scholarly journals Model for in-vivo estimation of stiffness of tibiofemoral joint using MR imaging and FEM analysis

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Sandeep Panwar Jogi ◽  
Rafeek Thaha ◽  
Sriram Rajan ◽  
Vidur Mahajan ◽  
Vasantha Kumar Venugopal ◽  
...  
Keyword(s):  
Finite Element ◽  
Soft Tissue ◽  
Knee Joint ◽  
Material Properties ◽  
Weight Bearing ◽  
Fem Analysis ◽  
Implant Design ◽  
Tibiofemoral Joint ◽  
Specific Stiffness ◽  
Subject Specific

Abstract Background Appropriate structural and material properties are essential for finite-element-modeling (FEM). In knee FEM, structural information could extract through 3D-imaging, but the individual subject’s tissue material properties are inaccessible. Purpose The current study's purpose was to develop a methodology to estimate the subject-specific stiffness of the tibiofemoral joint using finite-element-analysis (FEA) and MRI data of knee joint with and without load. Methods In this study, six Magnetic Resonance Imaging (MRI) datasets were acquired from 3 healthy volunteers with axially loaded and unloaded knee joint. The strain was computed from the tibiofemoral bone gap difference (ΔmBGFT) using the knee MR images with and without load. The knee FEM study was conducted using a subject-specific knee joint 3D-model and various soft-tissue stiffness values (1 to 50 MPa) to develop subject-specific stiffness versus strain models. Results Less than 1.02% absolute convergence error was observed during the simulation. Subject-specific combined stiffness of weight-bearing tibiofemoral soft-tissue was estimated with mean values as 2.40 ± 0.17 MPa. Intra-subject variability has been observed during the repeat scan in 3 subjects as 0.27, 0.12, and 0.15 MPa, respectively. All subject-specific stiffness-strain relationship data was fitted well with power function (R2 = 0.997). Conclusion The current study proposed a generalized mathematical model and a methodology to estimate subject-specific stiffness of the tibiofemoral joint for FEM analysis. Such a method might enhance the efficacy of FEM in implant design optimization and biomechanics for subject-specific studies. Trial registration The institutional ethics committee (IEC), Indian Institute of Technology, Delhi, India, approved the study on 20th September 2017, with reference number P-019; it was a pilot study, no clinical trail registration was recommended.

The Effect of Varying the Density-Modulus Relationship Used to Apply Material Properties in a Finite Element Model of the Distal Ulna

2008 ◽  
Author(s):  
Rebecca L. Austman ◽  
Jaques S. Milner ◽  
David W. Holdsworth ◽  
Cynthia A. Dunning
Keyword(s):  
Computed Tomography ◽  
Finite Element ◽  
Material Properties ◽  
Cost Effective ◽  
Element Model ◽  
Implant Design ◽  
Timely Manner ◽  
Distal Ulna ◽  
Subject Specific

In many areas of orthopaedic biomechanics, such as implant design, properly developed Finite Element (FE) models can be a great companion to in-vitro studies, as they may allow a wider range of experimental variables to be explored in a cost-effective and timely manner. One challenge in developing these models is the assignment of accurate material properties to bone. Through the use of computed tomography (CT), many recent studies have developed subject-specific FE models, where material properties of bone are assigned based on density information derived from the scans. This involves the use of an equation to relate density and elastic modulus. There are several such relationships from which to choose in the literature. Most FE studies tend to use one of these multiple equations without justification or investigation into its appropriateness for the model.

scholarly journals Experimental & FEM Analysis of Orthodontic Mini-Implant Design on Primary Stability

2021 ◽  
Vol 11 (12) ◽  
pp. 5461
Author(s):  
Elmedin Mešić ◽  
Enis Muratović ◽  
Lejla Redžepagić-Vražalica ◽  
Nedim Pervan ◽  
Adis J. Muminović ◽  
...  
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Primary Stability ◽  
Fem Analysis ◽  
Implant Design ◽  
Special Focus ◽  
Engineering System ◽  
Mini Implants ◽  
Pull Out ◽  
Computer Aided

