Development of 3D Finite Element Model of Human Elbow to Study Elbow Dislocation and Instability

2009 ◽  
Author(s):  
Samer Khodor Al Kork ◽  
Farid Amirouche ◽  
Edward Abraham ◽  
Mark Gonzalez
Keyword(s):  
Finite Element ◽  
Medial Collateral Ligament ◽  
Inverse Dynamics ◽  
Elbow Dislocation ◽  
Lateral Collateral Ligament ◽  
Element Model ◽  
Fe Model ◽  
Collateral Ligament ◽  
Coronoid Fracture ◽  
Flexion Extension

The mechanics of elbow dislocation and its stages of dislocation are complex and not well understood. Reconstructing a fall where someone lands on their hand is one of the most challenging problem in biomechanics. Current models which attempt to reconstruct falls usually focus on experimental kinematical conditions that cause the fall coupled with inverse dynamics to determine the joint and muscles forces [1,2] to provide on insight into the joint instability. Our hypothesis based on our experimental investigation is that the mechanism of posterior elbow dislocation is initiated at radial head where the ulna and coronoid fracture followed by anterior tearing of the joint capsule, lateral collateral ligament will then rupture followed by posterior medial collateral ligament rupture and then the medial collateral ligament peeling off the ulna. In this study we developed a quasi-static three-dimensional finite element of human elbow joint, and conducted several cadaveric studies to study elbow dislocation. The FE model is used to investigate how the ligaments, cartilages behave under different flexion, extension of the elbow. Dislocation is investigated as function of different loads and moments applied to the radius-ulna with arm being flexed and configured into a supination or pronation.

A Biomechanical Model of Lumbar Spine

2000 ◽  
Author(s):  
Subramanya Uppala ◽  
Robert X. Gao ◽  
Scott Cowan ◽  
K. Francis Lee
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Biomechanical Model ◽  
Element Model ◽  
Fe Model ◽  
Flexion Extension ◽  
Cortical Shell ◽  
Three Dimensional Finite Element

Abstract The strength and stability of the lumbar spine are determined not only by the bone and muscles, but also by the visco-elastic structures and the interplay between the different components of the spine, such as ligaments, capsules, annulus fibrosis, and articular cartilage. In this paper we present a non-linear three-dimensional Finite Element model of the lumbar spine. Specifically, a three-dimensional FE model of the L4-5 one-motion segment/2 vertebrae was developed. The cortical shell and the cancellous bone of the vertebral body were modeled as 3D isoparametric eight-nodal elements. Finite element models of spinal injuries with fixation devices are also developed. The deformations across the different sections of the spine are observed under the application of axial compression, flexion/extension, and lateral bending. The developed FE models provided input to both the fixture design and experimental studies.

The role of the posterior bundle of the medial collateral ligament in posteromedial rotatory instability of the elbow

2018 ◽  
Vol 100-B (8) ◽  
pp. 1060-1065 ◽  
Author(s):  
J-T. Hwang ◽  
M. N. Shields ◽  
L. J. Berglund ◽  
A. W. Hooke ◽  
J. S. Fitzsimmons ◽  
...  
Keyword(s):  
Contact Pressure ◽  
Medial Collateral Ligament ◽  
Lateral Collateral Ligament ◽  
Collateral Ligament ◽  
Coronoid Fracture ◽  
Rotatory Instability ◽  
Intact Group ◽  
Joint Contact ◽  
The Mean ◽  
Contact Pressures

Aims The aim of this study was to evaluate two hypotheses. First, that disruption of posterior bundle of the medial collateral ligament (PMCL) has to occur for the elbow to subluxate in cases of posteromedial rotatory instability (PMRI) and second, that ulnohumeral contact pressures increase after disruption of the PMCL. Materials and Methods Six human cadaveric elbows were prepared on a custom-designed apparatus which allowed muscle loading and passive elbow motion under gravitational varus. Joint contact pressures were measured sequentially in the intact elbow (INTACT), followed by an anteromedial subtype two coronoid fracture (COR), a lateral collateral ligament (LCL) tear (COR + LCL), and a PMCL tear (COR + LCL + PMCL). Results There was no subluxation or joint incongruity in the INTACT, COR, and COR + LCL specimens. All specimens in the COR + LCL + PMCL group subluxated under gravity-varus loads. The mean articular contact pressure of the COR + LCL group was significantly higher than those in the INTACT and the COR groups. The mean articular contact pressure of the COR + LCL + PMCL group was significantly higher than that of the INTACT group, but not higher than that of the COR + LCL group. Conclusion In the presence of an anteromedial fracture and disruption of the LCL, the posterior bundle of the MCL has to be disrupted for gross subluxation of the elbow to occur. However, elevated joint contact pressures are seen after an anteromedial fracture and LCL disruption even in the absence of such subluxation. Cite this article: Bone Joint J 2018;100-B:1060–5.

