Dissertations / Theses on the topic 'Biomechanics of articular cartilage'
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1
Gratz, Kenneth R. "Biomechanics of articular cartilage defects." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2007. http://wwwlib.umi.com/cr/ucsd/fullcit?p3284116.
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Thesis (Ph. D.)--University of California, San Diego, 2007.Title from first page of PDF file (viewed January 9, 2008). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
2
Olsen, Sigb. "Modelling of articular cartilage load-carriage biomechanics." Thesis, Queensland University of Technology, 2003.
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Kerin, Alexander James. "The mechanical failure of articular cartilage." Thesis, University of Bristol, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.265315.
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Stewart, Kevin Matthew. "MECHANICAL SIMULATION OF ARTICULAR CARTILAGE BASED ON EXPERIMENTAL RESULTS." DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/93.
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Recently, a constituent based cartilage growth finite element model (CGFEM) was developed in order to predict articular cartilage (AC) biomechanical properties before and after growth. Previous research has noted limitations in the CGFEM such as model convergence with growth periods greater than 12 days. The main aims of this work were to address these limitations through (1) implementation of an exact material Jacobian matrix definition using the Jaumann-Kirchhoff (J-K) method and (2) quantification of elastic material parameters based upon research findings of the Cal Poly Cartilage Biomechanics Group (CPGBG). The J-K method was successfully implemented into the CGFEM and exceeded the maximum convergence strains for both the “pushed forward, then differentiated” (PFD) and “differentiated, then pushed forward” (DPF) methods, while maintaining correct material stress responses. Elastic parameters were optimized for confined compression (CC), unconfined compression (UCC), and uniaxial tension (UT) protocols. This work increases the robustness of the CGFEM through the J-K method, as well as defines an accurate starting point for AC growth based on the optimized material parameters.
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Wong, Benjamin L. "Biomechanics of cartilage articulation effects of degeneration, lubrication, and focal articular defects /." Diss., [La Jolla] : University of California, San Diego, 2009. http://wwwlib.umi.com/cr/ucsd/fullcit?p3356137.
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Thesis (Ph. D.)--University of California, San Diego, 2009.Title from first page of PDF file (viewed June 15, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
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Kashani, Jamal. "An innovative agent-based cellular automata framework for simulating articular cartilage biomechanics." Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/107203/1/Jamal_Kashani_Thesis.pdf.
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Mammalian tissues and organs are complex in structure and function and can degenerate because of diseases. It is not possible to study in full their characteristics with traditional laboratory methods making it difficult to extend our knowledge of tissue function in vivo. This thesis presents a novel computational cellular automata agent and new rules of interaction that can simulate behaviours within and outside such biological components in computational simulations. The new computational methodology was applied to articular cartilage to simulate its complex porous single-phase osmosis-governed structure and characteristics. The results demonstrate that this new computational agent can be used to study other single-phase multi-component materials.
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Motavalli, Sayyed Mostafa. "DEPTH-DEPENDENT BIAXIAL MECHANICAL BEHAVIOR OF NATIVE AND TISSUE ENGINEERING ARTICULAR CARTILAGE." Case Western Reserve University School of Graduate Studies / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=case1390313405.
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Arabshahi, Zohreh. "New mechanical indentation framework for functional assessment of articular cartilage." Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/119696/1/Zohreh_Arabshahi_Thesis.pdf.
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In this research, two new mechanical indentation frameworks were established where the two different indenters (cylindrical and ring-shaped flat-ended indenters) were integrated with ultrasound for assessing functional properties of articular cartilage during loading/unloading. The aim of establishing these framewoks was to address some of the limitations to the conventional indentation techniques. Two new parameters within these frameworks were developed and their capacity to distinguish between normal and different types of cartilage degeneration models during deformation/recovery, was investigated. The ring-shaped flat-ended indenter, integrated with an ultrasound transducer, was shown to be capable of distinguishing normal from artificially degraded bovine osteochondral samples.
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Schöne, Martin. "Possibilities of Articular Cartilage Quantification Based on High-Frequency Ultrasound Scans and Ultrasound Palpation." Doctoral thesis, Humboldt-Universität zu Berlin, 2020. http://dx.doi.org/10.18452/21781.
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In der Diagnostik und Reparatur von hyalinem Gelenkknorpel sind neue Methoden zur Quantifizierung von Struktur und mechanischer Belastbarkeit gefragt, um die Behandlung von Knorpelschäden an Millionen von Patienten weltweit zu verbessern.
Mittels hochfrequentem, fokussierten Ultraschall werden Oberflächenparameter für Reflektivität und Rauheit an Gelenkknorpel bestimmt. Es wird gezeigt wie die Oberflächenneigung kontrolliert werden kann. Die Ergebnisse vermitteln ein besseres Verständnis über die Zusammensetzung der Ultraschallsignale aus reflektierten und gestreuten Komponenten.
3D Ultraschallscans von Knorpelregeneraten erlauben die Defektstellen volumetrisch zu Quantifizieren. Die Proben wurden zusätzlich nach etablierten Bewertungssystemen benotet, welche auf makroskopischer Beurteilungen, MRT-Scans und Histologie basieren. Die ultraschallbasierten Volumendaten zeigten dabei gute Korrelationen mit den Punktwertungen.
Die im Labor verwendeten Messaufbauten zur biomechanischen Charakterisierung von Gelenkknorpel können am Patienten nicht angewandt werden. Daher können Ärzte die Festigkeit von Knorpel bisher nur mittels manueller Palpation abschätzen. Diese Arbeit entwickelt eine Methode der Ultraschall-Palpation (USP), die es erlaubt, die während der manuellen Palpation erzeugte Kraft und Deformation, basierend auf Ultraschallechos, aufzunehmen. Es wurde einen Prototyp entwickelt womit gezeigt werden konnte, dass USP eine ausreichende Genauigkeit und Reproduzierbarkeit aufweist. Wiederholte Messungen können zusätzlich zeitabhängige biomechanische Parameter von Knorpel ableiten.
Zusammenfassend zeigt diese Arbeit verbesserte und neue Möglichkeiten zur strukturellen und biomechanischen Charakterisierung von hyalinem Gelenkknorpel bzw. den Ergebnissen von Knorpelreparatur basierend auf Ultraschalldaten. Diese Methoden haben das Potenzial die Diagnostik von Gelenkknorpel und die Quantifizierung von Knorpelreparatur zu verbessern.In the diagnostics and repair of hyaline articular cartilage, new methods to quantify structure and mechanical capacity are required to improve the treatment of cartilage defects for millions of patients worldwide. This thesis uses high frequency focused ultrasound to derive surface parameters for reflectivity and roughness from articular cartilage. It is shown how to control the inclination dependency to gain more reliable results. Furthermore, the results provided a better understanding of the composition of ultrasonic signals from reflected and scattered components. 3D ultrasound scans of cartilage repair tissue were performed to quantify defect sites after cartilage repair volumetrically. The samples were also graded according to established scoring systems based on macroscopic evaluation, MRI scans and histology. The ultrasound-based volumetric parameters showed good correlation with these scores. Complex biomechanical measurement setups used in laboratories cannot be applied to the patient. Therefore, currently physicians have to estimate the stiffness of cartilage by means of manual palpation. In the last part of this thesis, a method denoted as ultrasound palpation is developed, which allows for measuring the applied force and strain during manual palpation in real time, solely based on the evaluation of the time of flight of ultrasound pulses. A prototype was developed and its measurement accuracy and reproducibility were characterized. It could be shown that ultrasound palpation has sufficient accuracy and reproducibility. Additionally, by repeated measurements it was possible to derive time-dependent biomechanical parameters of cartilage. In summary, this work shows improved and new possibilities for structural and biomechanical characterization of hyaline articular cartilage and the outcomes of cartilage repair based on ultrasound data. The methods have the potential to improve the diagnostics of articular cartilage and quantification of its repair.
