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Sample records for disco articular adherido

  1. Signal processing for distributed sensor concept: DISCO

    NASA Astrophysics Data System (ADS)

    Rafailov, Michael K.

    2007-04-01

    Distributed Sensor concept - DISCO proposed for multiplication of individual sensor capabilities through cooperative target engagement. DISCO relies on ability of signal processing software to format, to process and to transmit and receive sensor data and to exploit those data in signal synthesis process. Each sensor data is synchronized formatted, Signal-to-Noise Ration (SNR) enhanced and distributed inside of the sensor network. Signal processing technique for DISCO is Recursive Adaptive Frame Integration of Limited data - RAFIL technique that was initially proposed [1] as a way to improve the SNR, reduce data rate and mitigate FPA correlated noise of an individual sensor digital video-signal processing. In Distributed Sensor Concept RAFIL technique is used in segmented way, when constituencies of the technique are spatially and/or temporally separated between transmitters and receivers. Those constituencies include though not limited to two thresholds - one is tuned for optimum probability of detection, the other - to manage required false alarm rate, and limited frame integration placed somewhere between the thresholds as well as formatters, conventional integrators and more. RAFIL allows a non-linear integration that, along with SNR gain, provides system designers more capability where cost, weight, or power considerations limit system data rate, processing, or memory capability [2]. DISCO architecture allows flexible optimization of SNR gain, data rates and noise suppression on sensor's side and limited integration, re-formatting and final threshold on node's side. DISCO with Recursive Adaptive Frame Integration of Limited data may have flexible architecture that allows segmenting the hardware and software to be best suitable for specific DISCO applications and sensing needs - whatever it is air-or-space platforms, ground terminals or integration of sensors network.

  2. DISCO 10-year retrospective survey results

    NASA Astrophysics Data System (ADS)

    Green, Edward J.; Sackett, William M.

    One hundred-eighty-eight new and prospective Ph.D.s have participated in a unique series of meetings designed to integrate young scientists into the research community and to foster interdisciplinary and interinstitutional research. These meetings, the Dissertations Symposia in Chemical Oceanography (DISCO), are sponsored by the Office of Naval Research, the National Science Foundation, and the Sea Grant Office of the National Oceanic and Atmospheric Administration. Expenses for the young marine chemists from academic institutions in the United States are totally provided by the sponsoring agencies. A number of new Ph.D.s from foreign schools have also participated by invitation; their expenses have been paid in part by their home countries or by the United Nations Educational, Scientific and Cultural Organization.

  3. DISCO: 3-D moving-mesh magnetohydrodynamics package

    NASA Astrophysics Data System (ADS)

    Duffell, Paul C.

    2016-05-01

    DISCO evolves orbital fluid motion in two and three dimensions, especially at high Mach number, for studying astrophysical disks. The software uses a moving-mesh approach with a dynamic cylindrical mesh that can shear azimuthally to follow the orbital motion of the gas, thus removing diffusive advection errors and permitting longer timesteps than a static grid. DISCO uses an HLLD Riemann solver and a constrained transport scheme compatible with the mesh motion to implement magnetohydrodynamics.

  4. The Swedish Version of the Diagnostic Interview for Social and Communication Disorders (DISCO-10). Psychometric Properties

    ERIC Educational Resources Information Center

    Nygren, Gudrun; Hagberg, Bibbi; Billstedt, Eva; Skoglund, Asa; Gillberg, Christopher; Johansson, Maria

    2009-01-01

    Psychometric properties of the Diagnostic Interview for Social and Communication Disorders schedule (DISCO) have only been studied in the UK. The authorised Swedish translation of the tenth version of the DISCO (DISCO-10) was used in interviews with close relatives of 91 Swedish patients referred for neuropsychiatrical assessment. Validity…

  5. DISCOS- DYNAMIC INTERACTION SIMULATION OF CONTROLS AND STRUCTURES (IBM VERSION)

    NASA Technical Reports Server (NTRS)

    Frisch, H. P.

    1994-01-01

    The Dynamic Interaction Simulation of Controls and Structure (DISCOS) program was developed for the dynamic simulation and stability analysis of passive and actively controlled spacecraft. In the use of DISCOS, the physical system undergoing analysis may be generally described as a cluster of contiguous flexible structures (bodies) that comprise a mechanical system, such as a spacecraft. The entire system (spacecraft) or portions thereof may be either spinning or nonspinning. Member bodies of the system may undergo large relative excursions, such as those of appendage deployment or rotor/ stator motion. The general system of bodies is, by its inherent nature, a feedback system in which inertial forces (such as those due to centrifugal and Coriolis acceleration) and the restoring and damping forces are motion-dependent. The system may possess a control system in which certain position and rate errors are actively controlled through the use of reaction control jets, servomotors, or momentum wheels. Bodies of the system may be interconnected by linear or nonlinear springs and dampers, by a gimbal and slider block mechanism, or by any combination of these. The DISCOS program can be used to obtain nonlinear and linearized time response of the system, interaction constant forces in the system, total system resonance properties, and frequency domain response and stability information for the system. DISCOS is probably the most powerful computational tool to date for the computer simulation of actively controlled coupled multi-flexible-body systems. The program is not easy to understand and effectively apply, but is not intended for simple problems. The DISCOS user is expected to have extensive working knowledge of rigid-body and flexible-body dynamics, finite-element techniques, numerical methods, and frequency-domain analysis. Various applications of DISCOS include simulation of the Shuttle payload deployment/retrieval mechanism, solar panel array deployment, antenna

  6. DISCOS- DYNAMIC INTERACTION SIMULATION OF CONTROLS AND STRUCTURES (IBM VERSION)

    NASA Technical Reports Server (NTRS)

    Frisch, H. P.

    1994-01-01

    The Dynamic Interaction Simulation of Controls and Structure (DISCOS) program was developed for the dynamic simulation and stability analysis of passive and actively controlled spacecraft. In the use of DISCOS, the physical system undergoing analysis may be generally described as a cluster of contiguous flexible structures (bodies) that comprise a mechanical system, such as a spacecraft. The entire system (spacecraft) or portions thereof may be either spinning or nonspinning. Member bodies of the system may undergo large relative excursions, such as those of appendage deployment or rotor/ stator motion. The general system of bodies is, by its inherent nature, a feedback system in which inertial forces (such as those due to centrifugal and Coriolis acceleration) and the restoring and damping forces are motion-dependent. The system may possess a control system in which certain position and rate errors are actively controlled through the use of reaction control jets, servomotors, or momentum wheels. Bodies of the system may be interconnected by linear or nonlinear springs and dampers, by a gimbal and slider block mechanism, or by any combination of these. The DISCOS program can be used to obtain nonlinear and linearized time response of the system, interaction constant forces in the system, total system resonance properties, and frequency domain response and stability information for the system. DISCOS is probably the most powerful computational tool to date for the computer simulation of actively controlled coupled multi-flexible-body systems. The program is not easy to understand and effectively apply, but is not intended for simple problems. The DISCOS user is expected to have extensive working knowledge of rigid-body and flexible-body dynamics, finite-element techniques, numerical methods, and frequency-domain analysis. Various applications of DISCOS include simulation of the Shuttle payload deployment/retrieval mechanism, solar panel array deployment, antenna

  7. DISCO: A 3D Moving-mesh Magnetohydrodynamics Code Designed for the Study of Astrophysical Disks

    NASA Astrophysics Data System (ADS)

    Duffell, Paul C.

    2016-09-01

    This work presents the publicly available moving-mesh magnetohydrodynamics (MHD) code DISCO. DISCO is efficient and accurate at evolving orbital fluid motion in two and three dimensions, especially at high Mach numbers. DISCO employs a moving-mesh approach utilizing a dynamic cylindrical mesh that can shear azimuthally to follow the orbital motion of the gas. The moving mesh removes diffusive advection errors and allows for longer time-steps than a static grid. MHD is implemented in DISCO using an HLLD Riemann solver and a novel constrained transport (CT) scheme that is compatible with the mesh motion. DISCO is tested against a wide variety of problems, which are designed to test its stability, accuracy, and scalability. In addition, several MHD tests are performed which demonstrate the accuracy and stability of the new CT approach, including two tests of the magneto-rotational instability, one testing the linear growth rate and the other following the instability into the fully turbulent regime.

  8. Towards Regeneration of Articular Cartilage

    PubMed Central

    Iwamoto, Masahiro; Ohta, Yoichi; Larmour, Colleen; Enomoto-Iwamoto, Motomi

    2014-01-01

    Articular cartilage is classified into permanent hyaline cartilage and has significant differences in structure, extracelluar matrix components, gene expression profile, and mechanical property from transient hyaline cartilage found in growth plate. In the process of synovial joint development, articular cartilage is originated from the interzone, developing at the edge of the cartilaginous anlagen, it establishes zonal structure over time and supports smooth movement of the synovial joint through life. The cascade actions of key regulators such as Wnts, GDF5, Erg, and PTHLH coordinate sequential steps of articular cartilage formation. Articular chondrocytes are restrictedly controlled not to differentiate into a hypertrophic stage by autocrine and paracrine factors and extracerllular matrix microenvironment, but retain potential to undergo hypertrophy. The basal calcified zone of articular cartilage is connected with subchondral bone, but not invaded by blood vessels nor replaced by bone, which is highly contrasted with the growth plate. Articular cartilage has limited regenerative capacity, but likely possesses and potentially uses intrinsic stem cell source in the superficial layer, Ranvier’s groove, the intra-articular tissues such as synovium and fat pad, and marrow below the subchondral bone. Considering the biological views on articular cartilage, several important points are raised for regeneration of articular cartilage. We should evaluate the nature of regenerated cartilage as permanent hyaline cartilage and not just hyaline cartilage. We should study how a hypertrophic phenotype of transplanted cells can be lastingly suppressed in regenerating tissue. Further, we should develop the methods and reagents to activate recruitment of intrinsic stem/progenitor cells into the damaged site. PMID:24078496

  9. DISCO-SCA and Properly Applied GSVD as Swinging Methods to Find Common and Distinctive Processes

    PubMed Central

    Van Deun, Katrijn; Van Mechelen, Iven; Thorrez, Lieven; Schouteden, Martijn; De Moor, Bart; van der Werf, Mariët J.; De Lathauwer, Lieven; Smilde, Age K.; Kiers, Henk A. L.

    2012-01-01

    Background In systems biology it is common to obtain for the same set of biological entities information from multiple sources. Examples include expression data for the same set of orthologous genes screened in different organisms and data on the same set of culture samples obtained with different high-throughput techniques. A major challenge is to find the important biological processes underlying the data and to disentangle therein processes common to all data sources and processes distinctive for a specific source. Recently, two promising simultaneous data integration methods have been proposed to attain this goal, namely generalized singular value decomposition (GSVD) and simultaneous component analysis with rotation to common and distinctive components (DISCO-SCA). Results Both theoretical analyses and applications to biologically relevant data show that: (1) straightforward applications of GSVD yield unsatisfactory results, (2) DISCO-SCA performs well, (3) provided proper pre-processing and algorithmic adaptations, GSVD reaches a performance level similar to that of DISCO-SCA, and (4) DISCO-SCA is directly generalizable to more than two data sources. The biological relevance of DISCO-SCA is illustrated with two applications. First, in a setting of comparative genomics, it is shown that DISCO-SCA recovers a common theme of cell cycle progression and a yeast-specific response to pheromones. The biological annotation was obtained by applying Gene Set Enrichment Analysis in an appropriate way. Second, in an application of DISCO-SCA to metabolomics data for Escherichia coli obtained with two different chemical analysis platforms, it is illustrated that the metabolites involved in some of the biological processes underlying the data are detected by one of the two platforms only; therefore, platforms for microbial metabolomics should be tailored to the biological question. Conclusions Both DISCO-SCA and properly applied GSVD are promising integrative methods for

  10. [Articular cartilage regeneration using scaffold].

    PubMed

    Ishimoto, Yoshiyuki; Hattori, Koji; Ohgushi, Hajime

    2008-12-01

    The self-healing capacity of articular cartilage for repair is limited. For articular cartilage injury, several surgical techniques are used in clinical practice, namely drilling, abrasion arthroplasty, microfracture, or autologous osteochondral grafting, while various methods of autologous chondrocyte transplantation to cartilage defect sites have been reported since 1990s. In a case of chondrocyte transplantation to cartilage defect site, the use of proper scaffold is important. Currently, collagen gel or PLGA is used widely as a scaffold. PMID:19043192

  11. Dimethyl sulphide biogeochemistry within a coccolithophore bloom (DISCO): an overview

    NASA Astrophysics Data System (ADS)

    Burkill, Peter H.; Archer, Stephen D.; Robinson, Carol; Nightingale, Philip D.; Groom, Stephen B.; Tarran, Glen A.; Zubkov, Mikhail V.

    This paper presents an overview of dimethyl sulphide biogeochemistry within a coccolithophore bloom (DISCO), an integrated, multidisciplinary Lagrangian process study of the routes, rates and controls on the biogeochemical cycling of dimethyl sulphide (DMS) within a growing bloom of the coccolithophorid alga, Emiliania huxleyi. The Lagrangian study took place between 16 and 26 June 1999 in the northern North Sea. It was preceded by an 8-d survey of ˜52,000 km 2 of the region to locate an E. huxleyi bloom suitable for study. Although not originally planned, the survey was carried out because heavy cloud cover precluded use of remote sensing to locate a suitable bloom. E. huxleyi blooms, typically common in the region during mid-summer, were unusually sparse in the study area. The bloom chosen for the process study was initially centred ˜58°56'N 02°52'E, and a 40-km 2 patch of water was labelled for study with ˜30 g sulphur hexafluoride (SF 6) on 16 June. The original patch was reinfused with further SF 6 on 24 June. During the process study, the SF 6-labelled patch moved in a south-easterly direction and the study ended when the patch subducted underneath less dense Norwegian coastal water. The process study comprised analyses of the time-varying biological, optical and physical properties of the patch as well as studies of DMS, dimethylsulphonioproprionate (DMSP), dimethylsulphoxide, nutrients, halocarbons, methylamines, carbon monoxide, dissolved organic carbon, and total dissolved nitrogen. The role of viruses, bacteria, phytoplankton, microzooplankton, and mesozooplankton, together with the dynamics of primary, new and bacterial production, plankton respiration, microzooplankton grazing, and sedimentation, were studied in relation to the biogeochemical cycling of DMS. Although the coccolithophore bloom water exhibited high optical backscatter, the algal community present was highly heterogeneous. Flagellates other than E. huxleyi were found to dominate the

  12. Fracture of articular cartilage.

    PubMed

    Chin-Purcell, M V; Lewis, J L

    1996-11-01

    Crack formation and propagation is a significant element of the degeneration process in articular cartilage. In order to understand this process, and separate the relative importance of structural overload and material failure, methods for measuring the fracture toughness of cartilage are needed. In this paper, two such methods are described and used to measure fracture properties of cartilage from the canine patella. A modified single edge notch (MSEN) specimen was used to measure J, and a trouser tear test was used to measure T, both measures of fracture toughness with units of kN/m. A pseudo-elastic modulus was also obtained from the MSEN test. Several potential error sources were examined, and results for the MSEN test compared with another method for measuring the fracture parameter for urethane rubber. Good agreement was found. The two test methods were used to measure properties of cartilage from the patellae of 12 canines: 4-9 specimens from each of 12 patellae, with 5 right-left pairs were tested. Values of J ranged from 0.14-1.2 kN/m. J values correlated with T and were an average of 1.7 times larger than T. A variety of failure responses was seen in the MSEN tests, consequently a grade of 0 to 3 was assigned to each test, where 0 represented a brittle-like crack with minimal opening and 3 represented plastic flow with no crack formation. The initial cracks in 12/82 specimens did not propagate and were assigned to grade 3. The method for reducing data in the MSEN test assumed pseudo-elastic response and could not be used for the grade 3 specimens. Stiffness did not correlate with J. Neither J nor T was statistically different between right-left pairs, but varied between animals. The test methods appear useful for providing a quantitative measure of fracture toughness for cartilage and other soft materials. PMID:8950659

  13. Development of artificial articular cartilage.

    PubMed

    Oka, M; Ushio, K; Kumar, P; Ikeuchi, K; Hyon, S H; Nakamura, T; Fujita, H

    2000-01-01

    Attempts have been made to develop an artificial articular cartilage on the basis of a new viewpoint of joint biomechanics in which the lubrication and load-bearing mechanisms of natural and artificial joints are compared. Polyvinyl alcohol hydrogel (PVA-H), 'a rubber-like gel', was investigated as an artificial articular cartilage and the mechanical properties of this gel were improved through a new synthetic process. In this article the biocompatibility and various mechanical properties of the new improved PVA-H is reported from the perspective of its usefulness as an artificial articular cartilage. As regards lubrication, the changes in thickness and fluid pressure of the gap formed between a glass plate and the specimen under loading were measured and it was found that PVA-H had a thicker fluid film under higher pressures than polyethylene (PE) did. The momentary stress transmitted through the specimen revealed that PVA-H had a lower peak stress and a longer duration of sustained stress than PE, suggesting a better damping effect. The wear factor of PVA-H was approximately five times that of PE. Histological studies of the articular cartilage and synovial membranes around PVA-H implanted for 8-52 weeks showed neither inflammation nor degenerative changes. The artificial articular cartilage made from PVA-H could be attached to the underlying bone using a composite osteochondral device made from titanium fibre mesh. In the second phase of this work, the damage to the tibial articular surface after replacement of the femoral surface in dogs was studied. Pairs of implants made of alumina, titanium or PVA-H on titanium fibre mesh were inserted into the femoral condyles. The two hard materials caused marked pathological changes in the articular cartilage and menisci, but the hydrogel composite replacement caused minimal damage. The composite osteochondral device became rapidly attached to host bone by ingrowth into the supporting mesh. The clinical implications of

  14. A comparison of the pharmacophore identification programs: Catalyst, DISCO and GASP.

    PubMed

    Patel, Yogendra; Gillet, Valerie J; Bravi, Gianpaolo; Leach, Andrew R

    2002-01-01

    Three commercially available pharmacophore generation programs, Catalyst/HipHop, DISCO and GASP, were compared on their ability to generate known pharmacophores deduced from protein-ligand complexes extracted from the Protein Data Bank. Five different protein families were included Thrombin, Cyclin Dependent Kinase 2, Dihydrofolate Reductase, HIV Reverse Transcriptase and Thermolysin. Target pharmacophores were defined through visual analysis of the data sets. The pharmacophore models produced were evaluated qualitatively through visual inspection and according to their ability to generate the target pharmacophores. Our results show that GASP and Catalyst outperformed DISCO at reproducing the five target pharmacophores. PMID:12602956

  15. Engineering lubrication in articular cartilage.

    PubMed

    McNary, Sean M; Athanasiou, Kyriacos A; Reddi, A Hari

    2012-04-01

    Despite continuous progress toward tissue engineering of functional articular cartilage, significant challenges still remain. Advances in morphogens, stem cells, and scaffolds have resulted in enhancement of the bulk mechanical properties of engineered constructs, but little attention has been paid to the surface mechanical properties. In the near future, engineered tissues will be able to withstand and support the physiological compressive and tensile forces in weight-bearing synovial joints such as the knee. However, there is an increasing realization that these tissue-engineered cartilage constructs will fail without the optimal frictional and wear properties present in native articular cartilage. These characteristics are critical to smooth, pain-free joint articulation and a long-lasting, durable cartilage surface. To achieve optimal tribological properties, engineered cartilage therapies will need to incorporate approaches and methods for functional lubrication. Steady progress in cartilage lubrication in native tissues has pushed the pendulum and warranted a shift in the articular cartilage tissue-engineering paradigm. Engineered tissues should be designed and developed to possess both tribological and mechanical properties mirroring natural cartilage. In this article, an overview of the biology and engineering of articular cartilage structure and cartilage lubrication will be presented. Salient progress in lubrication treatments such as tribosupplementation, pharmacological, and cell-based therapies will be covered. Finally, frictional assays such as the pin-on-disk tribometer will be addressed. Knowledge related to the elements of cartilage lubrication has progressed and, thus, an opportune moment is provided to leverage these advances at a critical step in the development of mechanically and tribologically robust, biomimetic tissue-engineered cartilage. This article is intended to serve as the first stepping stone toward future studies in functional

  16. Engineering Lubrication in Articular Cartilage

    PubMed Central

    McNary, Sean M.; Athanasiou, Kyriacos A.

    2012-01-01

    Despite continuous progress toward tissue engineering of functional articular cartilage, significant challenges still remain. Advances in morphogens, stem cells, and scaffolds have resulted in enhancement of the bulk mechanical properties of engineered constructs, but little attention has been paid to the surface mechanical properties. In the near future, engineered tissues will be able to withstand and support the physiological compressive and tensile forces in weight-bearing synovial joints such as the knee. However, there is an increasing realization that these tissue-engineered cartilage constructs will fail without the optimal frictional and wear properties present in native articular cartilage. These characteristics are critical to smooth, pain-free joint articulation and a long-lasting, durable cartilage surface. To achieve optimal tribological properties, engineered cartilage therapies will need to incorporate approaches and methods for functional lubrication. Steady progress in cartilage lubrication in native tissues has pushed the pendulum and warranted a shift in the articular cartilage tissue-engineering paradigm. Engineered tissues should be designed and developed to possess both tribological and mechanical properties mirroring natural cartilage. In this article, an overview of the biology and engineering of articular cartilage structure and cartilage lubrication will be presented. Salient progress in lubrication treatments such as tribosupplementation, pharmacological, and cell-based therapies will be covered. Finally, frictional assays such as the pin-on-disk tribometer will be addressed. Knowledge related to the elements of cartilage lubrication has progressed and, thus, an opportune moment is provided to leverage these advances at a critical step in the development of mechanically and tribologically robust, biomimetic tissue-engineered cartilage. This article is intended to serve as the first stepping stone toward future studies in functional

  17. Discos de acresção em sistemas Be-X

    NASA Astrophysics Data System (ADS)

    Lopes de Oliveira, R.; Janot-Pacheco, E.

    2003-08-01

    Alguns fenômenos de outbursts em Be-X sugerem a existência, mesmo que temporária, de um disco de acresção quando da passagem do objeto compacto pelo periastro orbital. Neste trabalho avaliamos a possibilidade de formação do disco de acresção em sistemas Be+estrela de neutrons e Be+anã branca, e a influência da excentricidade orbital na ocorrência deste fenômeno. Utilizamos a expressão analítica para o momento angular específico da matéria constituinte de um meio em expansão lenta, como é o caso do disco circunstelar das estrelas Be, proposta por Wang(1981), sob a condição básica de que o raio de circularização deva ser maior do que o raio de Alfvén. Concluímos que existe um limite para o período orbital do sistema acima do qual não é possível a formação do disco de acresção, e que este valor aumenta para sistemas com excentricidade orbital maior.

  18. Observaciones del disco solar y de una protuberancia quiescente en radiación ultravioleta

    NASA Astrophysics Data System (ADS)

    Cirigliano, D.; Vial, J.-C.; Rovira, M.

    Observaciones del disco solar y de una protuberancia quiescente en el rango de longitudes de onda ultravioleta fueron obtenidas con el instrumento CDS (Coronal Diagnostic Spectrograph) y SUMER (Solar Ultraviolet Measurements of emitted radiation) a bordo de la sonda SOHO. El propósito es investigar las velocidades macroscópicas de varias especies metálicas que se observan tanto en el disco solar como en el plasma de las protuberancias. Para calcular las velocidades del disco solar aplicamos una técnica mixta para modelar la distribución de estructuras en UV en el Sol quieto. Las velocidades macroscópicas en las protuberancias se calcularon a partir de los corrimientos Doppler en cada línea espectral y luego se tomaron las del disco solar como referencia. Obtuvimos valores absolutos para las velocidades macroscópicas entre 5 y 40 km/seg. También detectamos comportamientos diferentes en las velocidades de las protuberancias en el centro con respecto a los bordes.

  19. Discos de acreción circumplanares: Modelo de Co-acreción

    NASA Astrophysics Data System (ADS)

    Parisi, M. G.; de Elía, G.