The main objective of this research is to establish a connection between orthodontic mini-implant design, pull-out force and primary stability by comparing two commercial mini-implants or temporary anchorage devices, Tomas®-pin and Perfect Anchor. Mini-implant geometric analysis and quantification of bone characteristics are performed, whereupon experimental in vitro pull-out test is conducted. With the use of the CATIA (Computer Aided Three-dimensional Interactive Application) CAD (Computer Aided Design)/CAM (Computer Aided Manufacturing)/CAE (Computer Aided Engineering) system, 3D (Three-dimensional) geometric models of mini-implants and bone segments are created. Afterwards, those same models are imported into Abaqus software, where finite element models are generated with a special focus on material properties, boundary conditions and interactions. FEM (Finite Element Method) analysis is used to simulate the pull-out test. Then, the results of the structural analysis are compared with the experimental results. The FEM analysis results contain information about maximum stresses on implant–bone system caused due to the pull-out force. It is determined that the core diameter of a screw thread and conicity are the main factors of the mini-implant design that have a direct impact on primary stability. Additionally, stresses generated on the Tomas®-pin model are lower than stresses on Perfect Anchor, even though Tomas®-pin endures greater pull-out forces, the implant system with implemented Tomas®-pin still represents a more stressed system due to the uniform distribution of stresses with bigger values.

A Determination of Material Properties of Flexible Structures Using EMA and FEM Analysis

2014 ◽  
Vol 693 ◽  
pp. 293-298 ◽  
Author(s):  
Rastislav Duris
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
Low Cost ◽  
Flexible Structures ◽  
Fem Analysis ◽  
Element Analysis ◽  
Structural Dynamic ◽  
Vibration Data ◽  
Complex Interactions ◽  
Applied Forces

Dynamic behavior of mechanical structures results from complex interactions between applied forces and the stiffness properties of the structure. Currently, many problems of structural dynamic analysis are solved using Finite Element Method (FEM). However, in recent years, the implementation of the Fast Fourier Transform (FFT) in low cost computer-based signal analyzers has provided a powerful tool for acquisition and analysis of vibration data. This article discusses combination of two approaches to structural dynamics testing; the experimental part which is referred to as Experimental Modal Analysis (EMA), respectively the analytical part, which is realized by Finite Element Analysis (FEA). Main goal of the paper is calculation of material properties from experimentally determined modal frequencies.

scholarly journals Effect of Cavity Design on the Strength of Direct Posterior Composite Restorations: An Empirical and FEM Analysis

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
V. Susila Anand ◽  
C. Kavitha ◽  
C. V. Subbarao
Keyword(s):  
Finite Element ◽  
Stainless Steel ◽  
Compressive Strength ◽  
Material Properties ◽  
Null Hypothesis ◽  
Fem Analysis ◽  
Empirical Testing ◽  
Composite Restorations ◽  
Concave Shape ◽  
Cavity Design

The aim of the present study was to verify the hypothesis that cavity design does not affect the strength of direct composite restorations as do material properties. Finite element modeling (FEM) and empirical testing were done for two cavity designs: a box shape (cube) and a concave shape (U). Two microhybrid composites were used to prepare the samples with the help of split stainless steel moulds. Compressive strength was tested. The results were statistically analyzed. Both FEA and empirical testing were complementary to each other in that the concave shape showed a significantly higher strength than box. Material properties affected the values only when box shape was used. The null hypothesis is thus rejected, and it is concluded that design significantly affects the strength of direct composite restorations.

Using Force and Kinematic Driven Finite Element Models to Analyze Contact Pressure Distributions on the Tibial Plateau

2007 ◽  
Author(s):  
Kristen R. Hovinga ◽  
Jiang Yao ◽  
Amy L. Lerner
Keyword(s):  
Finite Element ◽  
Articular Cartilage ◽  
Soft Tissue ◽  
Mr Imaging ◽  
Load Distribution ◽  
Tibial Plateau ◽  
Fe Analysis ◽  
Implant Design ◽  
Finite Element Models ◽  
Pressure Distributions

Finite element (FE) models have become an effective tool in studying soft tissue behavior in the knee joint, including meniscal translation and deformation, as well as articular cartilage contact [1–2]. These models are also useful in osteoarthritis research and implant design [3–4]. Our group has previously used a kinematic-driven FE analysis to study the effect of weightbearing on the load distribution of tibio-menisco-femoral contact using MR imaging [5].

