Femoral strength is better predicted by finite element models than QCT and DXA
Femoral strength is better predicted by finite element models than QCT and DXA
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DOI：
10.1016/s0021-9290(99)00099-8
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发表时间：
1999-10-01
影响因子：
2.4
通讯作者：
Fyhrie, DP
中科院分区：
文献类型：
--
作者：
Cody, DD;Gross, GJ;Fyhrie, DP
如果有准确的方法预测和监测体内的骨强度，临床医生和患者将受益。采用定量计算机断层扫描(QCT)和双能X线骨密度仪(DXA)对51例成人股骨(年龄21~93岁，女性23例，男性28例)的骨密度和骨几何参数进行了测量。使用QCT和DXA获得的区域骨密度和尺寸来建立统计模型来预测体外股骨强度。QCT数据也构成了预测结构刚度的三维有限元模型的基础。将股骨分为两组，使用模型训练集(n=25)建立预测极限载荷的统计模型，并使用测试集(n=26)验证这些模型。本研究的主要目的是测试DXA、QCT和FE技术在以股骨颈骨折为主的简单载荷配置中无创预测骨折载荷的能力。载荷配置模拟正常步态的单站相部分；在87%的标本中，出现临床表现的头下骨折。训练/测试研究设计提供了一种工具，用于验证预测模型在用于具有“未知”强度特征的样本时是可靠的。有限元方法比DXA模型至少多解释20%的强度差异。计划中的FE技术改进预计将进一步改善这些结果。三维有限元模型是一种很有前途的预测断裂载荷的方法，并可用于监测活体强度的变化。(C)1999爱思唯尔科学有限公司。保留所有权利。
Clinicians and patients would benefit if accurate methods of predicting and monitoring bone strength in-vivo were available. A group of 51 human femurs (age range 21-93; 23 females, 28 males) were evaluated for bone density and geometry using quantitative computed tomography (QCT) and dual energy X-ray absorptiometry (DXA). Regional bone density and dimensions obtained from QCT and DXA were used to develop statistical models to predict femoral strength ex vivo. The QCT data also formed the basis of a three-dimensional finite element (FE) models to predict structural stiffness. The femurs were separated into two groups; a model training set (n = 25) was used to develop statistical models to predict ultimate load, and a test set (n = 26) was used to validate these models. The main goal of this study was to test the ability of DXA, QCT and FE techniques to predict fracture load non-invasively, in a simple load configuration which produces predominantly femoral neck fractures. The load configuration simulated the single stance phase portion of normal gait; in 87% of the specimens, clinical appearing sub-capital fractures were produced. The training/test study design provided a tool to validate that the predictive models were reliable when used on specimens with "unknown" strength characteristics. The FE method explained at least 20% more of the variance in strength than the DXA models. Planned refinements of the FE technique are expected to further improve these results. Three-dimensional FE models are a promising method for predicting fracture load, and may be useful in monitoring strength changes in vivo. (C) 1999 Elsevier Science Ltd. All rights reserved.