Development and Validation of a Three-Dimensional Finite Element Model of Cervical Spine (C3-C5)

2010 ◽  
Author(s):  
N. Bahramshahi ◽  
H. Ghaemi ◽  
K. Behdinan
Keyword(s):  
Finite Element ◽  
Cervical Spine ◽  
Three Dimensional ◽  
Element Model ◽  
Intervertebral Discs ◽  
Fe Model ◽  
Two Phase ◽  
Finite Element Software ◽  
Flexion Extension ◽  
Disc Bulge

The objective of this investigation is to develop a detailed, non-linear asymmetric three-dimensional anatomically and mechanically accurate FE model of complete middle cervical spine (C3-C5) using Hypermesh and MSC.Marc software. To achieve this goal, the components of the cervical spine are modeled using 20-noded hexagonal elements. The model includes the intervertebral disc, cortical bone, cancellous bone, endplates, and ligaments. The structure and dimensions of each spinal component are compared with experimentally measured values. In addition, the soil mechanics formulation of MSC.Marc finite element software is applied to model the mechanical behaviour of vertebrae and intervertebral discs as linear isotropic two-phase (biphasic) material. The FE simulation is conducted to investigate compression, flexion\extension and right\Left lateral bending modes. The simulation results are validated and compared closely with the published experimental data and the existing FE models. In general, results show greater flexibility in flexion and less flexibility in extension. The flexion/extension curves are asymmetric with a greater magnitude in flexion than in extension. In addition, the variations of the predicted lateral C4-C5 disc bulge are investigated and the results show that the maximum disc bulge occurs at the C4-C5 anterior location.

Finite Element Analysis of the Distributed Vibration Absorbers for Structural Noise Control

2005 ◽  
Author(s):  
Ashwini Gautam ◽  
Chris Fuller ◽  
James Carneal
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Base Plate ◽  
Element Model ◽  
Fe Model ◽  
Vibration Absorbers ◽  
Element Analysis ◽  
Poroelastic Media ◽  
Hexahedral Elements ◽  
Component Models

This work presents an extensive analysis of the properties of distributed vibration absorbers (DVAs) and their effectiveness in controlling the sound radiation from the base structure. The DVA acts as a distributed mass absorber consisting of a thin metal sheet covering a layer of acoustic foam (porous media) that behaves like a distributed spring-mass-damper system. To assess the effectiveness of these DVAs in controlling the vibration of the base structures (plate) a detailed finite elements model has been developed for the DVA and base plate structure. The foam was modeled as a poroelastic media using 8 node hexahedral elements. The structural (plate) domain was modeled using 16 degree of freedom plate elements. Each of the finite element models have been validated by comparing the numerical results with the available analytical and experimental results. These component models were combined to model the DVA. Preliminary experiments conducted on the DVAs have shown an excellent agreement between the results obtained from the numerical model of the DVA and from the experiments. The component models and the DVA model were then combined into a larger FE model comprised of a base plate with the DVA treatment on its surface. The results from the simulation of this numerical model have shown that there has been a significant reduction in the vibration levels of the base plate due to DVA treatment on it. It has been shown from this work that the inclusion of the DVAs on the base plate reduces their vibration response and therefore the radiated noise. Moreover, the detailed development of the finite element model for the foam has provided us with the capability to analyze the physics behind the behavior of the distributed vibration absorbers (DVAs) and to develop more optimized designs for the same.

scholarly journals Repair of a Divergent Elbow Dislocation with Distal Ulnar Fracture in a Dog Using TightRope and External Skeletal Fixation

