Articoli di riviste: "Articular cartilage"

1

Wardale, R. J., e V. C. Duance. "Quantification and immunolocalisation of porcine articular and growth plate cartilage collagens". Journal of Cell Science 105, n. 4 (1 agosto 1993): 975–84. http://dx.doi.org/10.1242/jcs.105.4.975.

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The collagens of growth plate and articular cartilage from 5–6 month old commercial pigs were characterised. Growth plate cartilage was found to contain less total collagen than articular cartilage as a proportion of the dry weight. Collagen types I, II, VI, IX and XI are present in both growth plate and articular cartilage whereas type X is found exclusively in growth plate cartilage. Types III and V collagen could not be detected in either cartilage. Type I collagen makes up at least 10% of the collagenous component of both cartilages. There are significant differences in the ratios of the quantifiable collagen types between growth plate and articular cartilage. Collagen types I, II, and XI were less readily extracted from growth plate than from articular cartilage following pepsin treatment, although growth plate cartilage contains less of the mature collagen cross-links, hydroxylysyl-pyridinoline and lysyl-pyridinoline. Both cartilages contain significant amounts of the divalent reducible collagen cross-links, hydroxylysyl-ketonorleucine and dehydro-hydroxylysinonorleucine. Immunofluorescent localisation indicated that type I collagen is located predominantly at the surface of articular cartilage but is distributed throughout the matrix in growth plate. Types II and XI are located in the matrix of both cartilages whereas type IX is predominantly pericellular in the calcifying region of articular cartilage and the hypertrophic region of the growth plate. Collagen type VI is located primarily as a diffuse area at the articular surface.

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Wardale, R. J., e V. C. Duance. "Characterisation of articular and growth plate cartilage collagens in porcine osteochondrosis". Journal of Cell Science 107, n. 1 (1 gennaio 1994): 47–59. http://dx.doi.org/10.1242/jcs.107.1.47.

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The articular and growth plate cartilages of osteochondrotic pigs were examined and compared with those from clinically normal animals. Both types of osteochondrotic cartilage showed considerable localised thickening apparently due to a lack of ossification. Histological examination of cartilage lesions demonstrated a breakdown in the normal pattern of chondrocyte maturation. Articular cartilage lesions lacked mature clones of chondrocytes in the calcifying region. Growth plate cartilage showed an accumulation of disorganised hypertrophic chondrocytes rather than the well-defined columns seen in normal tissue. The overall percentages of collagen in osteochondrotic lesions from both articular and growth plate cartilage were significantly reduced compared with levels in unaffected cartilage. There were substantial increases in the proportion of type I collagen in lesions from both osteochondrotic articular and growth plate cartilages and a reduction in the proportion of type II collagen. Type X collagen was detected in osteochondrotic but not normal articular cartilage. The proportion of type X collagen was unchanged in osteochondrotic growth plate cartilage. The levels of the collagen cross-links, hydroxylysylpyridinoline, hydroxylysyl-ketonorleucine and dehydrohydroxylysinonorleucine were radically reduced in samples from osteochondrotic growth-plate cartilage lesions when compared with normal tissue. Less dramatic changes were observed in articular cartilage although there was a significant decrease in the level of hydroxylysylketonorleucine in osteochondrotic lesions. Immunofluorescence examination of osteochondrotic lesions showed a considerable disruption of the organisation of the collagenous components within both articular and growth-plate cartilages. Normal patterns of staining of types I and VI collagen seen at the articular surface in unaffected tissue were replaced by a disorganised, uneven stain in osteochondrotic articular cartilage lesions. Incomplete removal of cartilage at the ossification front of osteochondrotic growth plate was demonstrated by immunofluorescence staining of type IX collagen. Type X collagen was produced in the matrix of the calcifying region of osteochondrotic articular cartilage by small groups of hypertrophic chondrocytes, but was not detected in normal articular cartilage. The distribution of type X collagen was unchanged in osteochondrotic growth plate cartilage.

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Gong, Huchen, Yutao Men, Xiuping Yang, Xiaoming Li e Chunqiu Zhang. "Experimental Study on Creep Characteristics of Microdefect Articular Cartilages in the Damaged Early Stage". Journal of Healthcare Engineering 2019 (13 novembre 2019): 1–9. http://dx.doi.org/10.1155/2019/8526436.

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Traumatic joint injury is known to cause cartilage deterioration and osteoarthritis. In order to study the mechanical mechanism of damage evolution on articular cartilage, taking the fresh porcine articular cartilage as the experimental samples, the creep experiments of the intact cartilages and the cartilages with different depth defect were carried out by using the noncontact digital image correlation technology. And then, the creep constitutive equations of cartilages were established. The results showed that the creep curves of different layers changed exponentially and were not coincident for the cartilage sample. The defect affected the strain values of the creep curves. The creep behavior of cartilage was dependent on defect depth. The deeper the defect was, the larger the strain value was. The built three-parameter viscoelastic constitutive equation had a good correlation with the experimental results and could predict the creep performance of the articular cartilage. The creep values of the microdefective cartilage in the damaged early stage were different from the diseased articular cartilage. These findings pointed out that defect could accelerate the damage of cartilage. It was helpful to study the mechanical mechanism of damage evolution.

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Sharifi, Ali Mohammad, Ali Moshiri e Ahmad Oryan. "Articular cartilage". Current Orthopaedic Practice 27, n. 6 (2016): 644–65. http://dx.doi.org/10.1097/bco.0000000000000425.

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5

McCarty, Eric C. "Articular Cartilage". Clinics in Sports Medicine 36, n. 3 (luglio 2017): i. http://dx.doi.org/10.1016/s0278-5919(17)30039-x.

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Rodkey, William G. "Articular cartilage". Journal of Equine Veterinary Science 17, n. 2 (febbraio 1997): 80. http://dx.doi.org/10.1016/s0737-0806(97)80334-6.

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7

Miller, Mark D. "Articular Cartilage". Clinics in Sports Medicine 36, n. 3 (luglio 2017): xiii—xiv. http://dx.doi.org/10.1016/j.csm.2017.04.002.

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8

Gradisar, Ivan A., e James A. Porterfield. "Articular cartilage". Topics in Geriatric Rehabilitation 4, n. 3 (aprile 1989): 1–9. http://dx.doi.org/10.1097/00013614-198904000-00004.

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9

Lees, Deborah, e Paul Partington. "Articular cartilage". Orthopaedics and Trauma 30, n. 3 (giugno 2016): 265–72. http://dx.doi.org/10.1016/j.mporth.2016.04.007.

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10

Simon, Timothy M., e Douglas W. Jackson. "Articular Cartilage". Sports Medicine and Arthroscopy Review 26, n. 1 (marzo 2018): 31–39. http://dx.doi.org/10.1097/jsa.0000000000000182.