    Los discos de acreción circumplanetarios precursores de los satélites regulares de los planetas gigantes, se pueden formar por cuatro mecanismos (Pollack y otros, 1991, In Uranus, Bergtralh, Miner y Mattews, Eds., p. 469, Univ. de Arizona Press, Tucson). En este trabajo estudiamos uno de tales mecanismos: el Modelo de Co-acreción. En dicho modelo, el disco circumplanetario se forma a partir de las colisiones mutuas entre planetesimales dentro de la esfera de Hill del planeta durante el proceso de formación planetaria. Realizamos un modelo semi-analítico para calcular la masa del disco y compararla con la masa requerida para formar los satélites regulares de los planetas gigantes. Hemos obtenido una cota superior para la masa del disco que resulta inferior a la masa de los satélites más grandes de los planetas gigantes. En principio, estos resultados permitirían descartar el modelo de co-acreción como uno de los procesos que podrían dar lugar a la formación de los satélites regulares. Estos resultados permiten obtener restricciones en el escenario de formación planetaria y en los mecanismos de formación de sistemas de satélites.

  20. Autophagy modulates articular cartilage vesicle formation in primary articular chondrocytes.

    PubMed

    Rosenthal, Ann K; Gohr, Claudia M; Mitton-Fitzgerald, Elizabeth; Grewal, Rupinder; Ninomiya, James; Coyne, Carolyn B; Jackson, William T

    2015-05-22

    Chondrocyte-derived extracellular organelles known as articular cartilage vesicles (ACVs) participate in non-classical protein secretion, intercellular communication, and pathologic calcification. Factors affecting ACV formation and release remain poorly characterized; although in some cell types, the generation of extracellular vesicles is associated with up-regulation of autophagy. We sought to determine the role of autophagy in ACV production by primary articular chondrocytes. Using an innovative dynamic model with a light scatter nanoparticle counting apparatus, we determined the effects of autophagy modulators on ACV number and content in conditioned medium from normal adult porcine and human osteoarthritic chondrocytes. Healthy articular chondrocytes release ACVs into conditioned medium and show significant levels of ongoing autophagy. Rapamycin, which promotes autophagy, increased ACV numbers in a dose- and time-dependent manner associated with increased levels of autophagy markers and autophagosome formation. These effects were suppressed by pharmacologic autophagy inhibitors and short interfering RNA for ATG5. Caspase-3 inhibition and a Rho/ROCK inhibitor prevented rapamycin-induced increases in ACV number. Osteoarthritic chondrocytes, which are deficient in autophagy, did not increase ACV number in response to rapamycin. SMER28, which induces autophagy via an mTOR-independent mechanism, also increased ACV number. ACVs induced under all conditions had similar ecto-enzyme specific activities and types of RNA, and all ACVs contained LC3, an autophagosome-resident protein. These findings identify autophagy as a critical participant in ACV formation, and augment our understanding of ACVs in cartilage disease and repair. PMID:25869133

  1. DISCOS- DYNAMIC INTERACTION SIMULATION OF CONTROLS AND STRUCTURES (DEC VAX VERSION)

    NASA Technical Reports Server (NTRS)

    Frisch, H. P.

    1994-01-01

    The Dynamic Interaction Simulation of Controls and Structure (DISCOS) program was developed for the dynamic simulation and stability analysis of passive and actively controlled spacecraft. In the use of DISCOS, the physical system undergoing analysis may be generally described as a cluster of contiguous flexible structures (bodies) that comprise a mechanical system, such as a spacecraft. The entire system (spacecraft) or portions thereof may be either spinning or nonspinning. Member bodies of the system may undergo large relative excursions, such as those of appendage deployment or rotor/ stator motion. The general system of bodies is, by its inherent nature, a feedback system in which inertial forces (such as those due to centrifugal and Coriolis acceleration) and the restoring and damping forces are motion-dependent. The system may possess a control system in which certain position and rate errors are actively controlled through the use of reaction control jets, servomotors, or momentum wheels. Bodies of the system may be interconnected by linear or nonlinear springs and dampers, by a gimbal and slider block mechanism, or by any combination of these. The DISCOS program can be used to obtain nonlinear and linearized time response of the system, interaction constant forces in the system, total system resonance properties, and frequency domain response and stability information for the system. DISCOS is probably the most powerful computational tool to date for the computer simulation of actively controlled coupled multi-flexible-body systems. The program is not easy to understand and effectively apply, but is not intended for simple problems. The DISCOS user is expected to have extensive working knowledge of rigid-body and flexible-body dynamics, finite-element techniques, numerical methods, and frequency-domain analysis. Various applications of DISCOS include simulation of the Shuttle payload deployment/retrieval mechanism, solar panel array deployment, antenna

  2. Identifying features of 'pathological demand avoidance' using the Diagnostic Interview for Social and Communication Disorders (DISCO).

    PubMed

    O'Nions, Elizabeth; Gould, Judith; Christie, Phil; Gillberg, Christopher; Viding, Essi; Happé, Francesca

    2016-04-01

    The term 'pathological demand avoidance' (PDA) was coined by Elizabeth Newson to describe children within the autism spectrum who exhibit obsessive resistance to everyday demands and requests (Newson et al., Arch Dis Child 88:595-600, 2003). Clinical accounts describe avoidance strategies including apparently strategic use of distraction or socially shocking behaviour, and obsessive need for control, reflected in domineering behaviour to peers and adults. Educational and management approaches effective for PDA reportedly differ from those for 'typical' autism spectrum disorders (ASD), and include novelty, humour and flexibility. Identification of PDA in individuals with ASD may have important implications for management (Eaton and Banting, J Learn Disabil Offending Behav 3:150-157, 2012). Despite increasing interest, no clinician-rated instrument for PDA has been developed. Here, items relevant to PDA were identified from the Diagnostic Interview for Social and Communication Disorder (DISCO) (Wing et al., J Child Psychol Psychiatry 43:307-325, 2002). The most PDA-specific subset of relevant DISCO items was selected, based on low endorsement in general across a sample of 153 individuals assessed for possible ASD using the DISCO. Having selected 11 DISCO PDA items for the measure, a subset of individuals with a high number of these features was identified (N = 27). Consistent with Newson's descriptions, this high scoring group was characterised by lack of co-operation, use of apparently manipulative behaviour, socially shocking behaviour, difficulties with other people, anxiety and sudden behavioural changes from loving to aggression. All but one case met criteria for an ASD. This study brings the field a step closer to a clinician-rated measure of PDA features and highlights the need for further elucidation of the PDA phenotype. PMID:26224583

  3. PhenDisco: phenotype discovery system for the database of genotypes and phenotypes.

    PubMed

    Doan, Son; Lin, Ko-Wei; Conway, Mike; Ohno-Machado, Lucila; Hsieh, Alex; Feupe, Stephanie Feudjio; Garland, Asher; Ross, Mindy K; Jiang, Xiaoqian; Farzaneh, Seena; Walker, Rebecca; Alipanah, Neda; Zhang, Jing; Xu, Hua; Kim, Hyeon-Eui

    2014-01-01

    The database of genotypes and phenotypes (dbGaP) developed by the National Center for Biotechnology Information (NCBI) is a resource that contains information on various genome-wide association studies (GWAS) and is currently available via NCBI's dbGaP Entrez interface. The database is an important resource, providing GWAS data that can be used for new exploratory research or cross-study validation by authorized users. However, finding studies relevant to a particular phenotype of interest is challenging, as phenotype information is presented in a non-standardized way. To address this issue, we developed PhenDisco (phenotype discoverer), a new information retrieval system for dbGaP. PhenDisco consists of two main components: (1) text processing tools that standardize phenotype variables and study metadata, and (2) information retrieval tools that support queries from users and return ranked results. In a preliminary comparison involving 18 search scenarios, PhenDisco showed promising performance for both unranked and ranked search comparisons with dbGaP's search engine Entrez. The system can be accessed at http://pfindr.net. PMID:23989082

  4. PhenDisco: phenotype discovery system for the database of genotypes and phenotypes

    PubMed Central

    Doan, Son; Lin, Ko-Wei; Conway, Mike; Ohno-Machado, Lucila; Hsieh, Alex; Feupe, Stephanie Feudjio; Garland, Asher; Ross, Mindy K; Jiang, Xiaoqian; Farzaneh, Seena; Walker, Rebecca; Alipanah, Neda; Zhang, Jing; Xu, Hua; Kim, Hyeon-Eui

    2014-01-01

    The database of genotypes and phenotypes (dbGaP) developed by the National Center for Biotechnology Information (NCBI) is a resource that contains information on various genome-wide association studies (GWAS) and is currently available via NCBI's dbGaP Entrez interface. The database is an important resource, providing GWAS data that can be used for new exploratory research or cross-study validation by authorized users. However, finding studies relevant to a particular phenotype of interest is challenging, as phenotype information is presented in a non-standardized way. To address this issue, we developed PhenDisco (phenotype discoverer), a new information retrieval system for dbGaP. PhenDisco consists of two main components: (1) text processing tools that standardize phenotype variables and study metadata, and (2) information retrieval tools that support queries from users and return ranked results. In a preliminary comparison involving 18 search scenarios, PhenDisco showed promising performance for both unranked and ranked search comparisons with dbGaP's search engine Entrez. The system can be accessed at http://pfindr.net. PMID:23989082

  5. Extra and Intra-articular Synovial Chondromatosis.

    PubMed

    Chaudhary, R K; Banskota, B; Rijal, S; Banskota, A K

    2015-01-01

    Synovial chondromatosis is not so rare intra-articular condition secondary to synovial metaplasia, that affects the knee joint. Extra-articular synovial chondromatosis however is an extremely rare condition that usually involves the synovial sheath or bursa of the foot or hand. We present two cases of synovial chondromatosis, one intra and one extra-articular. The first case was a 25 year old lady who presented with pain, swelling and restricted range of motion of left knee and was found to have an intra-articular synovial chondromatosis which was treated successfully by joint debridement. The second case was that of a 22 year old man who presented with right knee pain and was diagnosed to have an extra-articular synovial chondromatosis of his right medial hamstring tendon sheath, excision of which resulted in complete relief of symptoms. PMID:27549506

  6. Extra-articular Manifestations in Rheumatoid Arthritis

    PubMed Central

    Cojocaru, Manole; Cojocaru, Inimioara Mihaela; Silosi, Isabela; Vrabie, Camelia Doina; Tanasescu, R

    2010-01-01

    ABSTRACT Rheumatoid arthritis (RA) is a systemic autoimmune disease whose main characteristic is persistent joint inflammation that results in joint damage and loss of function. Although RA is more common in females, extra-articular manifestations of the disease are more common in males. The extra-articular manifestations of RA can occur at any age after onset. It is characterised by destructive polyarthritis and extra-articular organ involvement, including the skin, eye, heart, lung, renal, nervous and gastrointestinal systems. The frequence of extra-articular manifestations in RA differs from one country to another. Extra-articular organ involvement in RA is more frequently seen in patients with severe, active disease and is associated with increased mortality. Incidence and frequence figures for extra-articular RA vary according to study design. Extra-articular involvement is more likely in those who have RF and/or are HLA-DR4 positive. Occasionally, there are also systemic manifestations such as vasculitis, visceral nodules, Sjögren's syndrome, or pulmonary fibrosis present. Nodules are the most common extra-articular feature, and are present in up to 30%; many of the other classic features occur in 1% or less in normal clinic settings. Sjögren's syndrome, anaemia of chronic disease and pulmonary manifestations are relatively common – in 6-10%, are frequently present in early disease and are all related to worse outcomes measures of rheumatoid disease in particular functional impairment and mortality. The occurrence of these systemic manifestations is a major predictor of mortality in patients with RA. This paper focuses on extra-articular manifestations, defined as diseases and symptoms not directly related to the locomotor system. PMID:21977172

  7. Supporting Biomaterials for Articular Cartilage Repair

    PubMed Central

    Duarte Campos, Daniela Filipa; Drescher, Wolf; Rath, Björn; Tingart, Markus

    2012-01-01

    Orthopedic surgeons and researchers worldwide are continuously faced with the challenge of regenerating articular cartilage defects. However, until now, it has not been possible to completely mimic the biological and biochemical properties of articular cartilage using current research and development approaches. In this review, biomaterials previously used for articular cartilage repair research are addressed. Furthermore, a brief discussion of the state of the art of current cell printing procedures mimicking native cartilage is offered in light of their use as future alternatives for cartilage tissue engineering. Inkjet cell printing, controlled deposition cell printing tools, and laser cell printing are cutting-edge techniques in this context. The development of mimetic hydrogels with specific biological properties relevant to articular cartilage native tissue will support the development of improved, functional, and novel engineered tissue for clinical application. PMID:26069634

  8. Characterization of cutaneous and articular sensory neurons

    PubMed Central

    da Silva Serra, Ines; Husson, Zoé; Bartlett, Jonathan D.

    2016-01-01

    Background A wide range of stimuli can activate sensory neurons and neurons innervating specific tissues often have distinct properties. Here, we used retrograde tracing to identify sensory neurons innervating the hind paw skin (cutaneous) and ankle/knee joints (articular), and combined immunohistochemistry and electrophysiology analysis to determine the neurochemical phenotype of cutaneous and articular neurons, as well as their electrical and chemical excitability. Results Immunohistochemistry analysis using RetroBeads as a retrograde tracer confirmed previous data that cutaneous and articular neurons are a mixture of myelinated and unmyelinated neurons, and the majority of both populations are peptidergic. In whole-cell patch-clamp recordings from cultured dorsal root ganglion neurons, voltage-gated inward currents and action potential parameters were largely similar between articular and cutaneous neurons, although cutaneous neuron action potentials had a longer half-peak duration (HPD). An assessment of chemical sensitivity showed that all neurons responded to a pH 5.0 solution, but that acid-sensing ion channel (ASIC) currents, determined by inhibition with the nonselective acid-sensing ion channel antagonist benzamil, were of a greater magnitude in cutaneous compared to articular neurons. Forty to fifty percent of cutaneous and articular neurons responded to capsaicin, cinnamaldehyde, and menthol, indicating similar expression levels of transient receptor potential vanilloid 1 (TRPV1), transient receptor potential ankyrin 1 (TRPA1), and transient receptor potential melastatin 8 (TRPM8), respectively. By contrast, significantly more articular neurons responded to ATP than cutaneous neurons. Conclusion This work makes a detailed characterization of cutaneous and articular sensory neurons and highlights the importance of making recordings from identified neuronal populations: sensory neurons innervating different tissues have subtly different properties

  9. GoDisco: Selective Gossip Based Dissemination of Information in Social Community Based Overlays

    NASA Astrophysics Data System (ADS)

    Datta, Anwitaman; Sharma, Rajesh

    We propose and investigate a gossip based, social principles and behavior inspired decentralized mechanism (GoDisco) to disseminate information in online social community networks, using exclusively social links and exploiting semantic context to keep the dissemination process selective to relevant nodes. Such a designed dissemination scheme using gossiping over a egocentric social network is unique and is arguably a concept whose time has arrived, emulating word of mouth behavior and can have interesting applications like probabilistic publish/subscribe, decentralized recommendation and contextual advertisement systems, to name a few. Simulation based experiments show that despite using only local knowledge and contacts, the system has good global coverage and behavior.

  10. Articular cartilage: structure and regeneration.

    PubMed

    Becerra, José; Andrades, José A; Guerado, Enrique; Zamora-Navas, Plácido; López-Puertas, José M; Reddi, A Hari

    2010-12-01

    Articular cartilage (AC) has no or very low ability of self-repair, and untreated lesions may lead to the development of osteoarthritis. One method that has been proven to result in long-term repair or isolated lesions is autologous chondrocyte transplantation. However, first generation of these cells' implantation has limitations, and introducing new effective cell sources can improve cartilage repair. AC provides a resilient and compliant articulating surface to the bones in diarthrodial joints. It protects the joint by distributing loads applied to it, so preventing potentially damaging stress concentrations on the bone. At the same time it provides a low-friction-bearing surface to enable free movement of the joint. AC may be considered as a visco- or poro-elastic fiber-composite material. Fibrils of predominantly type II collagen provide tensile reinforcing to a highly hydrated proteoglycan gel. The tissue typically comprises 70% water and it is the structuring and retention of this water by the proteoglycans and collagen that is largely responsible for the remarkable ability of the tissue to support compressive loads. PMID:20836752

  11. Imaging Cleared Intact Biological Systems at a Cellular Level by 3DISCO

    PubMed Central

    Ertürk, Ali; Lafkas, Daniel; Chalouni, Cecile

    2014-01-01

    Tissue clearing and subsequent imaging of transparent organs is a powerful method to analyze fluorescently labeled cells and molecules in 3D, in intact organs. Unlike traditional histological methods, where the tissue of interest is sectioned for fluorescent imaging, 3D imaging of cleared tissue allows examination of labeled cells and molecules in the entire specimen. To this end, optically opaque tissues should be rendered transparent by matching the refractory indices throughout the tissue. Subsequently, the tissue can be imaged at once using laser-scanning microscopes to obtain a complete high-resolution 3D image of the specimen. A growing list of tissue clearing protocols including 3DISCO, CLARITY, Sca/e, ClearT2, and SeeDB provide new ways for researchers to image their tissue of interest as a whole. Among them, 3DISCO is a highly reproducible and straightforward method, which can clear different types of tissues and can be utilized with various microscopy techniques. This protocol describes this straightforward procedure and presents its various applications. It also discusses the limitations and possible difficulties and how to overcome them. PMID:25046566

  12. Inhibition of β-Catenin Signaling in Articular Chondrocytes Results in Articular Cartilage Destruction

    PubMed Central

    Zhu, Mei; Chen, Mo; Zuscik, Michael; Wu, Qiuqian; Wang, Yong-Jun; Rosier, Randy N.; O’Keefe, Regis J.; Chen, Di

    2009-01-01

    Objective Osteoarthritis is a degenerative joint disease whose molecular mechanism is currently unknown. Wnt/β-catenin signaling has been demonstrated to play a critical role in the development and function of articular chondrocytes. To determine the role of β-catenin signaling in articular chondrocyte function, we generated Col2a1-ICAT–transgenic mice to inhibit β-catenin signaling in chondrocytes. Methods The expression of the ICAT transgene was determined by immunostaining and Western blot analysis. Histologic analyses were performed to determine changes in articular cartilage structure and morphology. Cell apoptosis was determined by TUNEL staining and the immunostaining of cleaved caspase 3 and poly(ADP-ribose) polymerase (PARP) proteins. Expression of Bcl-2, Bcl-xL, and Bax proteins and caspase 9 and caspase 3/7 activities were examined in primary sternal chondrocytes isolated from 3-day-old neonatal Col2a1-ICAT–transgenic mice and their wild-type littermates and in primary chicken and porcine articular chondrocytes. Results Expression of the ICAT transgene was detected in articular chondrocytes of the transgenic mice. Associated with this, age-dependent articular cartilage destruction was observed in Col2a1-ICAT– transgenic mice. A significant increase in cell apoptosis in articular chondrocytes was identified by TUNEL staining and the immunostaining of cleaved caspase 3 and PARP proteins in these transgenic mice. Consistent with this, Bcl-2 and Bcl-xL expression were decreased and caspase 9 and caspase 3/7 activity were increased, suggesting that increased cell apoptosis may contribute significantly to the articular cartilage destruction observed in Col2a1-ICAT–transgenic mice. Conclusion Inhibition of β-catenin signaling in articular chondrocytes causes increased cell apoptosis and articular cartilage destruction in Col2a1-ICAT–transgenic mice. PMID:18576323

  13. Articular chondrocyte metabolism and osteoarthritis

    SciTech Connect

    Leipold, H.R.

    1989-01-01

    The three main objectives of this study were: (1) to determine if depletion of proteoglycans from the cartilage matrix that occurs during osteoarthritis causes a measurable increase of cartilage proteoglycan components in the synovial fluid and sera, (2) to observe what effect intracellular cAMP has on the expression of matrix components by chondrocytes, and (3) to determine if freshly isolated chondrocytes contain detectable levels of mRNA for fibronectin. Canine serum keratan sulfate and hyaluronate were measured to determine if there was an elevation of these serum glycosaminoglycans in a canine model of osteoarthritis. A single intra-articular injection of chymopapain into a shoulder joint increased serum keratan sulfate 10 fold and hyaluronate less than 2 fold in 24 hours. Keratan sulfate concentrations in synovial fluids of dogs about one year old were unrelated to the presence of spontaneous cartilage degeneration in the joints. High keratan sulfate in synovial fluids correlated with higher keratan sulfate in serum. The mean keratan sulfate concentration in sera of older dogs with osteoarthritis was 37% higher than disease-free controls, but the difference between the groups was not statistically significant. Treatment of chondrocytes with 0.5 millimolar (mM) dibutyryl cAMP (DBcAMP) caused the cells to adopt a more rounded morphology. There was no difference between the amount of proteins synthesized by cultures treated with DBcAMP and controls. The amount of fibronectin (FN) in the media of DBcAMP treated cultures detected by an ELISA was specifically reduced, and the amount of {sup 35}S-FN purified by gelatin affinity chromatography decreased. Moreover, the percentage of FN containing the extra domain. A sequence was reduced. Concomitant with the decrease in FN there was an increase in the concentration of keratan sulfate.

  14. Intra-articular therapy in osteoarthritis

    PubMed Central

    Uthman, I; Raynauld, J; Haraoui, B

    2003-01-01

    The medical literature was reviewed from 1968–2002 using Medline and the key words "intra-articular" and "osteoarthritis" to determine the various intra-articular therapies used in the treatment of osteoarthritis. Corticosteroids and hyaluronic acid are the most frequently used intra-articular therapies in osteoarthritis. Other intra-articular substances such as orgotein, radiation synovectomy, dextrose prolotherapy, silicone, saline lavage, saline injection without lavage, analgesic agents, non-steroidal anti-inflammatory drugs, glucosamine, somatostatin, sodium pentosan polysulfate, chloroquine, mucopolysaccharide polysulfuric acid ester, lactic acid solution, and thiotepa cytostatica have been investigated as potentially therapeutic in the treatment of arthritic joints. Despite the lack of strong, convincing, and reproducible evidence that any of the intra-articular therapies significantly alters the progression of osteoarthritis, corticosteroids and hyaluronic acid are widely used in patients who have failed other therapeutic modalities for lack of efficacy or toxicity. As a practical approach for a knee with effusion, steroid injections should be considered while the presence of symptomatic "dry" knees may favour the hyaluronic acid approach. The virtual absence of serious side effects, coupled with the perceived benefits, make these approaches attractive. PMID:12954956

  15. NIFTI and DISCOS: New concepts for a compact accelerator neutron source for boron neutron capture therapy applications

    SciTech Connect

    Powell, J.; Ludewig, H.; Todosow, M.; Reich, M.

    1995-06-01

    Two new concepts, NIFTI and DISCOS, are described. These concepts enable the efficient production of epithermal neutrons for BNCT (Boron Neutron Capture Therapy) medical treatment, utilizing a low current, low energy proton beam impacting on a lithium target. The NIFTI concept uses fluoride compounds, such as lead or beryllium fluoride, to efficiently degrade high energy neutrons from the lithium target to the lower energies required for BNCT. The fluoride compounds are in turn encased in an iron layer that strongly impedes the transmission of neutrons with energies above 24 KeV. Lower energy neutrons readily pass through this iron filter, which has a deep window in its scattering cross section at 24 KeV. The DISCOS concept uses a rapidly rotating, high g disc to create a series of thin ({approximately} 1 micron thickness) liquid lithium targets in the form of continuous films or sheets of discrete droplets--through which the proton beam passes. The average energy lost by a proton as it passes through a single target is small, approximately 10 KeV. Between the targets, the proton beam is re-accelerated by an applied DC electric field. The DISCOS approach enables the accelerator--target facility to operate with a beam energy only slightly above the threshold value for neutron production--resulting in an output beam of low-energy epithermal neutrons--while achieving a high yield of neutrons per milliamp of proton beam current. Parametric trade studies of the NIFTI and DISCOS concepts are described. These include analyses of a broad range of NIFTI designs using the Monte carlo MCNP neutronics code, as well as mechanical and thermal-hydraulic analyses of various DISCOS designs.