VCOT Open ◽  
2021 ◽  
Vol 04 (01) ◽  
pp. e58-e64
Author(s):  
Marcos Garcia ◽  
Camille Bismuth ◽  
Claire Deroy-Bordenave
Keyword(s):  
Elbow Dislocation ◽  
Lateral Collateral Ligament ◽  
Normal Activity ◽  
Long Term Results ◽  
Collateral Ligament ◽  
Elbow Luxation ◽  
Ulnar Fracture ◽  
Fixation System

AbstractThe aim of this study was to report the outcome in a 6-year-old male English Setter dog that suffered a combination of divergent elbow dislocation and open distal ulnar fracture. This study is a case report. After surgical reduction in the elbow luxation, the dog was treated with the TightRope fixation system used as replacement of the lateral collateral ligament, a radioulnar positional screw, and external skeletal fixation. Removal of all implants was performed 3 months postoperatively. The 6-month follow-up visit found the dog without lameness, displaying normal activity, and with normal elbow range of motion and normal Campbell's test. Successful surgical management was achieved with good long-term results using TightRope, a positional screw, and an external skeletal fixator.

Finite Element Model of Human Cochlea Considering of the Helicotrema Size

2013 ◽  
Vol 456 ◽  
pp. 576-581 ◽  
Author(s):  
Li Fu Xu ◽  
Na Ta ◽  
Zhu Shi Rao ◽  
Jia Bin Tian
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Basilar Membrane ◽  
Round Window ◽  
Element Model ◽  
Oval Window ◽  
Fe Model ◽  
Cochlear Duct ◽  
Human Cochlea ◽  
Set Up

A 2-D finite element model of human cochlea is established in this paper. This model includes the structure of oval window, round window, basilar membrane and cochlear duct which is filled with fluid. The basilar membrane responses are calculated with sound input on the oval window membrane. In order to study the effects of helicotrema on basilar membrane response, three different helicotrema dimensions are set up in the FE model. A two-way fluid-structure interaction numerical method is used to compute the responses in the cochlea. The influence of the helicotrema is acquired and the frequency selectivity of the basilar membrane motion along the cochlear duct is predicted. These results agree with the experiments and indicate much better results are obtained with appropriate helicotrema size.

A Finite Element Model of the Human Knee Joint for the Study of Tibio-Femoral Contact

2002 ◽  
Vol 124 (3) ◽  
pp. 273-280 ◽  
Author(s):  
Tammy L. Haut Donahue ◽  
M. L. Hull ◽  
Mark M. Rashid ◽  
Christopher R. Jacobs
Keyword(s):  
Finite Element ◽  
Articular Cartilage ◽  
Three Dimensional ◽  
Element Model ◽  
Maximum Pressure ◽  
Contact Behavior ◽  
Element Size ◽  
Solid Models ◽  
Flexion Extension ◽  
Three Dimensional Coordinate

As a step towards developing a finite element model of the knee that can be used to study how the variables associated with a meniscal replacement affect tibio-femoral contact, the goals of this study were 1) to develop a geometrically accurate three-dimensional solid model of the knee joint with special attention given to the menisci and articular cartilage, 2) to determine to what extent bony deformations affect contact behavior, and 3) to determine whether constraining rotations other than flexion/extension affects the contact behavior of the joint during compressive loading. The model included both the cortical and trabecular bone of the femur and tibia, articular cartilage of the femoral condyles and tibial plateau, both the medial and lateral menisci with their horn attachments, the transverse ligament, the anterior cruciate ligament, and the medial collateral ligament. The solid models for the menisci and articular cartilage were created from surface scans provided by a noncontacting, laser-based, three-dimensional coordinate digitizing system with an root mean squared error (RMSE) of less than 8 microns. Solid models of both the tibia and femur were created from CT images, except for the most proximal surface of the tibia and most distal surface of the femur which were created with the three-dimensional coordinate digitizing system. The constitutive relation of the menisci treated the tissue as transversely isotropic and linearly elastic. Under the application of an 800 N compressive load at 0 degrees of flexion, six contact variables in each compartment (i.e., medial and lateral) were computed including maximum pressure, mean pressure, contact area, total contact force, and coordinates of the center of pressure. Convergence of the finite element solution was studied using three mesh sizes ranging from an average element size of 5 mm by 5 mm to 1 mm by 1 mm. The solution was considered converged for an average element size of 2 mm by 2 mm. Using this mesh size, finite element solutions for rigid versus deformable bones indicated that none of the contact variables changed by more than 2% when the femur and tibia were treated as rigid. However, differences in contact variables as large as 19% occurred when rotations other than flexion/extension were constrained. The largest difference was in the maximum pressure. Among the principal conclusions of the study are that accurate finite element solutions of tibio-femoral contact behavior can be obtained by treating the bones as rigid. However, unrealistic constraints on rotations other than flexion/extension can result in relatively large errors in contact variables.