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11

Hayes, Donald W., Randall L. Brower e Kelly J. John. "Articular Cartilage". Clinics in Podiatric Medicine and Surgery 18, n. 1 (gennaio 2001): 35–53. http://dx.doi.org/10.1016/s0891-8422(23)01166-7.

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12

Chetina, E. V., e E. V. Chetina. "Inhibition of activity of collagen degradation in cartilage of patients with osteoarthrosis byactivation of glycolysis". Osteoporosis and Bone Diseases 14, n. 1 (15 aprile 2011): 8–12. http://dx.doi.org/10.14341/osteo201118-12.

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Aim. To study the effect of glycolysis activators deferrioxamine (DFO), CoCl2, V(SO4)2 and mimosine on collagen cleavage activity by collagenase in osteoarthritic (OA) articular cartilage explants. Materials and methods. 32 OA articular cartilages obtained after arthroplasty were examined in the study. Cartilages were cultured in the presence of 10-50μM DFO, CoCl2, V(SO4)2 or mimosine. Collagen cleavage activity was measured by ELISA. Inhibition of protein or DNA synthesis in the presence of [3H]-labeled proline or thymidine, respectively, was used for evaluation of examined agent toxicity. Results. Glycolysis activators DFO, CoCl2, V(SO4)2 or mimosine were capable of inhibiting type II collagen cleavage activity in OA articular cartilage explants. The examined agents have shown no toxic effect in the concentrations used. Conclusion. Glycolysis activation in articular chondrocytes may offer a means of inhibiting articular cartilage destruction in OA patients.

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13

Li, Yefu, e Lin Xu. "Advances in understanding cartilage remodeling". F1000Research 4 (28 agosto 2015): 642. http://dx.doi.org/10.12688/f1000research.6514.1.

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Cartilage remodeling is currently among the most popular topics in osteoarthritis research. Remodeling includes removal of the existing cartilage and replacement by neo-cartilage. As a loss of balance between removal and replacement of articular cartilage develops (particularly, the rate of removal surpasses the rate of replacement), joints will begin to degrade. In the last few years, significant progress in molecular understanding of the cartilage remodeling process has been made. In this brief review, we focus on the discussion of some current “controversial” observations in articular cartilage degeneration: (1) the biological effect of transforming growth factor-beta 1 on developing and mature articular cartilages, (2) the question of whether aggrecanase 1 (ADAMTS4) and aggrecanase 2 (ADAMTS5) are key enzymes in articular cartilage destruction, and (3) chondrocytes versus chondron in the development of osteoarthritis. It is hoped that continued discussion and investigation will follow to better clarify these topics. Clarification will be critical for those in search of novel therapeutic targets for the treatment of osteoarthritis.

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Hayes, Anthony J., John Whitelock e James Melrose. "Regulation of FGF-2, FGF-18 and Transcription Factor Activity by Perlecan in the Maturational Development of Transitional Rudiment and Growth Plate Cartilages and in the Maintenance of Permanent Cartilage Homeostasis". International Journal of Molecular Sciences 23, n. 4 (9 febbraio 2022): 1934. http://dx.doi.org/10.3390/ijms23041934.

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The aim of this study was to highlight the roles of perlecan in the regulation of the development of the rudiment developmental cartilages and growth plate cartilages, and also to show how perlecan maintains permanent articular cartilage homeostasis. Cartilage rudiments are transient developmental templates containing chondroprogenitor cells that undergo proliferation, matrix deposition, and hypertrophic differentiation. Growth plate cartilage also undergoes similar changes leading to endochondral bone formation, whereas permanent cartilage is maintained as an articular structure and does not undergo maturational changes. Pericellular and extracellular perlecan-HS chains interact with growth factors, morphogens, structural matrix glycoproteins, proteases, and inhibitors to promote matrix stabilization and cellular proliferation, ECM remodelling, and tissue expansion. Perlecan has mechanotransductive roles in cartilage that modulate chondrocyte responses in weight-bearing environments. Nuclear perlecan may modulate chromatin structure and transcription factor access to DNA and gene regulation. Snail-1, a mesenchymal marker and transcription factor, signals through FGFR-3 to promote chondrogenesis and maintain Acan and type II collagen levels in articular cartilage, but prevents further tissue expansion. Pre-hypertrophic growth plate chondrocytes also express high Snail-1 levels, leading to cessation of Acan and CoI2A1 synthesis and appearance of type X collagen. Perlecan differentially regulates FGF-2 and FGF-18 to maintain articular cartilage homeostasis, rudiment and growth plate cartilage growth, and maturational changes including mineralization, contributing to skeletal growth.

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Lychagin, A. V., S. V. Ivannikov, V. I. Yusupov, L. A. Semenova, E. D. Startseva, V. V. Surin, I. O. Tinkova et al. "Laser treatment of chondromalacia lesions in the articular cartilage". Laser Medicine 25, n. 4 (15 aprile 2022): 9–15. http://dx.doi.org/10.37895/2071-8004-2021-25-4-9-15.

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Objective: to select optimal parameters of two-wave near-infrared laser irradiation for the arthroscopic treatment of chondromalacia foci in the articular cartilage. Material and methods. Bull articular cartilages were treated with laser light delivered by a fifi ber and having various parameters. Human articular cartilages with chondromalacia foci taken during the total knee replacement were also treated with laser light delivered by a fifi ber and having various parameters. The processed cartilage samples were examined macroscopically and then histologically. Changes in the structure of ar[1] ticular cartilage after laser irradiation were assessed. Results. A two-second irradiation with two-wave laser light (λ = 0.97 μm / 30 W and λ = 1.55 μm / 15 W) causes a rapid “melting” of lesion margins without macroscopically visible carbonization with a wide thermally affected zone in the irradiated area. Histologically, cartilage preparations irradiated with two-wave laser light (wavelengths λ = 1.55 μm / 5 W and λ = 0.97 μm / 3 W) for 2 sec demonstrated slight changes in the cartilage structure without thermal destruction of chondrocytes.Conclusion. The optimal combination for laser irradiation of the cartilage tissue in the saline solution environment which restores articular cartilage shape is two-wave laser light λ = 0.97 μm at power of 3 W and λ = 1.55 μm at power of 5 W from the distance of 1–2 mm under 2 sec exposure.

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Horky, D., e F. Tichy. "Submicroscopic structure of canine articular cartilage". Veterinární Medicína 49, No. 6 (29 marzo 2012): 207–16. http://dx.doi.org/10.17221/5697-vetmed.