  16. DISCO: An object-oriented system for music composition and sound design

    SciTech Connect

    Kaper, H. G.; Tipei, S.; Wright, J. M.

    2000-09-05

    This paper describes an object-oriented approach to music composition and sound design. The approach unifies the processes of music making and instrument building by using similar logic, objects, and procedures. The composition modules use an abstract representation of musical data, which can be easily mapped onto different synthesis languages or a traditionally notated score. An abstract base class is used to derive classes on different time scales. Objects can be related to act across time scales, as well as across an entire piece, and relationships between similar objects can replicate traditional music operations or introduce new ones. The DISCO (Digital Instrument for Sonification and Composition) system is an open-ended work in progress.

  17. Three-Dimensional Study of Alzheimer's Disease Hallmarks Using the iDISCO Clearing Method.

    PubMed

    Liebmann, Thomas; Renier, Nicolas; Bettayeb, Karima; Greengard, Paul; Tessier-Lavigne, Marc; Flajolet, Marc

    2016-07-26

    Amyloidosis is a major problem in over one hundred diseases, including Alzheimer's disease (AD). Using the iDISCO visualization method involving targeted molecular labeling, tissue clearing, and light-sheet microscopy, we studied plaque formation in the intact AD mouse brain at up to 27 months of age. We visualized amyloid plaques in 3D together with tau, microglia, and vasculature. Volume imaging coupled to automated detection and mapping enables precise and fast quantification of plaques within the entire intact mouse brain. The present methodology is also applicable to analysis of frozen human brain samples without specialized preservation. Remarkably, amyloid plaques in human brain tissues showed greater 3D complexity and surprisingly large three-dimensional amyloid patterns, or TAPs. The ability to visualize amyloid in 3D, especially in the context of their micro-environment, and the discovery of large TAPs may have important scientific and medical implications. PMID:27425620

  18. Intra-articular risks of suprapatellar nailing.

    PubMed

    Beltran, Michael J; Collinge, Cory A; Patzkowski, Jeanne C; Masini, Brendan D; Blease, Robert E; Hsu, Joseph R

    2012-12-01

    To determine the risks to local anatomy near the starting point for tibial nailing during suprapatellar nailing, 15 fresh-frozen hemipelvis specimens were nailed using a suprapatellar technique. After nail passage, the menisci and articular surfaces, anterior cruciate ligament (ACL) insertion, intermeniscal ligament, and fat pad were assessed for injury. The distance from the entry portal to the menisci, articular surfaces, and ACL insertion was determined. Medial meniscus injury occurred in 1 (6.7%) specimen and medial articular injury in 2 (13%). Nails passed through the fat pad in all specimens; intermeniscal ligament injury occurred in 3 (20%) specimens. The ACL insertion and lateral structures were not injured in any specimen. The distance from the entry portal margin to the lateral and medial menisci was 6.46±2.47 mm and 4.74±3.17 mm, respectively. The distances to the lateral and medial articular margins measured 10.33±3.62 mm and 6.54±3.57 mm, respectively. The distance to the ACL insertion averaged 5.80±3.94 mm. Suprapatellar nailing is associated with a risk of injury to anterior knee structures comparable to other nailing techniques. Additional clinical studies are warranted to further define the role of this technique in the management of tibial fractures. PMID:23550286

  19. Body Weight Independently Affects Articular Cartilage Catabolism

    PubMed Central

    Denning, W. Matt; Winward, Jason G.; Pardo, Michael Becker; Hopkins, J. Ty; Seeley, Matthew K.

    2015-01-01

    Although obesity is associated with osteoarthritis, it is unclear whether body weight (BW) independently affects articular cartilage catabolism (i.e., independent from physiological factors that also accompany obesity). The primary purpose of this study was to evaluate the independent effect of BW on articular cartilage catabolism associated with walking. A secondary purpose was to determine how decreased BW influenced cardiovascular response due to walking. Twelve able-bodied subjects walked for 30 minutes on a lower-body positive pressure treadmill during three sessions: control (unadjusted BW), +40%BW, and -40%BW. Serum cartilage oligomeric matrix protein (COMP) was measured immediately before (baseline) and after, and 15 and 30 minutes after the walk. Heart rate (HR) and rate of perceived exertion (RPE) were measured every three minutes during the walk. Relative to baseline, average serum COMP concentration was 13% and 5% greater immediately after and 15 minutes after the walk. Immediately after the walk, serum COMP concentration was 14% greater for the +40%BW session than for the -40%BW session. HR and RPE were greater for the +40%BW session than for the other two sessions, but did not differ between the control and -40%BW sessions. BW independently influences acute articular cartilage catabolism and cardiovascular response due to walking: as BW increases, so does acute articular cartilage catabolism and cardiovascular response. These results indicate that lower-body positive pressure walking may benefit certain individuals by reducing acute articular cartilage catabolism, due to walking, while maintaining cardiovascular response. Key points Walking for 30 minutes with adjustments in body weight (normal body weight, +40% and -40% body weight) significantly influences articular cartilage catabolism, measured via serum COMP concentration. Compared to baseline levels, walking with +40% body weight and normal body weight both elicited significant increases in

  20. Evolução temporal de discos circunstelares em estrelas Be

    NASA Astrophysics Data System (ADS)

    Fernandes, M. V. M.; Leister, N. V.; Levenhagen, R. S.

    2003-08-01

    A pesquisa do mecanismo que leva uma estrela do tipo Be a perder massa e formar um envelope circunstelar, nomeado como fenômeno Be, é uma questão em aberto, intrigante, e que adquire contornos interessantes em face às informações espectroscópicas de alta resolução. Nesta última década, consolida-se a idéia de que a forma destes envelopes é de tipo discóide, obedecendo a uma lei Kepleriana de velocidades, e mais ainda, recentemente há evidências de que a distribuição de matéria nestes discos pode assumir um caráter de anel. Medidas de algumas dimensões de discos circunstelares puderam ser obtidas pela análise de espectros de alta resolução e alta relação sinal-ruído para as estrelas Be: alpha Eri (HD 10144, B3Vpe), omicron And (HD 217675, B6IIIpe), e eta Cen (HD el972, B1.5Vne), no período dos anos de 1991 a 2001. Alguns modelos clássicos de envelope predizem uma distribuição de massa que decresce suavemente a partir da superfície estelar. Entretanto, considerando que a separação de picos de emissão em perfis de linhas do HeI e H-alpha, alargados por efeitos cinemáticos, é função do raio estelar e da velocidade rotacional projetada (vsini); nossos resultados sugerem a presença de um anel de matéria circunstelar, que aparece logo após a ejeção do material fotosférico, imediatamente acima da superfície estelar, e que se expande para raios maiores ao longo do tempo, eventualmente desconectando-se da superfície por uma região de densidade de matéria mínima. Tais interpretações revivem a idéia de que anéis de matéria circunstelar podem ser os responsáveis por algumas variabilidades em perfis de linhas de emissão, como as variações V/R.

  1. A minimally invasive treatment for lumbar disc herniation: DiscoGel® chemonucleolysis in patients unresponsive to chemonucleolysis with oxygen-ozone.

    PubMed

    Stagni, S; de Santis, F; Cirillo, L; Dall'olio, M; Princiotta, C; Simonetti, L; Stafa, A; Leonardi, M

    2012-03-01

    A multitude of therapies is available to treat disc herniation, ranging from conservative methods (medication and physical therapy) to minimally invasive (percutaneous) treatments and surgery. O₂-O₃ chemonucleolysis (O₂-O₃ therapy) is one of the minimally invasive treatments with the best cost/benefit ratio and lowest complication rate. Another substance recently made available exploiting the chemical properties of pure ethanol is DiscoGel®, a radiopaque gelified ethanol more viscous than absolute alcohol 8,9. The present study aimed to assess the therapeutic outcome of DiscoGel® chemonucleolysis in patients with lumbar disc herniation unresponsive to O₂-O₃ therapy. Thirty-two patients aged between 20 and 79 years were treated by DiscoGel® chemonucleolysis between December 2008 and January 2010. The treatment was successful (improvement in pain) in 24 out of 32 patients. DiscoGel® is safe and easy to handle and there were no complications related to product diffusivity outside the treatment site. The therapeutic success rate of DiscoGel® chemonucleolysis in patients unresponsive to O₂-O₃ therapy was satisfactory. Among other methods used to treat lumbar disc herniation, DiscoGel® chemonucleolysis can be deemed an intermediate procedure bridging conservative medical treatments and surgery. PMID:22440607

  2. A Minimally Invasive Treatment for Lumbar Disc Herniation: DiscoGel® Chemonucleolysis in Patients Unresponsive to Chemonucleolysis with Oxygen-Ozone

    PubMed Central

    Stagni, S.; de Santis, F.; Cirillo, L.; Dall’Olio, M.; Princiotta, C.; Simonetti, L.; Stafa, A.; Leonardi, M.

    2012-01-01

    Summary A multitude of therapies is available to treat disc herniation, ranging from conservative methods (medication and physical therapy) to minimally invasive (percutaneous) treatments and surgery. O2-O3 chemonucleolysis (O2-O3 therapy) is one of the minimally invasive treatments with the best cost/benefit ratio and lowest complication rate. Another substance recently made available exploiting the chemical properties of pure ethanol is DiscoGel®, a radiopaque gelified ethanol more viscous than absolute alcohol8,9. The present study aimed to assess the therapeutic outcome of DiscoGel® chemonucleolysis in patients with lumbar disc herniation unresponsive to O2-O3 therapy. Thirty-two patients aged between 20 and 79 years were treated by DiscoGel® chemonucleolysis between December 2008 and January 2010. The treatment was successful (improvement in pain) in 24 out of 32 patients. DiscoGel® is safe and easy to handle and there were no complications related to product diffusivity outside the treatment site. The therapeutic success rate of DiscoGel® chemonucleolysis in patients unresponsive to O2-O3 therapy was satisfactory. Among other methods used to treat lumbar disc herniation, DiscoGel® chemonucleolysis can be deemed an intermediate procedure bridging conservative medical treatments and surgery. PMID:22440607

  3. Articular synovial chondromatosis of the finger.

    PubMed

    Sano, Kazufumi; Hashimoto, Tomohisa; Kimura, Kazumasa; Ozeki, Satoru

    2014-10-01

    A 40-year-old woman presented with a six-month history of synovial chondromatosis of the metacarpophalangeal joint of the right ring finger, which was resected through both dorsal and volar incisions. To our knowledge there have been only 17 reported cases of articular synovial chondromatosis of the digital joint so far. We present a case affecting the metacarpophalangeal joint with a review of scattered information found in other 17 reports. PMID:23596991

  4. Surface of articular cartilage: immunohistological studies.

    PubMed

    Duance, V C

    1983-10-01

    Using several physical techniques the surface of articular cartilage has been reported to be structurally different from the deeper layers. In this paper using immunohistochemical methods, the surface has been shown to contain a characteristically different collagen, Type I in contrast to Type II which is the major collagen of cartilage. These results support previous proposals for a surface layer, or lamina splendens, the presence of which would be of considerable importance in understanding the degradation of cartilage in arthritides. PMID:6678620

  5. Hereditary uricemia and articular gout in chickens.

    PubMed

    Cole, R K; Austic, R E

    1980-05-01

    Ten generations of selection for uricemia and articular gout have led to the development of the HUA line which is characterized by a threefold increase in plasma level of uric acid when compared to the control LUA line, even when fed diets containing normal levels of protein. Articular gout results in many cases, especially among adult males fed a normal breeder diet. Restriction protein level of the diet delays or prevents the development of articular gout in mature males of the HUA line. The data suggest that relatively few genes are responsible for the defect in renal transport of uric acid which underlies the uricemia and gout. The association of lower levels of uric acid with dominant white plumage color suggests a linkage of a major recessive gene for the I gene. Ambient temperature, because of its effect on food consumption, influences the level of uric acid in blood plasma. The HUA line and its control (LUA line), both sex-linked dwarfs, would appear to provide an excellent animal model for the experimental study of gout in man. PMID:7393846

  6. Vitrification of intact human articular cartilage.

    PubMed

    Jomha, Nadr M; Elliott, Janet A W; Law, Garson K; Maghdoori, Babak; Forbes, J Fraser; Abazari, Alireza; Adesida, Adetola B; Laouar, Leila; Zhou, Xianpei; McGann, Locksley E

    2012-09-01

    Articular cartilage injuries do not heal and large defects result in osteoarthritis with major personal and socioeconomic costs. Osteochondral transplantation is an effective treatment for large joint defects but its use is limited by the inability to store cartilage for long periods of time. Cryopreservation/vitrification is one method to enable banking of this tissue but decades of research have been unable to successfully preserve the tissue while maintaining cartilage on its bone base - a requirement for transplantation. To address this limitation, human knee articular cartilage from total knee arthroplasty patients and deceased donors was exposed to specified concentrations of 4 different cryoprotective agents for mathematically determined periods of time at lowering temperatures. After complete exposure, the cartilage was immersed in liquid nitrogen for up to 3 months. Cell viability was 75.4 ± 12.1% determined by membrane integrity stains and confirmed with a mitochondrial assay and pellet culture documented production of sulfated glycosaminoglycans and collagen II similar to controls. This report documents successful vitrification of intact human articular cartilage on its bone base making it possible to bank this tissue indefinitely. PMID:22698720

  7. Various Spectrum of MRI Findings in Articular and Para-articular Tuberculosis: Pictorial Assay.

    PubMed

    Panchal, Hiten; Chiripal, Priyanka

    2015-12-01

    Tuberculosis continues to be a health-related issue in India. Musculoskeletal tuberculosis is noted to occur dramatically as isolates, primarily accounting for large numbers of extra-pulmonary tuberculosis since early diagnosis is always a priority; with good prognosis, it is a curable disease. Delayed treatment is associated with severe morbidity. Musculoskeletal tuberculosis accounts for a large number of extra-pulmonary tuberculosis. In this article, we describe various articular and para-articular MRI spectrum findings that are seen in patients with tuberculosis. MRI is the perfect modality to study the extent of involvement and its related complications. PMID:26730089

  8. Distinguishing ankle and knee articular cartilage.

    PubMed

    Cole, Ada A; Margulis, Arkady; Kuettner, Klaus E

    2003-06-01

    Degenerative changes in the tall and femoral distal cartilages of more than 2,000 tissue donors were graded based on the appearance of articular cartilage and osteophytes. In the ankle and the knee the degenerative changes increased with age; however, the rate of degeneration in the ankle was slower than in the knee. The degenerative changes in the ankle were more severe in men than in women, were predominantly bilateral, and seemed to be correlated with weight. The slower rate of change in the ankle may be caused, in part, by the biochemical and biomechanical tissue properties that distinguish ankle cartilage from that of the knee. PMID:12911243

  9. Treatment of articular fractures with continuous passive motion.

    PubMed

    Onderko, Laura Lynn; Rehman, Saqib

    2013-07-01

    This article presents a review of the basic science and current research on the use of continuous passive motion therapy after surgery for an intra-articular fracture. This information is useful for surgeons in the postoperative management of intra-articular fractures in determining the best course of treatment to reduce complications and facilitate quicker recovery. PMID:23827837

  10. A fonte ionizante do disco de acreção no núcleo de NGC1097

    NASA Astrophysics Data System (ADS)

    Silva, R. N.; Storchi-Bergmann, T.

    2003-08-01

    Observações em raios-X revelam o "coração" dos núcleos ativos de galáxias, pois esse tipo de radiação provém das suas regiões mais internas, próximas ao buraco negro central. Neste trabalho apresentamos observações em raios-X da região central da galáxia NGC1097, que hospeda um buraco negro supermassivo e um disco de acreção cuja emissão vem sendo observada há dez anos através da linha de emissão Ha larga (10000 km/s) e de duplo pico. As observações em raios-X - que foram obtidas com o Telescópio Chandra - foram combinadas com observações no ultravioleta obtidas com o Telescópio Espacial Hubble e são usadas para estudar as características da fonte central que ioniza o disco de acreção. A distribuição espectral de energia é comparada com a predita por modelos, em particular o de uma estrutura "ADAF" ("advection dominated accretion flow") na parte interna do disco. Tal estrutura produz um espectro de emissão de linhas estreitas tipo LINER, como observado em NGC1097 e em rádio-galáxias que apresentam linhas de Balmer largas de duplo pico. Apresentamos também uma comparação entre outros LINERs com linhas de emissão largas de duplo pico, disponíveis na literatura ou nos arquivos do Chandra e do Telescópio Espacial Hubble e discutimos as correspondentes implicações para modelos da fonte central.

  11. PRP and Articular Cartilage: A Clinical Update

    PubMed Central

    Rossi, Roberto; Castoldi, Filippo; Michielon, Gianni

    2015-01-01

    The convincing background of the recent studies, investigating the different potentials of platelet-rich plasma, offers the clinician an appealing alternative for the treatment of cartilage lesions and osteoarthritis. Recent evidences in literature have shown that PRP may be helpful both as an adjuvant for surgical treatment of cartilage defects and as a therapeutic tool by intra-articular injection in patients affected by osteoarthritis. In this review, the authors introduce the trophic and anti-inflammatory properties of PRP and the different products of the available platelet concentrates. Then, in a complex scenario made of a great number of clinical variables, they resume the current literature on the PRP applications in cartilage surgery as well as the use of intra-articular PRP injections for the conservative treatment of cartilage degenerative lesions and osteoarthritis in humans, available as both case series and comparative studies. The result of this review confirms the fascinating biological role of PRP, although many aspects yet remain to be clarified and the use of PRP in a clinical setting has to be considered still exploratory. PMID:26075244

  12. Toward patient-specific articular contact mechanics

    PubMed Central

    Ateshian, Gerard A.; Henak, Corinne R.; Weiss, Jeffrey A.

    2015-01-01

    The mechanics of contacting cartilage layers is fundamentally important to understanding the development, homeostasis and pathology of diarthrodial joints. Because of the highly nonlinear nature of both the materials and the contact problem itself, numerical methods such as the finite element method are typically incorporated to obtain solutions. Over the course of five decades, we have moved from an initial qualitative understanding of articular cartilage material behavior to the ability to perform complex, three-dimensional contact analysis, including multiphasic material representations. This history includes the development of analytical and computational contact analysis methods that now provide the ability to perform highly nonlinear analyses. Numerical implementations of contact analysis based on the finite element method are rapidly advancing and will soon enable patient-specific analysis of joint contact mechanics using models based on medical image data. In addition to contact stress on the articular surfaces, these techniques can predict variations in strain and strain through the cartilage layers, providing the basis to predict damage and failure. This opens up exciting areas for future research and application to patient-specific diagnosis and treatment planning applied to a variety of pathologies that affect joint function and cartilage homeostasis. PMID:25698236

  13. Imaging of articular cartilage: current concepts

    PubMed Central

    RONGA, MARIO; ANGERETTI, GLORIA; FERRARO, SERGIO; DE FALCO, GIOVANNI; GENOVESE, EUGENIO A.; CHERUBINO, PAOLO

    2014-01-01

    Magnetic resonance imaging (MRI) is the gold standard method for non-invasive assessment of joint cartilage, providing information on the structure, morphology and molecular composition of this tissue. There are certain minimum requirements for a MRI study of cartilage tissue: machines with a high magnetic field (> 1.5 Tesla); the use of surface coils; and the use of T2-weighted, proton density-weighted fast-spin echo (T2 FSE-DP) and 3D fat-suppressed T1-weighted gradient echo (3D-FS T1W GRE) sequences. For better contrast between the different joint structures, MR arthography is a method that can highlight minimal fibrillation or fractures of the articular surface and allow evaluation of the integrity of the native cartilage-repair tissue interface. To assess the biochemical composition of cartilage and cartilage repair tissue, various techniques have been proposed for studying proteoglycans [dGEMRIC, T1rho mapping, sodium (23Na) imaging MRI, etc.], collagen, and water distribution [T2 mapping, “magnetisation transfer contrast”, diffusion-weighted imaging (DWI), and so on]. Several MRI classifications have been proposed for evaluating the processes of joint degeneration (WORMS, BLOKS, ICRS) and post-surgical maturation of repair tissue (MOCART, 3D MOCART). In the future, isotropic 3D sequences set to improve image quality and facilitate the diagnosis of disorders of articular structures adjacent to cartilage. PMID:25606557

  14. [Articular chondrocalcinosis after 80 years of age].

    PubMed

    Memin, Y; Monville, C; Ryckewaert, A

    1978-02-01

    In 108 women over 80 (mean age 88,4 years, extremes 80 and 99 years) hospitalized in a geriatric service for various reasons, radiograms were made of both knees in the frontal aspect on standard film to detect calcinosis of the meniscus and chondrocalcinosis of the joint. In 25 women (23.1%) the radiographs revealed calcinosis of the meniscus with or without chondrocalcinosis. In these 25 cases a lateral X-ray was also made of the two knees, frontal X-rays were made of the pelvis, thumbs and shoulders. In 22 cases (88%) these revealed calcification of the fibrocartilages or articular cartilages in joints other than the knee. Seven of the 25 women had at least one attack of articular inflammation (especially of the knee) resembling a pseudo-gout crisis. The frequency of chronic arthropathies resembling arthroses was high in the 25 patients with chondrocalcinosis: 8 (32%) had an internal or external femoro-tibial arthrosis, as against 11 of the 83 patients (13%) of the same age without chondrocalcinosis, a significant difference. Eleven of the 25 women had signs of femororotular arthrosis on the lateral X-rays of the knees, 5 had coxarthrosis (with in 3 cases a radiological image of fibrocartilaginous or coxofemoral cartilaginous calcification). One women had chronic radiocarpal arthropathy evocative or chondrocalcinosis. Ten had a scaphotrapezoidal arthrosis, 5 arthrosis of the shoulder, 3 with radiological aspect of glenohumeral chondrocalcinosis. PMID:644241

  15. Aquecimento alfvênico viscoso-resistivo em discos de acresção ao redor de estrelas T Tauri clássicas

    NASA Astrophysics Data System (ADS)

    Santana, W. M.; Vasconcelos, M. J.

    2003-08-01

    Com a crescente disponibilidade de dados observacionais sobre estrelas T Tauri, a busca por modelos mais precisos vem se tornando cada vez maior. Estes modelos devem explicar, entre outras coisas, o mecanismo dissipativo responsável pelo transporte de momento angular no disco de acresção que acredita-se, circunda estas estrelas. O mecanismo mais viável, do ponto de vista teórico, é uma instabilidade MHD conhecida como "instabilidade magnetorotacional ou Balbus-Hawley" (IBH). Esta instabilidade veio mostrar que o campo magnético desempenha um papel importante na evolução destes objetos mas requer, no entanto, um acoplamento mínimo entre o gás e o campo magnético no disco que não é atingido para os valores de temperatura obtidos do modelo padrão. Contudo, alguns mecanismos de aquecimento para o disco precisam ser examinados. Neste trabalho, propomos a dissipação de ondas Alfvén como uma fonte de aquecimento para o disco. Se o gás apresentar uma condutividade elétrica finita e viscosidade, teremos um tipo de amortecimento para as ondas denominado amortecimento viscoso-resistivo que será aqui considerado. Este mecanismo é aplicado ao modelo de disco em camadas. Calculam-se as taxas de aquecimento Alfvênico, a temperatura efetiva do disco bem como as taxas de ionização decorrentes deste aquecimento e do aquecimento gerado pela absorção de raios cósmicos. Comparações com os dados observacionais de Kitamura et. al. (2001) são efetuadas, ressaltando-se os pontos comuns entre suas observações e nossos dados teóricos.

