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Braesch-Andersen A, Wu D, Ferguson SJ, Persson C, Isaksson P. Application of phase-field fracture theories and digital volume correlation to synchrotron X-ray monitored fractures in human trabecular bone: A case study. J Mech Behav Biomed Mater 2022; 135:105446. [PMID: 36154992 DOI: 10.1016/j.jmbbm.2022.105446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 08/10/2022] [Accepted: 09/01/2022] [Indexed: 11/25/2022]
Abstract
Fracture processes of trabecular bone have been studied using various approaches over the years. However, reliable methods to analyse fracture at the single trabecula level are limited. In this study, a digital volume correlation (DVC) and a phase-field fracture model are applied and contrasted for human trabecular bone to analyse its failure under global compression at high resolution. A human trabecular bone sample was fractured in situ under synchrotron-based X-ray micro computed tomography (CT). Reconstructed CT data was then used in DVC algorithms to obtain high-resolution displacement fields in the bone at different load steps. A high-resolution specimen-specific structural mesh was discretized from the CT data and used for the phase-field simulation of the fracturing bone. The DVC analysis showed opening mode cracks as well as shear mode cracks. Strains in cracked regions were analysed. The load distribution in the trabecular structure resulted in two completely separated fracture regions in the sample body. A phenomenon that was also captured in the phase-field model. The results encourage us to believe improvements in boundary conditions and material models are worthwhile pursuing. Findings in this study support further development of a phase-field method to analyse fracture in samples with complex morphology, such as trabecular bone, and the capacity of DVC to quantify strains and slowly growing stable fractures during step-wise loading of trabecular bone.
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Affiliation(s)
| | - Dan Wu
- Department of Materials Science and Engineering, Uppsala University, Sweden
| | | | - Cecilia Persson
- Department of Materials Science and Engineering, Uppsala University, Sweden
| | - Per Isaksson
- Department of Materials Science and Engineering, Uppsala University, Sweden.
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2
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Purcell P, McEvoy F, Tiernan S, Sweeney D, Morris S. A combined experimental and computational study of mechanical properties after balloon kyphoplasty. Proc Inst Mech Eng H 2021; 235:897-906. [PMID: 33928812 DOI: 10.1177/09544119211013927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Vertebral compression fractures rank among the most frequent injuries to the musculoskeletal system, with more than 1 million fractures per annum worldwide. The past decade has seen a considerable increase in the utilisation of surgical procedures such as balloon kyphoplasty to treat these injuries. While many kyphoplasty studies have examined the risk of damage to adjacent vertebra after treatment, recent case reports have also emerged to indicate the potential for the treated vertebra itself to re-collapse after surgery. The following study presents a combined experimental and computational study of balloon kyphoplasty which aims to establish a methodology capable of evaluating these cases of vertebral re-collapse. Results from both the experimental tests and computational models showed significant increases in strength and stiffness after treatment, by factors ranging from 1.44 to 1.93, respectively. Fatigue tests on treated specimens showed a 37% drop in the rate of stiffness loss compared to the untreated baseline case. Further analysis of the computational models concluded that inhibited PMMA interdigitation at the interface during kyphoplasty could reverse improvements in strength and stiffness that could otherwise be gained by the treatment.
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Affiliation(s)
- Philip Purcell
- Bioengineering Technology Centre, Technological University Dublin, Dublin, Ireland.,CADFEM Ireland, Dublin, Ireland.,Dundalk Institute of Technology, Dundalk, Co. Louth, Ireland
| | - Fiona McEvoy
- Bioengineering Technology Centre, Technological University Dublin, Dublin, Ireland
| | - Stephen Tiernan
- Bioengineering Technology Centre, Technological University Dublin, Dublin, Ireland
| | | | - Seamus Morris
- Mater Misericordiae University Hospital, National Spinal Injuries Unit, Dublin, Ireland
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Purcell P, Tyndyk M, McEvoy F, Tiernan S, Sweeney D, Morris S. A Multiscale Finite Element Analysis of Balloon Kyphoplasty to Investigate the Risk of Bone-Cement Separation In Vivo. Int J Spine Surg 2021; 15:302-314. [PMID: 33900988 DOI: 10.14444/8040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND During the past decade there has been a significant increase in the number of vertebral fractures being treated with the balloon kyphoplasty procedure. Although previous investigations have found kyphoplasty to be an effective treatment for reducing patient pain and lowering cement-leakage risk, there have been reports of vertebral recollapse following the procedure. These reports have indicated evidence of in vivo bone-cement separation leading to collapse of the treated vertebra. METHODS The following study documents a multiscale analysis capable of evaluating the risk of bone-cement interface separation during lying, standing, and walking activities following balloon kyphoplasty. RESULTS Results from the analysis found that instances of reduced cement interlock could initiate both tensile and shear separation of the interface region at up to 7 times the failure threshold during walking or up to 1.9 times the threshold during some cases for standing. Lying prone offered the best protection from interface failure in all cases, with a minimum safety factor of 2.95. CONCLUSIONS The results of the multiscale analysis show it is essential for kyphoplasty simulations to take account of the micromechanical behavior of the bone-cement interface to be truly representative of the in vivo situation after the treatment. The results further illustrate the importance of ensuring adequate cement infiltration into the compacted bone periphery during kyphoplasty through a combination of new techniques, tools, and biomaterials in a multifaceted approach to solve this complex challenge.
