Comparison of four methods to simulate swelling in poroelastic finite element models of intervertebral discs

2011 ◽  
Vol 4 (7) ◽  
pp. 1234-1241 ◽  
Author(s):  
Fabio Galbusera ◽  
Hendrik Schmidt ◽  
Jérôme Noailly ◽  
Andrea Malandrino ◽  
Damien Lacroix ◽  
...  
Keyword(s):  
Finite Element ◽  
Intervertebral Discs ◽  
Finite Element Models

scholarly journals Finite element and deformation analyses predict pattern of bone failure in loaded zebrafish spines

2019 ◽  
Vol 16 (160) ◽  
pp. 20190430 ◽  
Author(s):  
Elis Newham ◽  
Erika Kague ◽  
Jessye A. Aggleton ◽  
Christianne Fernee ◽  
Kate Robson Brown ◽  
...  
Keyword(s):  
Finite Element ◽  
Disease Process ◽  
Intervertebral Discs ◽  
Vertebral Compression Fractures ◽  
Finite Element Models ◽  
Micro Computed Tomography ◽  
Spinal Motion ◽  
Biomechanical Models ◽  
Testing Stage ◽  
Ultimate Failure

The spine is the central skeletal support structure in vertebrates consisting of repeated units of bone, the vertebrae, separated by intervertebral discs (IVDs) that enable the movement of the spine. Spinal pathologies such as idiopathic back pain, vertebral compression fractures and IVD failure affect millions of people worldwide. Animal models can help us to understand the disease process, and zebrafish are increasingly used as they are highly genetically tractable, their spines are axially loaded like humans, and they show similar pathologies to humans during ageing. However, biomechanical models for the zebrafish are largely lacking. Here, we describe the results of loading intact zebrafish spinal motion segments on a material testing stage within a micro-computed tomography machine. We show that vertebrae and their arches show predictable patterns of deformation prior to their ultimate failure, in a pattern dependent on their position within the segment. We further show using geometric morphometrics which regions of the vertebra deform the most during loading, and that finite-element models of the trunk subjected reflect the real patterns of deformation and strain seen during loading and can therefore be used as a predictive model for biomechanical performance.

scholarly journals Finite Element and deformation analyses predict pattern of bone failure in loaded zebrafish spines

2019 ◽  
Author(s):  
Elis Newman ◽  
Erika Kague ◽  
Jessye A. Aggleton ◽  
Christianne Fernee ◽  
Kate Robson Brown ◽  
...  
Keyword(s):  
Finite Element ◽  
Disease Process ◽  
Intervertebral Discs ◽  
Vertebral Compression Fractures ◽  
Finite Element Models ◽  
Micro Computed Tomography ◽  
Spinal Motion ◽  
Biomechanical Models ◽  
Testing Stage ◽  
Ultimate Failure

AbstractThe spine is the central skeletal support structure in vertebrates consisting of repeated units of bone, the vertebrae, separated by intervertebral discs that enable the movement of the spine. Spinal pathologies such as idiopathic back pain, vertebral compression fractures and intervertebral disc failure affect millions of people world-wide. Animal models can help us to understand the disease process, and zebrafish are increasingly used as they are highly genetically tractable, their spines are axially loaded like humans, and they show similar pathologies to humans during ageing. However biomechanical models for the zebrafish are largely lacking. Here we describe the results of loading intact zebrafish spinal motion segments on a material testing stage within a micro Computed Tomography machine. We show that vertebrae and their arches show predictable patterns of deformation prior to their ultimate failure, in a pattern dependent on their position within the segment. We further show using geometric morphometrics which regions of the vertebra deform the most during loading, and that Finite Element models of the trunk subjected reflect the real patterns of deformation and strain seen during loading and can therefore be used as a predictive model for biomechanical performance.

scholarly journals Finite element models can reproduce the effect of nucleotomy on the multi-axial compliance of human intervertebral discs

2020 ◽  
Vol 23 (13) ◽  
pp. 934-944
Author(s):  
Marc A. Stadelmann ◽  
Roland Stocker ◽  
Ghislain Maquer ◽  
Sven Hoppe ◽  
Peter Vermathen ◽  
...  
Keyword(s):  
Finite Element ◽  
Intervertebral Discs ◽  
Finite Element Models

scholarly journals The Verification of Human Lumbar Vertebrae and Intervertebral Disc Finite Element Models under Mechanical Forces