  16. Follistatin Alleviates Synovitis and Articular Cartilage Degeneration Induced by Carrageenan

    PubMed Central

    Yamada, Jun; Abula, Kahaer; Inoue, Makiko; Sekiya, Ichiro; Muneta, Takeshi

    2014-01-01

    Activins are proinflammatory cytokines which belong to the TGFβ superfamily. Follistatin is an extracellular decoy receptor for activins. Since both activins and follistatin are expressed in articular cartilage, we hypothesized that activin-follistatin signaling participates in the process of joint inflammation and cartilage degeneration. To test this hypothesis, we examined the effects of follistatin in a carrageenan-induced mouse arthritis model. Synovitis induced by intra-articular injection of carrageenan was significantly alleviated by preinjection with follistatin. Macrophage infiltration into the synovial membrane was significantly reduced in the presence of follistatin. In addition, follistatin inhibited proteoglycan erosion induced by carrageenan in articular cartilage. These data indicate that activin-follistatin signaling is involved in joint inflammation and cartilage homeostasis. Our data suggest that follistatin can be a new therapeutic target for inflammation-induced articular cartilage degeneration. PMID:25574420

  17. Simultaneous magnetic resonance imaging and consolidation measurement of articular cartilage.

    PubMed

    Wellard, Robert Mark; Ravasio, Jean-Philippe; Guesne, Samuel; Bell, Christopher; Oloyede, Adekunle; Tevelen, Greg; Pope, James M; Momot, Konstantin I

    2014-01-01

    Magnetic resonance imaging (MRI) offers the opportunity to study biological tissues and processes in a non-disruptive manner. The technique shows promise for the study of the load-bearing performance (consolidation) of articular cartilage and changes in articular cartilage accompanying osteoarthritis. Consolidation of articular cartilage involves the recording of two transient characteristics: the change over time of strain and the hydrostatic excess pore pressure (HEPP). MRI study of cartilage consolidation under mechanical load is limited by difficulties in measuring the HEPP in the presence of the strong magnetic fields associated with the MRI technique. Here we describe the use of MRI to image and characterize bovine articular cartilage deforming under load in an MRI compatible consolidometer while monitoring pressure with a Fabry-Perot interferometer-based fiber-optic pressure transducer. PMID:24803188

  18. Tissue Engineering of Articular Cartilage with Biomimetic Zones

    PubMed Central

    Klein, Travis J.; Malda, Jos; Sah, Robert L.

    2009-01-01

    Articular cartilage damage is a persistent and increasing problem with the aging population, and treatments to achieve biological repair or restoration remain a challenge. Cartilage tissue engineering approaches have been investigated for over 20 years, but have yet to achieve the consistency and effectiveness for widespread clinical use. One of the potential reasons for this is that the engineered tissues do not have or establish the normal zonal organization of cells and extracellular matrix that appears critical for normal tissue function. A number of approaches are being taken currently to engineer tissue that more closely mimics the organization of native articular cartilage. This review focuses on the zonal organization of native articular cartilage, strategies being used to develop such organization, the reorganization that occurs after culture or implantation, and future prospects for the tissue engineering of articular cartilage with biomimetic zones. PMID:19203206

  19. Simultaneous Magnetic Resonance Imaging and Consolidation Measurement of Articular Cartilage

    PubMed Central

    Wellard, Robert Mark; Ravasio, Jean-Philippe; Guesne, Samuel; Bell, Christopher; Oloyede, Adekunle; Tevelen, Greg; Pope, James M.; Momot, Konstantin I.

    2014-01-01

    Magnetic resonance imaging (MRI) offers the opportunity to study biological tissues and processes in a non-disruptive manner. The technique shows promise for the study of the load-bearing performance (consolidation) of articular cartilage and changes in articular cartilage accompanying osteoarthritis. Consolidation of articular cartilage involves the recording of two transient characteristics: the change over time of strain and the hydrostatic excess pore pressure (HEPP). MRI study of cartilage consolidation under mechanical load is limited by difficulties in measuring the HEPP in the presence of the strong magnetic fields associated with the MRI technique. Here we describe the use of MRI to image and characterize bovine articular cartilage deforming under load in an MRI compatible consolidometer while monitoring pressure with a Fabry-Perot interferometer-based fiber-optic pressure transducer. PMID:24803188

  20. Fractures of the articular processes of the cervical spine

    SciTech Connect

    Woodring, J.H.; Goldstein, S.J.

    1982-08-01

    Fractures of the articular processes occurred in 16 (20.8%) of 77 patients with cervical spine fractures as demonstrated by multidirectional tomography. Plain films demonstrated the fractures in only two patients. Acute cervical radiculopathy occurred in five of the patients with articular process fractures (superior process, two cases; inferior process, three cases). Persistent neck pain occurred in one other patient without radiculopathy. Three patients suffered spinal cord damage at the time of injury, which was not the result of the articular process fracture itself. In the other seven cases, no definite sequelae occurred. However, disruption of the facet joint may predispose to early degenerative joint disease and chronic pain; unilateral or bilateral facet dislocation was present in five patients. In patients with cervical trauma who develop cervical radiculopathy, tomography should be performed to evaluate the articular processes.

  1. A literature review of lasers and articular cartilage.

    PubMed

    Vangsness, C T; Ghaderi, B

    1993-05-01

    Articles from the English literature concerning lasers and articular cartilage were reviewed. Different experimental methods and laser systems were analyzed. Many studies lacked scientific validity. Future investigations with sound biologic foundations are recommended. PMID:8327386

  2. Extra-Articular Ganglion Cysts around the Knee Joint

    PubMed Central

    Park, Sang-Eun; Panchal, Karnav; Kim, Young-Yul; Ji, Jong-Hun; Park, Sung-Ryeoll; Park, Min-Kyu

    2015-01-01

    Purpose The purpose of this study was to report clinical results of open excision of extra-articular ganglion cysts around the knee joint combined with arthroscopic management of intra-articular pathologies if present. Materials and Methods Of the total 107 cases of cystic lesions around the knee, 23 cases of extra-articular ganglion cysts were reviewed between January 2006 and July 2011. There were 13 males and 10 females with a mean age of 48 years (range, 30 to 73 years). The mean follow-up duration was 40 months (range, 30 to 60 months). Preoperative magnetic resonance imaging (MRI) scan was done in all cases. Open surgical excision of the cyst was performed after arthroscopic management of intra-articular pathologies in all but 1 case. At the last follow-up, Lysholm and International Knee Documentation Committee (IKDC) scores were evaluated and MRI was conducted to detect recurrence. Results The mean Lysholm and IKDC scores showed significant improvement (p=0.005 and 0.013, respectively).The location of the cysts was anterior in 9, lateral in 7, medial in 6, and posterosuperior in 1. Intra-articular pathologies were found in 16/23 cases (69.6%). In 10/23 cases (43%), the cyst was connected to the knee joint. Three months postoperative MRI did not show any recurrence of ganglion cysts except for 1 case. Conclusions In the treatment of extra-articular ganglion cysts, MRI can be useful for detecting intra-articular lesions and connecting orifices, and arthroscopic management of intra-articular pathologies with open excision of the cyst should be considered as a viable treatment option. PMID:26672721

  3. Extending the NIF DISCO framework to automate complex workflow: coordinating the harvest and integration of data from diverse neuroscience information resources.

    PubMed

    Marenco, Luis N; Wang, Rixin; Bandrowski, Anita E; Grethe, Jeffrey S; Shepherd, Gordon M; Miller, Perry L

    2014-01-01

    This paper describes how DISCO, the data aggregator that supports the Neuroscience Information Framework (NIF), has been extended to play a central role in automating the complex workflow required to support and coordinate the NIF's data integration capabilities. The NIF is an NIH Neuroscience Blueprint initiative designed to help researchers access the wealth of data related to the neurosciences available via the Internet. A central component is the NIF Federation, a searchable database that currently contains data from 231 data and information resources regularly harvested, updated, and warehoused in the DISCO system. In the past several years, DISCO has greatly extended its functionality and has evolved to play a central role in automating the complex, ongoing process of harvesting, validating, integrating, and displaying neuroscience data from a growing set of participating resources. This paper provides an overview of DISCO's current capabilities and discusses a number of the challenges and future directions related to the process of coordinating the integration of neuroscience data within the NIF Federation. PMID:25018728

  4. Articular cartilage: from formation to tissue engineering.

    PubMed

    Camarero-Espinosa, Sandra; Rothen-Rutishauser, Barbara; Foster, E Johan; Weder, Christoph

    2016-05-26

    Hyaline cartilage is the nonlinear, inhomogeneous, anisotropic, poro-viscoelastic connective tissue that serves as friction-reducing and load-bearing cushion in synovial joints and is vital for mammalian skeletal movements. Due to its avascular nature, low cell density, low proliferative activity and the tendency of chondrocytes to de-differentiate, cartilage cannot regenerate after injury, wear and tear, or degeneration through common diseases such as osteoarthritis. Therefore severe damage usually requires surgical intervention. Current clinical strategies to generate new tissue include debridement, microfracture, autologous chondrocyte transplantation, and mosaicplasty. While articular cartilage was predicted to be one of the first tissues to be successfully engineered, it proved to be challenging to reproduce the complex architecture and biomechanical properties of the native tissue. Despite significant research efforts, only a limited number of studies have evolved up to the clinical trial stage. This review article summarizes the current state of cartilage tissue engineering in the context of relevant biological aspects, such as the formation and growth of hyaline cartilage, its composition, structure and biomechanical properties. Special attention is given to materials development, scaffold designs, fabrication methods, and template-cell interactions, which are of great importance to the structure and functionality of the engineered tissue. PMID:26923076

  5. A possible barrier function of the articular surface.

    PubMed

    Takada, N; Wada, I; Sugimura, I; Sakuma, E; Maruyama, H; Matsui, N

    1999-12-01

    Since MacConaill first reported the existence of a thin additional layer of the articular cartilage and named it the lamina splendens, there have been various opinions as to the role of this layer in the lubrication of the articular surface. We studied the superficial portion of the articular cartilage in the 20 day-old and 30 day-old rats using light and transmission electron microscopy. Furthermore, we studied the articular cartilage of the rat whose "cover layer" had been removed mechanically. Also, intraarticular latex beads injection, intraarticular dye injection using lithium carmine and supravital staining experiments were performed. On day 20, dye injected intraarticularly was clearly observed by light microscopy in chondrocytes situated in the deeper layers. The dye injected in the 30 day-old rats, however, was not seen in the chondrocytes but was found only in the superficial layer. Dye was found in the chondrocytes when supravital staining was performed in the articular cartilage of 30 day-old rats after mechanical removal of the cover layer. By transmission electron microscopy, a superficial layer consisted of fine filamentous structures was observed on the articular surface of the 30 day-old rats. The cover layer was destroyed by intraarticular injected latex beads in 30 day-old rats. These findings strongly support the idea that the cover layer acts as a barrier against substances which invade from the surface of the articular cartilage. The development period of the cover layer coincides with the initiation of weight bearing, and joint cartilage debris and pressure changes might further promote maturation. PMID:10659579

  6. Intra-articular injection of Torin 1 reduces degeneration of articular cartilage in a rabbit osteoarthritis model

    PubMed Central

    Cheng, N-T.; Cui, Y-P.

    2016-01-01

    Objectives Recent studies have shown that systemic injection of rapamycin can prevent the development of osteoarthritis (OA)-like changes in human chondrocytes and reduce the severity of experimental OA. However, the systemic injection of rapamycin leads to many side effects. The purpose of this study was to determine the effects of intra-articular injection of Torin 1, which as a specific inhibitor of mTOR which can cause induction of autophagy, is similar to rapamycin, on articular cartilage degeneration in a rabbit osteoarthritis model and to investigate the mechanism of Torin 1’s effects on experimental OA. Methods Collagenase (type II) was injected twice into both knees of three-month-old rabbits to induce OA, combined with two intra–articular injections of Torin 1 (400 nM). Degeneration of articular cartilage was evaluated by histology using the Mankin scoring system at eight weeks after injection. Chondrocyte degeneration and autophagosomes were observed by transmission electron microscopy. Matrix metallopeptidase-13 (MMP-13) and vascular endothelial growth factor (VEGF) expression were analysed by quantitative RT-PCR (qPCR).Beclin-1 and light chain 3 (LC3) expression were examined by Western blotting. Results Intra-articular injection of Torin 1 significantly reduced degeneration of the articular cartilage after induction of OA. Autophagosomes andBeclin-1 and LC3 expression were increased in the chondrocytes from Torin 1-treated rabbits. Torin 1 treatment also reduced MMP-13 and VEGF expression at eight weeks after collagenase injection. Conclusion Our results demonstrate that intra-articular injection of Torin 1 reduces degeneration of articular cartilage in collagenase-induced OA, at least partially by autophagy activation, suggesting a novel therapeutic approach for preventing cartilage degeneration and treating OA. Cite this article: N-T. Cheng, A. Guo, Y-P. Cui. Intra-articular injection of Torin 1 reduces degeneration of articular cartilage in a

  7. Remobilization does not fully restore immobilization induced articular cartilage atrophy.

    PubMed

    Haapala, J; Arokoski, J P; Hyttinen, M M; Lammi, M; Tammi, M; Kovanen, V; Helminen, H J; Kiviranta, I

    1999-05-01

    The recovery of articular cartilage from immobilization induced atrophy was studied. The right hind limbs of 29-week-old beagle dogs were immobilized for 11 weeks and then remobilized for 50 weeks. Cartilage from the immobilized knee was compared with tissue from age matched control animals. After the immobilization period, uncalcified articular cartilage glycosaminoglycan concentration was reduced by 20% to 23%, the reduction being largest (44%) in the superficial zone. The collagen fibril network showed no significant changes, but the amount of collagen crosslinks was reduced (13.5%) during immobilization. After remobilization, glycosaminoglycan concentration was restored at most sites, except for in the upper parts of uncalcified cartilage in the medial femoral and tibial condyles (9% to 17% less glycosaminoglycans than in controls). The incorporation of 35SO4 was not changed, and remobilization also did not alter the birefringence of collagen fibrils. Remobilization restored the proportion of collagen crosslinks to the control level. The changes induced by joint unloading were reversible at most sites investigated, but full restoration of articular cartilage glycosaminoglycan concentration was not obtained in all sites, even after remobilization for 50 weeks. This suggests that lengthy immobilization of a joint can cause long lasting articular cartilage proteoglycan alterations at the same time as collagen organization remains largely unchanged. Because proteoglycans exert strong influence on the biomechanical properties of cartilage, lengthy immobilization may jeopardize the well being of articular cartilage. PMID:10335301

  8. The Functions of BMP3 in Rabbit Articular Cartilage Repair

    PubMed Central

    Zhang, Zhe; Yang, Wenyu; Cao, Yiting; Shi, Yanping; Lei, Chen; Du, Bo; Li, Xuemin; Zhang, Qiqing

    2015-01-01

    Bone morphogenetic proteins (BMPs) play important roles in skeletal development and repair. Previously, we found fibroblast growth factor 2 (FGF2) induced up-regulation of BMP2, 3, 4 in the process of rabbit articular cartilage repair, which resulted in satisfactory repair effects. As BMP2/4 show a clearly positive effect for cartilage repair, we investigated the functions of BMP3 in rabbit articular cartilage repair. In this paper, we find that BMP3 inhibits the repair of partial-thickness defect of articular cartilage in rabbit by inducing the degradation of extracellular matrix, interfering with the survival of chondrocytes surrounding the defect, and directly inhibiting the expression of BMP2 and BMP4. Meanwhile BMP3 suppress the repair of full-thickness cartilage defect by destroying the subchondral bone through modulating the proliferation and differentiation of bone marrow stem cells (BMSCs), and directly increasing the expression of BMP4. Although BMP3 has different functions in the repair of partial and full-thickness defects of articular cartilage in rabbit, the regulation of BMP expression is involved in both of them. Together with our previous findings, we suggest the regulation of the BMP signaling pathway by BMP3 is essential in articular cartilage repair. PMID:26528966

  9. The Functions of BMP3 in Rabbit Articular Cartilage Repair.

    PubMed

    Zhang, Zhe; Yang, Wenyu; Cao, Yiting; Shi, Yanping; Lei, Chen; Du, Bo; Li, Xuemin; Zhang, Qiqing

    2015-01-01

    Bone morphogenetic proteins (BMPs) play important roles in skeletal development and repair. Previously, we found fibroblast growth factor 2 (FGF2) induced up-regulation of BMP2, 3, 4 in the process of rabbit articular cartilage repair, which resulted in satisfactory repair effects. As BMP2/4 show a clearly positive effect for cartilage repair, we investigated the functions of BMP3 in rabbit articular cartilage repair. In this paper, we find that BMP3 inhibits the repair of partial-thickness defect of articular cartilage in rabbit by inducing the degradation of extracellular matrix, interfering with the survival of chondrocytes surrounding the defect, and directly inhibiting the expression of BMP2 and BMP4. Meanwhile BMP3 suppress the repair of full-thickness cartilage defect by destroying the subchondral bone through modulating the proliferation and differentiation of bone marrow stem cells (BMSCs), and directly increasing the expression of BMP4. Although BMP3 has different functions in the repair of partial and full-thickness defects of articular cartilage in rabbit, the regulation of BMP expression is involved in both of them. Together with our previous findings, we suggest the regulation of the BMP signaling pathway by BMP3 is essential in articular cartilage repair. PMID:26528966

  10. Targeting TGFβ Signaling in Subchondral Bone and Articular Cartilage Homeostasis

    PubMed Central

    Zhen, Gehau; Cao, Xu

    2014-01-01

    Osteoarthritis (OA) is the most common degenerative joint disease, and there is no disease-modifying therapy for OA currently available. Targeting of articular cartilage alone may not be sufficient to halt this disease progression. Articular cartilage and subchondral bone act as a functional unit. Increasing evidence indicates that transforming growth factor β (TGFβ) plays a crucial role in maintaining homeostasis of both articular cartilage and subchondral bone. Activation of extracellular matrix latent TGFβ at the appropriate time and location is the prerequisite for its function. Aberrant activation of TGFβ in the subchondral bone in response to abnormal mechanical loading environment induces formation of osteroid islets at onset of osteoarthritis. As a result, alteration of subchondral bone structure changes the stress distribution on the articular cartilage and leads to its degeneration. Thus, inhibition of TGFβ activity in the subchondral bone may provide a new avenue of treatment for OA. In this review, we will respectively discuss the role of TGFβ in homeostasis of articular cartilage and subchondral bone as a novel target for OA therapy. PMID:24745631

  11. Leptin plays a catabolic role on articular cartilage.

    PubMed

    Bao, Jia-peng; Chen, Wei-ping; Feng, Jie; Hu, Peng-fei; Shi, Zhong-li; Wu, Li-dong

    2010-10-01

    Leptin has been shown to play a crucial role in the regulation of body weight. There is also evidence that this adipokine plays a key role in the process of osteoarthritis. However, the precise role of leptin on articular cartilage metabolism is not clear. We investigate the role of leptin on articular cartilage in vivo in this study. Recombinant rat leptin (100 μg) was injected into the knee joints of rats, 48 h later, messenger RNA (mRNA) expression and protein levels of basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), matrix metalloproteinases 2 and 9 (MMP-2, MMP-9), cathepsin D, and collagen II from articular cartilage were analyzed by real-time quantitative polymerase chain reaction (PCR) and western blot. Two important aggrecanases ADAMTS-4 and -5 (a disintegrin and metalloproteinase with thrombospondin motifs 4 and 5) were also analyzed by real-time quantitative PCR. Besides, articular cartilage was also assessed for proteoglycan/GAG content by Safranin O staining. Leptin significantly increased both gene and protein levels of MMP-2, MMP-9, cathepsin D, and collagen II, while decreased bFGF markedly in cartilage. Moreover, the gene expression of ADAMTS-4 and -5 were markedly increased, and histologically assessed depletion of proteoglycan in articular cartilage was observed after treatment with leptin. These results strongly suggest that leptin plays a catabolic role on cartilage metabolism and may be a disadvantage factor involve in the pathological process of OA. PMID:19876764

  12. Intra-articular Placement of an Intraosseous Catheter.

    PubMed

    Grabel, Zachary; DePasse, J Mason; Lareau, Craig R; Born, Christopher T; Daniels, Alan H

    2015-02-01

    Gaining vascular access is essential in the resuscitation of critically ill patients. Intraosseous (IO) placement is a fundamentally important alternative to intravenous (IV) access in conditions where IV access delays resuscitation or is not possible. This case report presents a previously unreported example of prehospital misplacement of an IO catheter into the intra-articular space of the knee joint. This report serves to inform civilian and military first responders, as well as emergency medicine physicians, of intra-articular IO line placement as a potential complication of IO vascular access. Infusion of large amounts of fluid into the joint space could damage the joint and be catastrophic to a patient who needs immediate IV fluids or medications. In addition, intra-articular IO placement could result in septic arthritis of the knee. PMID:25483729

  13. Radiography of rabbit articular cartilage with diffraction-enhanced imaging.

    PubMed

    Muehleman, Carol; Chapman, L Dean; Kuettner, Klaus E; Rieff, Joel; Mollenhauer, Juergen A; Massuda, Koichi; Zhong, Zhong

    2003-05-01

    Articular cartilage of synovial joints is not visible with conventional X-ray imaging. Hence, the gradual degeneration and destruction of articular cartilage, which is characteristic of degenerative joint diseases, is only detected at a late stage when the cartilage is lost and the joint space that it once occupied narrows. The development of an X-ray imaging technique that could detect both the degenerative cartilage and bone features of joint diseases is of special interest. Here we show, for the first time, that a high-contrast imaging technique, diffraction-enhanced X-ray imaging (DEI), allows the visualization of articular cartilage of both disarticulated and articulated rabbit knee joints. Furthermore, a single cartilage lesion can be visualized within an intact joint. The results suggest that DEI has the potential to be of use in the study of cartilage degeneration. PMID:12704696

  14. Three-dimensional collagen architecture in bovine articular cartilage.

    PubMed

    Jeffery, A K; Blunn, G W; Archer, C W; Bentley, G

    1991-09-01

    The three-dimensional architecture of bovine articular cartilage collagen and its relationship to split lines has been studied with scanning electron microscopy. In the middle and superficial zones, collagen was organised in a layered or leaf-like manner. The orientation was vertical in the intermediate zone, curving to become horizontal and parallel to the articular surface in the superficial zone. Each leaf consisted of a fine network of collagen fibrils. Adjacent leaves merged or were closely linked by bridging fibrils and were arranged according to the split-line pattern. The surface layer (lamina splendens) was morphologically distinct. Although ordered, the overall collagen structure was different in each plane (anisotropic) a property described in previous morphological and biophysical studies. As all components of the articular cartilage matrix interact closely, the three-dimensional organisation of collagen is important when considering cartilage function and the processes of cartilage growth, injury and repair. PMID:1894669

  15. Use magnetic resonance imaging to assess articular cartilage

    PubMed Central

    Wang, Yuanyuan; Wluka, Anita E.; Jones, Graeme; Ding, Changhai

    2012-01-01

    Magnetic resonance imaging (MRI) enables a noninvasive, three-dimensional assessment of the entire joint, simultaneously allowing the direct visualization of articular cartilage. Thus, MRI has become the imaging modality of choice in both clinical and research settings of musculoskeletal diseases, particular for osteoarthritis (OA). Although radiography, the current gold standard for the assessment of OA, has had recent significant technical advances, radiographic methods have significant limitations when used to measure disease progression. MRI allows accurate and reliable assessment of articular cartilage which is sensitive to change, providing the opportunity to better examine and understand preclinical and very subtle early abnormalities in articular cartilage, prior to the onset of radiographic disease. MRI enables quantitative (cartilage volume and thickness) and semiquantitative assessment of articular cartilage morphology, and quantitative assessment of cartilage matrix composition. Cartilage volume and defects have demonstrated adequate validity, accuracy, reliability and sensitivity to change. They are correlated to radiographic changes and clinical outcomes such as pain and joint replacement. Measures of cartilage matrix composition show promise as they seem to relate to cartilage morphology and symptoms. MRI-derived cartilage measurements provide a useful tool for exploring the effect of modifiable factors on articular cartilage prior to clinical disease and identifying the potential preventive strategies. MRI represents a useful approach to monitoring the natural history of OA and evaluating the effect of therapeutic agents. MRI assessment of articular cartilage has tremendous potential for large-scale epidemiological studies of OA progression, and for clinical trials of treatment response to disease-modifying OA drugs. PMID:22870497