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Affiliation(s)
- Philip Purcell
- Bioengineering Technology Centre, Technological University Dublin, Tallaght Campus, Dublin, Ireland.,CADFEM Ireland, The Steelworks, Dublin, Ireland.,Department of Electronic and Mechanical Engineering, Dundalk Institute of Technology, Dundalk, Ireland
| | | | - Fiona McEvoy
- Bioengineering Technology Centre, Technological University Dublin, Tallaght Campus, Dublin, Ireland
| | - Stephen Tiernan
- Bioengineering Technology Centre, Technological University Dublin, Tallaght Campus, Dublin, Ireland
| | | | - Seamus Morris
- Mater Misericordiae University Hospital, National Spinal Injuries Unit, Ireland
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4
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Lin X, Zhao J, Gao L, Zhang C, Gao H. Ratcheting-fatigue behavior of trabecular bone under cyclic tensile-compressive loading. J Mech Behav Biomed Mater 2020; 112:104003. [PMID: 32823002 DOI: 10.1016/j.jmbbm.2020.104003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 07/12/2020] [Accepted: 07/20/2020] [Indexed: 10/23/2022]
Abstract
This study aims to investigate the ratcheting-fatigue behaviors of trabecular bone under cyclic tension-compression, which are produced due to the accumulations of residual strain in trabecular bone. Simultaneously, the effects of different loading conditions on ratcheting behaviors of trabecular bone were probed. It is found that the gap between ratcheting strains under three stress amplitudes will gradually widen. As the stress amplitude increases, the ratcheting strain also increases. Mean stress has a significant effect on the ratcheting strain. When the mean stress is 0 MPa and 0.155 MPa, the ratcheting strain increases with the number of cycles. However, when the mean stress is -0.155 MPa, the ratcheting strain decreases as the cycle goes on. The existence of double stress peak holding time causes the creep deformation of trabecular bone, which leads to the increase of ratcheting strain. It is also noted that the ratcheting strain is greatly increased with prolongation of stress peak holding time. The digital image correlation (DIC) technique was applied to analyze the fatigue failure of trabecular bone under cyclic tension-compression. It is found that the increase of stress amplitude accelerates the damage of sample and further reduces its fatigue life. Cracks are observed in trabecular bone sample, and it is noted that the crack propagation is rapid during cyclic loading.
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Affiliation(s)
- Xianglong Lin
- Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control, School of Mechanical Engineering, Tianjin University of Technology, Tianjin, 300384, PR China; National Demonstration Center for Experimental Mechanical and Electrical Engineering Education, Tianjin University of Technology, Tianjin, 300384, PR China
| | - Jie Zhao
- Institute of Coal Chemistry, Chinese Academy of Science, Taiyuan, 030001, PR China
| | - Lilan Gao
- Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control, School of Mechanical Engineering, Tianjin University of Technology, Tianjin, 300384, PR China; National Demonstration Center for Experimental Mechanical and Electrical Engineering Education, Tianjin University of Technology, Tianjin, 300384, PR China.
| | - Chunqiu Zhang
- Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control, School of Mechanical Engineering, Tianjin University of Technology, Tianjin, 300384, PR China; National Demonstration Center for Experimental Mechanical and Electrical Engineering Education, Tianjin University of Technology, Tianjin, 300384, PR China
| | - Hong Gao
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
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Mouss ME, Zellagui S, Nasraoui M, Hambli R. Parametric investigation of the effects of load level on fatigue crack growth in trabecular bone based on artificial neural network computation. Proc Inst Mech Eng H 2020; 234:784-793. [DOI: 10.1177/0954411920924509] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study reports the development of an artificial neural network computation model to predict the accumulation of crack density and crack length in cancellous bone under a cyclic load. The model was then applied to conduct a parametric investigation into the effects of load level on fatigue crack accumulation in cancellous bone. The method was built in three steps: (1) conducting finite element simulations to predict fatigue growth of different three-dimensional micro-computed tomography cancellous bone specimens considering input combinations based on a factorial experimental design; (2) performing a training stage of an artificial neural network based on the results of step 1; and (3) applying the trained artificial neural network to rapidly predict the crack density and the crack length growth for cancellous bone under a cyclic loading for a given applied apparent strain, cycle frequency, bone volume fraction, bone density and apparent elastic modulus.
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Affiliation(s)
- Marouane El Mouss
- University of Orléans, University of Tours, INSA CVL, LaMé, Orléans, France
| | - Said Zellagui
- University of Orléans, University of Tours, INSA CVL, LaMé, Orléans, France
| | - Makrem Nasraoui
- University of Orléans, University of Tours, INSA CVL, LaMé, Orléans, France
| | - Ridha Hambli
- University of Orléans, University of Tours, INSA CVL, LaMé, Orléans, France
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6
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Abstract
The mechanical properties of bone are fundamental to the ability of our skeletons to support movement and to provide protection to our vital organs. As such, deterioration in mechanical behavior with aging and/or diseases such as osteoporosis and diabetes can have profound consequences for individuals' quality of life. This article reviews current knowledge of the basic mechanical behavior of bone at length scales ranging from hundreds of nanometers to tens of centimeters. We present the basic tenets of bone mechanics and connect them to some of the arcs of research that have brought the field to recent advances. We also discuss cortical bone, trabecular bone, and whole bones, as well as multiple aspects of material behavior, including elasticity, yield, fracture, fatigue, and damage. We describe the roles of bone quantity (e.g., density, porosity) and bone quality (e.g., cross-linking, protein composition), along with several avenues of future research.