2021 ◽  
Vol 15 ◽  
pp. 1-10
Author(s):  
Mohankumar Palaniswamy ◽  
Anis Suhaila Shuib ◽  
Khai Ching Ng ◽  
Shajan Koshy
Keyword(s):  
Finite Element ◽  
Lumbar Vertebrae ◽  
Well Being ◽  
Intervertebral Discs ◽  
Finite Element Models ◽  
Geometrical Analysis ◽  
Total Deformation ◽  
Element Analysis ◽  
Significant Difference ◽  
Validation Procedure

Bone, being nonhomogeneous in nature need a complicated and time-consuming process to undergo computed simulation like finite element analysis. To overcome this hurdle, assuming a nonhomogeneous model as homogeneous could be a solution. The objective of this study is to focus on developing a homogeneous human lumbar finite element models and verify them under mechanical force by measuring disc stress, disc strain, disc deformation, total strain, and total deformation. Experimental and geometrical analysis were performed before verifying the lumbar model. To verify the models’ reliability, nonhomogeneous lumbar models were also developed. Five different static structural simulations were performed on four lumbar segments, and twenty parameters were measured. Numerically, out of twenty, eighteen parameters showed very less or no significant difference between homogeneous and nonhomogeneous models of the intervertebral discs and lumbar vertebrae. At the same time, proper caution to be provided while examining the results. With this validation procedure, researchers can process artifact images to get more information which enables them to contribute to the patient’s well-being.

Patient-specific spine models. Part 1: Finite element analysis of the lumbar intervertebral disc—a material sensitivity study

2002 ◽  
Vol 216 (5) ◽  
pp. 299-314 ◽  
Author(s):  
M J Fagan ◽  
S Julian ◽  
D J Siddall ◽  
A M Mohsen
Keyword(s):  
Finite Element ◽  
Intervertebral Disc ◽  
Material Properties ◽  
Intervertebral Discs ◽  
Basic Material ◽  
Patient Specific ◽  
Finite Element Models ◽  
Torsional Loading ◽  
Non Linear ◽  
Linear Material

If patient-specific finite element models of the spine could be developed, they would offer enormous opportunities in the diagnosis and management of back problems. Several generic models have been developed in the past, but there has been very little detailed examination of the sensitivity of these models' characteristics to the input parameters. This relationship must be thoroughly understood if representative patient-specific models are to be realized and used with confidence. In particular, the performance of the intervertebral discs are central to any spine model and need detailed investigation first. A generic non-linear model of an intervertebral disc was developed and subjected to compressive, flexion and torsional loading regimes. The effects of both material and geometric non-linearities were investigated for the three loading schemes and the results compared with experimental data. The basic material properties of the fibres, annulus and nucleus were then varied and the effects on the stiffness, annulus bulge and annulus stresses analysed. The results showed that the non-linear geometry assumption had a significant effect on the compression characteristics, whereas the non-linear material option did not. In contrast, the material non-linearity was more important for the flexural and torsional loading schemes. Thus, the inclusion of non-linear material and geometry analysis options in finite element models of intervertebral discs is necessary to predict in vivo load-deflection characteristics accurately. When the influence of the material properties was examined in detail, it was found that the fibre properties did not have a significant effect on the compressive stiffness of the disc but did affect the flexural and torsional stiffnesses by up to ±20 per cent. All loading modes were sensitive to the annulus properties with stiffnesses varying by up to ±16 per cent. The model also revealed that for a particular compressive deformation or flexural or torsional rotation, the disc bulge was not sensitive to any of the material properties over the range of properties considered. The annulus stresses did differ significantly as the material properties were varied (up to 70 per cent under a compressive load and 60 per cent during disc flexion).

A Finite Element Analysis of the General Rolling Contact Problem for a Viscoelastic Rubber Cylinder

1988 ◽  
Vol 16 (1) ◽  
pp. 18-43 ◽  
Author(s):  
J. T. Oden ◽  
T. L. Lin ◽  
J. M. Bass
Keyword(s):  
Finite Element ◽  
Variational Principles ◽  
Standing Waves ◽  
Rolling Contact ◽  
Finite Element Models ◽  
Viscoelastic Cylinder ◽  
Element Analysis ◽  
Elastic Rubber ◽  
Frictional Effects ◽  
Rough Foundation

Abstract Mathematical models of finite deformation of a rolling viscoelastic cylinder in contact with a rough foundation are developed in preparation for a general model for rolling tires. Variational principles and finite element models are derived. Numerical results are obtained for a variety of cases, including that of a pure elastic rubber cylinder, a viscoelastic cylinder, the development of standing waves, and frictional effects.

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