  16. Cryoprotectant kinetic analysis of a human articular cartilage vitrification protocol.

    PubMed

    Shardt, Nadia; Al-Abbasi, Khaled K; Yu, Hana; Jomha, Nadr M; McGann, Locksley E; Elliott, Janet A W

    2016-08-01

    We recently published a protocol to vitrify human articular cartilage and a method of cryoprotectant removal in preparation for transplantation. The current study's goal was to perform a cryoprotectant kinetic analysis and theoretically shorten the procedure used to vitrify human articular cartilage. First, the loading of the cryoprotectants was modeled using Fick's law of diffusion, and this information was used to predict the kinetics of cryoprotectant efflux after the cartilage sample had been warmed. We hypothesized that diffusion coefficients obtained from the permeation of individual cryoprotectants into porcine articular cartilage could be used to provide a reasonable prediction of the cryoprotectant loading and of the combined cryoprotectant efflux from vitrified human articular cartilage. We tested this hypothesis with experimental efflux measurements. Osteochondral dowels from three patients were vitrified, and after warming, the articular cartilage was immersed in 3 mL X-VIVO at 4 °C in two consecutive solutions, each for 24 h, with the solution osmolality recorded at various times. Measured equilibrium values agreed with theoretical values within a maximum of 15% for all three samples. The results showed that diffusion coefficients for individual cryoprotectants determined from experiments with 2-mm thick porcine cartilage can be used to approximate the rate of efflux of the combined cryoprotectants from vitrified human articular cartilage of similar thickness. Finally, Fick's law of diffusion was used in a computational optimization to shorten the protocol with the constraint of maintaining the theoretical minimum cryoprotectant concentration needed to achieve vitrification. The learning provided by this study will enable future improvements in tissue vitrification. PMID:27221520

  17. Colo-articular fistula following a Girdlestone resection arthroplasty

    PubMed Central

    El-Daly, Ibraheim; Natarajan, Brenavan; Rajakulendran, Karthig; Symons, Sean

    2014-01-01

    Colo-articular fistulas are rare complications that are usually associated with inflammatory, infective or malignant bowel disease. We report the case of a 44-year-old male who was found to have a colo-articular fistula intra-operatively during the washout of a septic hip joint. The patient had no pre-existing bowel disease, but was an intravenous drug user, who had previously undergone a Girdlestone procedure for osteomyelitis of the proximal femur. The patient was managed through a multi-disciplinary team approach with subsequent debridement and formation of a transverse loop colostomy to control the faeculent fistulous discharge. PMID:24876512

  18. Corrective Osteotomies for Malunited Extra-Articular Calcaneal Fractures.

    PubMed

    Ketz, John; Clare, Michael; Sanders, Roy

    2016-03-01

    The most effective way to treat calcaneal malunions is avoidance. With any articular fracture, progressive arthrosis and dysfunction are common. By restoring the anatomy initially through reduction, late reconstructive options become less complicated. Numerous studies have shown that restoration of the anatomic alignment either through percutaneous or open techniques is effective. In patients with no or minimal articular degeneration, extrarticular joint-sparing procedures can be performed. This represents a small select group who may benefit from simple osteotomy procedures with associated soft tissue reconstruction, if needed. PMID:26915784

  19. Postnatal development of collagen structure in ovine articular cartilage

    PubMed Central

    2010-01-01

    Background Articular cartilage (AC) is the layer of tissue that covers the articulating ends of the bones in diarthrodial joints. Across species, adult AC shows an arcade-like structure with collagen predominantly perpendicular to the subchondral bone near the bone, and collagen predominantly parallel to the articular surface near the articular surface. Recent studies into collagen fibre orientation in stillborn and juvenile animals showed that this structure is absent at birth. Since the collagen structure is an important factor for AC mechanics, the absence of the adult Benninghoff structure has implications for perinatal AC mechanobiology. The current objective is to quantify the dynamics of collagen network development in a model animal from birth to maturity. We further aim to show the presence or absence of zonal differentiation at birth, and to assess differences in collagen network development between different anatomical sites of a single joint surface. We use quantitative polarised light microscopy to investigate properties of the collagen network and we use the sheep (Ovis aries) as our model animal. Results Predominant collagen orientation is parallel to the articular surface throughout the tissue depth for perinatal cartilage. This remodels to the Benninghoff structure before the sheep reach sexual maturity. Remodelling of predominant collagen orientation starts at a depth just below the future transitional zone. Tissue retardance shows a minimum near the articular surface at all ages, which indicates the presence of zonal differentiation at all ages. The absolute position of this minimum does change between birth and maturity. Between different anatomical sites, we find differences in the dynamics of collagen remodelling, but no differences in adult collagen structure. Conclusions The collagen network in articular cartilage remodels between birth and sexual maturity from a network with predominant orientation parallel to the articular surface to a

  20. Effects of surgically induced instability on rat knee articular cartilage.

    PubMed Central

    Williams, J M; Felten, D L; Peterson, R G; O'Connor, B L

    1982-01-01

    Degenerative lesions in the articular cartilage were present following transection of the anterior cruciate ligament in the rat. These lesions included surface disruptions, a reduction in matrix proteoglycans, and cellular changes and therefore were similar to lesions seen in dogs following transection of the anterior cruciate ligament as well as lesions seen in other mechanical derangement models. Lesions were more frequently encountered in animals that had been exercised on a treadmill. This suggests that the rat knee joint may be a useful small animal model in studying the effect of mechanical derangement on articular tissues. Images Figs. 1-2 Figs. 3-4 Figs. 5-6 PMID:7076535

  1. Damage Control Mechanisms in Articular Cartilage

    PubMed Central

    Martin, James A; Scherb, MB; Lembke, Lois A; Buckwalter, Joseph

    2000-01-01

    Articular chondrocytes maintain cartilage throughout life by replacing lost or damaged matrix with freshly synthesized material. Synthesis activity is regulated, rapidly increasing to well above basal levels in response to cartilage injury. Such responses suggest that synthesis activity is linked to the rate of matrix loss by endogenous "damage control" mechanisms. As a major stimulator of matrix synthesis in cartilage, insulin-like growth factor I (IGF-I) is likely to play a role in such mechanisms. Although IGF-I is nearly ubiquitous, its bioavailability in cartilage is controlled by IGF-I binding proteins (IGFBPs) secreted by chondrocytes. IGFBPs are part of a complex system, termed the IGF-I axis, that tightly regulates IGF-I activities. For the most part, IGFBPs block IGF-I activity by sequestering IGF-I from its cell surface receptor. We recently found that the expression of one binding protein, IGFBP-3, increases with chondrocyte age, paralleling an age-related decline in synthesis activity. In addition, IGFBP-3 is overexpressed in osteoarthritic cartilage, leading to metabolic disturbances that contribute to cartilage degeneration. These observations indicate that IGFBP-3 plays a crucial role in regulating matrix synthesis in cartilage, and suggest that cartilage damage control mechanisms may fail due to age-related changes in IGFBP-3 expression or distribution. Our investigation of this hypothesis began with immunolocalization studies to determine the tissue distribution of IGFBP-3 in human cartilage. We found that IGFBP-3 accumulated around chondrocytes in the pericellular/territorial matrix, where it co-localized with fibronectin, but not with the other matrix proteins tenascin-C and type VI collagen. This result suggested that the IGFBP-3 distribution is determined by binding to fibronectin. Binding studies using purified proteins demonstrated that IGFBP-3 does in fact bind to fibronectin, but not to tenascin-C or type VI collagen. Finally, we

  2. Extending the NIF DISCO framework to automate complex workflow: coordinating the harvest and integration of data from diverse neuroscience information resources

    PubMed Central

    Marenco, Luis N.; Wang, Rixin; Bandrowski, Anita E.; Grethe, Jeffrey S.; Shepherd, Gordon M.; Miller, Perry L.

    2014-01-01

    This paper describes how DISCO, the data aggregator that supports the Neuroscience Information Framework (NIF), has been extended to play a central role in automating the complex workflow required to support and coordinate the NIF’s data integration capabilities. The NIF is an NIH Neuroscience Blueprint initiative designed to help researchers access the wealth of data related to the neurosciences available via the Internet. A central component is the NIF Federation, a searchable database that currently contains data from 231 data and information resources regularly harvested, updated, and warehoused in the DISCO system. In the past several years, DISCO has greatly extended its functionality and has evolved to play a central role in automating the complex, ongoing process of harvesting, validating, integrating, and displaying neuroscience data from a growing set of participating resources. This paper provides an overview of DISCO’s current capabilities and discusses a number of the challenges and future directions related to the process of coordinating the integration of neuroscience data within the NIF Federation. PMID:25018728

  3. Role of Articular Disc in Condylar Regeneration of the Mandible

    PubMed Central

    Hayashi, Hidetaka; Fujita, Tadashi; ShIrakura, Maya; Tsuka, Yuji; Fujii, Eri; Terao, Akiko; Tanimoto, Kotaro

    2014-01-01

    The articular disc in the temporomandibular joint plays an important role in mandibular growth. Functional appliances induce regeneration of the condyle even after condylectomy. The aim of this study was to examine the role of the articular disc in regeneration of the condyle after unilateral condylectomy with use of a functional appliance in growing rats. Fifty growing rats were subjected to unilateral condylectomy and then half of them underwent discectomy. The functional appliance was applied to half of the rats in each group to induce regeneration of the condyle. Four and eight weeks later, morphometric and histologic analyses of the mandible were performed. Regeneration of the condyle was demonstrated in the two condylectomy groups. In the condylectomy+appliance group, the shape and cartilage of the condyle were equivalent to a normal condyle. However, regeneration of the condyle was not observed in the two discectomy groups even with the use of the functional appliance. The articular disc appears to be crucial in the regeneration of a damaged condyle, suggesting that defects or damage to the articular disc may influence mandibular growth and regeneration or repair of the condyle. PMID:25030880

  4. Editorial Commentary: Knee Lateral Extra-articular Tenodesis.

    PubMed

    Lubowitz, James H

    2015-10-01

    Knee lateral extra-articular tenodesis (LET) can be combined with anterior cruciate ligament (ACL) reconstruction with a goal of reducing anterolateral rotatory instability. Like double-bundle ACL reconstruction, LET combined with ACL reconstruction reduces pivot-shift, a subjective test, but results in no significant difference in clinical outcome. PMID:26433239

  5. Current Concepts of Articular Cartilage Restoration Techniques in the Knee

    PubMed Central

    Camp, Christopher L.; Stuart, Michael J.; Krych, Aaron J.

    2014-01-01

    Context: Articular cartilage injuries are common in patients presenting to surgeons with primary complaints of knee pain or mechanical symptoms. Treatment options include comprehensive nonoperative management, palliative surgery, joint preservation operations, and arthroplasty. Evidence Acquisition: A MEDLINE search on articular cartilage restoration techniques of the knee was conducted to identify outcome studies published from 1993 to 2013. Special emphasis was given to Level 1 and 2 published studies. Study Design: Clinical review. Level of Evidence: Level 3. Results: Current surgical options with documented outcomes in treating chondral injuries in the knee include the following: microfracture, osteochondral autograft transfer, osteochondral allograft transplant, and autologous chondrocyte transplantation. Generally, results are favorable regarding patient satisfaction and return to sport when proper treatment algorithms and surgical techniques are followed, with 52% to 96% of patients demonstrating good to excellent clinical outcomes and 66% to 91% returning to sport at preinjury levels. Conclusion: Clinical, functional, and radiographic outcomes may be improved in the majority of patients with articular cartilage restoration surgery; however, some patients may not fully return to their preinjury activity levels postoperatively. In active and athletic patient populations, biological techniques that restore the articular surface may be options that provide symptom relief and return patients to their prior levels of function. PMID:24790697

  6. Corrective Osteotomy for Intra-Articular Distal Humerus Malunion

    PubMed Central

    Kinaci, Ahmet; Buijze, Geert A.; Leeuwen, Diederik H.van; Jupiter, Jesse B.; Marti, Rene K.; Kloen, Peter

    2016-01-01

    Background: An intra-articular distal humerus malunion can be disabling. To improve function, reduce pain and/or prevent further secondary osteoarthritis an intra-articular corrective osteotomy can be considered. Herein we present the indications, practical guidelines for pre- operative planning and surgical technique. Subsequently, we provide long-term results in a small series. Methods: We included six consecutive patients operated for intra-articular distal humerus malunion. Mean follow-up was 88 months. At lastest follow up elbow function was assessed according to standardized questionnaires and classification systems. Results: All six patients healed their osteotomies. Three patients had a postoperative complication which were treated succesfully. Range of motion improved significantly and all patients were satisfied with the outcome. The elbow performance scores were good to excellent in all. Correlation analyses showed that age and level of osteoarthritis are very strong predictors for the long-term elbow function and quality of life. Conclusion: An intra-articular corrective osteotomy for a malunited distal humerus fracture is a worthwhile procedure. Based on our results it should particularly be considered in young patients with minimal osteoarthritis and moderate to severe functional disability and/or pain. PMID:27200396

  7. Telomere erosion and senescence in human articular cartilage chondrocytes.

    PubMed

    Martin, J A; Buckwalter, J A

    2001-04-01

    Aging and the degeneration of articular cartilage in osteoarthritis are distinct processes, but a strong association exists between age and the incidence and prevalence of osteoarthritis. We hypothesized that this association is due to in vivo replicative senescence, which causes age-related declines in the ability of chondrocytes to maintain articular cartilage. For this hypothesis to be tested, senescence-associated markers were measured in human articular chondrocytes from donors ranging in age from 1 to 87 years. These measures included in situ staining for senescence-associated beta-galactosidase activity, (3)H-thymidine incorporation assays for mitotic activity, and Southern blots for telomere length determinations. We found that senescence-associated beta-galactosidase activity increased with age, whereas both mitotic activity and mean telomere length declined. These findings indicate that chondrocyte replicative senescence occurs in vivo and support the hypothesis that the association between osteoarthritis and aging is due in part to replicative senescence. The data also imply that transplantation procedures performed to restore damaged articular surfaces could be limited by the inability of older chondrocytes to form new cartilage after transplantation. PMID:11283188

  8. Extra-articular ankle stabilization: a case series.

    PubMed

    Roukis, Thomas S

    2010-06-01

    Maintenance of the foot at 90 degrees to the lower leg following posterior calf lengthening or to prevent an equinus contracture in situations in which splint, cast, or external fixation is deemed inappropriate is a challenge. The author presents an observational case series involving 9 extra-articular ankle stabilizations performed in 9 consecutive patients. Each patient underwent his or her index surgery followed by percutaneous placement of 2 smooth 2.8-mm or larger diameter Steinmann pins extra-articular to the ankle joint. There were 6 men and 3 women with a mean age of 56.1 years (range, 31-73 years). Five patients had diabetes with peripheral neuropathy, 2 had critical limb ischemia, 1 had alcohol-induced neuropathy, 1 had lupus, and 1 was an active smoker. Eight patients had posterior calf lengthening, and 1 had open metatarsal fractures with severe soft-tissue disruption with an inability to use splint immobilization. Three patients had a transmetatarsal amputation, 2 patients had Chopart amputations, 2 patients had forefoot plastic surgery reconstructive procedures, 1 had a complex Charcot reconstruction, and 1 had a splittibialis anterior tendon transfer. Extra-articular ankle stabilization fixation was retained for a mean of 5.5 weeks (range, 2-10 weeks). Mean follow-up was 12 months (range, 1-17 months). All extra-articular stabilization procedures were deemed successful. When properly performed, extra-articular stabilization to maintain the foot at 90 degrees to the lower leg represents a safe, simple, reliable, and minimally invasive technique useful in situations in which traditional splint or cast immobilization is not possible and when external fixation is deemed inappropriate. PMID:20508012

  9. The Role of Tissue Engineering in Articular Cartilage Repair and Regeneration

    PubMed Central

    Zhang, Lijie; Hu, Jerry; Athanasiou, Kyriacos A.

    2011-01-01

    Articular cartilage repair and regeneration continue to be largely intractable due to the poor regenerative properties of this tissue. The field of articular cartilage tissue engineering, which aims to repair, regenerate, and/or improve injured or diseased articular cartilage functionality, has evoked intense interest and holds great potential for improving articular cartilage therapy. This review provides an overall description of the current state and progress in articular cartilage repair and regeneration. Traditional therapies and related problems are introduced. More importantly, a variety of promising cell sources, biocompatible tissue engineered scaffolds, scaffoldless techniques, growth factors, and mechanical stimuli used in current articular cartilage tissue engineering are reviewed. Finally, the technical and regulatory challenges of articular cartilage tissue engineering and possible future directions are discussed. PMID:20201770

  10. Datação do disco galáctico pela nucleocosmocronologia do [Th/Eu

    NASA Astrophysics Data System (ADS)

    del Peloso, E. F.; da Silva, L.; Arany-Prado, L. I.

    2003-08-01

    A nucleocosmocronologia emprega abundâncias de nuclídeos radioativos na datação de escalas de tempo astrofísicas. O 232Th é um nuclídeo radioativo com meia-vida de 14 Gano, enquanto que os dois isótopos mais abundantes do Eu são estáveis. O decaimento radioativo do Th modifica as razões de abundâncias [Th/Eu], fornecendo assim um meio de sondar a escala de formação das populações estelares. O objetivo deste trabalho é averiguar a possibilidade de estimar uma idade para o disco Galáctico através da nucleocosmocronologia do [Th/Eu] e investigar o nível de incerteza associado a esta estimativa. Para tanto, foi selecionada uma amostra de 20 estrelas anãs ou subgigantes de tipos espectrais F5 a G9, com -1,00 £ [Fe/H] £ +0,30 e idade(Gano) £ 13. As abundâncias de Th e Eu foram obtidas por síntese espectral das linhas localizadas em 4019,1 Å e 4129,7 Å, respectivamente. Uma comparação destas abundâncias com outros resultados da literatura demonstra que nossos valores apresentam dispersão 2 a 3 vezes menor que qualquer trabalho anterior. Os parâmetros atmosféricos e abundâncias dos elementos que contaminam as regiões espectrais destas linhas foram determinados por nós, de maneira totalmente autoconsistente, através de análise espectral detalhada diferencial em relação ao Sol. As idades estelares individuais foram determinadas através de curvas isócronas teóricas no diagrama HR. Foi realizada, então, uma análise cronológica dos gráficos [Th/Eu] vs. [Fe/H] e [Th/Eu] vs. idade. Os dados estelares foram comparados a curvas calculadas para 3 idades do disco Galáctico - 9, 12, 15 Gano - e foi estudada a sensibilidade à idade assumida no cálculo do ajuste destas curvas aos dados. Estas curvas foram calculadas com base num modelo analítico de evolução química da Galáxia que leva em consideração a formação de refugos, que são compostos pelos remanescentes da evolução estelar, pelos resíduos da formação de estrelas de

  11. Fucose content of keratan sulphates from bovine articular cartilage.

    PubMed Central

    Tai, G H; Brown, G M; Morris, H G; Huckerby, T N; Nieduszynski, I A

    1991-01-01

    Alkaline-borohydride-reduced keratan sulphate chains were isolated from bovine articular cartilage (6-8-year-old animals). Nine keratan sulphate fractions of increasing molecular weight were prepared by gel-permeation chromatography on a calibrated column of TSK 30 XL. The samples were analysed for fucose and galactose contents (% by wt. of keratan sulphate) and fucose/galactose ratio. The fucose content increased with molecular size, but the galactose content remained constant. It was concluded that the alpha(1----3)-linked fucose [Thornton, Morris, Cockin, Huckerby, Nieduszynski, Carlstedt, Hardingham & Ratcliffe (1989) Biochem. J. 260, 277-282] was located within the poly-N-acetyl-lactosamine repeat sequence of articular-cartilage keratan sulphate. PMID:1991030

  12. Treatment of articular cartilage lesions of the knee

    PubMed Central

    Falah, Mazen; Nierenberg, Gabreil; Soudry, Michael; Hayden, Morris

    2010-01-01

    Treatment of articular cartilage lesions in the knee remains a challenge for the practising orthopaedic surgeon. A wide range of options are currently practised, ranging from conservative measures through various types of operations and, recently, use of growth factors and emerging gene therapy techniques. The end result of these methods is usually a fibrous repair tissue (fibrocartilage), which lacks the biomechanical characteristics of hyaline cartilage that are necessary to withstand the compressive forces distributed across the knee. The fibrocartilage generally deteriorates over time, resulting in a return of the original symptoms and occasionally reported progression to osteoarthritis. Our purpose in this study was to review the aetiology, pathogenesis and treatment options for articular cartilage lesions of the knee. At present, autologous cell therapies, growth factor techniques and biomaterials offer more promising avenues of research to find clinical answers. PMID:20162416

  13. Structural and metabolic changes in articular cartilage induced by iodoacetate.

    PubMed Central

    Dunham, J.; Hoedt-Schmidt, S.; Kalbhen, D. A.

    1992-01-01

    The chemically induced injury to articular cartilage, caused by two successive intra-articular injections of sodium iodoacetate, has been used in studies on the effects of anti-inflammatory and of potentially chondroprotective agents. It has been assumed that the injurious effects are caused by inhibition of the glycolytic pathway. In the present study this inhibition has been shown to be greater than expected from in vitro studies, and to influence equally other oxidative pathways. However, the response is clearly not a simple one in that some of the surface chondrocytes, and synovial lining cells in close proximity to the cartilage, show virtually no inhibition. Images Fig. 2 Fig. 3 Fig. 4 PMID:1390193

  14. 3D braid scaffolds for regeneration of articular cartilage.

    PubMed

    Ahn, Hyunchul; Kim, Kyoung Ju; Park, Sook Young; Huh, Jeong Eun; Kim, Hyun Jeong; Yu, Woong-Ryeol

    2014-06-01

    Regenerating articular cartilage in vivo from cultured chondrocytes requires that the cells be cultured and implanted within a biocompatible, biodegradable scaffold. Such scaffolds must be mechanically stable; otherwise chondrocytes would not be supported and patients would experience severe pain. Here we report a new 3D braid scaffold that matches the anisotropic (gradient) mechanical properties of natural articular cartilage and is permissive to cell cultivation. To design an optimal structure, the scaffold unit cell was mathematically modeled and imported into finite element analysis. Based on this analysis, a 3D braid structure with gradient axial yarn distribution was designed and manufactured using a custom-built braiding machine. The mechanical properties of the 3D braid scaffold were evaluated and compared with simulated results, demonstrating that a multi-scale approach consisting of unit cell modeling and continuum analysis facilitates design of scaffolds that meet the requirements for mechanical compatibility with tissues. PMID:24556323

  15. A Simulation Trainer for Complex Articular Fracture Surgery

    PubMed Central

    Yehyawi, Tameem M.; Thomas, Thaddeus P.; Ohrt, Gary T.; Marsh, J. Lawrence; Karam, Matthew D.; Brown, Thomas D.; Anderson, Donald D.