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Affiliation(s)
- Elise F Morgan
- Orthopaedic and Developmental Biomechanics Laboratory, Department of Mechanical Engineering, Boston University, Boston, Massachusetts 02215, USA;
| | - Ginu U Unnikrisnan
- Orthopaedic and Developmental Biomechanics Laboratory, Department of Mechanical Engineering, Boston University, Boston, Massachusetts 02215, USA;
| | - Amira I Hussein
- Orthopaedic and Developmental Biomechanics Laboratory, Department of Mechanical Engineering, Boston University, Boston, Massachusetts 02215, USA;
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7
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Purcell P, Tiernan S, McEvoy F, Morris S. Strong similarities in the creep and damage behaviour of a synthetic bone model compared to human trabecular bone under compressive cyclic loading. J Mech Behav Biomed Mater 2015; 48:51-59. [DOI: 10.1016/j.jmbbm.2015.03.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 03/20/2015] [Accepted: 03/21/2015] [Indexed: 11/27/2022]
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8
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Hambli R, Frikha S, Toumi H, Tavares JMRS. Finite element prediction of fatigue damage growth in cancellous bone. Comput Methods Biomech Biomed Engin 2015; 19:563-70. [DOI: 10.1080/10255842.2015.1048687] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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9
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Uniaxial and Multiaxial Fatigue Life Prediction of the Trabecular Bone Based on Physiological Loading: A Comparative Study. Ann Biomed Eng 2015; 43:2487-502. [DOI: 10.1007/s10439-015-1305-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 03/19/2015] [Indexed: 11/26/2022]
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10
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Oftadeh R, Perez-Viloria M, Villa-Camacho JC, Vaziri A, Nazarian A. Biomechanics and mechanobiology of trabecular bone: a review. J Biomech Eng 2015; 137:1944602. [PMID: 25412137 PMCID: PMC5101038 DOI: 10.1115/1.4029176] [Citation(s) in RCA: 222] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 11/17/2014] [Accepted: 11/20/2014] [Indexed: 12/29/2022]
Abstract
Trabecular bone is a highly porous, heterogeneous, and anisotropic material which can be found at the epiphyses of long bones and in the vertebral bodies. Studying the mechanical properties of trabecular bone is important, since trabecular bone is the main load bearing bone in vertebral bodies and also transfers the load from joints to the compact bone of the cortex of long bones. This review article highlights the high dependency of the mechanical properties of trabecular bone on species, age, anatomic site, loading direction, and size of the sample under consideration. In recent years, high resolution micro finite element methods have been extensively used to specifically address the mechanical properties of the trabecular bone and provide unique tools to interpret and model the mechanical testing experiments. The aims of the current work are to first review the mechanobiology of trabecular bone and then present classical and new approaches for modeling and analyzing the trabecular bone microstructure and macrostructure and corresponding mechanical properties such as elastic properties and strength.
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Affiliation(s)
- Ramin Oftadeh
- Center for Advanced Orthopaedic Studies,
Department of Orthopaedic Surgery,
Beth Israel Deaconess Medical Center,
Harvard Medical School,
Boston, MA 02215
- Department of Mechanical Engineering,
Northeastern University,
Boston, MA 02115
| | - Miguel Perez-Viloria
- Center for Advanced Orthopaedic Studies,
Department of Orthopaedic Surgery,
Beth Israel Deaconess Medical Center,
Harvard Medical School,
Boston, MA 02215
| | - Juan C. Villa-Camacho
- Center for Advanced Orthopaedic Studies,
Department of Orthopaedic Surgery,
Beth Israel Deaconess Medical Center,
Harvard Medical School,
Boston, MA 02215
| | - Ashkan Vaziri
- Department of Mechanical Engineering,
Northeastern University,
Boston, MA 02115
| | - Ara Nazarian
- Center for Advanced Orthopaedic Studies,
Department of Orthopaedic Surgery,
Beth Israel Deaconess Medical Center,
Harvard Medical School,
Boston, MA 02215
e-mail:
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11
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Reeve J, Loveridge N. The fragile elderly hip: mechanisms associated with age-related loss of strength and toughness. Bone 2014; 61:138-48. [PMID: 24412288 PMCID: PMC3991856 DOI: 10.1016/j.bone.2013.12.034] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 12/24/2013] [Accepted: 12/31/2013] [Indexed: 01/23/2023]
Abstract
Every hip fracture begins with a microscopic crack, which enlarges explosively over microseconds. Most hip fractures in the elderly occur on falling from standing height, usually sideways or backwards. The typically moderate level of trauma very rarely causes fracture in younger people. Here, this paradox is traced to the decline of multiple protective mechanisms at many length scales from nanometres to that of the whole femur. With normal ageing, the femoral neck asymmetrically and progressively loses bone tissue precisely where the cortex is already thinnest and is also compressed in a sideways fall. At the microscopic scale of the basic remodelling unit (BMU) that renews bone tissue, increased numbers of actively remodelling BMUs associated with the reduced mechanical loading in a typically inactive old age augments the numbers of mechanical flaws in the structure potentially capable of initiating cracking. Menopause and over-deep osteoclastic resorption are associated with incomplete BMU refilling leading to excessive porosity, cortical thinning and disconnection of trabeculae. In the femoral cortex, replacement of damaged bone or bone containing dead osteocytes is inefficient, impeding the homeostatic mechanisms that match strength to habitual mechanical usage. In consequence the participation of healthy osteocytes in crack-impeding mechanisms is impaired. Observational studies demonstrate that protective crack deflection in the elderly is reduced. At the most microscopic levels attention now centres on the role of tissue ageing, which may alter the relationship between mineral and matrix that optimises the inhibition of crack progression and on the role of osteocyte ageing and death that impedes tissue maintenance and repair. This review examines recent developments in the understanding of why the elderly hip becomes fragile. This growing understanding is suggesting novel testable approaches for reducing risk of hip fracture that might translate into control of the growing worldwide impact of hip fractures on our ageing populations.