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Mouw, Janna Kay. "Mechanoregulation of chondrocytes and chondroprogenitors the role of TGF-BETA and SMAD signaling /." Diss., Available online, Georgia Institute of Technology, 2005, 2005. http://etd.gatech.edu/theses/available/etd-11232005-103041/.
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Thesis (Ph. D.)--Bioengineering, Georgia Institute of Technology, 2006.Harish Radhakrishna, Committee Member ; Christopher Jacobs, Committee Member ; Andres Garcia, Committee Member ; Marc E. Levenston, Committee Chair ; Barbara Boyan, Committee Member.
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Nugent, Gayle E. "Biomechanical regulation of articular cartilage metabolism of proteoglycan 4 and articular surface integrity." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2006. http://wwwlib.umi.com/cr/ucsd/fullcit?p3310007.
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Thesis (Ph. D.)--University of California, San Diego, 2006.Title from first page of PDF file (viewed September 19, 2006). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
12
Nguyen, Thanh Cong. "Mathematical Modelling of the Biomechanical Properties of Articular Cartilage." Thesis, Queensland University of Technology, 2005. https://eprints.qut.edu.au/16120/1/Thanh_Cong_Nguyen_Thesis.pdf.
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Articular cartilage is the translucent, heterogeneous three-component biological load processing gel that overlays the end of the articulating bones of mammalian joints. Normally, healthy intact articular cartilage performs two biomechanical functions very effectively. These are (i) redistribution of stresses due to loads acting on the joint; (ii) act as a near-frictionless interface between contacting bone ends. These principal functions are enabled by its highly elastic properties. Under normal physiological conditions, these essential biomechanical functions are provided over the lifetime of a mammalian joint with little or no degenerative changes. However, certain levels of physiological and traumatic loads and degenerative processes induced by activities such as running, walking, extreme sport, and aging can alter the composition and structure of the tissue, leading to changes in its biomechanical properties. This, inturn, influences its functional characteristics. The most common degenerative change in articular cartilage is osteoarthritis and the management and treatment of this disease is pivotal to all research targeted toward articular cartilage.
Several scientific groups around the world have developed models of articular cartilage to predict its fundamental and functional responses to load and altered biochemical conditions through both in vivo and in vitro studies. The most predominant of these models are the biphasic and triphasic models, which are based on the conceptualisation of articular cartilage as a dispersed mixture of its three main components namely collagen fibrils proteoglycan aggregates and water. The triphasic model is an extension of the biphasic model and incorporates swelling as a separate identifiable component of the tissue's biomechanical response. While these models are capable of predicting the elastic and viscoelastic behaviour and certain aspects of the swelling characteristics of articular cartilage, they are incapable of accounting for its short-term responses where the fluid component is the main carrier of the applied pressure.
The hydrostatic and swelling components of the fluid content determine the manner of stress-sharing and hence transient load processing within the matrix as stress is transmitted to the underlying structure. Furthermore, the understanding of the nature of this stress-sharing between fluid and solid components of the tissue is fundamental to the comprehension of the nature of degeneration and its biomechanical consequence in the function of the articulating joint. The inability of the biphasic and triphasic theories to predict, in accordance with experimental results, the transient behaviour of the loaded matrix fluid requires a more representative model. This imperative therefore forms the basis for the research work presented in this thesis.
In this thesis, a new mathematical model of articular cartilage load carriage is presented which can predict the transient load-induced responses. The model is based on a continuum framework invoking the principle of mechanical consolidation of fluid-saturated, swollen porous elastic materials. The cartilage matrix is conceptualised as a heterogeneous anisotropic fluid-saturated porous material in which its solid component responds to load as a hyperelastic material and whose interaction with the swelling component produces a partially distributed time-varying permeability.
In accordance with the principle of consolidation, a phenomenological approach is adopted for developing both analogue/engineering models and mathematical models for the tissue. The models are then used to predict both bulk matrix responses and the properties of the hypothetical layers of the tissue when subjected to physiological loading conditions. Ultimately, the generalized mathematical model is used to analyse the effect of superficial layer laceration on the stress-processing or stress-sharing characteristic of normal healthy articular cartilage. Finally, predicted results are shown to compare with experimental data demonstrating that the new models for swelling deformation, the hyperelastic law for solid skeletal structure and the distributed, time-dependent permeability are representative of the articular cartilage.
13
Nguyen, Thanh Cong. "Mathematical Modelling of the Biomechanical Properties of Articular Cartilage." Queensland University of Technology, 2005. http://eprints.qut.edu.au/16120/.
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Articular cartilage is the translucent, heterogeneous three-component biological load processing gel that overlays the end of the articulating bones of mammalian joints. Normally, healthy intact articular cartilage performs two biomechanical functions very effectively. These are (i) redistribution of stresses due to loads acting on the joint; (ii) act as a near-frictionless interface between contacting bone ends. These principal functions are enabled by its highly elastic properties. Under normal physiological conditions, these essential biomechanical functions are provided over the lifetime of a mammalian joint with little or no degenerative changes. However, certain levels of physiological and traumatic loads and degenerative processes induced by activities such as running, walking, extreme sport, and aging can alter the composition and structure of the tissue, leading to changes in its biomechanical properties. This, inturn, influences its functional characteristics. The most common degenerative change in articular cartilage is osteoarthritis and the management and treatment of this disease is pivotal to all research targeted toward articular cartilage. Several scientific groups around the world have developed models of articular cartilage to predict its fundamental and functional responses to load and altered biochemical conditions through both in vivo and in vitro studies. The most predominant of these models are the biphasic and triphasic models, which are based on the conceptualisation of articular cartilage as a dispersed mixture of its three main components namely collagen fibrils proteoglycan aggregates and water. The triphasic model is an extension of the biphasic model and incorporates swelling as a separate identifiable component of the tissue's biomechanical response. While these models are capable of predicting the elastic and viscoelastic behaviour and certain aspects of the swelling characteristics of articular cartilage, they are incapable of accounting for its short-term responses where the fluid component is the main carrier of the applied pressure. The hydrostatic and swelling components of the fluid content determine the manner of stress-sharing and hence transient load processing within the matrix as stress is transmitted to the underlying structure. Furthermore, the understanding of the nature of this stress-sharing between fluid and solid components of the tissue is fundamental to the comprehension of the nature of degeneration and its biomechanical consequence in the function of the articulating joint. The inability of the biphasic and triphasic theories to predict, in accordance with experimental results, the transient behaviour of the loaded matrix fluid requires a more representative model. This imperative therefore forms the basis for the research work presented in this thesis. In this thesis, a new mathematical model of articular cartilage load carriage is presented which can predict the transient load-induced responses. The model is based on a continuum framework invoking the principle of mechanical consolidation of fluid-saturated, swollen porous elastic materials. The cartilage matrix is conceptualised as a heterogeneous anisotropic fluid-saturated porous material in which its solid component responds to load as a hyperelastic material and whose interaction with the swelling component produces a partially distributed time-varying permeability. In accordance with the principle of consolidation, a phenomenological approach is adopted for developing both analogue/engineering models and mathematical models for the tissue. The models are then used to predict both bulk matrix responses and the properties of the hypothetical layers of the tissue when subjected to physiological loading conditions. Ultimately, the generalized mathematical model is used to analyse the effect of superficial layer laceration on the stress-processing or stress-sharing characteristic of normal healthy articular cartilage. Finally, predicted results are shown to compare with experimental data demonstrating that the new models for swelling deformation, the hyperelastic law for solid skeletal structure and the distributed, time-dependent permeability are representative of the articular cartilage.