    2013-01-01

    Background: The purposes of this study were (1) to develop a physical model to improve articular fracture reduction skills, (2) to develop objective assessment methods to evaluate these skills, and (3) to assess the construct validity of the simulation. Methods: A surgical simulation was staged utilizing surrogate tibial plafond fractures. Multiple three-segment radio-opacified polyurethane foam fracture models were produced from the same mold, ensuring uniform surgical complexity between trials. Using fluoroscopic guidance, five senior and seven junior orthopaedic residents reduced the fracture through a limited anterior window. The residents were assessed on the basis of time to completion, hand movements (tracked with use of a motion capture system), and quality of the obtained reduction. Results: All but three of the residents successfully reduced and fixed the fracture fragments (one senior resident and two junior residents completed the reduction but were unsuccessful in fixating all fragments). Senior residents had an average time to completion of 13.43 minutes, an average gross articular step-off of 3.00 mm, discrete hand motions of 540 actions, and a cumulative hand motion distance of 79 m. Junior residents had an average time to completion of 14.75 minutes, an average gross articular step-off of 3.09 mm, discrete hand motions of 511 actions, and a cumulative hand motion distance of 390 m. Conclusions: The large difference in cumulative hand motion distance, despite comparable numbers of discrete hand motion events, indicates that senior residents were more precise in their hand motions. The present experiment establishes the basic construct validity of the simulation trainer. Further studies are required to demonstrate that this laboratory-based model for articular fracture reduction training, along with an objective assessment of performance, can be used to improve resident surgical skills. PMID:23824397

  16. Finite element formulation of biphasic poroviscoelastic model for articular cartilage.

    PubMed

    Suh, J K; Bai, S

    1998-04-01

    The purpose of the present study was to develop a computationally efficient finite element model that could be useful for parametric analysis of the biphasic poroviscoelastic (BPVE) behavior of articular cartilage under various loading conditions. The articular cartilage was modeled as the BPVE mixture of a porous, linear viscoelastic, and incompressible solid and an inviscid and incompressible fluid. A finite element (FE) formulation of the BPVE model was developed using two different algorithms, the continuous and discrete spectrum relaxation functions for the viscoelasticity of the solid matrix. These algorithms were applied to the creep and stress relaxation responses to the confined compression of articular cartilage, and a comparison of their performances was made. It was found that the discrete spectrum algorithm significantly saved CPU time and memory, as compared to the continuous spectrum algorithm. The consistency analysis for the present FE formulation was performed in comparison with the IMSL, a commercially available numerical software package. It was found that the present FE formulation yielded consistent results in predicting model behavior, whereas the IMSL subroutine produced inconsistent results in the velocity field, and thereby in the strain calculation. PMID:10412380

  17. Repair and tissue engineering techniques for articular cartilage

    PubMed Central

    Makris, Eleftherios A.; Gomoll, Andreas H.; Malizos, Konstantinos N.; Hu, Jerry C.; Athanasiou, Kyriacos A.

    2015-01-01

    Chondral and osteochondral lesions due to injury or other pathology commonly result in the development of osteoarthritis, eventually leading to progressive total joint destruction. Although current progress suggests that biologic agents can delay the advancement of deterioration, such drugs are incapable of promoting tissue restoration. The limited ability of articular cartilage to regenerate renders joint arthroplasty an unavoidable surgical intervention. This Review describes current, widely used clinical repair techniques for resurfacing articular cartilage defects; short-term and long-term clinical outcomes of these techniques are discussed. Also reviewed is a developmental pipeline of regenerative biological products that over the next decade could revolutionize joint care by functionally healing articular cartilage. These products include cell-based and cell-free materials such as autologous and allogeneic cell-based approaches and multipotent and pluripotent stem-cell-based techniques. Central to these efforts is the prominent role that tissue engineering has in translating biological technology into clinical products; therefore, concomitant regulatory processes are also discussed. PMID:25247412

  18. The effects of exercise on human articular cartilage

    PubMed Central

    Eckstein, F; Hudelmaier, M; Putz, R

    2006-01-01

    The effects of exercise on articular hyaline articular cartilage have traditionally been examined in animal models, but until recently little information has been available on human cartilage. Magnetic resonance imaging now permits cartilage morphology and composition to be analysed quantitatively in vivo. This review briefly describes the methodological background of quantitative cartilage imaging and summarizes work on short-term (deformational behaviour) and long-term (functional adaptation) effects of exercise on human articular cartilage. Current findings suggest that human cartilage deforms very little in vivo during physiological activities and recovers from deformation within 90 min after loading. Whereas cartilage deformation appears to become less with increasing age, sex and physical training status do not seem to affect in vivo deformational behaviour. There is now good evidence that cartilage undergoes some type of atrophy (thinning) under reduced loading conditions, such as with postoperative immobilization and paraplegia. However, increased loading (as encountered by elite athletes) does not appear to be associated with increased average cartilage thickness. Findings in twins, however, suggest a strong genetic contribution to cartilage morphology. Potential reasons for the inability of cartilage to adapt to mechanical stimuli include a lack of evolutionary pressure and a decoupling of mechanical competence and tissue mass. PMID:16637874

  19. Effects of vimentin disruption on the mechanoresponses of articular chondrocyte.

    PubMed

    Chen, Cheng; Yin, Li; Song, Xiongbo; Yang, Hao; Ren, Xiang; Gong, Xiaoyuan; Wang, Fuyou; Yang, Liu

    2016-01-01

    Human articular cartilage is subjected to repetitive mechanical loading during life time. As the only cellular component of articular cartilage, chondrocytes play a key role in the mechanotransduction within this tissue. The mechanoresponses of chondrocytes are largely determined by the cytoskeleton. Vimentin intermediate filaments, one of the major cytoskeletal components, have been shown to regulate chondrocyte phenotype. However, the contribution of vimentin in chondrocyte mechanoresponses remains less studied. In this study, we seeded goat articular chondrocytes on a soft polyacrylamide gel, and disrupted the vimentin cytoskeleton using acrylamide. Then we applied a transient stretch or compression to the cells, and measured the changes of cellular stiffness and traction forces using Optical Magnetic Twisting Cytometry and Traction Force Microscopy, respectively. In addition, to study the effects of vimentin disruption on the intracellular force generation, we treated the cells with a variety of reagents that are known to increase or decrease cytoskeletal tension. We found that, after a compression, the contractile moment and cellular stiffness were not affected in untreated chondrocytes, but were decreased in vimentin-disrupted chondrocytes; after a stretch, vimentin-disrupted chondrocytes showed a lower level of fluidization-resolidification response compared to untreated cells. Moreover, vimentin-disrupted chondrocytes didn't show much difference to control cells in responding to reagents that target actin and ROCK pathway, but showed a weaker response to histamine and isoproterenol. These findings confirmed chondrocyte vimentin as a major contributor in withstanding compressive loading, and its minor role in regulating cytoskeletal tension. PMID:26616052

  20. Multiscale Biofabrication of Articular Cartilage: Bioinspired and Biomimetic Approaches.

    PubMed

    Tatman, Philip David; Gerull, William; Sweeney-Easter, Sean; Davis, Jeffrey Isaac; Gee, Albert O; Kim, Deok-Ho

    2015-12-01

    Articular cartilage is the load-bearing tissue found inside all articulating joints of the body. It vastly reduces friction and allows for smooth gliding between contacting surfaces. The structure of articular cartilage matrix and cellular composition is zonal and is important for its mechanical properties. When cartilage becomes injured through trauma or disease, it has poor intrinsic healing capabilities. The spectrum of cartilage injury ranges from isolated areas of the joint to diffuse breakdown and the clinical appearance of osteoarthritis. Current clinical treatment options remain limited in their ability to restore cartilage to its normal functional state. This review focuses on the evolution of biomaterial scaffolds that have been used for functional cartilage tissue engineering. In particular, we highlight recent developments in multiscale biofabrication approaches attempting to recapitulate the complex 3D matrix of native articular cartilage tissue. Additionally, we focus on the application of these methods to engineering each zone of cartilage and engineering full-thickness osteochondral tissues for improved clinical implantation. These methods have shown the potential to control individual cell-to-scaffold interactions and drive progenitor cell differentiation into a chondrocyte lineage. The use of these bioinspired nanoengineered scaffolds hold promise for recreation of structure and function on the whole tissue level and may represent exciting new developments for future clinical applications for cartilage injury and restoration. PMID:26200439

  1. Colonies in engineered articular cartilage express superior differentiation.

    PubMed

    Selvaratnam, L; Abd Rahim, S; Kamarul, T; Chan, K Y; Sureshan, S; Penafort, R; Ng, C L L

    2005-07-01

    In view of poor regeneration potential of the articular cartilage, in-vitro engineering of cartilage tissue offers a promising option for progressive joint disease. This study aims to develop a biologically engineered articular cartilage for autologous transplantation. The initial work involved determination of chondrocyte yield and viability, and morphological analysis. Cartilage was harvested from the knee, hip and shoulder joints of adult New Zealand white rabbits and chondrocytes were isolated by enzymatic digestion of the extra-cellular matrix before serial cultivation in DMEM/Ham's F12 media as monolayer cultures. No differences were noted in cell yield. Although chondrocytes viability was optimal (>93%) following harvest from native cartilage, their viability tended to be lowered on passaging. Chondrocytes aggregated in isogenous colonies comprising ovoid cells with intimate intracellular contacts and readily exhibited Safranin-O positive matrix; features typically associated with articular cartilage in-vivo. However, chondrocytes also existed concurrently in scattered bipolar/multipolar forms lacking Safranin-O expression. Therefore, early data demonstrated successful serial culture of adult chondrocytes with differentiated morphology seen in established chondrocyte colonies synthesizing matrix proteoglycans. PMID:16381284

  2. Intra-Articular Injections of Polyphenols Protect Articular Cartilage from Inflammation-Induced Degradation: Suggesting a Potential Role in Cartilage Therapeutics.

    PubMed

    Natarajan, Venkatachalam; Madhan, Balaraman; Tiku, Moti L

    2015-01-01

    Arthritic diseases, such as osteoarthritis and rheumatoid arthritis, inflict an enormous health care burden on society. Osteoarthritis, a degenerative joint disease with high prevalence among older people, and rheumatoid arthritis, an autoimmune inflammatory disease, both lead to irreversible structural and functional damage to articular cartilage. The aim of this study was to investigate the effect of polyphenols such as catechin, quercetin, epigallocatechin gallate, and tannic acid, on crosslinking type II collagen and the roles of these agents in managing in vivo articular cartilage degradation. The thermal, enzymatic, and physical stability of bovine articular cartilage explants following polyphenolic treatment were assessed for efficiency. Epigallocatechin gallate and tannic acid-treated explants showed >12 °C increase over native cartilage in thermal stability, thereby confirming cartilage crosslinking. Polyphenol-treated cartilage also showed a significant reduction in the percentage of collagen degradation and the release of glycosaminoglycans against collagenase digestion, indicating the increase physical integrity and resistance of polyphenol crosslinked cartilage to enzymatic digestion. To examine the in vivo cartilage protective effects, polyphenols were injected intra-articularly before (prophylactic) and after (therapeutic) the induction of collagen-induced arthritis in rats. The hind paw volume and histomorphological scoring was done for cartilage damage. The intra-articular injection of epigallocatechin gallate and tannic acid did not significantly influence the time of onset or the intensity of joint inflammation. However, histomorphological scoring of the articular cartilage showed a significant reduction in cartilage degradation in prophylactic- and therapeutic-groups, indicating that intra-articular injections of polyphenols bind to articular cartilage and making it resistant to degradation despite ongoing inflammation. These studies establish

  3. Intra-Articular Injections of Polyphenols Protect Articular Cartilage from Inflammation-Induced Degradation: Suggesting a Potential Role in Cartilage Therapeutics

    PubMed Central

    Natarajan, Venkatachalam; Madhan, Balaraman; Tiku, Moti L.

    2015-01-01

    Arthritic diseases, such as osteoarthritis and rheumatoid arthritis, inflict an enormous health care burden on society. Osteoarthritis, a degenerative joint disease with high prevalence among older people, and rheumatoid arthritis, an autoimmune inflammatory disease, both lead to irreversible structural and functional damage to articular cartilage. The aim of this study was to investigate the effect of polyphenols such as catechin, quercetin, epigallocatechin gallate, and tannic acid, on crosslinking type II collagen and the roles of these agents in managing in vivo articular cartilage degradation. The thermal, enzymatic, and physical stability of bovine articular cartilage explants following polyphenolic treatment were assessed for efficiency. Epigallocatechin gallate and tannic acid-treated explants showed >12 °C increase over native cartilage in thermal stability, thereby confirming cartilage crosslinking. Polyphenol-treated cartilage also showed a significant reduction in the percentage of collagen degradation and the release of glycosaminoglycans against collagenase digestion, indicating the increase physical integrity and resistance of polyphenol crosslinked cartilage to enzymatic digestion. To examine the in vivo cartilage protective effects, polyphenols were injected intra-articularly before (prophylactic) and after (therapeutic) the induction of collagen-induced arthritis in rats. The hind paw volume and histomorphological scoring was done for cartilage damage. The intra-articular injection of epigallocatechin gallate and tannic acid did not significantly influence the time of onset or the intensity of joint inflammation. However, histomorphological scoring of the articular cartilage showed a significant reduction in cartilage degradation in prophylactic- and therapeutic-groups, indicating that intra-articular injections of polyphenols bind to articular cartilage and making it resistant to degradation despite ongoing inflammation. These studies establish

  4. Condições físicas do disco de acréscimo da nova-anã V4140 SGR

    NASA Astrophysics Data System (ADS)

    Borges, B.; Baptista, R.

    2003-08-01

    Discos de acréscimo são aparatos cósmicos que permitem que matéria seja eficientemente acrescida sobre uma fonte compacta pela remoção de momento angular via tensões viscosas enquanto transforma a energia potencial gravitacional em calor e, posteriormente, em radiação. Sistemas binários semi-ligados, como Variáveis Cataclísmicas (VCs) não-magnéticas, são talvez os melhores ambientes encontrados para o estudo da física desses discos de acréscimo. O desenvolvimento de técnicas de imageamento indireto, como o mapeamento por eclipses (MME) e a tomografia Doppler, permitiu avanços importantes na compreensão da física dos processos de acréscimo desses sistemas. V4140 Sagitarii é uma VC eclipsante de curto período orbital (~ 90 min) que não havia sido classificada como nova-anã ou polar. Neste trabalho apresentamos a análise do mapeamento por eclipse feito com dados de fotometria CCD nas bandas B, V e R de V4140 Sgr realizada no LNA. O objeto foi observado no declínio de erupção em julho de 1992 e em erupção em julho de 2001, isso indicou a classificação do sistema como uma nova-anã. A análise, feita sobre os mapas já apresentados em trabalho anterior, apresenta (i) diagrama cor-cor, que indica uma emissão opticamente espessa nas partes internas do disco em quiescência (R < RL1); (ii) diagrama cor-magnitude, usado para inferir uma distância de 600 +/- 10 pc ao sistema; (iii) a distribuição radial de temperatura observada que concorda com a lei de disco espesso em estado estacionário TµR-3/4, com temperaturas em torno de 10000 K e 3000 K ns partes internas e externas do disco em quiescência, respectivamente; (iv) a evolução da distribuição de temperatura no declínio de erupção; (v) estimativa da transferência de massa de 109.9+/-0.1 M¤/ano em quiescência, similar àquelas observadas em novas-like. O sistema é comparado à outras novas-anãs (e.g. OY Car e Z Cha) em quiescência e erupção, mostrando-se tratar um

  5. Regeneration of Articular Cartilage Surface: Morphogens, Cells, and Extracellular Matrix Scaffolds.

    PubMed

    Sakata, Ryosuke; Iwakura, Takashi; Reddi, A Hari

    2015-10-01

    The articular cartilage is a well-organized tissue for smooth and friction-free joint movement for locomotion in animals and humans. Adult articular cartilage has a very low self-regeneration capacity due to its avascular nature. The regeneration of articular cartilage surface is critical to prevent the progression to osteoarthritis (OA). Although various joint resurfacing procedures in experimental articular cartilage defects have been developed, no standardized clinical protocol has yet been established. The three critical ingredients for tissue regeneration are morphogens and growth factors, cells, and scaffolds. The concepts based on the regeneration triad have been extensively investigated in animal models. However, these studies in animal models have demonstrated variable results and outcomes. An optimal animal model must precisely mimic and model the sequence of events in articular cartilage regeneration in human. In this article, the progress and remaining challenges in articular cartilage regeneration in animal models are reviewed. The role of individual morphogens and growth factors in cartilage regeneration has been investigated. In normal articular cartilage homeostasis, morphogens and growth factors function sequentially in tissue regeneration. Mesenchymal stem cell-based repair of articular cartilage defects, performed with or without various growth factors and scaffolds, has been widely attempted in animal models. Stem cells, including embryonic and adult stem cells and induced pluripotent stem cells, have also been reported as attractive cell sources for articular cartilage surface regeneration. Several studies with regard to scaffolds have been advanced, including recent investigations based on nanomaterials, functional mechanocompatible scaffolds, multilayered scaffolds, and extracellular matrix scaffolds for articular cartilage surface regeneration. Continuous refinement of animal models in chondral and osteochondral defects provide opportunities

  6. ROCK inhibitor prevents the dedifferentiation of human articular chondrocytes

    SciTech Connect

    Matsumoto, Emi; Furumatsu, Takayuki; Kanazawa, Tomoko; Tamura, Masanori; Ozaki, Toshifumi

    2012-03-30

    Highlights: Black-Right-Pointing-Pointer ROCK inhibitor stimulates chondrogenic gene expression of articular chondrocytes. Black-Right-Pointing-Pointer ROCK inhibitor prevents the dedifferentiation of monolayer-cultured chondrocytes. Black-Right-Pointing-Pointer ROCK inhibitor enhances the redifferentiation of cultured chondrocytes. Black-Right-Pointing-Pointer ROCK inhibitor is useful for preparation of un-dedifferentiated chondrocytes. Black-Right-Pointing-Pointer ROCK inhibitor may be a useful reagent for chondrocyte-based regeneration therapy. -- Abstract: Chondrocytes lose their chondrocytic phenotypes in vitro. The Rho family GTPase ROCK, involved in organizing the actin cytoskeleton, modulates the differentiation status of chondrocytic cells. However, the optimum method to prepare a large number of un-dedifferentiated chondrocytes is still unclear. In this study, we investigated the effect of ROCK inhibitor (ROCKi) on the chondrogenic property of monolayer-cultured articular chondrocytes. Human articular chondrocytes were subcultured in the presence or absence of ROCKi (Y-27632). The expression of chondrocytic marker genes such as SOX9 and COL2A1 was assessed by quantitative real-time PCR analysis. Cellular morphology and viability were evaluated. Chondrogenic redifferentiation potential was examined by a pellet culture procedure. The expression level of SOX9 and COL2A1 was higher in ROCKi-treated chondrocytes than in untreated cells. Chondrocyte morphology varied from a spreading form to a round shape in a ROCKi-dependent manner. In addition, ROCKi treatment stimulated the proliferation of chondrocytes. The deposition of safranin O-stained proteoglycans and type II collagen was highly detected in chondrogenic pellets derived from ROCKi-pretreated chondrocytes. Our results suggest that ROCKi prevents the dedifferentiation of monolayer-cultured chondrocytes, and may be a useful reagent to maintain chondrocytic phenotypes in vitro for chondrocyte

  7. Importance of reference gene selection for articular cartilage mechanobiology studies

    PubMed Central

    Al-Sabah, A.; Stadnik, P.; Gilbert, S.J.; Duance, V.C.; Blain, E.J.

    2016-01-01

    Summary Objective Identification of genes differentially expressed in mechano-biological pathways in articular cartilage provides insight into the molecular mechanisms behind initiation and/or progression of osteoarthritis (OA). Quantitative PCR (qPCR) is commonly used to measure gene expression, and is reliant on the use of reference genes for normalisation. Appropriate validation of reference gene stability is imperative for accurate data analysis and interpretation. This study determined in vitro reference gene stability in articular cartilage explants and primary chondrocytes subjected to different compressive loads and tensile strain, respectively. Design The expression of eight commonly used reference genes (18s, ACTB, GAPDH, HPRT1, PPIA, RPL4, SDHA and YWHAZ) was determined by qPCR and data compared using four software packages (comparative delta-Ct method, geNorm, NormFinder and BestKeeper). Calculation of geometric means of the ranked weightings was carried out using RefFinder. Results Appropriate reference gene(s) for normalisation of mechanically-regulated transcript levels in articular cartilage tissue or isolated chondrocytes were dependent on experimental set-up. SDHA, YWHAZ and RPL4 were the most stable genes whilst glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and to a lesser extent Hypoxanthine-guanine phosphoribosyltransferase (HPRT), showed variable expression in response to load, demonstrating their unsuitability in such in vitro studies. The effect of using unstable reference genes to normalise the expression of aggrecan (ACAN) and matrix metalloproteinase 3 (MMP3) resulted in inaccurate quantification of these mechano-sensitive genes and erroneous interpretation/conclusions. Conclusion This study demonstrates that commonly used ‘reference genes’ may be unsuitable for in vitro cartilage chondrocyte mechanobiology studies, reinforcing the principle that careful validation of reference genes is essential prior to each experiment to

  8. Biochemical analysis of normal articular cartilage in horses.

    PubMed

    Vachon, A M; Keeley, F W; McIlwraith, C W; Chapman, P

    1990-12-01

    Articular cartilage specimens from the distal articular surface of 32 radiocarpal bones from 24 2- to 5-year-old horses were analyzed. The total collagen content was determined on the basis of the 4-hydroxyproline content, using a colorimetric method. A method for estimating the proportions of types-I and -II collagen by measuring spectrophotometric densities of specific cyanogen bromide peptide bands from mixtures of types-I and -II collagen on sodium dodecyl sulfate-polyacrylamide gels was used. The cyanogen bromide peptides representative of each collagen types-I and -II were identified. The peptide ratios were then computed for each of several standards of type-I and -II mixtures. A standard curve was derived from the correlation between these ratios and the corresponding proportions of type-II collagen in standard mixtures. Galactosamine and glucosamine content (hexosamines) were measured by ion chromatography. The galactosamine-to-glucosamine ratio, chondroitin sulfate and keratan sulfate values, and total glycosaminoglycan content were derived from the measured hexosamine content. The total collagen content averaged 556 mg/g (55.6 mg/100 mg) of tissue (dry weight, [dw]). Type-II collagen was the major collagen type in normal articular cartilage specimens. The ratio of the area under the alpha 1 (II)CB10 peak to the area under the alpha 1 (I)CB 7,8 + alpha 1 (II)CB11 peak was a second-order polynomial function of the proportion of type-II collagen in the specimens. The mean galactosamine and glucosamine content were 20.6 mg/g and 7.9 mg/g (dw), respectively. The mean galactosamine-to-glucosamine ratio was 3.74 +/- 0.62.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2085215

  9. Mechanical properties of normal and osteoarthritic human articular cartilage.

    PubMed

    Robinson, Dale L; Kersh, Mariana E; Walsh, Nicole C; Ackland, David C; de Steiger, Richard N; Pandy, Marcus G

    2016-08-01

    Isotropic hyperelastic models have been used to determine the material properties of normal human cartilage, but there remains an incomplete understanding of how these properties may be altered by osteoarthritis. The aims of this study were to (1) measure the material constants of normal and osteoarthritic human knee cartilage using isotropic hyperelastic models; (2) determine whether the material constants correlate with histological measures of structure and/or cartilage tissue damage; and (3) quantify the abilities of two common isotropic hyperelastic material models, the neo-Hookean and Yeoh models, to describe articular cartilage contact force, area, and pressure. Small osteochondral specimens of normal and osteoarthritic condition were retrieved from human cadaveric knees and from the knees of patients undergoing total knee arthroplasty and tested in unconfined compression at loading rates and large strains representative of weight-bearing activity. Articular surface contact area and lateral deformation were measured concurrently and specimen-specific finite element models then were used to determine the hyperelastic material constants. Structural parameters were measured using histological techniques while the severity of cartilage damage was quantified using the OARSI grading scale. The hyperelastic material constants correlated significantly with OARSI grade, indicating that the mechanical properties of cartilage for large strains change with tissue damage. The measurements of contact area described anisotropy of the tissue constituting the superficial zone. The Yeoh model described contact force and pressure more accurately than the neo-Hookean model, whereas both models under-predicted contact area and poorly described the anisotropy of cartilage within the superficial zone. These results identify the limits by which isotropic hyperelastic material models may be used to describe cartilage contact variables. This study provides novel data for the

  10. Patterns of radiocarpal joint articular cartilage wear in cadavers.

    PubMed

    Gorniak, Gerard C; Conrad, Will; Conrad, Erin; Decker, Bonnie

    2012-05-01

    The radiocarpal joint transmits about 80% of the compression forces crossing the wrist. However, primary osteoarthritis of this joint is surprisingly uncommon, suggesting that articular cartilage wear is not sufficient to produce arthritic symptoms. By examining the distal radius, scaphoid, and lunate in aged cadavers, wear patterns were charted and measured, allowing assessment of radiocarpal joint wear and mechanics. Bilateral radiocarpal joints of 16 females and 14 males (age 77.7 ± 14.4, N = 30) were exposed and measurements of the wear recorded microscopically. Wear locations were mapped, and X-Y loci and wear areas calculated. Gender right and sides compared. Over 95% of distal radius wear showed distinct radial-scaphoid and radial-lunate wear areas. These bilateral areas were in the palmar half of the distal radius. One main central wear area was seen in 95% of the scaphoid, and 97% of the lunate articular surfaces that were examined. Articular wear showed a circular pattern and was minimal in 95.7% of the surfaces, and the lunate showed the largest wear area. Wear patterns in males and females support the literature that for most ADLs the wrist is in slight extension and ulnar deviation. There are gender differences, but wear areas between sides were similar. Female wear indicates their wrist is positioned more often in a more extended and ulnarly deviated position than males. The wear patterns suggest rotational movements of the scaphoid and lunate during wrist motion and that the wrist is most often used in neutral flexion/extension to slight extension. PMID:22095798

  11. Membrane channel gene expression in human costal and articular chondrocytes

    PubMed Central

    Asmar, A.; Barrett-Jolley, R.; Werner, A.; Kelly, R.; Stacey, M.

