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 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.

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 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 STRESS ANALYSIS OF INDIGENOUSLY DESIGNED ENERGY STORING POLYPROPYLENE CO-POLYMER (PPCP) PROSTHETIC FOOT

2020 ◽  
pp. 1-3
Author(s):  
Sachin S Bhagat ◽  
A.G Indalkar ◽  
Avinash Phirke
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Stress Analysis ◽  
Maximum Stress ◽  
Element Model ◽  
Heel Strike ◽  
Loading Conditions ◽  
Design Modification ◽  
Prosthetic Foot ◽  
Von Mises

Polypropylene Co-polymer (PPCP) Prosthetic Foot Model, Indigenously designed at All India Institute of Physical Medicine and Rehabilitation (AIIPMR), Mumbai. More commonly, this design is known as Modified Flex foot. Various researcher’s contributed towards its design modification, material optimization, patient trial & clinical implications and further improvements. As such, this study was conducted to observe & understand the stress analysis of this modified flexfoot under loading conditions at various orientation of gait. Finite element analysis (FEA) method was used with Ansys 12.0 software. Study objectives was to construct and analyze the finite element model, to find out & understand failure prone areas in the present design of PPCP prosthetic foot. This study was conducted into five phases. At initial phase, actual foot design was constructed and input parameters like geometrical parameters were calculated considering the standard length transtibial amputee. Similarly Material properties, loading conditions & boundary conditions were determined. AutCAD model was constructed using input parametrs & imported into Ansys 12.0 software. Finite element model were constructed and analyzed. Results were noted, which were displyed in the form of several contour plots & through colours that correspond to different stress values. FEA results obtained for various stress values like, Elemental stress, shearing stress & Von Mises stresses (Combination stresses). Peak Von Mises stress value of 28112 Mpa, observed at lower ankle fillet region during heel strike orientation of the gait. Study concluded that lower ankle fillet region & Midfoot spring region will be subjected to maximum stress during heel strike, Mid stance & push off. It was concluded that lower ankle fillet region & Midfoot spring region will be subjected to maximum stress during heel strike, Mid stance & push off.

Development and Validation of a Three-Dimensional Finite Element Model of the Face

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
G. G. Barbarino ◽  
M. Jabareen ◽  
J. Trzewik ◽  
A. Nkengne ◽  
G. Stamatas ◽  
...  
Keyword(s):  
Finite Element ◽  
Magnetic Resonance ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Magnetic Resonance Images ◽  
Dimensional Finite Element ◽  
The Face ◽  
Three Dimensional Finite Element ◽  
Tissue Aging

A detailed three-dimensional finite element model of the face is presented in this paper. Bones, muscles, skin, fat, and superficial muscoloaponeurotic system were reconstructed from magnetic resonance images and modeled according to anatomical, plastic, and reconstructive surgery literature. The finite element mesh, composed of hexahedron elements, was generated through a semi-automatic procedure with an effective compromise between the detailed representation of anatomical parts and the limitation of the computational time. Nonlinear constitutive equations are implemented in the finite element model. The corresponding model parameters were selected according to previous work with mechanical measurements on soft facial tissue, or based on reasonable assumptions. Model assumptions concerning tissue geometry, interactions, mechanical properties, and the boundary conditions were validated through comparison with experiments. The calculated response of facial tissues to gravity loads, to the application of a pressure inside the oral cavity and to the application of an imposed displacement was shown to be in good agreement with the data from corresponding magnetic resonance images and holographic measurements. As a first application, gravimetric soft tissue descent was calculated from the long time action of gravity on the face in the erect position, with tissue aging leading to a loss of stiffness. Aging predictions are compared with the observations from an “aging database” with frontal photos of volunteers at different age ranges (i.e., 20–40 years and 50–70 years).

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