14
Lathrop, Rebecca Leeann. "Investigation of Measurable Biomechanical Factors that may Influence Articular Cartilage Degeneration in the Knee." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1396013092.
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Gu, Marine D. "Investigating a Relationship Between Speed of Sound and Hydrogel Water Content via Ultrasound for Future Articular Cartilage Applications." Case Western Reserve University School of Graduate Studies / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=case1372930630.
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Vanderploeg, Eric James. "Mechanotransduction in Engineered Cartilaginous Tissues: In Vitro Oscillatory Tensile Loading." Diss., Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-05192006-110158/.
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Thesis (Ph. D.)--Mechanical Engineering, Georgia Institute of Technology, 2007.Radhakrishna, Harish, Committee Member ; LaPlaca, Michelle, Committee Member ; Nerem, Robert, Committee Member ; Garcia, Andres, Committee Member ; Levenston, Marc, Committee Chair.
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Fong, Man-kit, and 方文傑. "An investigation of biomechanical properties of collagen fibrils extracted from osteoarthritic and osteoporotic cartilages." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B47753146.
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Osteoarthritis (OA) is one of the most concerned diseases in the field of orthopaedics. During the process of this disease, articular cartilages are degenerated and worn out at the end stage, which create pain and disabilities to the patients. Although multiple mechanical and biochemical factors may initiate and/or enhance the progression of OA, alternation of biomechanical properties of articular cartilage is one of the products. There are several major components in articular cartilage; it is believed that each of their contribution cannot be entirely neglected. Superficial zone is mainly consisted with collagen and it was found that the biomechanical properties of this part of cartilage are also alternated significantly as a result of OA. Hence, degeneration of collagen network also occurs. Alternatively, osteoporosis (OP) is another common disease, which is associated to the decrease of bone mineral density; the effect of OP on articular cartilage is limited. In reverse, increasing bone mineral density in subchondral plate alters the loads distribution on articular cartilage and possibly leads to OA. This current study investigated the morphological and biomechanical properties of individual collagen fibrils extracted from OA, OP and healthy cartilages.
A total of ten joint specimens were recruited, 3 OA joints were from 3 OA patients, 3 OP joints were from 3 OP patients, and 4 joints were from 2 healthy individuals. All cartilages were harvested from non weight-bearing zone, and average diameters were calculated from 350 fibrils’ measurements. In addition, 50 fibrils were randomly selected for nano-indentation under ambient condition. However, the representation of biomechanical properties tested at low humidity may be questionable. This current study also investigated the stiffness of hydrated fibrils.
The results showed that the collagen fibrils extracted from OA cartilages were thinner than the ones extracted from OP and healthy cartilages. It was believe that the fibrillation and derangement of collagen network spread from superficial zone towards deeper zones. However, the number of thinner collagen fibrils increased in OA specimens could be the reason of the loss of larger fibrils and/or fragmentation occurred in the superficial zone, where contains thinner fibrils. The biomechanical tests showed that fibrils extracted from OA cartilages owned the highest elastic modulus, while the ones from OP had the lowest; significant differences were found between all groups when tested under ambient condition. Alternatively, the same pattern of results could also be found when hydrated fibrils were tested; however, due to the limited amount of samples, only the difference between OA and OP were considered significant. In addition, no individual difference was found; no significant difference between samples within each group could be observed. Since nano-indentations were performed at the center of each fibril, the elastic moduli measured represented the stiffness of the crosslinks and molecules within fibrils. Assuming the triple helix structure of collagen is relatively tough, the decrease of tensile modulus of superficial zone in OA cartilages could due to the changes of the crosslinks between fibrils in collagen network.published_or_final_version
Orthopaedics and Traumatology
Master
Master of Philosophy
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Accardi, Mario Alberto. "Numerical and experimental characterisation of articular cartilage : a study on biomechanics and biotribology, osteoarthritis and tissue engineering solutions." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/11042.
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Articular Cartilage (AC) is a soft tissue covering the articulating surface of human and animal joints. The tissue has remarkable and highly complex mechanical and wear properties allowing the joint to undergo complex kinematics and function correctly for several decades. However, trauma and degenerative joint diseases such as osteoarthritis (OA) can cause damage and excessive wear of the tissue and due to its limited regenerative capabilities, can severely compromise joint movement and impair the quality of life. OA is the most common type of degenerative joint disease and the primary cause of joint replacement surgery leading to high associated healthcare costs. Although the exact cause of this pathology remains unknown, it is thought to be mechanically induced via excessive and abnormal stresses and strains in AC which cause altered biochemical properties and a gradual decrease in the mechanical quality of the tissue. There is currently no available cure for OA and the disease is currently being diagnosed only via imaging techniques which are based upon morphological changes of the tissue, when the pathology is already in its advanced stages and has caused irreversible changes to the AC. In this respect, one of the greatest challenges to now remains the early diagnosis of OA, potentially by assessing biochemical and mechanical changes, allowing early treatments and prevention of disability thus improving the patient’s life. Hence, there is a need to apply fundamental engineering principles to the medical world in order to shed light on the pathogenesis and progression of OA. Furthermore, the need for artificial substitutes of AC has called for a deep understanding of the mechanical behaviour of the tissue in order to design and mimic the response of the real tissue in the most accurate manner. In this research a combination of numerical (finite element) and experimental techniques involving mechanical and tribological tests were used to fully characterise the mechanical behaviour of the tissue. Selective degradation of the AC constituents was then induced to simulate OA (OA-like AC) and the effect of different stages of degradation on the mechanical and tribological response as well as the wear properties of the tissue was investigated. The mechanical properties of osteoarthritic AC were then evaluated and compared to the OA-like AC in order to correlate similarities in the variations to the structure and the mechanical response as a result of degradation. Quantifying the mechanical response of the tissue at different stages of OA and different levels of degradation was done to ensure both a thorough understanding of the effect of the pathology’s progression on AC as well as to provide a potential map of mechanical quality and degradation, contributing to the potential future diagnosis of OA via mechanical parameters rather than morphological alone. Having investigated structural and mechanical variation in early OA, a promising solution to treat localised early OA and AC defects was also investigated as part of this research. In particular, novel micro fibrous tissue engineered scaffolds have been mechanically and tribologically assessed and compared to AC demonstrating the strong potential of matrix-assisted autologous chondrocyte implantation (MACI). Finally, the numerical models developed to characterise the AC using numerical – experimental methods, namely advanced biphasic models incorporating fine material descriptions such as intrinsic viscoelasticity as well as transverse isotropy, were applied to a patient specific 3D menisectomised tibio-femoral joint contact model in order to demonstrate the implications that the implementation of different AC models have for the prediction of the joint response to repeated walking cycles. The results obtained from the models were then used to predict the most likely location for the origin of mechanical damage and OA.
