scholarly journals Finite Element Modelling Simulated Meniscus Translocation and Deformation during Locomotion of the Equine Stifle

Animals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 502
Author(s):  
Pasquale Zellmann ◽  
Iris Ribitsch ◽  
Stephan Handschuh ◽  
Christian Peham
Keyword(s):  
Finite Element ◽  
Lateral Meniscus ◽  
Element Model ◽  
Magnetic Resonance Images ◽  
Fem Model ◽  
Stifle Joint ◽  
Loading Patterns ◽  
Articular Cartilages ◽  
Tissue Material ◽  
Treatment Surgery

We developed a finite element model (FEM) of the equine stifle joint to identify pressure peaks and simulate translocation and deformation of the menisci. A series of sectional magnetic resonance images (1.5 T) of the stifle joint of a 23 year old Shetland pony gelding served as basis for image segmentation. Based on the 3D polygon models of femur, tibia, articular cartilages, menisci, collateral ligaments and the meniscotibial ligaments, an FEM model was generated. Tissue material properties were assigned based on data from human (Open knee(s) project) and bovine femoro-tibial joint available in the literature. The FEM model was tested across a range of motion of approximately 30°. Pressure load was overall higher in the lateral meniscus than in the medial. Accordingly, the simulation showed higher translocation and deformation in the lateral compared to the medial meniscus. The results encourage further refinement of this model for studying loading patterns on menisci and articular cartilages as well as the resulting mechanical stress in the subchondral bone (femur and tibia). A functional FEM model can not only help identify segments in the stifle which are predisposed to injury, but also to better understand the progression of certain stifle disorders, simulate treatment/surgery effects and to optimize implant/transplant properties.

scholarly journals Biomechanical characteristics of tibio-femoral joint after partial medial meniscectomy in different flexion angles: a finite element analysis

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Xiaohui Zhang ◽  
Shuo Yuan ◽  
Jun Wang ◽  
Bagen Liao ◽  
De Liang
Keyword(s):  
Finite Element ◽  
Articular Cartilage ◽  
Finite Element Model ◽  
Medial Meniscus ◽  
Lateral Meniscus ◽  
Element Model ◽  
Magnetic Resonance Images ◽  
Biomechanical Analysis ◽  
Joint Stress ◽  
Tibiofemoral Joint

Abstract Background Recent studies have pointed out that arthroscopy, the commonly-used surgical procedure for meniscal tears, may lead to an elevated risk of knee osteoarthritis (KOA). The biomechanical factors of KOA can be clarified by the biomechanical analysis after arthroscopic partial meniscectomy (APM). This study aimed to elucidate the cartilage stress and meniscus displacement of the tibiofemoral joint under flexion and rotation loads after APM. Methods A detailed finite element model of the knee bone, cartilage, meniscus, and major ligaments was established by combining computed tomography and magnetic resonance images. Vertical load and front load were applied to simulate different knee buckling angles. At the same time, by simulating flexion of different degrees and internal and external rotations, the stresses on tibiofemoral articular cartilage and meniscus displacement were evaluated. Results Generally, the contact stress on both the femoral tibial articular cartilage and the meniscus increased with the increased flexion degree. Moreover, the maximum stress on the tibial plateau gradually moved backward. The maximum position shift value of the lateral meniscus was larger than that of the medial meniscus. Conclusion Our finite element model provides a realistic three-dimensional model to evaluate the influence of different joint range of motion and rotating tibiofemoral joint stress distribution. The decreased displacement of the medial meniscus may explain the higher pressure on the knee components. These characteristics of the medial tibiofemoral joint indicate the potential biomechanical risk of knee degeneration.

The Effect of Kinematic and Kinetic Changes on Meniscal Strains During Gait

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
Nathan A. Netravali ◽  
Seungbum Koo ◽  
Nicholas J. Giori ◽  
Thomas P. Andriacchi
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
External Rotation ◽  
Lateral Meniscus ◽  
Element Model ◽  
Magnetic Resonance Images ◽  
Heel Strike ◽  
Tibial Rotation ◽  
Cadaveric Specimen ◽  
Medial Meniscectomy

The menisci play an important role in load distribution, load bearing, joint stability, lubrication, and proprioception. Partial meniscectomy has been shown to result in changes in the kinematics and kinetics at the knee during gait that can lead to progressive meniscal degeneration. This study examined changes in the strains within the menisci associated with kinematic and kinetic changes during the gait cycle. The gait changes considered were a 5 deg shift toward external rotation of the tibia with respect to the femur and an increased medial-lateral load ratio representing an increased adduction moment. A finite element model of the knee was developed and tested using a cadaveric specimen. The cadaver was placed in positions representing heel-strike and midstance of the normal gait, and magnetic resonance images were taken. Comparisons of the model predictions to boundaries digitized from images acquired in the loaded states were within the errors produced by a 1 pixel shift of either meniscus. The finite element model predicted that an increased adduction moment caused increased strains of both the anterior and posterior horns of the medial meniscus. The lateral meniscus exhibited much lower strains and had minimal changes under the various loading conditions. The external tibial rotational change resulted in a 20% decrease in the strains in the posterior medial horn and increased strains in the anterior medial horn. The results of this study suggest that the shift toward external tibial rotation seen clinically after partial medial meniscectomy is not likely to cause subsequent degenerative medial meniscal damage, but the consequence of this kinematic shift on the pathogenesis of osteoarthritis following meniscectomy requires further consideration.

