Browsing by Subject "Subchondral bone"

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    Complex and elementary histological scoring systems for articular cartilage repair
    (F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2015) Orth, Patrick; Madry, Henning
    The repair of articular cartilage defects is increasingly moving into the focus of experimental and clinical investigations. Histological analysis is the gold standard for a valid and objective evaluation of cartilaginous repair tissue and predominantly relies on the use of established scoring systems. In the past three decades, numerous elementary and complex scoring systems have been described and modified, including those of O’Driscoll, Pineda, Wakitani, Sellers and Fortier for entire defects as well as those according to the International Cartilage Repair Society (ICRS-I/II) for osteochondral tissue biopsies. Yet, this coexistence of different grading scales inconsistently addressing diverse parameters may impede comparability between reported study outcomes. Furthermore, validation of these histological scoring systems has only seldom been performed to date. The aim of this review is (1) to give a comprehensive overview and to compare the most important established histological scoring systems for articular cartilage repair, (2) to describe their specific advantages and pitfalls, and (3) to provide valid recommendations for their use in translational and clinical studies of articular cartilage repair.
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    Correlation between 3D microstructural and 2D histomorphometric properties of subchondral bone with healthy and degenerative cartilage of the knee joint
    (F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2014) Lahm, Andreas; Kasch, Richard; Spank, Heiko; Erggelet, Christoph; Esser, Jan; Merk, Harry; Mrosek, Eike
    Cartilage degeneration of the knee joint is considered to be a largely mechanically driven process. We conducted a microstructural and histomorphometric analysis of subchondral bone samples of intact cartilage and in samples with early and higher- grade arthritic degeneration to compare the different states and correlate the findings with the condition of hyaline cartilage. These findings will enable us to evaluate changes in biomechanical properties of subchondral bone during the evolution of arthritic degeneration, for which bone density alone is an insufficient parameter. From a continuous series of 80 patients undergoing implantation of total knee endoprosthesis 30 osteochondral samples with lesions macroscopically classified as ICRS grade 1b (group A) and 30 samples with ICRS grade 3a or 3b lesions (group B) were taken. The bone samples were assessed by 2D histomorphometry (semiautomatic image analysis system) and 3D microstructural analysis (high-resolution microCT system). The cartilage was examined using the semiquantitative real-time PCR gene expression of collagen type I and II and aggrecan. Both histomorphometry and microstructural and biomechanical analysis of subchondral bone in groups A and B consistently revealed progressive changes of both bone and cartilage compared with healthy controls. The severity of cartilage degeneration as assessed by RT PCR was significantly correlated with BV/TV (Bone Volume Fraction), Tb.Th (Trabecular Thickness) showed a slight increase. Tb.N (Trabecular Number), Tb.Sp (Trabecular separation) SMI (Structure Model Index), Conn.D (Connectivity Density) and DA (Degree of Anisotropy) were inversely correlated. We saw sclerotic transformation and phagocytic reticulum cells. Bone volume fraction decreased with an increasing distance from the cartilage with the differences compared with healthy controls becoming greater in more advanced cartilage damage. The density of subchondral bone alone is considered an unreliable parameter for classifying changes evolving over time. The progressive damage of subchondral bone seen in the present study correlates well with cartilage changes. Trabecular orientation is also impaired, which explains the changes in biomechanical parameters and the inadequate load transfer and excessive loading of cartilage. Besides subchondral bone density, which in turn correlates with cartilage thickness, other parameters such as structure model index and grade of anisotropy best reflect mechanical properties such as Young modulus, compressive strength, tensile stress, and failure energy. However, it remains unclear whether the mechanical interaction of the mineralized subchondral tissues with articular cartilage works vice versa. The possibility of a biochemical signalling from the degenerating cartilage via the synovial fluid and bone- cartilage crosstalks via subchondral pores may indeed explain a certain depth dependency of subchondral bone changes.
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    Multichromatic TTF staining characterizes cartilage matrix in osteoarthritis and bone development
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2019) Feng, Yu; Cai, Zhe; Cheung, Wing ki; Yang, Kedi; Xu, Lei; Weijia Lu, William; Yang, Haibo; Chiu, Kwong-Yuen
    Various histological staining methods have been explored to detect the joint lesions in osteoarthritis (OA), but these histological stains cannot comprehensively present the comparatively complex structures of articular cartilage in knee OA. In addition, no integrated histological staining method can be used to evaluate efficiently both the subzone region and matrix composition in cartilage containing tissues. Therefore, in this study, a novel multichromatic staining method termed TTF staining, using Toluidine Blue (T), Tartrazine (T) and Fast Green (F) sequential combined staining for histological analysis, has been exploited to characterize the changes of matrix components and contents in cartilage during OA and in the bone development. This specific TTF staining profile can be used to differentiate the major compartments of knee joint region, including the synovium, meniscus, multiple subzones of cartilage and subchondral bone. An anterior cruciate ligament transection induced OA model in rat has been established to profoundly present the alterations of glycosaminoglycans in cartilage degeneration by TTF staining profile. The changes of TTF staining profile in the chondrification and ossification centers of the postnatal rat knee joint indicate the developmental features of cartilage matrix during the growth of bone. In summary, we have developed an effective histological staining method that enables us to identify the subzones of cartilage in detail and to define the matrix features of bone development. Therefore, finally using this new TTF staining method may help us to exploit a histopathological grading system to assess cartilage lesions in clinical disease.