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Canine articular cartilage was studied in male dogs at age 1, 4, 5 and 8 years. Samples collected from four hip joints and two humeral joints in each age category were processed by standard methods to be examined by scanning and transmission electron microscopy. The cartilage of both joints was similar in structure. In the superficial cartilage layer of one-year-old animals, individual spindle-shaped chondrocytes in the extracellular matrix were, together with associated collagen fibrils, located parallel to the surface. When viewed by scanning electron microscopy, they were distinctly prominent above the surrounding surface. Changes in the thickness and arrangement of both the chondrosynovial membrane and intercellular matrix were apparent in the 4-, 5- and 8-year-old animals, indicating the onset or progression of an osteoarthritic process. The middle cartilage layer in young animals showed elliptical chondrocytes occurring in pairs. The voluminous cytoplasm contained a great amount of granular endoplasmic reticulum, a large Golgi complex and numerous transport vesicles. The pericellular matrix, up to 1 µm thick, was composed of aperiodic fibrils. In the old animals the pericellular matrix was absent and was replaced by thick collagen fibrils with a marked periodicity. The deep cartilage layer in young dogs included groups of three to four chondrocytes situated in a common territory. The cytoplasm contained distinct bundles of intermediary filaments. The pericellular matrix occasionally formed septa between adjoining cells. The intracellular matrix included bundles of collagen fibrils arranged in a matted structure. In the old animals aggregation of chondrocytes into groups almost disappeared. The cytoplasm showed only short cisternae of granular endoplasmic reticulum, small numbers of mitochondria and transport vesicles, frequent lipid droplets and small glycogen deposits. The intercellular matrix consisted of only short collagen fibrils with no distinct periodicity.

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Poole, A. R., C. Webber, I. Pidoux, H. Choi e L. C. Rosenberg. "Localization of a dermatan sulfate proteoglycan (DS-PGII) in cartilage and the presence of an immunologically related species in other tissues." Journal of Histochemistry & Cytochemistry 34, n. 5 (maggio 1986): 619–25. http://dx.doi.org/10.1177/34.5.3701029.

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A monoclonal antibody to a core-protein-related epitope of a small dermatan sulfate-rich proteoglycan (DS-PGII) isolated from adult bovine articular cartilage (22) was used to localize this molecule, or molecules containing this epitope, in bovine articular cartilages, in cartilage growth plate, and in other connective tissues. Using an indirect method employing peroxidase-labeled pig anti-mouse immunoglobulin G, DS-PGII was shown to be present mainly in the superficial zone of adult articular condylar cartilage of the metacarpal-phalangeal joint. In fetal articular and epiphyseal cartilages, the molecule was uniformly distributed throughout the matrix. By approximately 10 months of age it was confined mainly to the superficial and middle zones of articular cartilage and the inter-territorial and pericellular matrix of the deep zone. DS-PGII was not detected in the primary growth plate of the fetus except in the proliferative zone, where it was sometimes present in trace amounts. In contrast, it was present throughout the adjacent matrix of developing epiphyseal cartilage. In the trabeculae of the metaphysis, strong staining for DS-PGII was seen in decalcified osteoid and bone immediately adjacent to osteoblasts. Staining was also observed on collagen fibrils in skin, tendon, and ligament and in the adventitia of the aorta and of smaller arterial vessels in the skin. These observations indicate that DS-PGII and/or molecules containing this epitope are widely distributed in collagenous tissues, where the molecule is intimately associated with collagen fibrils; in adult cartilage this association is limited mainly to the narrow parallel arrays of fibrils which are found in the superficial zone at the articular surface. From its intimate association and other studies, this molecule may play an important role in determining the sizes and tensile properties of collagen fibrils; it may also be involved in the calcification of osteoid but not of cartilage.

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Pordzik, Johannes, Anke Bernstein, Julius Watrinet, Hermann O. Mayr, Sergio H. Latorre, Hagen Schmal e Michael Seidenstuecker. "Correlation of Biomechanical Alterations under Gonarthritis between Overlying Menisci and Articular Cartilage". Applied Sciences 10, n. 23 (4 dicembre 2020): 8673. http://dx.doi.org/10.3390/app10238673.

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Just like menisci, articular cartilage is exposed to constant and varying stresses. Injuries to the meniscus are associated with the development of gonarthritis. Both the articular cartilage and the menisci are subject to structural changes under gonarthritis. The aim of this study was to investigate biomechanical alterations in articular cartilage and the menisci under gonarthritis by applying an indentation method. The study assessed 11 menisci from body donors as controls and 21 menisci from patients with severe gonarthritis. For the simultaneous examination of the articular cartilage and the menisci, we only tested the joint surfaces of the tibial plateau covered by the corresponding menisci. Over the posterior horn of the meniscus, the maximum applied load—the highest load registered by the load cell—of the arthritic samples of 0.02 ± 0.02 N was significantly greater (p = 0.04) than the maximum applied load of the arthritis-free samples of 0.01 ± 0.01 N. The instantaneous modulus (IM) at the center of the arthritic cartilage covered by the meniscus with 3.5 ± 2.02 MPa was significantly smaller than the IM of the arthritis-free samples with 5.17 ± 1.88 MPa (p = 0.04). No significant difference was found in the thickness of the meniscus-covered articular cartilage between the arthritic and arthritis-free samples. Significant correlations between the articular cartilage and the corresponding menisci were not observed at any point. In this study, the biomechanical changes associated with gonarthritis affected the posterior horn of the meniscus and the mid region of the meniscus-covered articular cartilage. The assessment of cartilage thickness as a structural characteristic of osteoarthritis may be misleading with regard to the interpretation of articular cartilage’s biomechanical properties.

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Khajehsaeid, Hesam, Zanko Abdollahpour e Hedyeh Farahmandpour. "Effect of Degradation and Osteoarthritis on the Viscoelastic Properties of Human Knee Articular Cartilage: An Experimental Study and Constitutive Modeling". Biomechanics 1, n. 2 (20 agosto 2021): 225–38. http://dx.doi.org/10.3390/biomechanics1020019.

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Articular cartilage, as a hydrated soft tissue which covers diarthrodial joints, has a pivotal role in the musculoskeletal system. Osteoarthritis is the most common degenerative disease that affects most individuals over the age of 55. This disease affects the elasticity, lubrication mechanism, damping function, and energy absorption capability of articular cartilage. In order to investigate the effect of osteoarthritis on the performance of articular cartilage, the mechanical behavior of human knee articular cartilage was experimentally investigated. Progressive cyclic deformation was applied beyond the physiological range to facilitate degradation of the tissue. The relaxation response of the damaged tissue was modeled by means of a fractional-order nonlinear viscoelastic model in the framework of finite deformations. It is shown that the proposed fractional model well reproduces the tissue’s mechanical behavior using a low number of parameters. Alteration of the model parameters was also investigated throughout the progression of tissue damage. This helps predict the mechanical behavior of the osteoarthritic tissue based on the level of previous damage. It is concluded that, with progression of osteoarthritis, the articular cartilage loses its viscoelastic properties such as damping and energy absorption capacity. This is also accompanied by a loss of stiffness which deteriorates more rapidly than viscosity does throughout the evolution of tissue damage. These results are thought to be significant in better understanding the degradation of articular cartilage and the progression of OA, as well as in the design of artificial articular cartilages.

