Date of download: 10/5/2017 Copyright © ASME. All rights reserved. From: Numerical Methodology to Evaluate the Effects of Bone Density and Cement Augmentation on Fixation Stiffness of Bone-Anchoring Devices J Biomech Eng. 2015;137(9):091005-091005-10. doi:10.1115/1.4030943 Figure Legend: Combined methodology for the structural investigation of anchoring fixation stiffness. The creation of μFE models at 26 μm element size was done from modified micro-CT images of trabecular bone merged with a scanned bone anchor. The creation of hFE models was, in parallel, done after volumetric meshing of a filled implanted bone cube and subsequent bone material mapping from the micro-CT images. Simulation of augmented fixation with cement was done by modification of the material mapping procedure within the cementing volume described as a dilation of various thicknesses around the voxelized bone anchor. For clarity, the images show a cut-view of the bone structures through one of the symmetry planes of the bone structures (mirroring axis).

Date of download: 10/5/2017 Copyright © ASME. All rights reserved. From: Numerical Methodology to Evaluate the Effects of Bone Density and Cement Augmentation on Fixation Stiffness of Bone-Anchoring Devices J Biomech Eng. 2015;137(9):091005-091005-10. doi:10.1115/1.4030943 Figure Legend: Load cases used to compute the 6D structural stiffness matrix of the implanted bone anchor with the hFE models. The highlighted area shows the upper nodes of the bone anchor rigidly connected to the central superior point at which displacements and rotations were applied. Elements are shown with local bone volume fraction ρ mapped from the modified micro-CT images.

Date of download: 10/5/2017 Copyright © ASME. All rights reserved. From: Numerical Methodology to Evaluate the Effects of Bone Density and Cement Augmentation on Fixation Stiffness of Bone-Anchoring Devices J Biomech Eng. 2015;137(9):091005-091005-10. doi:10.1115/1.4030943 Figure Legend: Correlations between the hFE and μFE predictions for stiffness coefficients in the six orthogonal load cases

Date of download: 10/5/2017 Copyright © ASME. All rights reserved. From: Numerical Methodology to Evaluate the Effects of Bone Density and Cement Augmentation on Fixation Stiffness of Bone-Anchoring Devices J Biomech Eng. 2015;137(9):091005-091005-10. doi:10.1115/1.4030943 Figure Legend: Relations between BV/TVglobal and the main stiffness components predicted by the μFE and hFE approaches

Date of download: 10/5/2017 Copyright © ASME. All rights reserved. From: Numerical Methodology to Evaluate the Effects of Bone Density and Cement Augmentation on Fixation Stiffness of Bone-Anchoring Devices J Biomech Eng. 2015;137(9):091005-091005-10. doi:10.1115/1.4030943 Figure Legend: Similarities observed in the stress distributions obtained for the μFE: (a) and the hFE models (b) for the five modeled specimens in simulated axial pull. Models are shown cut through one of the symmetry planes of the bone structures.

Date of download: 10/5/2017 Copyright © ASME. All rights reserved. From: Numerical Methodology to Evaluate the Effects of Bone Density and Cement Augmentation on Fixation Stiffness of Bone-Anchoring Devices J Biomech Eng. 2015;137(9):091005-091005-10. doi:10.1115/1.4030943 Figure Legend: Correlation coefficients between stiffness components of the: (a) Sfδ, (b) Sfθ, and (c) Smθ submatrices and BV/TVglobal for the hFE models without cement (white) and with different cement thicknesses (light gray = 0.8 mm; dark gray = 1.6 mm; and black = 2.4 mm)

Date of download: 10/5/2017 Copyright © ASME. All rights reserved. From: Numerical Methodology to Evaluate the Effects of Bone Density and Cement Augmentation on Fixation Stiffness of Bone-Anchoring Devices J Biomech Eng. 2015;137(9):091005-091005-10. doi:10.1115/1.4030943 Figure Legend: Correlation coefficients between stiffness components of the: (a) Sfδ, (b) Sfθ, and (c) Smθ submatrices with axial pull-out stiffness Sf3δ3 for the hFE models without cement (white) and with different cement thicknesses (light gray = 0.8 mm; dark gray = 1.6 mm; and black = 2.4 mm)

Date of download: 10/5/2017 Copyright © ASME. All rights reserved. From: Numerical Methodology to Evaluate the Effects of Bone Density and Cement Augmentation on Fixation Stiffness of Bone-Anchoring Devices J Biomech Eng. 2015;137(9):091005-091005-10. doi:10.1115/1.4030943 Figure Legend: Relations between the predicted hFE axial pull-out stiffness Sf3δ3 and BV/TVglobal for different cement thicknesses

Date of download: 10/5/2017 Copyright © ASME. All rights reserved. From: Numerical Methodology to Evaluate the Effects of Bone Density and Cement Augmentation on Fixation Stiffness of Bone-Anchoring Devices J Biomech Eng. 2015;137(9):091005-091005-10. doi:10.1115/1.4030943 Figure Legend: The effect of cement augmentation on peak stresses within bone, as predicted by the hFE models