Finite Element Mesh Generator Applying Constraints’ Propagation and Isoparametric Mapping

1991 ◽  
Author(s):  
J. Rodriguez ◽  
M. Him
Keyword(s):  
Finite Element ◽  
Mesh Generation ◽  
Element Model ◽  
Finite Element Mesh ◽  
Fe Model ◽  
Element Analysis ◽  
Element Mesh ◽  
Mesh Generator ◽  
Generation Algorithm ◽  
Essential Input

Abstract This paper presents a finite element mesh generation algorithm (PREPAT) designed to automatically discretize two-dimensional domains. The mesh generation algorithm is a mapping scheme which creates a uniform isoparametric FE model based on a pre-partitioned domain of the component. The proposed algorithm provides a faster and more accurate tool in the pre-processing phase of a Finite Element Analysis (FEA). A primary goal of the developed mesh generator is to create a finite element model requiring only essential input from the analyst. As a result, the generator code utilizes only a sketch, based on geometric primitives, and information relating to loading/boundary conditions. These conditions represents the constraints that are propagated throughout the model and the available finite elements are uniformly mapped in the resulting sub-domains. Relative advantages and limitations of the mesh generator are discussed. Examples are presented to illustrate the accuracy, efficiency and applicability of PREPAT.

FEBio finite element model of a pediatric cervical spine

2021 ◽  
pp. 1-7
Author(s):  
Sean M. Finley ◽  
J. Harley Astin ◽  
Evan Joyce ◽  
Andrew T. Dailey ◽  
Douglas L. Brockmeyer ◽  
...  
Keyword(s):  
Finite Element ◽  
Cervical Spine ◽  
Finite Element Model ◽  
Material Properties ◽  
Surgical Simulation ◽  
Element Model ◽  
Axial Stiffness ◽  
Published Data ◽  
Axial Tension ◽  
Flexion Extension

OBJECTIVE The underlying biomechanical differences between the pediatric and adult cervical spine are incompletely understood. Computational spine modeling can address that knowledge gap. Using a computational method known as finite element modeling, the authors describe the creation and evaluation of a complete pediatric cervical spine model. METHODS Using a thin-slice CT scan of the cervical spine from a 5-year-old boy, a 3D model was created for finite element analysis. The material properties and boundary and loading conditions were created and model analysis performed using open-source software. Because the precise material properties of the pediatric cervical spine are not known, a published parametric approach of scaling adult properties by 50%, 25%, and 10% was used. Each scaled finite element model (FEM) underwent two types of simulations for pediatric cadaver testing (axial tension and cardinal ranges of motion [ROMs]) to assess axial stiffness, ROM, and facet joint force (FJF). The authors evaluated the axial stiffness and flexion-extension ROM predicted by the model using previously published experimental measurements obtained from pediatric cadaveric tissues. RESULTS In the axial tension simulation, the model with 50% adult ligamentous and annulus material properties predicted an axial stiffness of 49 N/mm, which corresponded with previously published data from similarly aged cadavers (46.1 ± 9.6 N/mm). In the flexion-extension simulation, the same 50% model predicted an ROM that was within the range of the similarly aged cohort of cadavers. The subaxial FJFs predicted by the model in extension, lateral bending, and axial rotation were in the range of 1–4 N and, as expected, tended to increase as the ligament and disc material properties decreased. CONCLUSIONS A pediatric cervical spine FEM was created that accurately predicts axial tension and flexion-extension ROM when ligamentous and annulus material properties are reduced to 50% of published adult properties. This model shows promise for use in surgical simulation procedures and as a normal comparison for disease-specific FEMs.

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