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Affiliation(s)
- Jonathan Reeve
- NIHR Musculoskeletal Biomedical Research Unit, Institute of Musculoskeletal Science, Nuffield Orthopaedic Centre, Oxford OX3 7HE, UK.
| | - Nigel Loveridge
- Orthopaedic Research Unit, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK; MRC Human Nutrition Research, Cambridge, UK.
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12
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Kosmopoulos V, Nana AD. Dual plating of humeral shaft fractures: orthogonal plates biomechanically outperform side-by-side plates. Clin Orthop Relat Res 2014; 472:1310-7. [PMID: 24218163 PMCID: PMC3940765 DOI: 10.1007/s11999-013-3379-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Accepted: 11/05/2013] [Indexed: 01/31/2023]
Abstract
BACKGROUND Single large-fragment plate constructs currently are the norm for internal fixation of middiaphyseal humerus fractures. In cases where humeral size is limited, however, dual small-fragment locking plate constructs may serve as an alternative. The mechanical effects of different possible plate configurations around the humeral diaphysis may be important, but to our knowledge, have yet to be investigated. QUESTIONS/PURPOSES We used finite element analysis to compare the simulated mechanical performance of five different dual small-fragment locking plate construct configurations for humeral middiaphyseal fracture fixation in terms of (1) stiffness, (2) stress shielding of bone, (3) hardware stresses, and (4) interfragmentary strain. METHODS Middiaphyseal humeral fracture fixation was simulated using the finite element method. Three 90° and two side-by-side seven-hole and nine-hole small-fragment dual locking plate configurations were tested in compression, torsion, and combined loading. The configurations chosen are based on implantation using either a posterior or anterolateral approach. RESULTS All three of the 90° configurations were more effective in restoring the intact compressive and torsional stiffness as compared with the side-by-side configurations, resulted in less stress shielding and stressed hardware, and showed interfragmentary strains between 5% to 10% in torsion and combined loading. CONCLUSIONS The nine-hole plate anterior and seven-hole plate lateral (90° apart) configuration provided the best fixation. Our findings show the mechanical importance of plate placement with relation to loading in dual-plate fracture-fixation constructs. CLINICAL RELEVANCE The results presented provide novel biomechanical information for the orthopaedic surgeon considering different treatment options for middiaphyseal humeral fractures.
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Affiliation(s)
- Victor Kosmopoulos
- Bone and Joint Research Center, Department of Orthopaedic Surgery, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard (CBH 407), Fort Worth, TX, 76107, USA,
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13
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Carretta R, Lorenzetti S, Müller R. Towards patient-specific material modeling of trabecular bone post-yield behavior. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2013; 29:250-272. [PMID: 23386574 DOI: 10.1002/cnm.2516] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Revised: 08/21/2012] [Accepted: 09/04/2012] [Indexed: 06/01/2023]
Abstract
Bone diseases such as osteoporosis are one of the main causes of bone fracture and often result in hospitalization and long recovery periods. Researchers are aiming to develop new tools that consider the multiple determinants acting at the different scales of bone, and which can be used to clinically estimate patient-specific fracture risk and also assess the efficacy of new therapies. The main step towards this goal is a deep understanding of the bone organ, and is achieved by modeling the complexity of the structure and the high variability of the mechanical outcome. This review uses a hierarchical approach to evaluate bone mechanics at the macroscale, microscale, and nanoscale levels and the interactions between scales. The first section analyzes the experimental evidence of bone mechanics in the elastic and inelastic regions, microdamage generation, and post-yield toughening mechanisms from the organ level to the ultrastructural level. On the basis of these observations, the second section provides an overview of the constitutive models available to describe bone mechanics and predict patient-specific outcomes. Overall, the role of the hierarchical structure of bone and the interplay between each level is highlighted, and their effect is evaluated in terms of modeling biological variability and patient specificity.
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14
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Hambli R, Hattab N. Application of Neural Network and Finite Element Method for Multiscale Prediction of Bone Fatigue Crack Growth in Cancellous Bone. MULTISCALE COMPUTER MODELING IN BIOMECHANICS AND BIOMEDICAL ENGINEERING 2013. [DOI: 10.1007/8415_2012_146] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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15
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Topoliński T, Cichański A, Mazurkiewicz A, Nowicki K. The relationship between trabecular bone structure modeling methods and the elastic modulus as calculated by FEM. ScientificWorldJournal 2012; 2012:827196. [PMID: 22629210 PMCID: PMC3354692 DOI: 10.1100/2012/827196] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Accepted: 01/19/2012] [Indexed: 11/17/2022] Open
Abstract
Trabecular bone cores were collected from the femoral head at the time of surgery (hip arthroplasty). Investigated were 42 specimens, from patients with osteoporosis and coxarthrosis. The cores were scanned used computer microtomography (microCT) system at an isotropic spatial resolution of 36 microns. Image stacks were converted to finite element models via a bone voxel-to-element algorithm. The apparent modulus was calculated based on the assumptions that for the elastic properties, E = 10 MPa and ν = 0.3. The compressive deformation as calculated by finite elements (FE) analysis was 0.8%. The models were coarsened to effectively change the resolution or voxel size (from 72 microns to 288 microns or from 72 microns to 1080 microns). The aim of our study is to determine how an increase in the distance between scans changes the elastic properties as calculated by FE models. We tried to find a border value voxel size at which the module values were possible to calculate. As the voxel size increased, the mean voxel volume increased and the FEA-derived apparent modulus decreased. The slope of voxel size versus modulus relationship correlated with several architectural indices of trabecular bone.