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Clark, Andrea L., Linda Mills, David A. Hart e Walter Herzog. "MUSCLE-INDUCED PATELLOFEMORAL JOINT LOADING RAPIDLY AFFECTS CARTILAGE mRNA LEVELS IN A SITE SPECIFIC MANNER". Journal of Musculoskeletal Research 08, n. 01 (marzo 2004): 1–12. http://dx.doi.org/10.1142/s0218957704001223.

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Mechanical loading of articular cartilage affects the synthesis and degradation of matrix macromolecules. Much of the work in this area has involved mechanical loading of articular cartilage explants or cells in vitro and assessing biological responses at the mRNA and protein levels. In this study, we developed a new experimental technique to load an intact patellofemoral joint in vivo using muscle stimulation. The articular cartilages were cyclically loaded for one hour in a repeatable and measurable manner. Cartilage was harvested from central and peripheral regions of the femoral groove and patella, either immediately after loading or after a three hour recovery period. Total RNA was isolated from the articular cartilage and biological responses were assessed on the mRNA level using the reverse transcriptase-polymerase chain reaction. Articular cartilage from intact patellofemoral joints demonstrated heterogeneity at the mRNA level for six of the genes assessed independent of the loading protocol. Cyclical loading of cartilage in its native environment led to alterations in mRNA levels for a subset of molecules when assessed immediately after the loading period. However, the increases in TIMP-1 and decreases in bFGF mRNA levels were transient; being present immediately after load application but not after a three hour recovery period.

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Müller, Andreas, e Friedrich P. Paulsen. "Impact of Vocal Cord Paralysis on Cricoarytenoid Joint". Annals of Otology, Rhinology & Laryngology 111, n. 10 (ottobre 2002): 896–901. http://dx.doi.org/10.1177/000348940211101006.

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To demonstrate structural changes in the cricoarytenoid joint after recurrent laryngeal nerve paralysis, we performed a laboratory investigation of fixed arytenoid cartilages from adult humans obtained during laser surgical arytenoidectomy in cases of bilateral vocal fold paralysis, analyzing the articular cartilage, the joint capsule, and the attached laryngeal musculature. Ten arytenoid cartilages from adult humans were studied by means of histology, as well as scanning and transmission electron microscopy. After long-standing denervation (>6 months), all arytenoid cartilages showed degenerative changes in their joint surface structure at various levels of intensity. The articular surface revealed fibrillation in some places, demasking of collagen fibrils next to the joint surface, and formation of chondrocyte clusters near the joint surface. All specimens also showed muscle atrophy. We conclude that long-standing recurrent laryngeal nerve paralysis does not result in ankylosis of the cricoarytenoid joint, as assumed, but the articular cartilage undergoes structural changes comparable to those in osteoarthritis. Structural changes in the articular cartilage and in the surrounding musculature hamper efforts at joint function recovery, as do procedures aiming solely at either medialization or lateralization of the vocal fold.

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Amaratunga, H. A., S. B. Adikari, H. J. Suraweera, A. W. M. W. D. B. Amunugama, M. R. Illeperuma, T. Sivakanesan, W. S. Rathnaweera e D. R. C. K. Dissanayake. "Histopathological changes due to osteoarthritis in articular cartilages of the knee". Sri Lanka Anatomy Journal 6, n. 2 (30 dicembre 2022): 22–33. http://dx.doi.org/10.4038/slaj.v6i2.162.

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Introduction: The bony ends of a synovial joint are lined by a specialised hyaline cartilage termed the articular cartilage. Articular cartilage can be affected with degenerative diseases such as osteoarthritis. Knee being one of the larger joints built for weight bearing is the commonest site for osteoarthritis. The aim of this study was to describe the macroscopic and microscopic features of articular cartilages of the knee joint in patients diagnosed with primary osteoarthritis.Methods: Seventy-two articular cartilages removed during total knee replacement surgery were observed for macroscopic damage and graded according to the direct visual assessment score. Thirty specimens randomly selected were processed for histology and stained with Safranin-O-fast green-iron hematoxylin and observed and scored using the Mankins histological and histochemical grading system.Results: majority of specimens showed severe damage in the medial compartment and much less damage in the lateral compartment. In the tibia the damage was greatest on the medial most edge where the articular cartilage was absent leaving the bone exposed. Anteromedial area was relatively spared. In the femur the middle part of the medial condyle was seen to be more severely damaged. A similar pattern was observed in 19 (63.3%) of the specimens and showed exposure of bone. In the lateral compartment worst damage was observed in the middle of the lateral femoral condyle, with the rest of the lateral compartment being well persevered. This pattern was observed in 26 (86.6%) of the knee specimens.Conclusion: OA of the medial compartment causes the two cartilage surfaces to grind together, mechanically denuding the cartilage layers, while the lateral compartment which receives much less mechanical stress is well preserved.

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Ulrich-Vinther, Michael, Michael D. Maloney, Edward M. Schwarz, Randy Rosier e Regis J. OʼKeefe. "Articular Cartilage Biology". Journal of the American Academy of Orthopaedic Surgeons 11, n. 6 (novembre 2003): 421–30. http://dx.doi.org/10.5435/00124635-200311000-00006.

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Rosenberg, Lawrence C. "Articular Cartilage Lesions". Journal of Bone & Joint Surgery 87, n. 4 (aprile 2005): 921–22. http://dx.doi.org/10.2106/00004623-200504000-00033.

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Dalziel, Rod. "The articular cartilage". Sports Medicine, Training and Rehabilitation 2, n. 3-4 (aprile 1991): 269–72. http://dx.doi.org/10.1080/15438629109511926.

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Grande, Daniel A., John A. Schwartz, Eric Brandel, Nadeen O. Chahine e Nicholas Sgaglione. "Articular Cartilage Repair". CARTILAGE 4, n. 4 (9 luglio 2013): 281–85. http://dx.doi.org/10.1177/1947603513494402.

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Trippel, Stephen B. "Articular cartilage research". Current Opinion in Rheumatology 2, n. 5 (ottobre 1990): 777–82. http://dx.doi.org/10.1097/00002281-199002050-00015.

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Carson, Juan R. "Articular Cartilage Repair". Science Insights 2018, n. 2018 (28 ottobre 2018): 1–4. http://dx.doi.org/10.15354/si.18.re082.

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Buckwalter, J. A. "Articular Cartilage Injuries". Clinical Orthopaedics and Related Research 402 (settembre 2002): 21–37. http://dx.doi.org/10.1097/00003086-200209000-00004.

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Kheir, Ehab, e David Shaw. "Hyaline articular cartilage". Orthopaedics and Trauma 23, n. 6 (dicembre 2009): 450–55. http://dx.doi.org/10.1016/j.mporth.2009.01.003.