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Griebel, Matthew Alexander. "Viscoelastic Anisotropic Finite Element Mixture Model of Articular Cartilage using Viscoelastic Collagen Fibers and Validation with Stress Relaxation Data." DigitalCommons@CalPoly, 2012. https://digitalcommons.calpoly.edu/theses/743.
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Experimental results show that collagen fibers exhibit stress relaxation under tension and a highly anisotropic distribution. To further develop the earlier model of Stender [1], the collagen constituent was updated to reflect its intrinsic viscoelasticity and anisotropic distribution, and integrated with an existing mixture model with glycosaminoglycans and ground substance matrix. A two-term Prony series expansion of the quasi-linear viscoelastic model was chosen to model the viscoelastic properties of the collagen fibers. Material parameters were determined by using the simplex method to minimize the sum of squared errors between model results and experimental stress relaxation data of tissue in tension. Collagen elastic fiber modulus was calculated by fitting to the equilibrium data and viscoelastic parameters were determined by fitting to the relaxation curve. Results of newborn (~1-3 week old) untreated bovine articular cartilage explants from the patellar femoral groove as well as explants cultured in transforming growth factor-β1 (TGF-β1), from both the superficial (~0-0.5 mm from the articular surface) and middle (~0.5-1.0 mm from the articular surface) layers were compared to examine the effects of TGF- β1. TGF-β1 has been shown to maintain or even enhance mechanical properties of articular cartilage in compression and tension [2, 3] and this study continues with the hope that it may be used to improve tissue engineering of mature cartilage to better survive implantation in vivo for the successful repair of articular cartilage defects. Results show that TGF-β1 has a maturational effect on collagen, causing the tissue to become stiffer through an increase in elastic collagen fiber modulus and less viscous through shorter relaxation time and less stress relaxation (tissue retained a higher percentage of residual stress). The results of this study further advance the understanding of the effects of location and treatment with TGF-β1.
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Both, Kathrin [Verfasser], Oliver [Akademischer Betreuer] [Gutachter] Lieleg, Daniel [Gutachter] Rixen, and Tannin A. [Gutachter] Schmidt. "Biotribology and biomechanics of articular cartilage / Kathrin Both ; Gutachter: Daniel Rixen, Oliver Lieleg, Tannin A. Schmidt ; Betreuer: Oliver Lieleg." München : Universitätsbibliothek der TU München, 2016. http://d-nb.info/1118722329/34.
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Wangerin, Spencer D. "Development and validation of a human knee joint finite element model for tissue stress and strain predictions during exercise." DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/1129.
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Osteoarthritis (OA) is a degenerative condition of cartilage and is the leading cost of disability in the United States. Motion analysis experiments in combination with knee-joint finite element (FE) analysis may be used to identify exercises that maintain knee-joint osteochondral (OC) loading at safe levels for patients at high-risk for knee OA, individuals with modest OC defects, or patients rehabilitating after surgical interventions. Therefore, a detailed total knee-joint FE model was developed by modifying open-source knee-joint geometries in order to predict OC tissue stress and strain during the stance phase of gait. The model was partially validated for predicting the timing and locations of maximum contact parameters (contact pressure, contact area, and principal Green-Lagrangian strain), but over-estimated contact parameters compared with both published in vivo studies and other FE analyses of the stance phase of gait. This suggests that the model geometry and kinematic boundary conditions utilized in this FE model are appropriate, but limitations in the material properties used, as well as potentially the loading boundary conditions represent primary areas for improvement.
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Horstman, Christopher Larry. "BIOMECHANICAL AND METABOLIC CHANGES WITHIN RABBIT ARTICULAR CARTILAGE FOLLOWING TREATMENT WITH RADIOFREQUENCY ENERGY." MSSTATE, 2005. http://sun.library.msstate.edu/ETD-db/theses/available/etd-11112005-081324/.
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The effects caused to articular cartilage by the remote use of arthroscopically-delivered RF energy to soft tissues in the joint are unknown. This investigation reported the short and long-term effects of bRF and mRF energy on the biomechanical properties and metabolic activity of articular cartilage. In addition, the effect of Cosequin® therapy was addressed. Thirty New Zealand white rabbits were randomly assigned to one of two treatment groups (Group 1 - placebo; Group 2 - Cosequin®). Histopathology, cell viability, GAG synthesis, and mechanical function of the articular cartilage were compared between groups. Data were analyzed using a mixed model ANOVA (p=0.05). Immediate chondrocyte death was created by both RF devices. This damage was noted to be superficial and did not lead to the progressive deterioration of the extracellular matrix or mechanical function of the articular cartilage. Cosequin® therapy was unable to demonstrate significant differences compared to the control group.
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Rone, Rebecca J. "Effects of hemi-joint culture on biomechanical and biochemical properties of articular cartilage." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2008. http://wwwlib.umi.com/cr/ucsd/fullcit?p1454200.
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Thesis (M.S.)--University of California, San Diego, 2008.Title from first page of PDF file (viewed July 31, 2008). Available via ProQuest Digital Dissertations. Includes bibliographical references (p. 91-96).
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Dua, Rupak. "Enhanced Anchorage of Tissue-Engineered Cartilage Using an Osteoinductive Approach." FIU Digital Commons, 2014. http://digitalcommons.fiu.edu/context/etd/article/2559/type/native/viewcontent.
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Articular cartilage injuries occur frequently in the knee joint. Several methods have been implemented clinically, to treat osteochondral defects but none have been able to produce a long term, durable solution. Photopolymerizable cartilage tissue engineering approaches appear promising; however, fundamentally, forming a stable interface between the tissue engineered cartilage and native tissue, mainly subchondral bone and native cartilage, remains a major challenge. The overall objective of this research is to find a solution for the current problem of dislodgment of tissue engineered cartilage at the defect site for the treatment of degraded cartilage that has been caused due to knee injuries or because of mild to moderate level of osteoarthritis. For this, an in-vitro model was created to analyze the integration of tissue engineered cartilage with the bone, healthy and diseased cartilage over time. We investigated the utility of hydroxyapatite (HA) nanoparticles to promote controlled bone-growth across the bone-cartilage interface in an in vitro engineered tissue model system using bone marrow derived stem cells. We also investigated the application of HA nanoparticles to promote enhance integration between tissue engineered cartilage and native cartilage both in healthy and diseased states. Samples incorporated with HA demonstrated significantly higher interfacial shear strength (at the junction between engineered cartilage and engineered bone and also with diseased cartilage) compared to the constructs without HA (p < 0.05), after 28 days of culture. These findings indicate that the incorporation of HA nanoparticles permits more stable anchorage of the injectable hydrogel-based engineered cartilage construct via augmented integration between bone and cartilage.
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Heymer, Andrea. "Chondrogenic differentiation of human mesenchymal stem cells and articular cartilage reconstruction." kostenfrei, 2008. http://www.opus-bayern.de/uni-wuerzburg/volltexte/2008/2944/.