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Affiliation(s)
- Tomasz Topoliński
- Faculty of Mechanical Engineering, University of Technology and Life Sciences, Kaliskiego 7 Street, 85-789 Bydgoszcz, Poland
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16
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Failure modelling of trabecular bone using a non-linear combined damage and fracture voxel finite element approach. Biomech Model Mechanobiol 2012; 12:225-41. [DOI: 10.1007/s10237-012-0394-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2011] [Accepted: 03/30/2012] [Indexed: 11/27/2022]
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17
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Kefalas V, Eftaxiopoulos D. Experimental study of cancellous bone under large strains and a constitutive probabilistic model. J Mech Behav Biomed Mater 2012; 6:41-52. [DOI: 10.1016/j.jmbbm.2011.10.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Revised: 10/21/2011] [Accepted: 10/22/2011] [Indexed: 11/29/2022]
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18
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Coto NP, Meira JBC, Brito e Dias R, Driemeier L, de Oliveira Roveri G, Noritomi PY. Assessment of nose protector for sport activities: finite element analysis. Dent Traumatol 2011; 28:108-13. [PMID: 21790992 DOI: 10.1111/j.1600-9657.2011.01046.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
There has been a significant increase in the number of facial fractures stemming from sport activities in recent years, with the nasal bone one of the most affected structures. Researchers recommend the use of a nose protector, but there is no standardization regarding the material employed. Clinical experience has demonstrated that a combination of a flexible and rigid layer of ethylene vinyl acetate (EVA) offers both comfort and safety to practitioners of sports. The aim of the present study was the investigation into the stresses generated by the impact of a rigid body on the nasal bone on models with and without an EVA protector. For such, finite element analysis was employed. A craniofacial model was constructed from images obtained through computed tomography. The nose protector was modeled with two layers of EVA (1 mm of rigid EVA over 2 mm of flexible EVA), following the geometry of the soft tissue. Finite element analysis was performed using the LS Dyna program. The bone and rigid EVA were represented as elastic linear material, whereas the soft tissues and flexible EVA were represented as hyperelastic material. The impact from a rigid sphere on the frontal region of the face was simulated with a constant velocity of 20 m s(-1) for 9.1 μs. The model without the protector served as the control. The distribution of maximal stress of the facial bones was recorded. The maximal stress on the nasal bone surpassed the breaking limit of 0.13-0.34 MPa on the model without a protector, while remaining below this limit on the model with the protector. Thus, the nose protector made from both flexible and rigid EVA proved effective at protecting the nasal bones under high-impact conditions.
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Affiliation(s)
- Neide Pena Coto
- Faculdade de Odontologia da Universidade de São Paulo, Brazil.
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19
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Fang G, Ji B, Liu XS, Guo XE. Quantification of trabecular bone microdamage using the virtual internal bond model and the individual trabeculae segmentation technique. Comput Methods Biomech Biomed Engin 2011; 13:605-15. [PMID: 20077238 DOI: 10.1080/10255840903405660] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Trabecular bone microdamage significantly influences the skeletal integrity and bone remodelling process. In this paper a novel constitutive model, called the virtual internal bond model (VIB), was adopted for simulating the damage behaviour of bone tissue. A unique 3D image analysis technique, named individual trabeculae segmentation, was used to analyse the effects of microarchitectures on the damage behaviours of trabecular bone. We demonstrated that the process of initiation and accumulation of microdamage in trabecular bone samples can be captured by the VIB-embedded finite-element method simulation without a separate fracture criterion. Our simulation results showed that the microdamage can occur at as early as about 0.2-0.4% apparent strain, and a large volume of microdamage was accumulated around the apparent yield strain. In addition we found that the plate-like trabeculae, especially the longitudinal ones, take crucial roles in the microdamage behaviours of trabecular bone.
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Affiliation(s)
- Guanhui Fang
- Department of Engineering Mechanics, Tsinghua University, Beijing, P. R. China
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Hambli R. Apparent damage accumulation in cancellous bone using neural networks. J Mech Behav Biomed Mater 2011; 4:868-78. [PMID: 21616468 DOI: 10.1016/j.jmbbm.2011.03.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Revised: 02/09/2011] [Accepted: 03/01/2011] [Indexed: 02/02/2023]
Abstract
In this paper, a neural network model is developed to simulate the accumulation of apparent fatigue damage of 3D trabecular bone architecture at a given bone site during cyclic loading. The method is based on five steps: (i) performing suitable numerical experiments to simulate fatigue accumulation of a 3D micro-CT trabecular bone samples taken from proximal femur for different combinations of loading conditions; (ii) averaging the sample outputs in terms of apparent damage at whole specimen level based on local tissue damage; (iii) preparation of a proper set of corresponding input-output data to train the network to identify apparent damage evolution; (iv) training the neural network based on the results of step (iii); (v) application of the neural network as a tool to estimate rapidly the apparent damage evolution at a given bone site. The proposed NN model can be incorporated into finite element codes to perform fatigue damage simulation at continuum level including some morphological factors and some bone material properties. The proposed neural network based multiscale approach is the first model, to the author's knowledge, that incorporates both finite element analysis and neural network computation to rapidly simulate multilevel fatigue of bone. This is beneficial to develop enhanced finite element models to investigate the role of damage accumulation on bone damage repair during remodelling.