The Role of Implant Design and Soft Tissue Structures on CCK Knee Joint Stability

2010 ◽  
Vol 25 (3) ◽  
pp. e80
Author(s):  
Aamer Malik ◽  
Xiaonan Wang ◽  
Douglas E. Padgett ◽  
Timothy M. Wright
Keyword(s):  
Soft Tissue ◽  
Knee Joint ◽  
Implant Design ◽  
Joint Stability ◽  
Tissue Structures

scholarly journals Evaluating the effects of material properties of artificial meniscal implant in the human knee joint using finite element analysis

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Duraisamy Shriram ◽  
Gideon Praveen Kumar ◽  
Fangsen Cui ◽  
Yee Han Dave Lee ◽  
Karupppasamy Subburaj
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Knee Joint ◽  
Material Properties ◽  
Element Analysis ◽  
Human Knee ◽  
Human Knee Joint

scholarly journals Development of a Lower Limb Finite Element Musculoskeletal Gait Simulation Framework Driven Solely by Inertial Measurement Unit Sensors

Biomechanics ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 293-306
Author(s):  
Sentong Wang ◽  
Kazunori Hase ◽  
Susumu Ota
Keyword(s):  
Finite Element ◽  
Knee Joint ◽  
Contact Mechanics ◽  
Lower Limb ◽  
Inertial Measurement Unit ◽  
Measurement Unit ◽  
Muscle Forces ◽  
Inertial Measurement ◽  
Medial Side ◽  
Subject Specific

Finite element musculoskeletal (FEMS) approaches using concurrent musculoskeletal and finite element models driven by motion data such as marker-based motion trajectory can provide insight into the interactions between the knee joint secondary kinematics, contact mechanics, and muscle forces in subject-specific biomechanical investigations. However, these data-driven FEMS systems have a major disadvantage that makes them challenging to apply in clinical environments, i.e., they require expensive and inconvenient equipment for data acquisition. In this study, we developed an FEMS model of the lower limb driven solely by inertial measurement unit sensors that include the tissue geometries of the entire knee joint, and that combine modeling of 16 muscles into a single framework. The model requires only the angular velocities and accelerations measured by the sensors as input. The target outputs (knee contact mechanics, secondary kinematics, and muscle forces) are predicted from the convergence results of iterative calculations of muscle force optimization and knee contact mechanics. To evaluate its accuracy, the model was compared with in vivo experimental data during gait. The maximum contact pressure (11.3 MPa) occurred on the medial side of the cartilage at the maximum loading response. The developed framework combines measurement convenience and accurate modeling, and shows promise for clinical applications aimed at understanding subject-specific biomechanics.

scholarly journals Tissue material properties and computational modelling of the human knee: A critical review

2017 ◽  
Author(s):  
Abby E Peters ◽  
Riaz Akhtar ◽  
Eithne J Comerford ◽  
Karl T Bates
Keyword(s):  
Systematic Review ◽  
Finite Element ◽  
Knee Joint ◽  
Mechanical Behaviour ◽  
Material Properties ◽  
Computational Modelling ◽  
Biological Tissues ◽  
Finite Element Models ◽  
Human Knee ◽  
Tissue Material

Understanding how structural and functional alterations of individual tissues impact on whole-joint function is challenging, particularly in humans where direct invasive experimentation is difficult. Finite element computational models produce quantitative predictions of the mechanical and physiological behaviour of multiple tissues simultaneously, thereby providing a means to study changes that occur through healthy ageing and disease such as osteoarthritis. As a result significant research investment has been placed in developing such models of the human knee. Previous work has highlighted that model predictions are highly sensitive to the various inputs used to build them, particularly the mathematical definition of material properties of biological tissues. The goal of this systematic review is two-fold. First, we provide a comprehensive summation and evaluation of existing material property data for human knee joint tissues, tabulating numerical values as a reference resource for future studies. Second, we review efforts to model whole-knee joint mechanical behaviour through finite element modelling with particular focus on how studies have sourced tissue material properties. The last decade has seen a renaissance in material testing fueled by development of a variety of new engineering techniques that allow the mechanical behaviour of both soft and hard tissues to be characterised at a spectrum of scales from nano- to bulk tissue level. As a result there now exists an extremely broad range of published values for human knee tissues. However, our systematic review highlights gaps and ambiguities that mean quantitative understanding of how tissue material properties alter with age and osteoarthritis is limited. It is therefore currently challenging to construct finite element models of the knee that are truly representative of a specific age or disease-state. Consequently, recent whole-joint finite element models have been highly generic in terms of material properties even relying on non-human data from multiple species. We highlight this by critically evaluating current ability to quantitatively compare and model 1) young and old and 2) healthy and osteoarthritis human knee joints. We suggest that future research into both healthy and diseased knee function will benefit greatly from a subject- or cohort-specific approach in which finite element models are constructed using material properties, medical imagery and loading data from cohorts with consistent demographics and/or disease states.

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