scholarly journals Biomechanical Characteristics of Tibio-Femoral Joint After Partial Medial Meniscectomy Under Different Flexion Angles：A Finite Element Analysis

2021 ◽  
Author(s):  
Xiaohui Zhang ◽  
Jun Wang ◽  
Shuo Yuan ◽  
Bagen Liao ◽  
De Liang
Keyword(s):  
Finite Element ◽  
Articular Cartilage ◽  
Finite Element Model ◽  
Medial Meniscus ◽  
Lateral Meniscus ◽  
Element Model ◽  
Magnetic Resonance Images ◽  
Biomechanical Analysis ◽  
Joint Stress ◽  
Tibiofemoral Joint

Abstract Background : Arthroscopy is a commonly-used surgical procedure for meniscal tears. However, recent studies have pointed out that arthroscopy may lead to an elevated risk of knee osteoarthritis(KOA). The biomechanical analysis after arthroscopic partial meniscectomy(APM) is helpful to clarify the biomechanical factors of KOA. Therefore, this study aims to elucidate cartilage stress and meniscus displacement of the tibiofemoral joint under flexion and rotation loads after APM.Methods：A detailed finite element model of the knee bone, cartilage, meniscus, and major ligaments was established by combining computed tomography and magnetic resonance images. Vertical load and front load were applied to simulate different knee buckling angles. At the same time, by simulating flexion of different degrees and internal and external rotations, the stresses on tibiofemoral articular cartilage and meniscus displacement were evaluated.Results：Generally, the contact stress on both the femoral tibial articular cartilage and the meniscus increased with the increased flexion degree. Moreover, the maximum stress on the tibial plateau gradually moved backward. The maximum position shift value of the lateral meniscus was larger than that of the medial meniscus.Conclusion：Our finite element model provides a realistic three-dimensional model to evaluate the influence of different joint range of motion and rotating tibiofemoral joint stress distribution. The decreased displacement of the medial meniscus may explain the higher pressure on the knee components. These characteristics of the medial tibiofemoral joint indicate the potential biomechanical risk of knee degeneration.

scholarly journals Piezoelectric Beam Finite Element Model and Its Reduction and Control

2021 ◽  
Vol 71 (1) ◽  
pp. 87-106
Author(s):  
Kutiš Vladimír ◽  
Paulech Juraj ◽  
Gálik Gálik ◽  
Murín Justín
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
State Space ◽  
State Space Model ◽  
Element Model ◽  
Functionally Graded ◽  
Fem Model ◽  
Space Model ◽  
Piezoelectric Beam ◽  
Reduced State

Abstract The paper deals with the development of the finite element method (FEM) model of piezoelectric beam elements, where the piezoelectric layers are located on the outer surfaces of the beam core, which is made of functionally graded material. The created FEM model of piezoelectric beam structure is reduced using the modal truncation method, which is one of model order reduction (MOR) method. The results obtain from reduced state-space model are compared with results obtain from finite element model. MOR state-space model is also used in the design of the linear quadratic regulator (LQR). Created reduced state-space model with feedback with the LQR controller is analysed and compared with the results from FEM model.

scholarly journals A Vision-Based Approach for Estimating Contact Forces: Applications to Robot-Assisted Surgery

2005 ◽  
Vol 2 (1) ◽  
pp. 53-60 ◽  
Author(s):  
C. W. Kennedy ◽  
J. P. Desai
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Real Time ◽  
Force Feedback ◽  
Element Model ◽  
Robot Arm ◽  
Robot Assisted ◽  
Interaction Forces ◽  
Fem Model ◽  
Nodal Displacements

The primary goal of this paper is to provide force feedback to the user using vision-based techniques. The approach presented in this paper can be used to provide force feedback to the surgeon for robot-assisted procedures. As proof of concept, we have developed a linear elastic finite element model (FEM) of a rubber membrane whereby the nodal displacements of the membrane points are measured using vision. These nodal displacements are the input into our finite element model. In the first experiment, we track the deformation of the membrane in real-time through stereovision and compare it with the actual deformation computed through forward kinematics of the robot arm. On the basis of accurate deformation estimation through vision, we test the physical model of a membrane developed through finite element techniques. The FEM model accurately reflects the interaction forces on the user console when the interaction forces of the robot arm with the membrane are compared with those experienced by the surgeon on the console through the force feedback device. In the second experiment, the PHANToM haptic interface device is used to control the Mitsubishi PA-10 robot arm and interact with the membrane in real-time. Image data obtained through vision of the deformation of the membrane is used as the displacement input for the FEM model to compute the local interaction forces which are then displayed on the user console for providing force feedback and hence closing the loop.