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21
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22
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Lee T, Garlapati RR, Lam K, Lee PVS, Chung YS, Choi JB, Vincent TBC, Das De S. Fast Tool for Evaluation of Iliac Crest Tissue Elastic Properties Using the Reduced-Basis Methods. J Biomech Eng 2010; 132:121009. [DOI: 10.1115/1.4001254] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Computationally expensive finite element (FE) methods are generally used for indirect evaluation of tissue mechanical properties of trabecular specimens, which is vital for fracture risk prediction in the elderly. This work presents the application of reduced-basis (RB) methods for rapid evaluation of simulation results. Three cylindrical transiliac crest specimens (diameter: 7.5 mm, length: 10–12 mm) were obtained from healthy subjects (20 year-old, 22 year-old, and 24 year-old females) and scanned using microcomputed tomography imaging. Cubic samples of dimensions 5×5×5 mm3 were extracted from the core of the cylindrical specimens for FE analysis. Subsequently, a FE solution library (test space) was constructed for each of the specimens by varying the material property parameters: tissue elastic modulus and Poisson’s ratio, to develop RB algorithms. The computational speed gain obtained by the RB methods and their accuracy relative to the FE analysis were evaluated. Speed gains greater than 4000 times, were obtained for all three specimens for a loss in accuracy of less than 1% in the maxima of von-Mises stress with respect to the FE-based value. The computational time decreased from more than 6 h to less than 18 s. RB algorithms can be successfully utilized for real-time reliable evaluation of trabecular bone elastic properties.
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Affiliation(s)
- Taeyong Lee
- Division of Bioengineering, National University of Singapore, Block E1, No. 08-03, 9 Engineering Drive 1, 117576, Singapore
| | - Revanth Reddy Garlapati
- Division of Bioengineering, National University of Singapore, Block E3A, No. 07-15, 7 Engineering Drive 1, 117574, Singapore
| | - Kathy Lam
- Division of Bioengineering, National University of Singapore, Block E3A, No. 07-15, 7 Engineering Drive 1, 117574, Singapore
| | - Peter Vee Sin Lee
- Department of Mechanical Engineering, Melbourne School of Engineering, University of Melbourne, 3010, Australia
| | - Yoon-Sok Chung
- Department of Endocrinology and Metabolism, School of Medicine, Ajou University, Suwon 443-749, Korea
| | - Jae Bong Choi
- Department of Mechanical Systems Engineering, Hansung University, 389 samsoon-dong 2-ga, Seongbuk-gu, Seoul, Korea
| | - Tan Beng Chye Vincent
- Department of Mechanical Engineering, Faculty of Engineering, National University of Singapore, 117576, Singapore
| | - Shamal Das De
- Department of Orthopaedic Surgery, Yong Loo Lin School of Medicine, National University Hospital, 119074, Singapore
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Shi X, Liu XS, Wang X, Guo XE, Niebur GL. Type and orientation of yielded trabeculae during overloading of trabecular bone along orthogonal directions. J Biomech 2010; 43:2460-6. [PMID: 20554282 DOI: 10.1016/j.jbiomech.2010.05.032] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Revised: 05/19/2010] [Accepted: 05/26/2010] [Indexed: 11/28/2022]
Abstract
Trabecular architecture plays a major role in bone mechanics. Osteoporosis leads to a transition from a plate-like to a more rod-like trabecular morphology, which may contribute to fracture risk beyond that predicted by changes in density. In this study, microstructural finite element analysis results were analyzed using individual trabeculae segmentation (ITS) to identify the type and orientation of trabeculae where tissue yielded during compressive overloads in two orthogonal directions. For both apparent loading conditions, most of the yielded tissue was found in longitudinally oriented plates. However, the primary loading mode of yielded trabeculae was axial compression with superposed bending for on-axis loading in contrast to bending for transverse loading. For either loading direction, most plate-like trabeculae yielded in the same loading mode, regardless of their orientation. In contrast, rods oriented parallel to the loading axis yielded in compression, while rods oblique or perpendicular to the loading axis yielded in combined bending and tension. The predominance of tissue yielding in plates during both on-axis and transverse overloading explains why on-axis overloading is detrimental to the off-axis mechanical properties. At the same time, a large fraction of the tissue in rod-like trabeculae parallel to the loading direction yielded in both on-axis and transverse loading. Hence, rods may be more likely to be damaged and potentially resorbed by damage mediated remodeling.