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Fan, Xiaolong. "Age and location-dependent biomechanical properties of kangaroo shoulder cartilage." Thesis, Queensland University of Technology, 2020. https://eprints.qut.edu.au/135523/1/Xiaolong_Fan_Thesis.pdf.
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This study attempts to explore the age- and location-dependent mechanical properties, compositional and structural features of shoulder cartilage, using kangaroo shoulder cartilage as a model. The indentation tests and microscopic investigations explains the biomechanical properties and its relationship with compositional and structural features of shoulder cartilage, which has provided hints on how shoulder cartilage adapts to different loadings within the joint, and how the shoulder cartilage grows and degrades with age. Further, the study provides a framework for study of location- and age-dependent biomechanical properties of shoulder cartilage.
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Thibbotuwawa, Noyel Deegayu Namal Bandara. "Experimental and numerical investigation of strain-rate-dependent behavior of kangaroo shoulder cartilage." Thesis, Queensland University of Technology, 2016. https://eprints.qut.edu.au/92607/1/Noyel%20Deegayu%20Namal%20Bandara_Thibbotuwawa_Thesis.pdf.
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This thesis introduces a new animal model, kangaroo, to biomechanical investigations of shoulder cartilage research. It examines the effect of cartilage structure and constituents on tissue behavior and its adaptation to mechanical loading. In doing so, the study explains the relationship of tissue's functional behaviors to its structure and constituents which has important implications for tissue engineering strategies catering joint specific cartilage tissue generation.
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Yamauchi, Kevin Akira. "Prediction of Articular Cartilage Remodeling During Dynamic Compression with a Finite Element Model." DigitalCommons@CalPoly, 2012. https://digitalcommons.calpoly.edu/theses/790.
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First, an in vitro growth experiment was performed to test the hypothesis that applying dynamic unconfined compression during culture produces het- erogeneous remodeling in newborn bovine articular cartilage explants. Het- erogeneous measures of cartilage microstructure were obtained by biochemical assays and quantified polarized light microscopy. Significant differences were measured between the GAG content in the inner and outer portions of the sam- ples stimulated with dynamic unconfined compression. The COL fiber network was found to be more highly aligned in the inner portion of the sample than in the peripheral region.
Next, a poroelastic finite element model with a remodeling subroutine was developed to test the hypothesis that the magnitude of relative interstitial fluid velocity and maximum principle strain stimulate GAG and COL fiber network remodeling, respectively, in articular cartilage during culture with dynamic unconfined compression. The GAG remodeling law was successful in predicting the heterogeneous changes in GAG content. The collagen remodeling law was not successful in predicting the changes in the COL network microstructural orientation, suggesting another mechanical cue is responsible for stimulating the remodeling of the COL fiber network.
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Moody, Hayley Ruscoe. "Benchmarking of the biomechanical characteristics of normal and degraded articular cartilage to facilitate mathematical modelling." Thesis, Queensland University of Technology, 2006. https://eprints.qut.edu.au/16402/1/Hayley_Moody_Thesis.pdf.
Full textAbstract:
In order to validate the appropriate functional characteristics of cartilage, we need to systematically study and understand what constitutes normality and degradation in cartilage. This thesis provides an important step in this direction.
To understand the mechanical repercussions of disruption to the matrix properties, cartilage is often artificially degraded using common enzymes. Although the process of artificial degradation does not provide an accurate representation of osteoarthritis, it can provide insight into the biomechanical properties of single matrix components by examining the behaviour of the tissue following its removal. Through histological analysis utilising the optical absorbance measurements of Safranin O stain, this work has demonstrated that for a given time and enzyme concentration, the action of Trypsin on proteoglycans is highly variable and is dependent on:
* The initial distribution and concentration of proteoglycans at different depths
* The intrinsic sample depth
* The location in the joint space, and
* The medium type.
These findings provide initial data towards a mathematical model which researchers can use to optimise Trypsin treatment of articular cartilage, and therefore model degeneration in vitro with a better degree of certainty.
The variability noted in the distribution and concentration of proteoglycans, and most likely the collagen network, creates a large variation in the compressive and tensile stiffness of all samples, and total failure strain energy. The average values for each of these tests indicate that a loss of proteoglycan through Trypsin treatment results in decreased compressive stiffness, increased tensile stiffness, and little change to the failure strains or total failure strain energy. Conversely, disruption to the collagen network shows increased compressive and tensile stiffness, as well as failure strain and total failure strain energy. Due to the large variation in the results for each treatment group, the average values for the treated samples fall within the range of results for normal cartilage. These values cannot therefore be used as dependable parameters to benchmark cartilage, since the parameters for artificially degraded cartilage are within the normal levels. The Yeoh and Polynomial hyperelastic laws were found to best represent the material characteristics of cartilage across the range of tested samples, regardless of differences in health and strength.
The results presented here provide important insight into the biomechanical outcomes of artificial degradation and provide direction for future research in this area.
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Moody, Hayley Ruscoe. "Benchmarking of the biomechanical characteristics of normal and degraded articular cartilage to facilitate mathematical modelling." Queensland University of Technology, 2006. http://eprints.qut.edu.au/16402/.
Full textAbstract:
In order to validate the appropriate functional characteristics of cartilage, we need to systematically study and understand what constitutes normality and degradation in cartilage. This thesis provides an important step in this direction. To understand the mechanical repercussions of disruption to the matrix properties, cartilage is often artificially degraded using common enzymes. Although the process of artificial degradation does not provide an accurate representation of osteoarthritis, it can provide insight into the biomechanical properties of single matrix components by examining the behaviour of the tissue following its removal. Through histological analysis utilising the optical absorbance measurements of Safranin O stain, this work has demonstrated that for a given time and enzyme concentration, the action of Trypsin on proteoglycans is highly variable and is dependent on: * The initial distribution and concentration of proteoglycans at different depths * The intrinsic sample depth * The location in the joint space, and * The medium type. These findings provide initial data towards a mathematical model which researchers can use to optimise Trypsin treatment of articular cartilage, and therefore model degeneration in vitro with a better degree of certainty. The variability noted in the distribution and concentration of proteoglycans, and most likely the collagen network, creates a large variation in the compressive and tensile stiffness of all samples, and total failure strain energy. The average values for each of these tests indicate that a loss of proteoglycan through Trypsin treatment results in decreased compressive stiffness, increased tensile stiffness, and little change to the failure strains or total failure strain energy. Conversely, disruption to the collagen network shows increased compressive and tensile stiffness, as well as failure strain and total failure strain energy. Due to the large variation in the results for each treatment group, the average values for the treated samples fall within the range of results for normal cartilage. These values cannot therefore be used as dependable parameters to benchmark cartilage, since the parameters for artificially degraded cartilage are within the normal levels. The Yeoh and Polynomial hyperelastic laws were found to best represent the material characteristics of cartilage across the range of tested samples, regardless of differences in health and strength. The results presented here provide important insight into the biomechanical outcomes of artificial degradation and provide direction for future research in this area.
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Petitjean, Noémie. "Nouveau dispositif fluidique pour la stimulation et la caractérisation biomécanique de microsphères : preuve de concept et application aux micropellets de cartilage." Thesis, Montpellier, 2020. http://www.theses.fr/2020MONTT047.