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Chu, Constance R., F. Richard Convery, Wayne H. Akeson, Marvin Meyers e David Amiel. "Articular Cartilage Transplantation". Clinical Orthopaedics and Related Research 360 (marzo 1999): 159–68. http://dx.doi.org/10.1097/00003086-199903000-00019.

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Newman, Alan P. "Articular Cartilage Repair". American Journal of Sports Medicine 26, n. 2 (marzo 1998): 309–24. http://dx.doi.org/10.1177/03635465980260022701.

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Articular cartilage can tolerate a tremendous amount of intensive and repetitive physical stress. However, it manifests a striking inability to heal even the most minor injury. Both the remarkable functional characteristics and the healing limitations reflect the intricacies of its structure and biology. Cartilage is composed of chondrocytes embedded within an extracellular matrix of collagens, proteoglycans, and noncollagenous proteins. Together, these substances maintain the proper amount of water within the matrix, which confers its unique mechanical properties. The structure and composition of articular cartilage varies three-dimensionally, according to its distance from the surface and in relation to the distance from the cells. The stringent structural and biological requirements imply that any tissue capable of successful repair or replacement of damaged articular cartilage should be similarly constituted. The response of cartilage to injury differs from that of other tissues because of its avascularity, the immobility of chondrocytes, and the limited ability of mature chondrocytes to proliferate and alter their synthetic patterns. Therapeutic efforts have focused on bringing in new cells capable of chondrogenesis, and facilitating access to the vascular system. This review presents the basic science background and clinical experience with many of these methods and information on synthetic implants and biological adhesives. Although there are many exciting avenues of study that warrant enthusiasm, many questions remain. These issues need to be addressed by careful basic science investigations and both short- and long-term clinical trials using controlled, prospective, randomized study design.

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Hayes, Donald W., e Ryan K. Averett. "Articular Cartilage Transplantation". Clinics in Podiatric Medicine and Surgery 18, n. 1 (gennaio 2001): 161–76. http://dx.doi.org/10.1016/s0891-8422(23)01172-2.

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34

Tarniţă, Daniela, Marius Catana e Dan Nicolae Tarnita. "Modeling and Finite Element Analysis of the Human Knee Joint Affected by Osteoarthritis". Key Engineering Materials 601 (marzo 2014): 147–50. http://dx.doi.org/10.4028/www.scientific.net/kem.601.147.

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Abstract (sommario):

The paper presents a complex three-dimensional model of the human knee joint, containing bones, ligaments, menisci, tibial and femoral cartilages. To investigate the role of the articular cartilage in the developing of the osteoarthritis, to analyze and simulate the biomechanical behavior of the human knee joint, a finite element analysis was performed. The non-linearities are due to the presence of the contact elements modeled between components surfaces and to the nonlinear properties of the cartilage, applying a load of 800 N and 1500 N, for 0o in flexion. The results show that misalignment (valgus variation) could damage the articular cartilage because they increase the stress magnitude, that progressively produce articular cartilage damage and it enhances the osteoarthritis phenomenon due to mechanical factors. The displacements and the Von Mises stress distributions on the cartilage and menisci for the virtual prototype, considering an angle of 10 degrees for valgus, are presented. The obtained values are comparable with the values obtained by other authors.

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Joiner, G. A., E. R. Bogoch, K. P. Pritzker, M. D. Buschmann, A. Chevrier e F. S. Foster. "High Frequency Acoustic Parameters of Human and Bovine Articular Cartilage following Experimentally-Induced Matrix Degradation". Ultrasonic Imaging 23, n. 2 (aprile 2001): 106–16. http://dx.doi.org/10.1177/016173460102300203.

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Matrix degradation and proteoglycan loss in articular cartilag eare features of early osteoarthritis. To determine the effect of matrix degradation and proteoglycan loss on ultrasound propagation in cartilage, we used papain and interleukin-1α to degrade the matrix proteoglycans of human and bovine cartilage samples, respectively. There is also minor collagen alteration associated with these chemical degradation methods. We compared the speed of sound and frequency dependent attenuation (20–40 MHz) of control and experimental paired samples. We found that a loss of matrix proteoglycans and collagen disruption resulted in a 20–30% increase in the frequency dependent attenuation and a 2% decrease in the speed of sound in both human and bovine cartilage. We conclude that the frequency dependent attenuation and speed of sound in articular cartilage are sensitive to experimental modification of the matrix proteoglycans and collagen. These findings suggest that ultrasound can potentially be used to detect morphologic changes in articular cartilage associated with the progression of osteoarthritis.

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Jurvelin, J., A.-M. Säämänen, J. Arokoski, H. J. Helminen, I. Kiviranta e M. Tammi. "Biomechanical Properties of the Canine Knee Articular Cartilage as Related to Matrix Proteoglycans and Collagen". Engineering in Medicine 17, n. 4 (ottobre 1988): 157–62. http://dx.doi.org/10.1243/emed_jour_1988_017_042_02.

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The instant, creep and equilibrium responses of canine knee articular cartilages were determined after a constant load application with an in situ indentation creep test and related to the chemical composition of the tissue. Instantly, the cartilage stiffness correlated inversely with the proportion of proteoglycans (PGs) extractable with guanidium chloride. The tibial cartilage, rich in PGs but relatively poor in collagen, showed a low resistance to instant rearrangement of the solid matrix after load application. However, the resistance of the tibial cartilage to water flow during creep deformation was similar or even higher than in the femur. The rate of creep correlated inversely with the PG content. The equilibrium modulus of the femoral cartilage (0.40 MPa), 29 per cent higher than in the tibia (0.31 MPa), was related to the content of PGs, while in the tibia the direct correlation between PGs and modulus was not observed. Our results suggest that while PGs control the fluid flow in articular cartilage, a high PG content alone does not guarantee high stiffness of the cartilage. Instead, the properties of the collagen network are suggested to control particularly the instant shape alterations of the articular cartilage under compression.

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Chubinskaya, Susan, Charis Merrihew, Gabriella Cs-Szabo, Juergen Mollenhauer, John McCartney, David C. Rueger e Klaus E. Kuettner. "Human Articular Chondrocytes Express Osteogenic Protein-1". Journal of Histochemistry & Cytochemistry 48, n. 2 (febbraio 2000): 239–50. http://dx.doi.org/10.1177/002215540004800209.

