scholarly journals Effect of Intraspecimen Spatial Variation in Tissue Mineral Density on the Apparent Stiffness of Trabecular Bone

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
Narges Kaynia ◽  
Elaine Soohoo ◽  
Tony M. Keaveny ◽  
Galateia J. Kazakia
Keyword(s):  
Finite Element ◽  
High Resolution ◽  
Spatial Variation ◽  
Trabecular Bone ◽  
Gold Standard ◽  
Mineral Density ◽  
Human Trabecular Bone ◽  
Apparent Stiffness ◽  
Tissue Mineral Density ◽  
Apparent Level

This study investigated the effects of intraspecimen variations in tissue mineral density (TMD) on the apparent-level stiffness of human trabecular bone. High-resolution finite element (FE) models were created for each of 12 human trabecular bone specimens, using both microcomputed tomography (μCT) and “gold-standard” synchrotron radiation μCT (SRμCT) data. Our results confirm that incorporating TMD spatial variation reduces the calculated apparent stiffness compared to homogeneous TMD models. This effect exists for both μCT- and SRμCT-based FE models, but is exaggerated in μCT-based models. This study provides a direct comparison of μCT to SRμCT data and is thereby able to conclude that the influence of including TMD heterogeneity is overestimated in μCT-based models.

scholarly journals Distinct Tissue Mineral Density in Plate‐ and Rod‐like Trabeculae of Human Trabecular Bone

2015 ◽  
Vol 30 (9) ◽  
pp. 1641-1650 ◽  
Author(s):  
Ji Wang ◽  
Galateia J Kazakia ◽  
Bin Zhou ◽  
X Tony Shi ◽  
X Edward Guo
Keyword(s):  
Trabecular Bone ◽  
Mineral Density ◽  
Human Trabecular Bone ◽  
Tissue Mineral Density

Individual Trabecula Segmentation (ITS)-Based Plate-Rod Microstructural Finite Element Model Predicts Nonlinear Mechanical Properties of Human Trabecular Bone

2012 ◽  
Author(s):  
Bin Zhou ◽  
Ji Wang ◽  
Arnav Sanyal ◽  
Aaron J. Fields ◽  
Hong Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
High Resolution ◽  
Trabecular Bone ◽  
Element Model ◽  
Bone Fragility ◽  
Fe Model ◽  
Computationally Efficient ◽  
Human Trabecular Bone ◽  
Voxel Model

Osteoporosis is a major bone disease characterized by low bone mass and microarchitecture deterioration, which affects primarily trabecular sites and leads to increased bone fragility. Trabecular bone mechanical properties have direct relations with bone fragility. High-resolution image based-finite element (FE) models with the detailed 3D microstructure have been widely utilized to assess the mechanical properties of trabecular bone. Voxel-based FE model can be generated by converting individual voxels of high resolution bone images into 8-node brick elements. A number of studies have compared mechanical properties predicted by the voxel model with those by mechanical testing and have demonstrated that the voxel FE model can accurately predict the Young’s modulus and yield strength of human trabecular bone (1). However, the computational expense of the voxel-based technique, in general, limits its clinical applications, especially the nonlinear analysis for whole bone strength. Thus, it is not applicable to apply this technique to clinical use with the respect of current computer capability. There is apparent need for an alternative modeling approach that is more computationally efficient while preserving the accuracy of the predictions.

Preparation of On-Axis Cylindrical Trabecular Bone Specimens Using Micro-CT Imaging

2004 ◽  
Vol 126 (1) ◽  
pp. 122-125 ◽  
Author(s):  
Xiang Wang, ◽  
Xiangyi Liu, and ◽  
Glen L. Niebur
Keyword(s):  
Finite Element ◽  
High Resolution ◽  
Coordinate System ◽  
Trabecular Bone ◽  
Cylindrical Specimen ◽  
Longitudinal Axis ◽  
Ct Imaging ◽  
Finite Element Models ◽  
Micro Ct ◽  
Average Deviation

The Orientation of trabecular bone specimens for mechanical testing must be carefully controlled. A method for accurately preparing on-axis cylindrical specimens using high-resolution micro-CT imaging was developed. Sixteen cylindrical specimens were prepared from eight bovine tibiae. High-resolution finite element models were generated from micro-CT images of parallelepipeds and used to determine the principal material coordinate system of each parallelepiped. A cylindrical specimen was then machined with a diamond coring bit. The resulting specimens were scanned again to evaluate the orientation. The average deviation between the principal fabric orientation and the longitudinal axis of the cylindrical specimen was only 4.70±3.11°.

scholarly journals The Quartic Piecewise-Linear Criterion for the Multiaxial Yield Behavior of Human Trabecular Bone

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
Arnav Sanyal ◽  
Joanna Scheffelin ◽  
Tony M. Keaveny
Keyword(s):  
Finite Element ◽  
Trabecular Bone ◽  
Volume Fraction ◽  
Yield Criterion ◽  
Shear Loading ◽  
Bone Volume ◽  
Mechanical Anisotropy ◽  
Bone Volume Fraction ◽  
Human Trabecular Bone ◽  
Strain Space

Prior multiaxial strength studies on trabecular bone have either not addressed large variations in bone volume fraction and microarchitecture, or have not addressed the full range of multiaxial stress states. Addressing these limitations, we utilized micro-computed tomography (μCT) based nonlinear finite element analysis to investigate the complete 3D multiaxial failure behavior of ten specimens (5 mm cube) of human trabecular bone, taken from three anatomic sites and spanning a wide range of bone volume fraction (0.09–0.36), mechanical anisotropy (range of E3/E1 = 3.0–12.0), and microarchitecture. We found that most of the observed variation in multiaxial strength behavior could be accounted for by normalizing the multiaxial strength by specimen-specific values of uniaxial strength (tension, compression in the longitudinal and transverse directions). Scatter between specimens was reduced further when the normalized multiaxial strength was described in strain space. The resulting multiaxial failure envelope in this normalized-strain space had a rectangular boxlike shape for normal–normal loading and either a rhomboidal boxlike shape or a triangular shape for normal-shear loading, depending on the loading direction. The finite element data were well described by a single quartic yield criterion in the 6D normalized-strain space combined with a piecewise linear yield criterion in two planes for normal-shear loading (mean error ± SD: 4.6 ± 0.8% for the finite element data versus the criterion). This multiaxial yield criterion in normalized-strain space can be used to describe the complete 3D multiaxial failure behavior of human trabecular bone across a wide range of bone volume fraction, mechanical anisotropy, and microarchitecture.

scholarly journals 3D Assessment of Cortical Bone Porosity and Tissue Mineral Density Using High-Resolution µCT: Effects of Resolution and Threshold Method

2013 ◽  
Vol 29 (1) ◽  
pp. 142-150 ◽  
Author(s):  
Paolo E Palacio-Mancheno ◽  
Adriana I Larriera ◽  
Stephen B Doty ◽  
Luis Cardoso ◽  
Susannah P Fritton
Keyword(s):  
High Resolution ◽  
Cortical Bone ◽  
Threshold Method ◽  
Mineral Density ◽  
Tissue Mineral Density
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