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Les pathologies du cartilage articulaire (CA) constituent aujourd’hui un problème de santé publique. L’ingénierie tissulaire, dont l’objectif est la création de nouveaux tissus contenant des cellules, est une solution thérapeutique prometteuse pour la réparation de lésions du CA mais nécessite encore des recherches pour améliorer les propriétés mécaniques des néo-tissus. Ce travail de thèse avait pour objectif l’analyse de l’impact de stimulations mécaniques sur le développement et le maintien du CA. Le micropellet de cartilage, conçu à partir de l’agrégation de cellules souches mésenchymateuses, a été choisi comme modèle biologique d’étude. Pour ce faire, un dispositif fluidique capable de stimuler et caractériser mécaniquement les micropellets de cartilage de petite taille et de forme irrégulière a été développé. Il permet de stimuler et caractériser simultanément 6 micropellets de cartilage par leur compression dans 6 puits coniques, grâce à différents signaux de pression. L’association du dispositif fluidique à un modèle numérique a rendu possible la caractérisation mécanique de diverses microsphères à base d’alginate, de collagène ou de collagène réticulé par comparaison à une méthode de caractérisation conventionnelle par compression entre deux surfaces planes. La fiabilité du dispositif pour l’application de stimuli mécaniques a été vérifiée en analysant les signaux de pression générés. La stimulation de micropellets de cartilage de 21 jours par un signal carré avec diverses amplitudes, fréquences et durées a montré que l’expression des gènes chondrocytaires pouvait être modulée par les stimulations mécaniques. Des déformations importantes des micropellets ont été observées sans toutefois les altérer structurellement. La caractérisation mécanique de micropellets de 21 jours a montré des résultats cohérents avec la bibliographie. Cette preuve de concept a montré l’intérêt du dispositif fluidique permettant la stimulation et la caractérisation de micropellets de cartilage, et a mis en évidence des pistes d’amélioration du système et des méthodes d’analyses numériques associées ainsi que des pistes de travail pour améliorer notre compréhension du développement du micropellet de cartilage lors de stimulations mécaniquesArticular cartilage (AC) pathologies have emerged as a public health problem. Tissue engineering, whose objective is to create new tissues with cells, is a promising therapeutic solution for the repair of AC lesions but still requires research to improve the mechanical properties of the new tissues. The objective of this PhD thesis work was to analyze the impact of mechanical stimuli in the development and maintenance of AC, based on the model of cartilage micropellet, derived from the aggregation of mesenchymal stem cells. For this purpose, a fluidic device able to mechanically stimulate and characterize small and irregularly shaped cartilage micropellets was developed. Six cartilage micropellets in six conical wells can be simultaneously stimulated by compression and characterized through different pressure signals. Associated to a numerical model, the fluidic device has been shown to allow the characterization of the mechanical properties of various microspheres made of alginate, collagen or cross-linked collagen as compared to a conventional characterization method by compression between two planar surfaces. The reliability of the device for the application of mechanical stimuli have been confirmed by analyzing the pressure signals generated. Stimulation of 21-day cartilage micropellets with a square-wave signal with various amplitudes, frequencies and durations have shown that chondrocyte gene expression could be modulated by mechanical stimuli. Moderate levels of deformation of the micropellets were observed without any obvious damage. The mechanical characterization of 21-day micropellets have shown results consistent with the literature. This proof of concept shows the interest of the fluidic device allowing the stimulation and characterization of cartilage micropellets and highlighted possibilities to improve the system and associated numerical analysis methods as well as directions to improve our understanding of cartilage micropellet development under mechanical stimulations
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Stender, Michael. "Predicting Articular Cartilage Constituent Material Properties Following In Vitro Growth Using a Proteoglycan-Collagen Mixture Model." DigitalCommons@CalPoly, 2011. https://digitalcommons.calpoly.edu/theses/463.
Full textAbstract:
A polyconvex continuum-level proteoglycan Cauchy stress function was developed based on the continuum electromechanical Poisson-Boltzmann unit cell model for proteoglycan interactions. The resulting proteoglycan model was combined with a novel collagen fibril model and a ground substance matrix material to create a polyconvex constitutive finite element model of articular cartilage. The true collagen fibril modulus , and the ground substance matrix shear modulus , were varied to obtain the best fit to experimental tension, confined compression, and unconfined compression data for native explants and explants cultured in insulin-like growth factor-1 (IGF-1) and transforming growth factor-β1 (TGF-β1). Results indicate that culture in IGF-1 results in a weakening of the COL fibers compared to native explants, and culture in TGF-β1 results in a strengthening of the COL fibers compared to native explants. These results elucidate the biomechanical changes in collagen fibril modulus, and ground matrix shear modulus following in vitro culture with IGF-1 and TGF-β1. Understanding the constitutive effects of growth factor stimulated culture may have applications in AC repair and tissue engineering.
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Kam, Kelsey Kiyo. "Poroelastic Finite Element Analysis of a Heterogeneous Articular Cartilage Explant Under Dynamic Compression in ABAQUS." DigitalCommons@CalPoly, 2011. https://digitalcommons.calpoly.edu/theses/540.
Full textAbstract:
A poroelastic finite element model of a heterogeneous articular cartilage disc was
created to examine the tissue response to low amplitude (± 2% strain), low
frequency (0.1 Hz) dynamic unconfined compression (UCC). A strong correlation
has been made between the relative fluid velocity and stimulation of
glycosaminoglycan synthesis. A contour plot of the model shows the relative fluid
velocity during compression exceeds a trigger value of 0.25 μm/s at the radial
periphery. Dynamic UCC biochemical results have also reported a higher
glycosaminoglycan content in this region versus that of day 0 specimens. Fluid
velocity was also found not to be the dominant physical mechanism that
stimulates collagen synthesis; the heterogeneity of the fluid velocity contour plot
conflicts with the homogeneous collagen content from the biochemical results. It
was also found that a Tresca (shear) stress trigger of 0.07 MPa could provide
minor stimulation of glycosaminoglycan synthesis. A feasibility study on
modeling a heterogeneous disc was conducted and found convergence issues with
the jump in properties from the superficial to middle layers of the disc. It is
believed that the superficial layer contains material properties that allow the tissue
to absorb much of the compressive strain, which in turn increases pressure and
causes convergence issues in ABAQUS. The findings in this thesis may help
guide the development of a growth and remodeling routine for articular cartilage.
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Danalache, Marina [Verfasser], and Ulf Krister [Akademischer Betreuer] Hofmann. "Biomechanical assessment of osteoarthritic articular cartilage and jaw periosteal cells-based bone constructs / Marina Danalache ; Betreuer: Ulf Krister Hofmann." Tübingen : Universitätsbibliothek Tübingen, 2020. http://d-nb.info/1212849906/34.
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Pyle, Jeffrey D. "Development and validation of a human hip joint finite element model for tissue stress and strain predictions during gait." DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/1131.
