 9.6 岁），并分析了小梁微结构、BMC、横截面积和皮质厚度的测量结果。对十六块椎骨进行了生物力学测试以测量抗压强度。为了估计所有 22 块椎骨带或不带皮质壳的椎骨压缩刚度，根据 mu CT 扫描创建了每个标本的两个高分辨率有限元模型（一个完整模型和一个去除壳的模型）并进行虚拟压缩。结果表明，BMC 和结构模型指数 (SMI) 是与强度关系最密切的参数（R-2 = 0.57）。在逐步多元回归模型中向 BMC 添加微架构变量改善了这种关联 (R-2 = 0.85)。然而，该回归模型中的微结构变量（各向异性程度、骨体积分数）与模型中不包含 BMC 时的微结构变量（SMI、平均小梁厚度）不同，并且后者的关联性稍弱（R-2 = 0.76）。有限元结果表明，皮质壳的物理存在并没有改变微结构和椎骨刚度之间的关系。我们得出的结论是，小梁微结构与整个椎骨的生物力学行为相关，并且微结构的作用是由 BMC 介导的，而不是由皮质壳介导的。骨矿工研究杂志 2009；24：1523-1530。 2009年3月30日在线发布；号码：10.1359/JBMR.090317
The role of trabecular microarchitecture in whole-vertebral biomechanical behavior remains unclear, and its influence may be obscured by such factors as overall bone mass, bone geometry, and the presence of the cortical shell. To address this issue, 22 human T9 vertebral bodies (11 female; 11 male; age range: 53-97 yr, 81.5 +/- 9.6 yr) were scanned with mu CT and analyzed for measures of trabecular microarchitecture, BMC, cross-sectional area, and cortical thickness. Sixteen of the vertebrae were biomechanically tested to measure compressive strength. To estimate vertebral compressive stiffness with and without the cortical shell for all 22 vertebrae, two high-resolution finite element models per specimen-one intact model and one with the shell removed-were created from the mu CT scans and virtually compressed. Results indicated that BMC and the structural model index (SMI) were the individual parameters most highly associated with strength (R-2 = 0.57 each). Adding microarchitecture variables to BMC in a stepwise multiple regression model improved this association (R-2 = 0.85). However, the microarchitecture variables in that regression model (degree of anisotropy, bone volume fraction) differed from those when BMC was not included in the model (SMI, mean trabecular thickness), and the association was slightly weaker for the latter (R-2 = 0.76). The finite element results indicated that the physical presence of the cortical shell did not alter the relationships between microarchitecture and vertebral stiffness. We conclude that trabecular microarchitecture is associated with whole-vertebral biomechanical behavior and that the role of microarchitecture is mediated by BMC but not by the cortical shell. J Bone Miner Res 2009;24:1523-1530. Published online on March 30, 2009; doi: 10.1359/JBMR.090317