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This study demonstrates for the first time that human articular chondrocytes express osteogenic protein-1 (OP-1). OP-1 was originally purified from bone matrix and was shown to induce cartilage and bone formation. Both OP-1 protein and message were present in human normal and osteoarthritic (OA) cartilages. OP-1 mRNA was upregulated in OA cartilage compared with normal adult tissues. However, the level of mature OP-1 protein in the same OA tissues was downregulated, whereas the pro-OP-1 remained high. Moreover, these two forms of OP-1 were localized in an inverted manner. Mature OP-1 was primarily detected in the superficial layer, whereas the pro-form was mostly in the deep layer of cartilage. The presence of pro- and mature OP-1 in extracts of normal and OA cartilages was confirmed by Western blotting. These findings imply that articular chondrocytes continue to express and synthesize OP-1 throughout adulthood. The observed patterns of the distribution of pro- and mature OP-1 also suggest differences in the processing of this molecule by normal and OA chondrocytes and by the cells in the superficial and deep layers. Distinct distribution of OP-1 and its potential activation in deep zones and regions of cloning in OA cartilages may provide clues to the potential involvement of endogenous OP-1 in repair mechanisms.

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Li, Xue, Jin Duo Ye, Chun Qui Zhang, Qian Qian Tian, Xian Kang Wang e Li Min Dong. "Numerical Simulation about Stretching Process in Different Layers of Cartilage". Applied Mechanics and Materials 441 (dicembre 2013): 480–83. http://dx.doi.org/10.4028/www.scientific.net/amm.441.480.

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Cartilage with complex structure is a porous viscoelastic material. The direction of arrangement of collagen fibers in different layer regions directly affects the mechanical properties of the cartilage layer region. It is very important to use the method of numerical simulation for studying cartilage damage and repair through experimental measurements of cartilage mechanical parameters of the different layers. Because of the relatively small size of the cartilage, it is very difficult to measure mechanical parameters of cartilages by tensile test. The paper for main problems in the tensile test of cartilages, first by porcine articular cartilage compression testing, measuring the displacement of cartilage areas of different layers, according to the characteristics of the displacement determines the size of areas of different layers of cartilage, and then designed the cartilage and substrate stretching models. Model includes two forms of direct bonding and embedding bonding to simulate stretching process of different layers of the cartilage area in numerical way, displacement fields and stress-strain fields of stretching cartilage in different layer regions are derived. The numerical results show that using the way of embedded bonding can make stress of articular well-distributed without stress concentration, so it is a good way of bonding methods. Paper of the research work laid the foundation for measuring mechanical parameters of cartilage by stretch experiment.

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Davies, Sherri R., Shinji Sakano, Yong Zhu e Linda J. Sandell. "Distribution of the Transcription Factors Sox9, AP-2, and [Delta]EF1 in Adult Murine Articular and Meniscal Cartilage and Growth Plate". Journal of Histochemistry & Cytochemistry 50, n. 8 (agosto 2002): 1059–65. http://dx.doi.org/10.1177/002215540205000808.

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Abstract (sommario):

The control of extracellular matrix (ECM) production is important for the development, maintenance, and repair of cartilage tissues. Matrix molecule synthesis is generally regulated by the rate of gene transcription determined by DNA transcription factors. We have shown that transcription factors Sox9, AP-2, and [delta]EF1 are able to alter the rate of CD-RAP transcription in vitro: Sox9 upregulates, AP-2 exhibits biphasic effects, and [delta]EF1 represses expression of the CD-RAP gene. To correlate these in vitro activities in vivo, transcription factors were co-immunolocalized with ECM proteins in three different cartilage tissues in which the rates of biosynthesis are quite different: articular, meniscal, and growth plate. Immunoreactivities of type II collagen and CD-RAP were higher in growth plate than in either the articular or meniscal cartilages and correlated positively with Sox9 protein. Sox9 staining decreased with hypertrophy and was low in articular and meniscal cartilages. In contrast, AP-2 and [delta]EF1 were low in proliferating chondrocytes but high in lower growth plate, articular, and meniscal cartilages. This increase was also accompanied by intense nuclear staining. These immunohistochemical results are the first to localize both [delta]EF1 and AP-2 to adult articular, meniscal, and growth plate cartilages and provide in vivo correlation of previous molecular biological studies.

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40

Gustafson, Scott B., Gayle W. Trotter, Robert W. Norrdin, Robert H. Wrigley e C. Lamar. "Evaluation of intra-articularly administered sodium monoiodoacetate-induced chemical injury to articular cartilage of horses". American Journal of Veterinary Research 53, n. 7 (1 luglio 1992): 1193–202. http://dx.doi.org/10.2460/ajvr.1992.53.7.1193.

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Summary Three doses of sodium monoiodoacetate (mia) were used to induce degenerative changes in articular cartilage in middle carpal joints of horses. Twelve young (2- to 5-year-old) horses, free of lameness, were randomly allotted to 3 groups. One middle carpal joint of each horse was injected with 0.9% NaCl solution (control joint). The contralateral middle carpal joint was injected with 0.09 mg of MlA/kg of body weight (group 1); 0.12 mg/kg (group 2); or 0.16 mg/kg (group 3). After mia administration, horses were allowed ad libitum exercise in a 2-acre paddock for 12 weeks. At the end of the study, gross and microscopic tissue changes were evaluated and biochemical analyses of articular cartilage were done. Grossly, diffuse partial thickness articular cartilage lesions were observed in group-2 (n = 2) and group-3 (n = 4) horses, but not in group-1 horses. Articular cartilage uronic acid content was significantly (P < 0.03) decreased in all mia-injected joints, compared with controls. Articular cartilage matrix staining with safranin-O was decreased in 3 of 4 mia- injected joints of group-1 horses and in all mia-injected joints of group-2 and group-3 horses, compared with controls (P < 0.06). Microscopic degenerative changes in articular cartilage were not significantly different between mia-injected and control joints in group-1 horses, but were increased (P<0.06) in all MlA-injected joints of group-2 and group-3 horses, compared with controls. Qualitatively, decreased matrix staining and degenerative changes were more severe in group-3 horses. On the basis of articular cartilage gross and microscopic changes, as well as biochemical changes, 0.12 mg of mia/kg injected intra-articularly was determined to induce moderate degrees of articular cartilage degeneration. This model of chemically induced articular cartilage injury could be useful for evaluating treatment effects of anti-arthritic drugs in horses.

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Cha, Ryota, Shuji Nakagawa, Yuji Arai, Atsuo Inoue, Naoki Okubo, Yuta Fujii, Kenta Kaihara et al. "Enhancing Cartilage Metabolism in Rats through a Novel Thermal Stimulation Technique with Photosensitizers". International Journal of Molecular Sciences 25, n. 12 (19 giugno 2024): 6728. http://dx.doi.org/10.3390/ijms25126728.