Full textAbstract:
Articular cartilage degeneration, called osteoarthritis, in the hip joint is a serious condition that affects millions of individuals yearly, with limited clinical solutions available to prevent or slow progression of damage. Additionally, the effects of high-risk factors (e.g. obesity, soft and hard tissue injuries, abnormal joint alignment, amputations) on the progression of osteoarthritis are not fully understood. Therefore, the objective of this thesis is to generate a finite element model for predicting osteochondral tissue stress and strain in the human hip joint during gait, with a future goal of using this model in clinically relevant studies aimed at prevention, treatment, and rehabilitation of OC injuries.
A subject specific finite element model (FEM) was developed from computerized tomography images, using rigid bones and linear elastic isotropic material properties for cartilage as a first step in model development. Peak contact pressures of 8.0 to 10.6 MPa and contact areas of 576 to 1010 mm2 were predicted by this FEM during the stance phase of gait. This model was validated with in vitro measurements and found to be in good agreement with experimentally measured contact pressures, and fair agreement with measured contact areas.
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Temple, Michele M. "Age- and site-associated biomechanical weakening of human articular cartilage relationship to cellularity, wear, matrix fragmentation, and the progression to osteoarthritis /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2005. http://wwwlib.umi.com/cr/ucsd/fullcit?p3187813.
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Thesis (Ph. D.)--University of California, San Diego, 2005.Title from first page of PDF file (viewed October 21, 2005). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
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Czapla, Nicholas. "Development and Validation of a Tibiofemoral Joint Finite Element Model and Subsequent Gait Analysis of Intact ACL and ACL Deficient Individuals." DigitalCommons@CalPoly, 2015. https://digitalcommons.calpoly.edu/theses/1488.
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Osteoarthritis (OA) is a degenerative condition of articular cartilage that affects more than 25 million people in the US. Joint injuries, like anterior cruciate ligament (ACL) tears, can lead to OA due to a change in articular cartilage loading. Gait analysis combined with knee joint finite element modeling (FEM) has been used to predict the articular cartilage loading. To predict the change of articular cartilage loading during gait due to various ACL injuries, a tibiofemoral FEM was developed from magnetic resonance images (MRIs) of a 33 year male, with no prior history of knee injuries. The FEM was validated for maximum contact pressure and anterior tibial translation using cadaver knee studies. The FEM was used to model gait of knees with an intact ACL, anteromedial (AM) bundle injury, posterolateral (PL) bundle injury, complete ACL injury, AM deficiency, PL deficiency, complete ACL rupture, as well as a bone-patellar tendon-bone (BPTB) graft. Generally, the predicted maximum contact pressure and contact area increased for all the ACL injuries when compared to intact ACLs. While an increase in maximum contact pressure and contact area is an indication of an increased risk of the development of OA, the percent of increase was typically small suggesting that walking is a safe activity for individuals with ACL injuries.
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Shields, Kelly J. "The Development of a Multi-Directional Wear Apparatus and the Characterization and Correlation of Biomechanical and Biotribological Properties of Bovine Articular Cartilage." VCU Scholars Compass, 2007. http://scholarscompass.vcu.edu/etd/1271.
Full textAbstract:
A multi-directional wear apparatus was developed to simulate the kinematic motion of diarthrodial joints. A comprehensive evaluation including biotribological and biomechanical characterization of articular surfaces was performed with concomitant translational and oscillating rotational motion similar to that experienced in vivo. Various system parameters were evaluated in the designed experiments including normal load magnitude (high/low), surface quality (defect/no defect), and wear pattern (with/without rotation). Biomechanical characterization was achieved through stress relaxation and dynamic cyclical testing. Quasi-linear viscoelastic theory was used to curve-fit the stress relaxation data, while the dynamic data was used to determine the dynamic properties through Fast Fourier Transform analysis and verify the assumptions posed with the QLV theory.Overall tissue compression was significantly dependent on load magnitude (pstatic was significantly dependent on surface quality (pinitial was significantly dependent on both surface quality (pComparisons of the curve-fit parameters showed a significant decrease in pre- vs post-wear elastic response, A, and viscous response, c. In addition, the short term relaxation response, τ1, showed a significant decrease between no defect (0.801 ± 0.13 sec) and a defect (0.679 ± 0.16 sec). lGlpost-wear/lGlpre-wear tan δ , was generally greater while lGl was less for those specimens experiencing rotation Qualitatively, SEM photographs revealed the mechanical degradation of the tissue surface due to wear. Surfaces with a defect had increased wear debris, which ultimately contributes to third body wear. Surfaces without a defect had preferentially aligned abrasions, while those surfaces outside the wear path showed no signs of wear.Significant correlation was detected between the μstatic and μinitial for both the nonliner viscous response, B (p2 (p<0.013 and p<0.062). Thus, the comprehensive evaluation of biomechanical and biotribological characteristics suggests the new wear regime and standardization of analysis techniques will aid in the development of functional articular repair and clinical repair techniques.
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Silva, Monica Maria Moreira 1960. "Estudo do comportamento biomecânico e da expressão galectina-3 e comp, biomarcadores do turnover de tecidos articulares da sínfise púbica de camundongos durante a prenhez e pos-parto." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317881.
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Orientadores: Paulo Pinto Joazeiro, Luiz Carlos AlvesTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-27T05:21:21Z (GMT). No. of bitstreams: 1 Silva_MonicaMariaMoreira_D.pdf: 3522039 bytes, checksum: c8adbfe076ccc79eaa19efeb2f0d8fe7 (MD5) Previous issue date: 2014
Resumo: Em camundongos, a sínfise púbica (SP) é metabolicamente ativa durante a prenhez. As adaptações orquestradas por hormônios e a sobrecarga mecânica imposta na sínfise, que gradualmente dá lugar ao ligamento interpúbico (Lip) e ao seu "relaxamento" no final da prenhez permitem a passagem da prole pelo canal do parto. Tais modificações oferecem oportunidade para estudo de remodelação de tecidos semelhantes às que ocorrem nas disfunções e distopias do assoalho pélvico feminino. Estudaram-se características morfológicas, imunohistoquímica das proteínas Galectina-3(GAL3) e CartilageOligomericProtein Matrix (COMP) e o comportamento biomecânico, na SP de camundongos fêmeas adultas jovens, durante a primeira prenhez e após o parto por meio de técnicas histológicas convencionais, imunohistoquímica, microscopia de luz, eletrônica de transmissão e varredura. Nas análises da organização fibrilar utilizou-se transformada rápida de Fourier (FFT) e do comportamento biomecânico ensaio destrutivo de tração uniaxial em máquina de testes universal com velocidade constante e força progressiva nas SP/Lip de camundongos C57BL6 grupos: (NP-controle), 12, 15 e 19 dias (d) após a verificação do plug vaginal e no 30, 50 e 100dias após o parto (dpp). No ensaio de tração uniaxial, a força máxima necessária para o início da ruptura do tecido diminuiu no decorrer da prenhez, sendo o menor valor medido no dia do parto, aumentou a partir deste dia, e no 10dpp retornou a valores próximos aosdos animais NP. A energia total de ruptura (ETR) diminuiu no 12d e a partir de 15d aumentou até o 5dpp, no 10dpp, diminuiu porém se manteve menor que o NP. Na Imunolocalização das proteínas COMP e GAL3 foram detectadas em todos os grupos, com variações no tipo celular e na localização. A morfologia bicorne do útero de camundongos e o peso do útero com os filhotes alteram os estímulos mecânicos nos tecidos interpúbicos e contribuem para sua remodelação. No 3dpp, quando os estímulos mecânicos foram abruptamente retirados no parto, observaram-se organelas compostas por microtúbulos semelhante a cílio solitário não móvel, citado como organela mecanosensorial. O comportamento biomecânico dos tecidos interpúbicos durante a prenhez e após o parto foi coerente com a histoarquitetura destes e a imunolocalização das proteínas COMP e GAL-3, à medida que o comportamento biomecânico dos tecidos se modifica são indicativos que essas proteínas estão envolvidas no remodelamento de transições de elementos ósseos e ligamentares e fibrocatilaginosas durante a prenhez e após o parto. Este remodelamento que proporciona afastamento de ossos púbicos e a rápida recuperação que se inicia pós-parto, oferece suporte ao canal de parto de animais que possuem útero bicorne a exemplo do camundongo, morcego e cobaia