Pipeline On-Bottom Stability Analysis Based on FEM Model

2011 ◽  
Author(s):  
Yong Bai ◽  
Zhimeng Yu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Design Procedure ◽  
Element Model ◽  
The Finite Element Method ◽  
Fem Model ◽  
Engineering Software ◽  
Calculation Results ◽  
Pipeline Design ◽  
Element Method

Pipeline on-bottom stability is one of the sophisticated problems in subsea pipeline design procedure. Due to the uncertainty of the pipe-soil interaction and environment loads, including wave, current, or earthquake, etc., it is classified as the typical nonlinear problem. The Finite Element Method is introduced into pipeline engineering several years ago. More and more special engineering software such as AGA, PONDUS are available in market. However, when doing a project, some abnormal data was found when compared the DnV calculation results and AGA. In order to know the behavior of pipeline on seabed under wave and current load, finite element method – ABAQUS is introduced to do this analysis. The ABAQUS/explicit is used to simulate 600s pipeline dynamic response. The pipeline is supposed to be exposed on seabed and the selected seabed model is large enough to avoid the edge effect. ABAQUS calculation results are compared with the requirements in DnV rules to verify the validity of finite element model.

A FEM Model Analysis of Human Lumbar Spine With Bi-Level Artificial Disc Replacement

2006 ◽  
Author(s):  
A. Faizan ◽  
A. Kiapour ◽  
V. K. Goel ◽  
A. Ivanov ◽  
A. Biyani ◽  
...  
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Bending Moment ◽  
Element Model ◽  
Good Alternative ◽  
Disc Replacement ◽  
Artificial Disc ◽  
Fem Model ◽  
Artificial Disc Replacement ◽  
Human Lumbar Spine

A finite element model of human lumbar spine (L3-S1 segment) was used to analyze biomechanical effects of the bi-level CHARITE artificial disc replacement (2LCHD) at L4-L5 and L5-S1 levels. The mechanical behavior and range of motion in implanted and intact models were compared using the finite element analyses and a hybrid loading protocol. In 2LCHD model the changes at L3-L4 level decreased by 25% also the model showed smooth changes in motion at implanted levels. In flexion there was an increase in facet loads at lower levels of 2LCHD however the bending moment in this model was less than intact model because of hybrid loading; in contrast, the facet loads in implanted model decreased in extension. It was observed that the bi-level disc replacement won’t affect much the kinematics of the spine and can be proposed as a good alternative for treatment in cases that disc degeneration occurs at more than one level of spine.

The Influence of Residual Stress on the Machining Deformation

2012 ◽  
Vol 426 ◽  
pp. 172-176
Author(s):  
Hun Guo
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Finite Element Model ◽  
Simulation Model ◽  
Elasticity Theory ◽  
Initial Stress ◽  
Fem Simulation ◽  
Element Model ◽  
Fem Model ◽  
Simulation Results

The key problems in 2D FEM simulation such as the establishment of finite element model, the initial stress loading, the distortion appraisal are solved and 2D FEM simulation model is built to analyze the milling distortion caused by the residual stress. The FEM model is verified by the elasticity theory. Some machining cases are simulated by using of the FEM model. The machining distortion caused by residual stress are analyzed and summarized using the simulation results.

Analysis on the Upholding Bracket for Bridge Fabricating System & the Building of its FEM Model

2012 ◽  
Vol 472-475 ◽  
pp. 641-644
Author(s):  
Quan Cai Li ◽  
Cui Rong Wu
Keyword(s):  
Finite Element ◽  
Structural Analysis ◽  
Finite Element Model ◽  
Static Analysis ◽  
Large Scale ◽  
Element Model ◽  
Fem Model ◽  
At Home

Bridge Fabricating System is one of the most widely used large-scale machinery equipment in construction fields like highway, railway both at home and abroad. Through structural analysis on the bridge fabricating system, and build a finite element model with ANSYS, we can form a found- ation for Static Analysis for it.

Study on Ship Hull Deformation by Integrated Model of Hull with Shaft

2014 ◽  
Vol 904 ◽  
pp. 450-453
Author(s):  
Xiang Kui Ruan ◽  
Ping Yang ◽  
Xin Ping Yan ◽  
Zhe Huang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Working Condition ◽  
Element Model ◽  
Integrated Model ◽  
Container Ship ◽  
Accurate Calculation ◽  
Fem Model ◽  
Large Container ◽  
Basic Content

Hull deformation directly influences the working condition of propulsion shaft, so that the reasonable and accurate calculation of deformation is the basic content of research on ship propulsion system. This paper, basing on a large container ship, built up an integrated finite element model of the hull with the propulsion shaft. By employing inertial relief method, the hull deformation at place of shaft supports is calculated under different loading conditions. The results are compared with those from a hull FEM model without shaft. Some valuable conclusions are made from the results analysis.

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