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Although the moderate thermal stimulation of articular cartilage exerts chondroprotective effects, it is difficult to effectively heat deep articular cartilage with conventional methods. Photosensitizers increase the ambient temperature using near-infrared (NIR) radiation, which has high tissue permeability. We hypothesized that the intra-articular administration of photosensitizers and NIR irradiation would exert a greater heating effect on articular cartilage. We aimed to evaluate the heating effect of this method on cultured chondrocytes and rat knee cartilage. In vitro, we irradiated a photosensitizer-containing medium with NIR and measured changes in the medium temperature, cytotoxicity, and gene expression of heat shock protein (HSP) 70 and aggrecan (ACAN). In vivo, the knee joints of rats treated with photosensitizers were irradiated with NIR, and changes in intra-articular temperature and gene expression were measured, alongside histological analysis. The results showed that the medium and intra-articular temperature were raised to approximately 40 °C with no apparent disruption to articular cartilage or the immunohistochemically enhanced staining of HSP70 in chondrocytes. The gene expression of HSP70 and ACAN was increased in both cultured and articular cartilage. In summary, this method can safely heat joints and enhance cartilage metabolism by inducing HSP70 expression in articular cartilage. It presents a new hyperthermia therapy with effective cartilage protection.

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42

Hayashi, Kei, Brian Caserto, Mary Norman, Hollis Potter, Matthew Koff e Sarah Pownder. "Magnetic Resonance Imaging T2 Values of Stifle Articular Cartilage in Normal Beagles". Veterinary and Comparative Orthopaedics and Traumatology 31, n. 02 (febbraio 2018): 108–13. http://dx.doi.org/10.3415/vcot-17-03-0093.

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Objectives The purpose of this study was to evaluate regional differences of canine stifle articular cartilage using the quantitative magnetic resonance imaging (MRI) technique of T2 mapping. Methods Fourteen stifle joints from seven juvenile male Beagle dogs with no evidence or prior history of pelvic limb lameness were imaged ex vivo using standard of care fast spin echo MRI and quantitative T2 mapping protocols. Regions of interest were compared between the femoral, patellar and tibial cartilages, as well as between the lateral and medial femorotibial compartments. Limbs were processed for histology with standard stains to confirm normal cartilage. Results The average T2 value of femoral trochlear cartilage (37.5 ± 2.3 ms) was significantly prolonged (p < 0.0001) as compared with the femoral condylar, patellar and tibial condylar cartilages (33.1 ± 1.5 ms, 32.8 ± 2.3 ms, and 28.0 ± 1.7 ms, respectively). When comparing medial and lateral condylar compartments, the lateral femoral condylar cartilage had the longest T2 values (34.8 ± 2.8 ms), as compared with the medial femoral condylar cartilage (30.9 ± 1.9 ms) and lateral tibial cartilage (29.1 ± 2.3 ms), while the medial tibial cartilage had the shortest T2 values (26.7 ± 2.4 ms). Clinical Significance As seen in other species, regional differences in T2 values of the canine stifle joint are identified. Understanding normal regions of anticipated prolongation in different joint compartments is needed when using quantitative imaging in models of canine osteoarthritis.

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43

A Soliman, Soha. "MMP-9 Expression in Normal Rabbit Chondrocytes". Cytology & Histology International Journal 5, n. 1 (2021): 1–9. http://dx.doi.org/10.23880/chij-16000131.

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Chondrocytes regulate anabolic and catabolic processes to maintain the extracellular matrix components. Catabolic activities depend on the proteolytic action of the matrix -degrading enzymes including ADAMTS (A disintegrin and metalloproteinases) and MMP (Matrix Metalloproteinase). The current study explored the distribution of MMP-9 in normal articular cartilages of the embryos rabbit. Articular cartilage has grown by appositional growth that the perichondrial stem cells differentiate into chondrocytes. MMP-9 positive perichondrial stem cells or chondroblasts and early chondrocytes. Mature chondrocytes exhibited weak immunoaffinity for MMP-9. In conclusion, MMP-9 was essential during chondrocytes growth. The current study alludes to the potential role of MMP-9 during the growth of the articular cartilage.

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44

Karpiński, Robert, Łukasz Jaworski, Józef Jonak e Przemysław Krakowski. "Stress distribution in the knee joint in relation to tibiofemoral angle using the finite element method". MATEC Web of Conferences 252 (2019): 07007. http://dx.doi.org/10.1051/matecconf/201925207007.

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The article presents the results of a preliminary study on the structural analysis of the knee joint, considering changes in the mechanical properties of the articular cartilage of the joint. Studies have been made due to the need to determine the tension distribution occurring in the cartilage of the human knee. This distribution could be the starting point for designing custom made human knee prosthesis. Basic anatomy, biomechanical analysis of the knee joint and articular cartilage was introduced. Based on a series of computed tomography [CT] scans, the 3D model of human knee joint was reverse-engineered, processed and exported to CAD software. The static mechanical analysis of the knee joint model was conducted using the finite element method [FEM], in three different values of tibiofemoral angle and with varying mechanical properties of the cartilage tissue. Main conclusions of the study are: the capability to absorb loads by articular cartilage of the knee joint is preliminary determined as decreasing with increasing degenerations of the cartilage and with age of a patient. Without further information on changes of cartilage’s mechanical parameters in time it is hard to determine the nature of relation between mentioned capability and these parameters.

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Wu, J. P., e T. B. Kirk. "Study of Altered Mechanical Properties of Articular Cartilage in Relation to the Collagen Network". Advanced Materials Research 41-42 (aprile 2008): 9–14. http://dx.doi.org/10.4028/www.scientific.net/amr.41-42.9.

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Articular cartilage is a semitransparent elastic material that covers on the two articulating bones in synovial joints. It acts as a cushion between the bones that transfers loads from one to another while attenuating dynamic stresses and providing almost frictionless contact surfaces for normal use of synovial joints without pains. Osteoarthritis causes a chronic joint pain and it is mainly due to malfunction of articular cartilage. The mechanical function of articular cartilage is derived from its unique microstructure. Therefore, study of the relationship between the mechanical function and microstructure of articular cartilage comprehends the aetiology and pathology of osteoarthritis. Confocal microscopy permits studying the internal microstructure of buck biological tissues without tissue sectioning and dehydration. This provides a way to study the relationship between the mechanical function and microstructure of articular cartilage. Using a fibre optic laser scanning confocal microscope, this study examines the pathological status of articular cartilage in relation to the mechanical function and 3D collagen network of articular cartilage. The results show that the 3D collagen structure and the mechanical function are different between normal and arthritic cartilage. Loss of the integrity of the 3D collagen network is closely related to cartilage softening.

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Abbass, Sadiq Jafer, e Farah Mohammed Reda Abdulateef. "FINITE ELEMENT ANALYSIS OF HUMAN AND ARTIFICIAL ARTICULAR CARTILAGE". Journal of Engineering 18, n. 04 (21 luglio 2023): 443–58. http://dx.doi.org/10.31026/j.eng.2012.04.06.

