Comparison of quantitative computed tomography-based measures in predicting vertebral compressive strength
Comparison of quantitative computed tomography-based measures in predicting vertebral compressive strength
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DOI：
10.1016/j.bone.2006.10.025
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发表时间：
2007-03-01
期刊：
影响因子：
4.1
通讯作者：
Motherway, Julie
中科院分区：
文献类型：
--
作者：
Buckley, Jenni M.;Loo, Kenneth;Motherway, Julie
目前正在开发从定量计算机断层扫描（QCT）扫描中获得的患者特异性测量值，作为椎体强度预测的临床工具。基于QCT的测量技术在结构复杂性方面差异很大，通常分为三类：（1）骨矿物质密度（BMD），（2）“固体力学”（MOS）模型，如最小轴向刚度（轴向刚度和椎骨高度的乘积），或（3）三维有限元（FE）模型。由于实验方案、样本量和人口统计学以及结果指标的差异，这些指标的相对性能没有明确的共识。本研究的目的是直接比较不同结构复杂程度的基于QCT的评估技术在预测实验椎体压缩强度方面的性能。对来自44具供体尸体（F= 32，M= 12; 85 +/- 8岁，最大= 97岁，最小= 54岁）的81个人体胸椎（T6-T10）进行QCT扫描，并在单轴压缩下进行破坏性测试。处理QCT扫描以生成FE模型和各种BMD和MOS测量。包括小梁骨矿物质密度（iBMD）、整体骨矿物质密度（iBMD）和轴向刚度。骨矿物质密度对抗压强度具有弱至中度预测性（tBMD和iBMD的R-2分别= 0.16和0.62）。体外椎体强度与轴向刚度（R-2 = 0.81）和FE强度测量值（R-2 = 0.80）密切相关，这两个指标的预测能力在统计学上相当（FE和轴向刚度之间的差异p > 0.05）。本研究的结果表明，椎体强度的非侵入性预测措施应包括一定程度的结构复杂性，特别是，总的几何和材料属性分布信息。对于孤立椎骨的单轴压缩，这是新的无创强度评估技术的当前生物力学测试范例。基于QCT的有限元和轴向刚度测量是实验强度的等效预测因子。然而，在放弃FE方法以支持更简单的技术之前，未来的工作应该研究FE方法与MOS测量的性能，用于更具生理学代表性的加载条件，例如，前弯或原位加载，椎间盘完整。(c)2006年爱思唯尔公司All rights reserved.
Patient-specific measures derived from quantitative computed tomography (QCT) scans are currently being developed as a clinical tool for vertebral strength prediction. QCT-based measurement techniques vary greatly in structural complexity and generally fall into one of three categories: (1) bone mineral density (BMD), (2) "mechanics of solids" (MOS) models, such as minimum axial rigidity (the product of axial stiffness and vertebral height), or (3) three-dimensional finite element (FE) models. There is no clear consensus as to the relative performance of these measures due to differences in experimental protocols, sample sizes and demographics, and outcome metrics. The goal of this study was to directly compare the performance of QCT-based assessment techniques of varying degrees of structural sophistication in predicting experimental vertebral compressive strength. Eighty-one human thoracic vertebrae (T6-T10) from 44 donors cadavers (F= 32, M= 12; 85 +/- 8 years old, max = 97 years old, min = 54 years old) were QCT scanned and destructively tested in uniaxial compression. The QCT scans were processed to generate FE models and various BMD and MOS measures. including trabecular bone mineral density (iBMD), integral bone mineral density (iBMD), and axial rigidity. Bone mineral density was weakly to moderately predictive of compressive strength (R-2 = 0.16 and 0.62 for tBMD and iBMD, respectively). In vitro vertebral strength was strongly correlated with both axial rigidity (R-2 = 0.81) and FE strength measurements (R-2 = 0.80), and the predictive capabilities of these two metrics were statistically equivalent (p > 0.05 for differences between FE and axial rigidity). The results of this study indicate that non-invasive predictive measures of vertebral strength should include some level of structural sophistication, specifically, gross geometric and material property distribution information. For uniaxial compression of isolated vertebrae, which is the current biomechanical testing paradigm for new non-invasive strength assessment techniques.. QCT-based FE and axial rigidity measures are equivalent predictors of experimental strength. However, before abandoning the FE method in favor of more simplistic techniques, future work should investigate the performance of the FE method versus MOS measures for more physiologically representative loading conditions, e.g., anterior bending or in situ loading with intervertebral discs intact. (c) 2006 Elsevier Inc. All rights reserved.