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Affiliation(s)
- Xiutao Shi
- Tissue Mechanics Laboratory, Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, IN 46556, USA
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Christen D, Webster DJ, Müller R. Multiscale modelling and nonlinear finite element analysis as clinical tools for the assessment of fracture risk. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2010; 368:2653-2668. [PMID: 20439267 DOI: 10.1098/rsta.2010.0041] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The risk of osteoporotic fractures is currently estimated based on an assessment of bone mass as measured by dual-energy X-ray absorptiometry. However, patient-specific finite element (FE) simulations that include information from multiple scales have the potential to allow more accurate prognosis. In the past, FE models of bone were limited either in resolution or to the linearization of the mechanical behaviour. Now, nonlinear, high-resolution simulations including the bone microstructure have been made possible by recent advances in simulation methods, computer infrastructure and imaging, allowing the implementation of multiscale modelling schemes. For example, the mechanical loads generated in the musculoskeletal system define the boundary conditions for organ-level, continuum-based FE models, whose nonlinear material properties are derived from microstructural information. Similarly microstructure models include tissue-level information such as the dynamic behaviour of collagen by modifying the model's constitutive law. This multiscale approach to modelling the mechanics of bone allows a more accurate characterization of bone fracture behaviour. Furthermore, such models could also include the effects of ageing, osteoporosis and drug treatment. Here we present the current state of the art for multiscale modelling and assess its potential to better predict an individual's risk of fracture in a clinical setting.
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Affiliation(s)
- David Christen
- Institute for Biomechanics, ETH Zürich, , Wolfgang-Pauli-Strasse 10, 8093 Zürich, Switzerland
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25
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Kadir MRA, Syahrom A, Öchsner A. Finite element analysis of idealised unit cell cancellous structure based on morphological indices of cancellous bone. Med Biol Eng Comput 2010; 48:497-505. [DOI: 10.1007/s11517-010-0593-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Accepted: 02/24/2010] [Indexed: 12/31/2022]
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26
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Gourion-Arsiquaud S, Allen MR, Burr DB, Vashishth D, Tang SY, Boskey AL. Bisphosphonate treatment modifies canine bone mineral and matrix properties and their heterogeneity. Bone 2010; 46:666-72. [PMID: 19925895 PMCID: PMC2823979 DOI: 10.1016/j.bone.2009.11.011] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Revised: 11/09/2009] [Accepted: 11/10/2009] [Indexed: 01/22/2023]
Abstract
Bone loss and alterations in bone quality are major causes leading to bone fragility in postmenopausal women. Although bisphosphonates are well known to reduce bone turnover and prevent bone loss in postmenopausal osteoporosis, their effects on other bone properties are not fully characterized. Changes in bone mineral and matrix properties may contribute to the anti-fracture efficacy observed with bisphosphonate treatments. The aim of this work was to analyze the effect of a 1-year treatment with either alendronate or risedronate, at low and high doses, on spatially resolved bone material and compositional properties that could contribute to the fracture efficacy of these agents. Distal tibias from 30 normal beagles that had been treated daily for 1 year with oral doses of vehicle (Veh), alendronate (Aln) at 0.2 or 1 mg/kg, and risedronate (Ris) at 0.1 or 0.5 mg/kg were analyzed by Fourier Transform Infrared imaging (FTIRI) to assess the changes in both mineral and matrix properties in discrete bone areas. The widths at half maximum of the pixel histograms for each FTIRI parameter were used to assess the heterogeneity of the bone tissue. Aln and Ris increased the mineral content and the collagen maturity mainly in cancellous bone and at the endocortical surface. Significant differences were observed in the mineral content and in the hydroxyapatite crystallinity distribution in bone tissue, which can contribute to reduced ductility and micro-crack accumulation. No significant differences were observed between low and high dose nor between Aln and Ris treatments. These results show that pharmacologic suppression of bone turnover increases the mineral and matrix bone tissue maturity in normal cancellous and endocortical bone areas where bone turnover is higher. These positive effects for decreased fracture risk are also associated with a loss of bone heterogeneity that could be one factor contributing to increased bone tissue brittleness and micro-crack accumulation.
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27
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Harrison NM, McHugh PE. Comparison of trabecular bone behavior in core and whole bone samples using high-resolution modeling of a vertebral body. Biomech Model Mechanobiol 2010; 9:469-80. [PMID: 20066462 DOI: 10.1007/s10237-009-0188-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2008] [Accepted: 12/23/2009] [Indexed: 11/26/2022]
Abstract
Computational analysis of trabecular bone normally involves the modeling of (experimental tests of) cored samples. However, the lack of constraint on the sides of the extracted trabecular bone samples limits the information that can be inferred regarding true in situ behavior. Here, the element-by-element voxel-based finite element method was applied via, a custom-written software suite (FEEBE), to a 72 microm resolution model of an ovine vertebra. The difference between the apparent modulus of eight concentric core cylinders when modeled as part of the whole bone (containing 84 x 10(6) degrees of freedom) and independent of the whole bone was investigated. The results showed that cored trabecular bone apparent modulus depended significantly on the core diameter when modeled as an extracted core (r (2) = 0.975) and as part of a whole bone (r (2) = 0.986). The cause of this result was separated into the side-artifact effect and bone volume fraction (BV/TV) effect. For the independently modeled cores, the apparent modulus of an inner core region of interest varied with increasing thickness of the outer annulus. This was attributed to the side-artifact effect, given that the BV/TV of the core region was constant. Within the whole trabecular structure, the side artifact was eliminated as the entire bone structure was modeled. However, a BV/TV effect influenced the apparent modulus depending on the size of the core selected for determining apparent modulus. Changing the size of the core varied the overall BV/TV of the core, and this significantly (r (2) = 0.999) influences the apparent modulus. Therefore, determining a 'true' apparent modulus for trabecular bone was not achievable. The independently modeled cores consistently under-predict the in vivo apparent modulus. It is recommended that if a 'true' apparent modulus is required, the BV/TV at which it is required needs to be first determined. Apparent modeling of entire bones at microscale resolution allowed regions of low and high tissue strains to be identified, consistent with patterns of trabecular bone remodeling and resorption reported in literature. The basivertebral vein cavity underwent the highest strains within the entire vertebral body, suggesting that failure might initiate here, despite containing visibly thicker struts and plate trabeculae. Although computationally expensive, analysis of the entire vertebral body provided a full picture of in situ trabecular bone deformation.