Abstract: In mice, the pubic symphysis (PS) is metabolically active during pregnancy. Adaptations orchestrated by hormones and mechanical overload that the symphysis goes through during this period, which gradually gives place to an interpubic ligament (IpL) and the relaxation at the end of pregnancy, allows the passage of offspring through the birth canal. Such changes provide an opportunity to study remodeling of tissues such as those that occur in disorders and dystopias of the female pelvic floor. We studied morphological, immunohistochemical analysis of galectin-3 (GAL3) and Cartilage Oligomeric Matrix Protein (COMP) proteins and the biomechanical behavior in young adult females PS mice during first pregnancy and postpartum (dpp) through conventional histological techniques, immunohistochemistry and light,transmition and scanning electron microscopies. In analyzes of fibrillar organization we used fast Fourier transform and the biomechanical behavior destructive tensile testing in a universal testing machine with constant speed and progressive force in the PS/IpL C57BL6 mice groups: (NP-control), 12, 15 and 19 days (d) after checking the vaginal plug and 3th, 5th and 10thpp. In tensile testing the maximum force required to initiate the rupture of the tissue decreased in the course of pregnancy, with the lowest value measured at day of birth, increasing from this day on and at the 10dpp returned to the NP individual¿s value.The total rupture energy (TRE) decreasesat d12 and increased from d15 until 5dpp, decreasing at the 10dpp but remained lower than the NP. Immunolocalization of COMP and GAL3 proteins were detected in all groups, with variations in cell type and location. The bicornuate uterus morphology of the mice and the weight of the uterus with cubs alter the mechanical stimuli in interpubic tissues, contribute to its remodeling. In 3dpp when mechanical stimuli were abruptly removed at birth. It was observed organelles consisting of microtubules that were similar to a solitary cilium quoted as mechanosensory organelle.The biomechanical behavior of interpubic tissues during pregnancy and after delivery was consistent with the histoarchitecture and immunolocalization of COMP and GAL-3 protein, as the biomechanical behavior of the tissue changes are indicative that these proteins are involved in the remodeling of transitions bony and ligamentous elements and fibrocartilaginous during pregnancy and after childbirth. This remodeling that provides removal of pubic bones and a quick postpartum recovery, offers birth canal support of animals that have bicornuate uterus such as the mouse, guinea pig and bat
Doutorado
Biologia Tecidual
Doutora em Biologia Celular e Estrutural
40
Getgood, Alan Martin John. "Articular cartilage tissue engineering." Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608764.
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Arkill, Kenton Paul. "Mass transport in articular cartilage." Thesis, University of Exeter, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.421565.
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Burgin, Leanne Victoria. "Impact loading of articular cartilage." Thesis, University of Aberdeen, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288339.
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Impact loads have been implicated in the initiation of secondary osteoarthritis but in the absence of defined injury this is difficult to rest rigorously. The response to controlled impacts of samples of cartilage and bone in isolation and together, may yield valuable insights into how tissue properties may influence degenerative changes associated with osteoarthritis. A rigid instrumented drop tower was constructed and interfaced to a LabVIEW software oscilloscope modified to capture and store data to disk. Controlled impact loads were applied to cores of articular cartilage, both isolated and in situ on the underlying bone or bonded to substrates of different material properties. Bovine tissue from the carpometacarpal joint and human cartilage from elderly femoral heads was used. The response of the samples was investigated in terms of a dynamic stiffness, energy absorbed and coefficient of restitution. In addition the quasistatic modulus was measured from compression tests in order to compare the values for the stiffness of cartilage and bone at different rates of stress and strain. Composition analysis was then performed on human cartilage samples to investigate if there was any correlation between the biochemical constituents and mechanical factors. The dynamic stiffness of the cartilage samples was governed by peak stress and did not show a high sensitivity to strain rate. Cartilage had good force attenuating properties in situ on bone and the substrates. The greater volume of the stiffer underlying substrate dominated the response of the composite samples. For the human cartilage samples the dynamic stiffness was most correlated to percentage collagen whereas the quasistatic modulus was most correlated with water content. Overall the biochemical composition was a poor predictor of stiffness which indicates the importance of interactions between the matrix constituents in the tissue response to an applied load.
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Rowles, Christopher. "Visualisation of Articular Cartilage Microstructure." Thesis, Curtin University, 2016. http://hdl.handle.net/20.500.11937/52984.
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This thesis developed image processing techniques enabling the detection and segregation of biological three dimensional images into its component features based upon shape and relative size of the features detected. The work used articular cartilage images and separated fibrous components from the cells and background noise. Measurement of individual components and their recombination into a composite image are possible. Developed software was used to analyse the development of hyaline cartilage in developing sheep embryos.
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Girdler, N. M. "The role of mandibular condylar cartilage in articular cartilage repair." Thesis, King's College London (University of London), 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309110.
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Chan, Alex Dart Ming. "Neurogenic modulation of articular cartilage degeneration." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ41123.pdf.
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Covert, Rebeccah Jean. "Durability evaluation of articular cartilage prostheses." Diss., Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/17596.
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Goldsmith, Andrew Alan John. "Biphasic modelling of synthetic articular cartilage." Thesis, University of Bath, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321846.
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Ardill, Jennifer Maureen. "Optical measurement of articular cartilage roughness." Thesis, Queen's University Belfast, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241325.
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Barton, Nicholas J. "Accurate assessment of articular cartilage roughness." Thesis, Queen's University Belfast, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334495.
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Eldridge, Suzanne. "Agrin contributes to articular cartilage homeostasis." Thesis, Queen Mary, University of London, 2016. http://qmro.qmul.ac.uk/xmlui/handle/123456789/12812.
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Osteoarthritis is a leading cause of disability for which there is no cure. We have discovered that the multidomain signalling protein Agrin, most commonly known for its requirement at the neuromuscular junction, strongly promotes chondrocyte differentiation and cartilage formation in vivo. Agrin is expressed in normal cartilage but absent in osteoarthritis. In vitro, Agrin knockdown resulted in the downregulation of the cartilage transcription factor SOX9 and other cartilage-specific extracellular matrix molecules. Conversely, the addition of exogenous Agrin supported cartilage differentiation in vitro and ectopic cartilage formation in vivo. In contrast to other biological contexts where Agrin signalling requires the interaction with either LRP4 or α-dystroglycan, chondrocytes require the presence of both receptors. Our results identify Agrin as a novel potent anabolic growth factor with strong therapeutic potential in cartilage regeneration.