    2016-01-01

    ABSTRACT Chondrocytes are the uniquely resident cells found in all types of cartilage and key to their function is the ability to respond to mechanical loads with changes of metabolic activity. This mechanotransduction property is, in part, mediated through the activity of a range of expressed transmembrane channels; ion channels, gap junction proteins, and porins. Appropriate expression of ion channels has been shown essential for production of extracellular matrix and differential expression of transmembrane channels is correlated to musculoskeletal diseases such as osteoarthritis and Albers-Schönberg. In this study we analyzed the consistency of gene expression between channelomes of chondrocytes from human articular and costal (teenage and fetal origin) cartilages. Notably, we found 14 ion channel genes commonly expressed between articular and both types of costal cartilage chondrocytes. There were several other ion channel genes expressed only in articular (6 genes) or costal chondrocytes (5 genes). Significant differences in expression of BEST1 and KCNJ2 (Kir2.1) were observed between fetal and teenage costal cartilage. Interestingly, the large Ca2+ activated potassium channel (BKα, or KCNMA1) was very highly expressed in all chondrocytes examined. Expression of the gap junction genes for Panx1, GJA1 (Cx43) and GJC1 (Cx45) was also observed in chondrocytes from all cartilage samples. Together, this data highlights similarities between chondrocyte membrane channel gene expressions in cells derived from different anatomical sites, and may imply that common electrophysiological signaling pathways underlie cellular control. The high expression of a range of mechanically and metabolically sensitive membrane channels suggest that chondrocyte mechanotransduction may be more complex than previously thought. PMID:27116676

  12. The collagen fibril organization in human articular cartilage.

    PubMed Central

    Minns, R J; Steven, F S

    1977-01-01

    In this scanning electron microscopic study blocks of collagen fibrils were prepared from human articular cartilage, using two techinques which selectively removed either the proteoglycans alone, or both the proteoglycans and the collagen fibrils, of the non-calcified cartilage layer. Amino acid analysis of the fibrils confirmed the purity of the collagen after proteoglycan extraction. The cartilage was scanned in four different ways: (1) normal to the articular surface, (2) in superficial sections, (3) on surfaces of blocks which had been broken in planes parallel to artificial splits make by the insertion of a pin, and (4) on fracture surfaces which traversed the calcified cartilage and the subchondral bone. Five features of the organization of the collagen fibrils were specially noted: (1) Individual fibrils within the trabeculae joined to form small fibre bundles which became grouped into larger bundles at the calcified/uncalcified interface. (2) Fibrils in the deep and middle zones which, exhibiting the characteristic surface periodicity of collagen, were generally oriented towars the articular surface in large bundles approximately 55 micronm across. (3) In the superficial zone, fibrils ran parallel to the surface. (4) The surface fibrils had random orientation, even at the bases of empty lacunae vacated by chondrocytes during specimen preparation. (5) The collagen fibrils of the lacunar walls appeared to be thinner and more closely packed than thos between the lacunae. The fine collagen fibrils associated with the lacunar walls were frequently observed to pass through a large lacunar space, resulting in the formation of two or more compartments, each of which was presumably filled with a chondrocyte in the living cartilage. Images Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 PMID:870478

  13. Optical clearing of articular cartilage: a comparison of clearing agents

    NASA Astrophysics Data System (ADS)

    Bykov, Alexander; Hautala, Tapio; Kinnunen, Matti; Popov, Alexey; Karhula, Sakari; Saarakkala, Simo; Nieminen, Miika T.; Tuchin, Valery

    2015-07-01

    Optical clearing technique was applied to the problem of OCT imaging of articular cartilage and subchondral bone. We show that optical clearing significantly enhances visualization of articular cartilage and cartilage-bone interface. The effect of different clearing agents was analyzed. For the clearing, iohexol solution and propylene glycol (PG) were used. Clearing was performed in vitro at room temperature by immersion method. Cylindrical osteochondral samples (d=4.8mm) were drilled from bovine lateral femur and stored in phosphate-buffered saline at -20°C until clearing. Monitoring of clearing process was performed using high-speed spectral-domain OCT system providing axial resolution of 5.8μm at 930nm. Total duration of experiment was 90-100min to ensure saturation of clearing. We have shown that iohexol solution and PG are capable to optically clear articular cartilage enabling reliable characterization of cartilagebone interface with OCT. Being a low osmolarity agent, iohexol provides minimal changes to the thickness of cartilage sample. Clearing saturation time for the cartilage sample with the thickness of 0.9 mm measured with OCT is of 50 min. However, less than 15 min is enough to reliably detect the rear cartilage boundary. Alternatively, PG significantly (60%) reduces the cartilage thickness enabling better visualization of subchondral bone. It was observed that PG has higher clearing rate. The clearing saturation time is of 30 min, however less than 5 min is enough to detect cartilage-bone interface. We conclude that iohexol solution is superior for OCT imaging of cartilage and cartilage-bone interface, while PG suits better for subhondral bone visualization.

  14. [Brucine chitosan thermosensitive hydrogel for intra-articular injection].

    PubMed

    Chen, Zhi-Peng; Liu, Wen; Chen, Hong-Xuan; Cai, Bao-Chang

    2012-05-01

    The aim of this study was to develop a sustained release converse thermosensitive hydrogel for intra-articular injection using chitosan-glycerol-borax as matrix, its physical properties and biocompatibility were investigated. Taking gelation time and gelation condition as index, the influence of concentration of chitosan, ratio of chitosan to glycerol, pH on physical properties of hydrogel were investigated. And then the in vitro drug release, rheological properties and biocompatibility were studied. The thermosensitive hydrogel flows easily at room temperature and turns to gelation at body temperature, which can certainly prolong the release of drug and has good biocompatibility. PMID:22812012

  15. Microscale surface friction of articular cartilage in early osteoarthritis.

    PubMed

    Desrochers, Jane; Amrein, Matthias W; Matyas, John R

    2013-09-01

    Articular cartilage forms the articulating surface of long bones and facilitates energy dissipation upon loading as well as joint lubrication and wear resistance. In normal cartilage, boundary lubrication between thin films at the cartilage surface reduces friction in the absence of interstitial fluid pressurization and fluid film lubrication by synovial fluid. Inadequate boundary lubrication is associated with degenerative joint conditions such as osteoarthritis (OA), but relations between OA and surface friction, lubrication and wear in boundary lubrication are not well defined. The purpose of the present study was to measure microscale boundary mode friction of the articular cartilage surface in an in vivo experimental model to better understand changes in cartilage surface friction in early OA. Cartilage friction was measured on the articular surface by atomic force microscopy (AFM) under applied loads ranging from 0.5 to 5 μN. Microscale AFM friction analyses revealed depth dependent changes within the top-most few microns of the cartilage surface in this model of early OA. A significant increase of nearly 50% was observed in the mean engineering friction coefficient for OA cartilage at the 0.5 μN load level; no significant differences in friction coefficients were found under higher applied loads. Changes in cartilage surface morphology observed by scanning electron microscopy included cracking and roughening of the surface indicative of disruption and wear accompanied by an apparent disintegration of the thin surface lamina from the underlying matrix. Immunohistochemical staining of lubricin - an important cartilage surface boundary lubricant - did not reveal differences in spatial distribution near the cartilage surface in OA compared to controls. The increase in friction at the 0.5 μN force level is interpreted to reflect changes in the interfacial mechanics of the thin surface lamina of articular cartilage: increased friction implies reduced

  16. [Joint morphogenesis and development of permanent articular cartilage].

    PubMed

    Ohta, Yoichi; Iwamoto, Masahiro

    2011-06-01

    During limb skeletogenesis progenitor mesenchymal cells aggregate at specific times and sites to form continuous precartilaginous condensations. With time the condensations undergo chondrogenesis and give rise to cartilaginous anlagen that exhibit incipient synovial joints at each end. A multitude of factors regulates subdivision into discrete skeletal elements and the formation, organization, morphogenesis and structure of the joints. This review summarizes recent advance of joint morphogenesis and actions of key players of joint and articular cartilage formation. In addition, we would like to discuss possible direction to translate basic research findings towards treatment of joint diseases. PMID:21628794

  17. Extra-articular Synovial Chondromatosis Eroding and Penetrating the Acromion

    PubMed Central

    El Rassi, George; Matta, Jihad; Hijjawi, Ayman; Khair, Ousama Abou; Fahs, Sara

    2015-01-01

    Synovial chondromatosis of the shoulder is an uncommon disorder. It usually affects the glenohumeral joint and is characterized by metaplasia of the synovium leading to the formation of osteochondral loose bodies. Few cases of extra-articular subacromial synovial chondromatosis involving the rotator cuff tendon have been reported in the literature. The treatment of previously reported cases consisted of open bursectomy and removal of loose bodies. We report a case of subacromial synovial chondromatosis without rotator cuff involvement but with severe erosion and fracture of the acromion. Treatment consisted of shoulder arthroscopy to remove all loose bodies, total bursectomy, and debridement of the acromion. Potential benefits of arthroscopy were also evaluated. PMID:26697302

  18. Extra-articular Synovial Chondromatosis Eroding and Penetrating the Acromion.

    PubMed

    El Rassi, George; Matta, Jihad; Hijjawi, Ayman; Khair, Ousama Abou; Fahs, Sara

    2015-10-01

    Synovial chondromatosis of the shoulder is an uncommon disorder. It usually affects the glenohumeral joint and is characterized by metaplasia of the synovium leading to the formation of osteochondral loose bodies. Few cases of extra-articular subacromial synovial chondromatosis involving the rotator cuff tendon have been reported in the literature. The treatment of previously reported cases consisted of open bursectomy and removal of loose bodies. We report a case of subacromial synovial chondromatosis without rotator cuff involvement but with severe erosion and fracture of the acromion. Treatment consisted of shoulder arthroscopy to remove all loose bodies, total bursectomy, and debridement of the acromion. Potential benefits of arthroscopy were also evaluated. PMID:26697302

  19. Effect of passive motion on articular cartilage in rat osteoarthritis

    PubMed Central

    QIAN, JIE; LIANG, JUN; WANG, YUBIN; WANG, HUIFANG

    2014-01-01

    The aim of the present study was to investigate the effect of moderate passive motion on articular cartilage in osteoarthritis (OA) caused by knee fracture. Sprague-Dawley rats (age, 8 weeks) with knee fractures were used to construct rat knee early- and middle-stage OA models. The stages were fixed for three and six weeks, with 20 rats analyzed at each stage. The experimental groups were exercised daily for 15 m/min with a specified duration. Following the completion of exercise, the effects of proper passive motion on cartilage thickness, the Mankin rating, cartilage collagen matrix, proteoglycan content and the morphological structure of the cartilage in the rat OA models were measured at the various degenerative stages caused by knee fracture. The proteoglycan content of the cartilage matrix, type II collagen fibers and the number of cartilage cells undergoing apoptosis were semiquantified. For early- and middle-stage OA, the cartilage layers in the three- or six-week experimental groups were significantly thicker and the levels of proteoglycans and type II collagen fibers in the weight-bearing area of the cartilage were significantly higher when compared with the control groups (P<0.05). In addition, the Mankin ratings were lower and ligament tension was increased when compared with the control group (P<0.05). In the early-stage OA group, significantly decreased apoptotic rates (P<0.05) were observed in the three- and six-week experimental groups, however, no significant decrease was observed in the middle-stage OA group. In the early-stage OA rats, the thickness of the cartilage layer, as well as the levels of proteoglycans and type II collagen fibers, in the six-week experimental group, were significantly higher compared with the control and three-week subgroups, and a decreased apoptotic rate was observed (P<0.05). In the six-week experimental middle-stage OA group, significant differences were observed in the content of proteoglycans and type II collagen

  20. Effect of passive motion on articular cartilage in rat osteoarthritis.

    PubMed

    Qian, Jie; Liang, Jun; Wang, Yubin; Wang, Huifang

    2014-08-01

    The aim of the present study was to investigate the effect of moderate passive motion on articular cartilage in osteoarthritis (OA) caused by knee fracture. Sprague-Dawley rats (age, 8 weeks) with knee fractures were used to construct rat knee early- and middle-stage OA models. The stages were fixed for three and six weeks, with 20 rats analyzed at each stage. The experimental groups were exercised daily for 15 m/min with a specified duration. Following the completion of exercise, the effects of proper passive motion on cartilage thickness, the Mankin rating, cartilage collagen matrix, proteoglycan content and the morphological structure of the cartilage in the rat OA models were measured at the various degenerative stages caused by knee fracture. The proteoglycan content of the cartilage matrix, type II collagen fibers and the number of cartilage cells undergoing apoptosis were semiquantified. For early- and middle-stage OA, the cartilage layers in the three- or six-week experimental groups were significantly thicker and the levels of proteoglycans and type II collagen fibers in the weight-bearing area of the cartilage were significantly higher when compared with the control groups (P<0.05). In addition, the Mankin ratings were lower and ligament tension was increased when compared with the control group (P<0.05). In the early-stage OA group, significantly decreased apoptotic rates (P<0.05) were observed in the three- and six-week experimental groups, however, no significant decrease was observed in the middle-stage OA group. In the early-stage OA rats, the thickness of the cartilage layer, as well as the levels of proteoglycans and type II collagen fibers, in the six-week experimental group, were significantly higher compared with the control and three-week subgroups, and a decreased apoptotic rate was observed (P<0.05). In the six-week experimental middle-stage OA group, significant differences were observed in the content of proteoglycans and type II collagen

  1. Intra-articular and Peri-articular Tumours and Tumour Mimics- What a Clinician and Onco-imaging Radiologist Should Know

    PubMed Central

    DHANDA, Sunita; QUEK, Swee Tian; BATHLA, Girish; JAGMOHAN, Pooja

    2014-01-01

    Definitive determination of the cause of articular swelling may be difficult based on just the clinical symptoms, physical examinations and laboratory tests. Joint disorders fall under the realms of rheumatology and general orthopaedics; however, patients with joint conditions manifesting primarily as intra-articular and peri-articular soft tissue swelling may at times be referred to an orthopaedic oncology department with suspicion of a tumour. In such a situation, an onco-radiologist needs to think beyond the usual neoplastic lesions and consider the diagnoses of various non-neoplastic arthritic conditions that may be clinically masquerading as masses. Differential diagnoses of articular lesions include infectious and non-infectious synovial proliferative processes, degenerative lesions, deposition diseases, vascular malformations, benign and malignant neoplasms and additional miscellaneous conditions. Many of these diseases have specific imaging findings. Knowledge of these radiological characteristics in an appropriate clinical context will allow for a more confident diagnosis. PMID:24876802

  2. Prevalence of articular chondrocalcinosis in elderly subjects in a rural area of Catalonia.

    PubMed Central

    Sanmartí, R; Pañella, D; Brancós, M A; Canela, J; Collado, A; Brugués, J

    1993-01-01

    OBJECTIVES--To undertake an epidemiological survey of the prevalence of radiological chondrocalcinosis in the elderly population of Osona, a rural area of Catalonia, north east Spain. METHODS--Knee and wrist radiographs were performed on 261 subjects (141 women, 120 men) aged at least 60 years, who attended a series of 35 general practitioners for various medical problems. RESULTS--Twenty seven subjects had articular chondrocalcinosis, which represents a crude prevalence of 10%. Articular chondrocalcinosis was more often observed in women than in men (14 v 6%). Articular chondrocalcinosis increases in occurrence with age, rising from 7% in subjects aged 60-69 years to 43% in subjects older than 80 years. A similar occurrence of articular chondrocalcinosis was noted in the indigenous population, in which several cases of familial chondrocalcinosis have previously been reported, and in subjects born in other areas of Spain. All but one subject with articular chondrocalcinosis had chondrocalcinosis of the knee. The occurrence of rheumatic disorders did not differ significantly between subjects with articular chondrocalcinosis and those without. CONCLUSIONS--Articular chondrocalcinosis is an age related disorder, which could partly explain the discrepancies in its prevalence reported in previous studies. In most subjects with articular chondrocalcinosis recruited from an unselected population the clinical manifestations are probably mild or even absent. PMID:8323393

  3. In vivo bone tunnel remodeling in symptomatic patients after ACL reconstruction: a retrospective comparison of articular and extra-articular fixation

    PubMed Central

    Mathis, Dominic T.; Rasch, Helmut; Hirschmann, Michael T.

    2015-01-01

    Summary Background there is only a paucity of studies dealing with bone remodeling within the tunnels after anterior cruciate ligament (ACL) reconstruction. The objective of this study was to evaluate the influence of tendon graft type and surgical fixation technique on bone tunnel remodeling in patients with symptomatic knees after ACL reconstruction. Methods in a retrospective study 99mTc-HDP bone tracer uptake (BTU) in SPECT/CT of 57 knees with symptoms of pain and/or instability after ACL reconstruction was investigated. All 57 knees were subdivided according their anatomy (femur and tibia), fixation (articular versus extra-articular fixation) and graft types into eight groups: femoral-articular versus extra-articular fixation using bone-patellar tendon-bone (BPTB) and hamstring autografts; tibial-articular versus extra-articular fixation using patellar tendon and hamstring autografts; BTU grading for each area of the localisation scheme were recorded. Tunnel diameter and length was measured in the CT scans. Results BTU was higher for the articular fixation in the femur and for the extra-articular fixation in the tibial tunnel. Patellar tendon graft fixation showed a significantly higher BTU in the superior-lateral and posterior-central area of the tibia, meaning the areas of the tibial tunnel near the entrance into the joint. Tunnel enlargement correlated significantly with increased BTU (p<0.05). Conclusion assessment of in vivo bone tunnel remodelling in symptomatic patients after ACL reconstruction revealed different patterns of BTU with regards to graft and fixation method. PMID:26958543

  4. Extra-articular hip impingement: a narrative review of the literature

    PubMed Central

    Cheatham, Scott W.

    2016-01-01

    There is growing subgroup of patients with poor outcomes after hip arthroscopy for intra-articular pathology suggesting unrecognized cause(s) of impingement may exist. Extra-articular hip impingement (EHI) is an emerging group of conditions that have been associated with intra-articular causes of impingement and may be an unrecognized source of pain. EHI is caused by abnormal contact between the extra-articular regions of the proximal femur and pelvis. This review discusses the most common forms for EHI including: central iliopsoas impingement, subspine impingement, ischiofemoral impingement, and greater trochanteric-pelvic impingement. The clinical presentation of each pathology will be discussed since EHI conditions share similar clinical features as the intra-articular pathology but also contain some unique characteristics. PMID:27069266

  5. Expression of Angiotensin II Receptor-1 in Human Articular Chondrocytes

    PubMed Central

    Kawakami, Yuki; Matsuo, Kosuke; Murata, Minako; Yudoh, Kazuo; Nakamura, Hiroshi; Shimizu, Hiroyuki; Beppu, Moroe; Inaba, Yutaka; Saito, Tomoyuki; Kato, Tomohiro; Masuko, Kayo

    2012-01-01

    Background. Besides its involvement in the cardiovascular system, the renin-angiotensin-aldosterone (RAS) system has also been suggested to play an important role in inflammation. To explore the role of this system in cartilage damage in arthritis, we investigated the expression of angiotensin II receptors in chondrocytes. Methods. Articular cartilage was obtained from patients with osteoarthritis, rheumatoid arthritis, and traumatic fractures who were undergoing arthroplasty. Chondrocytes were isolated and cultured in vitro with or without interleukin (IL-1). The expression of angiotensin II receptor types 1 (AT1R) and 2 (AT2R) mRNA by the chondrocytes was analyzed using reverse transcription-polymerase chain reaction (RT-PCR). AT1R expression in cartilage tissue was analyzed using immunohistochemistry. The effect of IL-1 on AT1R/AT2R expression in the chondrocytes was analyzed by quantitative PCR and flow cytometry. Results. Chondrocytes from all patient types expressed AT1R/AT2R mRNA, though considerable variation was found between samples. Immunohistochemical analysis confirmed AT1R expression at the protein level. Stimulation with IL-1 enhanced the expression of AT1R/AT2R mRNA in OA and RA chondrocytes. Conclusions. Human articular chondrocytes, at least partially, express angiotensin II receptors, and IL-1 stimulation induced AT1R/AT2R mRNA expression significantly. PMID:23346400

  6. Quantitative proteomic profiling of human articular cartilage degradation in osteoarthritis.

    PubMed

    Lourido, Lucía; Calamia, Valentina; Mateos, Jesús; Fernández-Puente, Patricia; Fernández-Tajes, Juan; Blanco, Francisco J; Ruiz-Romero, Cristina

    2014-12-01

    Osteoarthritis (OA) is the most common rheumatic pathology and is characterized primarily by articular cartilage degradation. Despite its high prevalence, there is no effective therapy to slow disease progression or regenerate the damaged tissue. Therefore, new diagnostic and monitoring tests for OA are urgently needed, which would also promote the development of alternative therapeutic strategies. In the present study, we have performed an iTRAQ-based quantitative proteomic analysis of secretomes from healthy human articular cartilage explants, comparing their protein profile to those from unwounded (early disease) and wounded (advanced disease) zones of osteoarthritic tissue. This strategy allowed us to identify a panel of 76 proteins that are distinctively released by the diseased tissue. Clustering analysis allowed the classification of proteins according to their different profile of release from cartilage. Among these proteins, the altered release of osteoprotegerin (decreased in OA) and periostin (increased in OA), both involved in bone remodelling processes, was verified in further analyses. Moreover, periostin was also increased in the synovial fluid of OA patients. Altogether, the present work provides a novel insight into the mechanisms of human cartilage degradation and a number of new cartilage-characteristic proteins with possible biomarker value for early diagnosis and prognosis of OA. PMID:25383958

  7. A nonlinear biphasic viscohyperelastic model for articular cartilage.

    PubMed

    García, José Jaime; Cortés, Daniel Humberto

    2006-01-01

    Experiments on articular cartilage have shown nonlinear stress-strain curves under finite deformations as well as intrinsic viscous effects of the solid phase. The aim of this study was to propose a nonlinear biphasic viscohyperelastic model that combines the intrinsic viscous effects of the proteoglycan matrix with a nonlinear hyperelastic constitutive equation. The proposed equation satisfies objectivity and reduces for uniaxial loading to a solid type viscous model in which the actions of the springs are represented by the hyperelastic function proposed by Holmes and Mow [1990. J. Biomechanics 23, 1145-1156.]. Results of the model, that were efficiently implemented in an updated Lagrangian algorithm, were compared with experimental infinitesimal data reported by DiSilverstro and Suh [2001. J. Biomechanics 34, 519-525.] and showed acceptable fitting for the axial force (R(2)=0.991) and lateral displacement (R(2)=0.914) curves in unconfined compression as well as a good fitting of the axial indentation force curve (R(2)=0.982). In addition, the model showed an excellent fitting of finite-deformation confined compression stress relaxation data reported by Ateshian et al. [1997. J. Biomechanics 30, 1157-1164.] and Huang et al. [2005. J. Biomechanics 38, 799-809.] (R(2)=0.993 and R(2)=0.995, respectively). The constitutive equation may be used to represent the mechanical behavior of the proteoglycan matrix in a fiber reinforced model of articular cartilage. PMID:16316659

  8. Hydrogels for the Repair of Articular Cartilage Defects

    PubMed Central

    Maher, Suzanne A.; Lowman, Anthony M.