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Affiliation(s)
- Noel M Harrison
- National Centre for Biomedical Engineering Science, National University of Ireland, Galway, Ireland.
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28
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Computational biomechanics of articular cartilage of human knee joint: Effect of osteochondral defects. J Biomech 2009; 42:2458-65. [DOI: 10.1016/j.jbiomech.2009.07.022] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Revised: 07/08/2009] [Accepted: 07/15/2009] [Indexed: 11/24/2022]
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29
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Kosmopoulos V, Keller TS, Schizas C. Early stage disc degeneration does not have an appreciable affect on stiffness and load transfer following vertebroplasty and kyphoplasty. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2008; 18:59-68. [PMID: 19034533 DOI: 10.1007/s00586-008-0828-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2008] [Revised: 10/31/2008] [Accepted: 11/03/2008] [Indexed: 12/30/2022]
Abstract
Vertebroplasty and kyphoplasty have been reported to alter the mechanical behavior of the treated and adjacent-level segments, and have been suggested to increase the risk for adjacent-level fractures. The intervertebral disc (IVD) plays an important role in the mechanical behavior of vertebral motion segments. Comparisons between normal and degenerative IVD motion segments following cement augmentation have yet to be reported. A microstructural finite element model of a degenerative IVD motion segment was constructed from micro-CT images. Microdamage within the vertebral body trabecular structure was used to simulate a slightly (I = 83.5% of intact stiffness), moderately (II = 57.8% of intact stiffness), and severely (III = 16.0% of intact stiffness) damaged motion segment. Six variable geometry single-segment cement repair strategies (models A-F) were studied at each damage level (I-III). IVD and bone stresses, and motion segment stiffness, were compared with the intact and baseline damage models (untreated), as well as, previous findings using normal IVD models with the same repair strategies. Overall, small differences were observed in motion segment stiffness and average stresses between the degenerative and normal disc repair models. We did however observe a reduction in endplate bulge and a redistribution in the microstructural tissue level stresses across both endplates and in the treated segment following early stage IVD degeneration. The cement augmentation strategy placing bone cement along the periphery of the vertebra (model E) proved to be the most advantageous in treating the degenerative IVD models by showing larger reductions in the average bone stresses (vertebral and endplate) as compared to the normal IVD models. Furthermore, only this repair strategy, and the complete cement fill strategy (model F), were able to restore the slightly damaged (I) motion segment stiffness above pre-damaged (intact) levels. Early stage IVD degeneration does not have an appreciable effect in motion segment stiffness and average stresses in the treated and adjacent-level segments following vertebroplasty and kyphoplasty. Placing bone cement in the periphery of the damaged vertebra in a degenerative IVD motion segment, minimizes load transfer, and may reduce the likelihood of adjacent-level fractures.
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Affiliation(s)
- Victor Kosmopoulos
- Department of Orthopaedic Surgery, Bone and Joint Research Center, University of North Texas Health Science Center, Fort Worth, TX 76107, USA.
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30
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Renders GAP, Mulder L, Langenbach GEJ, van Ruijven LJ, van Eijden TMGJ. Biomechanical effect of mineral heterogeneity in trabecular bone. J Biomech 2008; 41:2793-8. [PMID: 18722619 DOI: 10.1016/j.jbiomech.2008.07.009] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Revised: 07/03/2008] [Accepted: 07/11/2008] [Indexed: 10/21/2022]
Abstract
Due to daily loading, trabecular bone is subjected to deformations (i.e., strain), which lead to stress in the bone tissue. When stress and/or strain deviate from the normal range, the remodeling process leads to adaptation of the bone architecture and its degree of mineralization to effectively withstand the sustained altered loading. As the apparent mechanical properties of bone are assumed to depend on the degree and distribution of mineralization, the goal of the present study was examine the influences of mineral heterogeneity on the biomechanical properties of trabecular bone in the human mandibular condyle. For this purpose nine right condyles from human dentate mandibles were scanned and evaluated with a microCT system. Cubic regional volumes of interest were defined, and each was transformed into two different types of finite element (FE) models, one homogeneous and one heterogeneous. In the heterogeneous models the element tissue moduli were scaled to the local degree of mineralization, which was determined using microCT. Compression and shear tests were simulated to determine the apparent elastic moduli in both model types. The incorporation of mineralization variation decreased the apparent Young's and shear moduli by maximally 21% in comparison to the homogeneous models. The heterogeneous model apparent moduli correlated significantly with bone volume fraction and degree of mineralization. It was concluded that disregarding mineral heterogeneity may lead to considerable overestimation of apparent elastic moduli in FE models.
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Affiliation(s)
- G A P Renders
- Department of Functional Anatomy, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Tafelbergweg 51, 1105 BD Amsterdam, the Netherlands.
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