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Joint diseases, such as osteoarthritis, induce pain and loss of mobility to millions of people around the world. Current clinical methods for the diagnosis of osteoarthritis include X-ray, magnetic resonance imaging, and arthroscopy. These methods may be insensitive to the earliest signs of osteoarthritis. This study investigates a new procedure that was developed and validated numerically for use in the evaluation of cartilage quality. This finite element model of the human articular cartilage could be helpful in providing insight into mechanisms of injury, effects of treatment, and the role of mechanical factors in degenerativeconditions, this three-dimensional finite element model is a useful tool for understanding of the stress distributions within articular cartilage in response to external loads and investigating both the prevention of injury and the pathological degeneration of the joints.In this study, 21 models were analysed by using ANSYS workbench v12.1: four normal articular cartilage models (distal femur, patella, medial and lateral tibia). A redesign to the distal femur model was done to get osteoarthritis articular cartilage (simple and deep) seven models by making partial cut without affecting the subchondral bone, and full cut with part of the subchondral bone in different diameters. Finally a treatment done by replacing the defective parts with artificial articular cartilages with different types of treatment. The finite element analysis studied depending on a Von Mises criteria and total deformation in different activities. The results shows that Autologous Chondrocyte Implementation is the best treatment way and it is close by 87.50% to normal cartilage. This procedure can be used as a diagnostic procedure for osteoarthritic patients and to choose the best treatment options.

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Reiter, Mary Pat, Shawn H. Ward, Barbara Perry, Adrian Mann, Joseph W. Freeman e Moti L. Tiku. "Intra-articular injection of epigallocatechin (EGCG) crosslinks and alters biomechanical properties of articular cartilage, a study via nanoindentation". PLOS ONE 17, n. 10 (25 ottobre 2022): e0276626. http://dx.doi.org/10.1371/journal.pone.0276626.

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Osteoarthritis and rheumatoid arthritis are debilitating conditions, affecting millions of people. Both osteoarthritis and rheumatoid arthritis degrade the articular cartilage (AC) at the ends of long bones, resulting in weakened tissue prone to further damage. This degradation impairs the cartilage’s mechanical properties leading to areas of thinned cartilage and exposed bone which compromises the integrity of the joint. No preventative measures exist for joint destruction. Discovering a way to slow the degradation of AC or prevent it would slow the painful progression of the disease, allowing millions to live pain-free. Recently, that the articular injection of the polyphenol epigallocatechin-gallate (EGCG) slows AC damage in an arthritis rat model. It was suggested that EGCG crosslinks AC and makes it resistant to degradation. However, direct evidence that intraarticular injection of EGCG crosslinks cartilage collagen and changes its compressive properties are not known. The aim of this study was to investigate the effects of intraarticular injection of EGCG induced biomechanical properties of AC. We hypothesize that in vivo exposure EGCG will bind and crosslink to AC collagen and alter its biomechanical properties. We developed a technique of nano-indentation to investigate articular cartilage properties by measuring cartilage compressive properties and quantifying differences due to EGCG exposure. In this study, the rat knee joint was subjected to a series of intraarticular injections of EGCG and contralateral knee joint was injected with saline. After the injections animals were sacrificed, and the knees were removed and tested in an anatomically relevant model of nanoindentation. All mechanical data was normalized to the measurements in the contralateral knee to better compare data between the animals. The data demonstrated significant increases for reduced elastic modulus (57.5%), hardness (83.2%), and stiffness (17.6%) in cartilage treated with injections of EGCG normalized to those treated with just saline solution when compared to baseline subjects without injections, with a significance level of alpha = 0.05. This data provides evidence that EGCG treated cartilage yields a strengthened cartilage matrix as compared to AC from the saline injected knees. These findings are significant because the increase in cartilage biomechanics will translate into resistance to degradation in arthritis. Furthermore, the data suggest for the first time that it is possible to strengthen the articular cartilage by intraarticular injections of polyphenols. Although this data is preliminary, it suggests that clinical applications of EGCG treated cartilage could yield strengthened tissue with the potential to resist or compensate for matrix degradation caused by arthritis.

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Neidel, J., J. Schmidt e M. H. Hackenbroch. "Intra-articular injections and articular cartilage metabolism". Archives of Orthopaedic and Trauma Surgery 111, n. 4 (1992): 237–42. http://dx.doi.org/10.1007/bf00571486.

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PENG, XIONGQI, GENG LIU e ZAOYANG GUO. "FINITE ELEMENT CONTACT ANALYSIS OF A HUMAN SAGITTAL KNEE JOINT". Journal of Mechanics in Medicine and Biology 10, n. 02 (giugno 2010): 225–36. http://dx.doi.org/10.1142/s0219519410003423.

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Abstract (sommario):

Articular cartilage is a vital component of human knee joints by providing a low-friction and wear-resistant surface in knee joints and distributing stresses to tibia. The degeneration or damage of articular cartilage will incur acute pain on the human knee joints. Hence, to understand the mechanism of normal and pathological functions of articular cartilage, it is very important to investigate the contact mechanics of the human knee joints. Experimental research has difficulties in reproducing the physiological conditions of daily activities and measuring the key factors such as contact-stress distributions inside knee joint without violating the physiological environment. On the other hand, numerical approaches such as finite element (FE) analysis provide a powerful tool in the biomechanics study of the human knee joint. This article presents a two-dimensional (2D) FE model of the human knee joints that includes the femur, tibia, patella, quadriceps, patellar tendon, and cartilages. The model is analyzed with dynamic loadings to study stress distribution in the tibia and contact area during contact with or without articular cartilage. The results obtained in this article are very helpful to find the pathological mechanism of knee joint degeneration or damage, and thus guide the therapy of knee illness and artificial joint replacement.

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SUN, XINGDONG, ZUNQIANG FAN, SHIZHONG ZHANG, DI WU, YUEXI ZHONG, HONGWEI ZHAO e LUQUAN REN. "A DAMAGE MECHANISM OF MICRO-PARTICLES ON ARTICULAR CARTILAGE OF KNEE BY NANOINDENTATION". Journal of Mechanics in Medicine and Biology 17, n. 08 (dicembre 2017): 1750116. http://dx.doi.org/10.1142/s0219519417501160.

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Articular cartilage plays an important role in organism due to its excellent shock absorbing and buffering functions. Increasing problems about damages of articular cartilage are making a great deal of trouble to human beings. The damage mechanism of articular cartilage is very complicated and keeps unclear. In this research, the damage mechanism was investigated from the perspective of micro-particle attrition by nanoindentation experiments. The micro-particle was simulated by the indenter in experiments. The experimental results demonstrated that the load from micro-particle could not maintain when water content was adequate. However, the load could maintain and increase after dehydration. It was found that the partial surface of articular cartilage was crushed and adhered to the indenter. The plastic energy was bigger than elastic energy in the nanoindentation process. Therefore, water content was the crucial factor to protect the articular cartilage from damage. And the recurring partial dehydration owing to ongoing compression enhanced the damage of micro-particle to articular cartilage. This research may provide a new understanding to the damage mechanism of articular cartilage.

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