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Effect of fabric on the accuracy of computed tomography-based finite element analyses of the vertebra

  • Yuanqiao WuEmail author
  • Elise F. Morgan
Original Paper
  • 46 Downloads

Abstract

Quantitative computed tomography (QCT)-based finite element (FE) models of the vertebra are widely used in studying spine biomechanics and mechanobiology, but their accuracy has not been fully established. Although the models typically assign material properties based only on local bone mineral density (BMD), the mechanical behavior of trabecular bone also depends on fabric. The goal of this study was to determine the effect of incorporating measurements of fabric on the accuracy of FE predictions of vertebral deformation. Accuracy was assessed by using displacement fields measured via digital volume correlation—applied to time-lapse microcomputed tomography (μCT)—as the gold standard. Two QCT-based FE models were generated from human L1 vertebrae (n = 11): the entire vertebral body and a cuboid-shaped portion of the trabecular centrum [dimensions: (20–30) × (15–20) × (15–20) mm3]. For axial compression boundary conditions, there was no difference (p = 0.40) in the accuracy of the FE-computed displacements for models using material properties based on local values of BMD versus those using material properties based on local values of fabric and volume fraction. However, when using BMD-based material properties, errors were higher for the vertebral-body models (8.4–50.1%) than cuboid models (1.5–19.6%), suggesting that these properties are inaccurate in the peripheral regions of the centrum. Errors also increased when assuming that the cuboid region experienced uniaxial loading during axial compression of the vertebra. These findings indicate that a BMD-based constitutive model is not sufficient for the peripheral region of the vertebral body when seeking accurate QCT-based FE modeling of the vertebra.

Keywords

Vertebral body Quantitative computed tomography Elastic property BMD Fabric Finite element analysis 

Notes

Acknowledgements

Funding was provided by the National Institutes of Health Grant AR054620 and the National Science Foundation Grant BES-9625030.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflicts of interest.

Supplementary material

10237_2019_1225_MOESM1_ESM.docx (3.5 mb)
Supplementary material 1 (DOCX 3550 kb)
10237_2019_1225_MOESM2_ESM.xlsx (80 kb)
Supplementary material 2 (XLSX 80 kb)

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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Department of Mechanical EngineeringBoston UniversityBostonUSA

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