    2011-01-01

    The repair of articular cartilage defects remains a significant challenge in orthopedic medicine. Hydrogels, three-dimensional polymer networks swollen in water, offer a unique opportunity to generate a functional cartilage substitute. Hydrogels can exhibit similar mechanical, swelling, and lubricating behavior to articular cartilage, and promote the chondrogenic phenotype by encapsulated cells. Hydrogels have been prepared from naturally derived and synthetic polymers, as cell-free implants and as tissue engineering scaffolds, and with controlled degradation profiles and release of stimulatory growth factors. Using hydrogels, cartilage tissue has been engineered in vitro that has similar mechanical properties to native cartilage. This review summarizes the advancements that have been made in determining the potential of hydrogels to replace damaged cartilage or support new tissue formation as a function of specific design parameters, such as the type of polymer, degradation profile, mechanical properties and loading regimen, source of cells, cell-seeding density, controlled release of growth factors, and strategies to cause integration with surrounding tissue. Some key challenges for clinical translation remain, including limited information on the mechanical properties of hydrogel implants or engineered tissue that are necessary to restore joint function, and the lack of emphasis on the ability of an implant to integrate in a stable way with the surrounding tissue. Future studies should address the factors that affect these issues, while using clinically relevant cell sources and rigorous models of repair. PMID:21510824

  9. Human Articular Chondrocytes Express Multiple Gap Junction Proteins

    PubMed Central

    Mayan, Maria D.; Carpintero-Fernandez, Paula; Gago-Fuentes, Raquel; Martinez-de-Ilarduya, Oskar; Wang, Hong-Zhang; Valiunas, Virginijus; Brink, Peter; Blanco, Francisco J.

    2014-01-01

    Osteoarthritis (OA) is the most common joint disease and involves progressive degeneration of articular cartilage. The aim of this study was to investigate if chondrocytes from human articular cartilage express gap junction proteins called connexins (Cxs). We show that human chondrocytes in tissue express Cx43, Cx45, Cx32, and Cx46. We also find that primary chondrocytes from adults retain the capacity to form functional voltage-dependent gap junctions. Immunohistochemistry experiments in cartilage from OA patients revealed significantly elevated levels of Cx43 and Cx45 in the superficial zone and down through the next approximately 1000 μm of tissue. These zones corresponded with regions damaged in OA that also had high levels of proliferative cell nuclear antigen. An increased number of Cxs may help explain the increased proliferation of cells in clusters that finally lead to tissue homeostasis loss. Conversely, high levels of Cxs in OA cartilage reflect the increased number of adjacent cells in clusters that are able to interact directly by gap junctions as compared with hemichannels on single cells in normal cartilage. Our data provide strong evidence that OA patients have a loss of the usual ordered distribution of Cxs in the damaged zones and that the reductions in Cx43 levels are accompanied by the loss of correct Cx localization in the nondamaged areas. PMID:23416160

  10. Delivering Agents Locally into Articular Cartilage by Intense MHz Ultrasound

    PubMed Central

    Nieminen, Heikki J.; Ylitalo, Tuomo; Suuronen, Jussi-Petteri; Rahunen, Krista; Salmi, Ari; Saarakkala, Simo; Serimaa, Ritva; Hæggström, Edward

    2015-01-01

    There is no cure for osteoarthritis. Current drug delivery relies on systemic delivery or injections into the joint. Because articular cartilage (AC) degeneration can be local and drug exposure outside the lesion can cause adverse effects, localized drug delivery could permit new drug treatment strategies. We investigated whether intense megahertz ultrasound (frequency: 1.138 MHz, peak positive pressure: 2.7 MPa, Ispta: 5 W/cm2, beam width: 5.7 mm at −6 dB, duty cycle: 5%, pulse repetition frequency: 285 Hz, mechanical index: 1.1) can deliver agents into AC without damaging it. Using ultrasound, we delivered a drug surrogate down to a depth corresponding to 53% depth of the AC thickness without causing histologically detectable damage to the AC. This may be important because early osteoarthritis typically exhibits histopathologic changes in the superficial AC. In conclusion, we identify intense megahertz ultrasound as a technique that potentially enables localized non-destructive delivery of osteoarthritis drugs or drug carriers into articular cartilage. PMID:25922135

  11. Radiation synovectomy stimulates glycosaminoglycan synthesis by normal articular cartilage

    SciTech Connect

    Myers, S.L.; Slowman, S.D.; Brandt, K.D.

    1989-07-01

    Radiation synovectomy has been considered a therapeutic alternative to surgical synovectomy. Whether intraarticular irradiation affects the composition or biochemistry, and therefore the biomechanical properties, of normal articular cartilage has not been established. In the present study, yttrium 90 silicate was injected into one knee of nine normal adult dogs, and three other dogs received nonradioactive yttrium silicate. When the animals were killed 4 to 13 weeks after the injection, synovium from the irradiated knees showed areas of necrosis and fibrosis. Up to 29% less hyaluronate was synthesized in vitro by the synovial intima from irradiated knees than by the intima from the contralateral knees (mean difference 18%). Morphologic abnormalities were not observed in articular cartilage from either the irradiated or control knees, nor did the water content or concentrations of uronic acid or DNA in cartilage from the irradiated knees differ from that in cartilage from the contralateral knees. However, net /sup 35/SO/sub 4/-labeled glycosaminoglycan synthesis in organ cultures of cartilage from irradiated knees was increased (mean difference 21%, p = 0.03) in comparison with that in cultures of contralateral knee cartilage.

  12. Resurfacing Damaged Articular Cartilage to Restore Compressive Properties

    PubMed Central

    Grenier, Stephanie; Donnelly, Patrick E.; Gittens, Jamila; Torzilli, Peter A.

    2014-01-01

    Surface damage to articular cartilage is recognized as the initial underlying process causing the loss of mechanical function in early-stage osteoarthritis. In this study, we developed structure-modifying treatments to potentially prevent, stabilize or reverse the loss in mechanical function. Various polymers (chondroitin sulfate, carboxymethylcellulose, sodium hyaluronate) and photoinitiators (riboflavin, irgacure 2959) were applied to the surface of collagenase-degraded cartilage and crosslinked in situ using UV light irradiation. While matrix permeability and deformation significantly increased following collagenase-induced degradation of the superficial zone, resurfacing using tyramine-substituted sodium hyaluronate and riboflavin decreased both values to a level comparable to that of intact cartilage. Repetitive loading of resurfaced cartilage showed minimal variation in the mechanical response over a 7 day period. Cartilage resurfaced using a low concentration of riboflavin had viable cells in all zones while a higher concentration resulted in a thin layer of cell death in the uppermost superficial zone. Our approach to repair surface damage initiates a new therapeutic advance in the treatment of injured articular cartilage with potential benefits that include enhanced mechanical properties, reduced susceptibility to enzymatic degradation and reduced adhesion of macrophages. PMID:25468298

  13. A reappraisal of the structure of normal canine articular cartilage.

    PubMed Central

    Dunham, J; Shackleton, D R; Billingham, M E; Bitensky, L; Chayen, J; Muir, I H

    1988-01-01

    It has been shown that some of the controversy over the structure of articular cartilage may be due to slight differences in the orientation of the sample that has been studied. As our decisive criterion we have used the simple physical fact that elongate proteins, such as collagen micelles, that can exhibit form-birefringence, had to show virtually straight extinction when viewed under crossed polars. The use of a variably adjustable microtome chuck facilitated small adjustments in the orientation of the cartilage to meet this criterion. Under these conditions, the collagen of the matrix has been shown to be aligned mainly perpendicularly to the surface which was bounded by a thin lamina in which the collagen showed birefringence at 90 degrees to that of the matrix. The conventionally described zonation of articular cartilage has been shown to be inadequate for that of the dog tibial plateau. The conventional Zone 2 has been shown to consist of two zones, Zones 2a and 2b, with different cell sizes, cell concentrations, and concentration of matrix components. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:3198487

  14. Combinatorial scaffold morphologies for zonal articular cartilage engineering.

    PubMed

    Steele, J A M; McCullen, S D; Callanan, A; Autefage, H; Accardi, M A; Dini, D; Stevens, M M

    2014-05-01

    Articular cartilage lesions are a particular challenge for regenerative medicine strategies as cartilage function stems from a complex depth-dependent organization. Tissue engineering scaffolds that vary in morphology and function offer a template for zone-specific cartilage extracellular matrix (ECM) production and mechanical properties. We fabricated multi-zone cartilage scaffolds by the electrostatic deposition of polymer microfibres onto particulate-templated scaffolds produced with 0.03 or 1.0mm(3) porogens. The scaffolds allowed ample space for chondrocyte ECM production within the bulk while also mimicking the structural organization and functional interface of cartilage's superficial zone. Addition of aligned fibre membranes enhanced the mechanical and surface properties of particulate-templated scaffolds. Zonal analysis of scaffolds demonstrated region-specific variations in chondrocyte number, sulfated GAG-rich ECM, and chondrocytic gene expression. Specifically, smaller porogens (0.03mm(3)) yielded significantly higher sGAG accumulation and aggrecan gene expression. Our results demonstrate that bilayered scaffolds mimic some key structural characteristics of native cartilage, support in vitro cartilage formation, and have superior features to homogeneous particulate-templated scaffolds. We propose that these scaffolds offer promise for regenerative medicine strategies to repair articular cartilage lesions. PMID:24370641

  15. Subtalar versus triple arthrodesis after intra-articular calcaneal fractures

    PubMed Central

    Kieboom, Brenda C. T.; Bessems, Gert H. J. M.; Vogels, Lucas M. M.; van Lieshout, Esther M. M.; Patka, Peter

    2010-01-01

    Depending upon initial treatment, between 2 and 30% of patients with a displaced intra-articular calcaneal fracture require a secondary arthrodesis. The aim of this study was to investigate the effect of subtalar versus triple arthrodesis on functional outcome. A total of 33 patients with 37 secondary arthrodeses (17 subtalar and 20 triple) with a median follow-up of 116 months were asked to complete questionnaires regarding disease-specific functional outcome (Maryland Foot Score, MFS), quality of life (SF-36) and overall satisfaction with the treatment (Visual Analogue Scale, VAS). Patient groups were comparable considering median age at fracture, initial treatment (conservative or operative), time to arthrodesis, median follow-up, and post-arthrodesis radiographic angles. The MFS score was similar after subtalar versus triple arthrodesis (59 vs. 56 points; P = 0.79). No statistically significant difference was found for the SF-36 (84 vs. 83 points; P = 0.67) and the VAS (5 vs. 6; P = 0.21). Smoking was statistically significantly associated with a non-union (χ2 = 6.60, P = 0.017). The current study suggests that there is no significant difference in functional outcome between an in situ subtalar or triple arthrodesis as a salvage technique for symptomatic arthrosis after an intra-articular calcaneal fracture. Smoking is a risk factor for non-union. PMID:21811905

  16. Ultrasound evaluation of site-specific effect of simulated microgravity on articular cartilage.

    PubMed

    Wang, Qing; Zheng, Yong-Ping; Wang, Xiao-Yun; Huang, Yan-Ping; Liu, Mu-Qing; Wang, Shu-Zhe; Zhang, Zong-Kang; Guo, Xia

    2010-07-01

    Space flight induces acute changes in normal physiology in response to the microgravity environment. Articular cartilage is subjected to high loads under a ground reaction force on Earth. The objectives of this study were to investigate the site dependence of morphological and ultrasonic parameters of articular cartilage and to examine the site-specific responses of articular cartilage to simulated microgravity using ultrasound biomicroscopy (UBM). Six rats underwent tail suspension (simulated microgravity) for four weeks and six other rats were kept under normal Earth gravity as controls. Cartilage thickness, ultrasound roughness index (URI), integrated reflection coefficient (IRC) and integrated backscatter coefficient (IBC) of cartilage tissues, as well as histological degeneration were measured at the femoral head (FH), medial femoral condyle (MFC), lateral femoral condyle (LFC), patello-femoral groove (PFG) and patella (PAT). The results showed site dependence not significant in all UBM parameters except cartilage thickness (p < 0.01) in the control specimens. Only minor changes in articular cartilage were induced by 4-week tail suspension, although there were significant decreases in cartilage thickness at the MFC and PAT (p < 0.05) and a significant increase in URI at the PAT (p < 0.01). This study suggested that the 4-week simulated microgravity had only mild effects on femoral articular cartilage in the rat model. This information is useful for human spaceflight and clinical medicine in improving understanding of the effect of microgravity on articular cartilage. However, the effects of longer duration microgravity experience on articular cartilage need further investigation. PMID:20620696

  17. MRI features of cervical articular process degenerative joint disease in Great Dane dogs with cervical spondylomyelopathy.

    PubMed

    Gutierrez-Quintana, Rodrigo; Penderis, Jacques

    2012-01-01

    Cervical spondylomyelopathy or Wobbler syndrome commonly affects the cervical vertebral column of Great Dane dogs. Degenerative changes affecting the articular process joints are a frequent finding in these patients; however, the correlation between these changes and other features of cervical spondylomyelopathy are uncertain. We described and graded the degenerative changes evident in the cervical articular process joints from 13 Great Danes dogs with cervical spondylomyelopathy using MR imaging, and evaluated the relationship between individual features of cervical articular process joint degeneration and the presence of spinal cord compression, vertebral foraminal stenosis, intramedullary spinal cord changes, and intervertebral disc degenerative changes. Degenerative changes affecting the articular process joints were common, with only 13 of 94 (14%) having no degenerative changes. The most severe changes were evident between C4-C5 and C7-T1 intervertebral spaces. Reduction or loss of the hyperintense synovial fluid signal on T2-weighted MR images was the most frequent feature associated with articular process joint degenerative changes. Degenerative changes of the articular process joints affecting the synovial fluid or articular surface, or causing lateral hypertrophic tissue, were positively correlated with lateral spinal cord compression and vertebral foraminal stenosis. Dorsal hypertrophic tissue was positively correlated with dorsal spinal cord compression. Disc-associated spinal cord compression was recognized less frequently. PMID:22236021

  18. Inter- and intra-specific scaling of articular surface areas in the hominoid talus

    PubMed Central

    Parr, William C H; Chatterjee, Helen J; Soligo, Christophe

    2011-01-01

    The morphology of postcranial articular surfaces is expected to reflect their weight-bearing properties, as well as the stability and mobility of the articulations to which they contribute. Previous studies have mainly confirmed earlier predictions of isometric scaling between articular surface areas and body mass; the exception to this is ‘male-type’, convex articular surface areas, which may scale allometrically due to differences in locomotor strategies within the analysed samples. In the present study, we used new surface scanning technology to quantify more accurately articular surface areas and to test those predictions within the talus of hominoid primates, including modern humans. Our results, contrary to predictions, suggest that there are no generalised rules of articular scaling within the talus of hominoids. Instead, we suggest that articular scaling patterns are highly context-specific, depending on the role of each articulation during locomotion, as well as taxon- and sex-specific differences in locomotion and ontogenetic growth trajectories within any given sample. While this may prove problematic for inferring body mass based on articular surface area, it also offers new opportunities of gaining substantial insights into the locomotor patterns of extinct species. PMID:21323919

  19. Viscoelastic properties of the pig temporomandibular joint articular soft tissues of the condyle and disc.

    PubMed

    Kuboki, T; Shinoda, M; Orsini, M G; Yamashita, A

    1997-11-01

    It has been suggested that a sustained loading condition such as clenching could compress the temporomandibular joint (TMJ) articular soft tissues. However, there is still no clear understanding of how the TM joint articular tissues respond under compression. To answer this question, we performed in vitro indentation tests on fresh articular discs and cartilage-bone systems of the condyles of 10 Yorkshire pigs (aged 7 months) using a self-developed indentation tester. The indenter was 5 mm in diameter and was controlled by means of a computer-aided feedback mechanism. Bilateral condyles from the same mandible were uniformly prepared; one was used for measurements under sustained compression (SC) and the other for measurements under intermittent compression (IC). The displacements of the indenter induced by a SC of 10, 20, and 30 Newtons (N, units of force) for 10 min and by an IC, also of 10, 20, and 30 N, with one-second duration and two-second intervals for 10 min were measured by means of a displacement sensor with a resolution of 0.001 mm. From these data, the indentation curves of the articular discs and the cartilage-bone systems were calculated. Both the disc and the articular cartilage showed characteristic displacement vs. time curves-namely, an instantaneous deformation upon load application, followed by a time-dependent creep phase of asymptotically increasing deformation under constant load. However, the indentation curves of the two tissues were not identical: The deformation of the articular cartilage was dose-dependent, but that of the disc was not. Moreover, the articular cartilage deformed significantly less under IC than under SC. This difference was not found in the disc. It can be concluded that both the disc and the articular cartilage of the pig temporomandibular joint have viscoelastic properties against compression; however, the disc is stiffer than the articular cartilage. PMID:9372793

  20. The relationship between the temporomandibular joint capsule, articular disc and jaw muscles.

    PubMed Central

    Schmolke, C

    1994-01-01

    The anatomy of the temporomandibular joint capsule and its possible relationships to other structures near the joint are not fully understood. A 3-dimensional analysis based on sagittal, frontal and horizontal serial sections through the human temporomandibular joint region was therefore undertaken. Capsular elements which directly connect the temporal bone with the mandible were seen only on the lateral side of the joint. In the posterior, anterior and medial regions of the joint the upper and lower laminae of the articular disc are attached separately either to the temporal bone or to the mandibular condyle. The shaping of the articular cavities and the texture of the joint capsule permit movements of the articular disc predominantly in the anteromedial direction. On the entire medial side of the joint the articular disc and its capsular attachments are in close contact with the fascia of the lateral pterygoid muscle whereby a small portion of the upper head of this muscle inserts directly into the anteromedial part of the articular disc. Thus both the upper and the lower heads of the lateral pterygoid muscle are likely to influence the position of the articular disc directly during temporomandibular joint movements. Laterally, the articular disc is attached to the fascia of the masseter muscle, and part of the lateral ligament inserts into the temporalis fascia. Since these attachments are relatively weak, neither the temporalis nor the masseter muscles are considered to act directly on the articular disc; instead, via afferents from muscle spindles, they may take part in signalling the position of the temporomandibular joint components, including that of the articular disc. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:8014124

  1. Advances in Surgical Management of Intra-articular Calcaneus Fractures.

    PubMed

    Hsu, Andrew R; Anderson, Robert B; Cohen, Bruce E

    2015-07-01

    Intra-articular calcaneus fractures are commonly sustained after high-energy trauma, and a variety of techniques exists for anatomic reduction and surgical fixation. Traditional approaches using an extended L-shaped lateral incision with lateral plating for open reduction and internal fixation have relatively high complication rates. Common complications include hematoma formation, skin edge necrosis, wound breakdown, and superficial or deep infection. As a result, less invasive techniques have been developed in recent years, including limited-incision sinus tarsi open reduction and internal fixation, percutaneous fixation, and arthroscopic-assisted fixation. These techniques are associated with lower complication rates and equivalent clinical and radiographic outcomes in certain fracture patterns and patient populations. PMID:26111874

  2. Studies on cathepsin B in human articular cartilage.

    PubMed Central

    Bayliss, M T; Ali, S Y

    1978-01-01

    The thiol proteinase cathepsin B (EC 3.4.22.1), previously called cathepsin B1, was assayed in human articular cartilage by its hydrolysis of the synthetic substrate alpha-N-benzoyl-DL-arginine 2-naphthylamide. The enzyme was activated by cysteine and EDTA and completely inhibited by iodoacetamide and HgCl2. It was also partially inhibited by whole human serum. Human osteoarthrotic cartilage had increased activity when compared with normal cartilage. Cathepsin B activity of normal cartilage was age-related, being high in juveniles and declining to low values in adult and elderly individuals. Cathepsin D and cathepsin B both exhibited a zonal variation through the cartilage depth; the surface cells appeared to contain more activity than those close to the subchondral bone. PMID:417724

  3. MRI rotating frame relaxation measurements for articular cartilage assessment

    PubMed Central

    Ellermann, Jutta; Ling, Wen; Nissi, Mikko J.; Arendt, Elizabeth; Carlson, Cathy S.; Garwood, Michael; Michaeli, Shalom; Mangia, Silvia

    2015-01-01

    In the present work we introduced two MRI rotating frame relaxation methods, namely adiabatic T1ρ and Relaxation Along a Fictitious Field (RAFF), along with an inversion-prepared Magnetization Transfer (MT) protocol for assessment of articular cartilage. Given the inherent sensitivity of rotating frame relaxation methods to slow molecular motions that are relevant in cartilage, we hypothesized that adiabatic T1ρ and RAFF would have higher sensitivity to articular cartilage degradation as compared to laboratory frame T2 and MT. To test this hypothesis, a proteoglycan depletion model was used. Relaxation time measurements were performed at 0 and 48 hours in ten bovine patellar specimens, 5 of which were treated with trypsin and 5 untreated controls were stored under identical conditions in isotonic saline for 48 hours. Relaxation times measured at 48 hours were longer than those measured at 0 hours in both groups. The changes in T2 and MT relaxation times after 48 hours were approximately 3 times larger in the trypsin treated specimens as compared to the untreated group, whereas increases of adiabatic T1ρ and RAFF were 4 to 5 fold larger. Overall, these findings demonstrate a higher sensitivity of adiabatic T1ρ and RAFF to the trypsin-induced changes in bovine patellar cartilage as compared to the commonly used T2 and MT. Since adiabatic T1ρ and RAFF are advantageous for human applications as compared to standard continuous-wave T1ρ methods, adiabatic T1ρ and RAFF are promising tools for assessing cartilage degradation in clinical settings. PMID:23993794

  4. Radiofrequency (electrosurgical) ablation of articular cartilage: a study in sheep.

    PubMed

    Turner, A S; Tippett, J W; Powers, B E; Dewell, R D; Mallinckrodt, C H

    1998-09-01

    The objective of this study was to examine the effect of a bipolar ablation probe on experimentally roughened articular cartilage and compare it with the traditional mechanical shaving technique using the knee joint of sheep. Twenty-eight skeletally mature ewes were divided randomly into two groups: one group was treated with a rotating shaving device and another group was treated using the bipolar ablation probe (Bipolar Arthroscopic Probe; Electroscope, Inc, Boulder, CO). Animals were killed at 0, 6, 12, and 24 weeks, and histological sections of the experimental limbs were compared with sections of the opposite limb using a modified Mankin scale. The following variables were used to determine scores: surface (0-6), cells (0-4), hypocellularity (0-3), matrix staining (transitional zone [0-4], radiate zone [0-4], and focal empty lacunae or hypereosinophilic cells (0-3). Differences in scores for all response variables were calculated as treated limb minus sham limb. Response variables were formed: score >0 recoded as 1 (favorable response treated better than sham), score of 0 recoded as 2 (neutral response no differences), and score <0 recoded as 3 (unfavorable response treated worse than sham). Bipolar ablative probe-treated limbs had 14.29% favorable responses and 35.71% favorable or neutral responses, whereas shave-treated limbs had 0% favorable and only 7.14% favorable or neutral responses. For all variables, bipolar ablative probe-treated limbs had more favorable responses. The less severe histological change in the bipolar ablative probe-treated joints compared with the shave-treated joints suggests that bipolar ablation of articular cartilage may be a better treatment for chondromalacia than the usual shaving methods of debridement. Further, there were no pathological changes in the subchondral bone. PMID:9754476

  5. Black Colouration of the Knee Articular Cartilage after Spontaneously Recurrent Haemarthrosis

    PubMed Central

    Ishimaru, Daichi; Ogawa, Hiroyasu; Akiyama, Haruhiko

    2016-01-01

    Mild discolouration of the articular cartilage is known to gradually occur during aging. However, pathological tissue pigmentation is occasionally induced under several specific conditions. In the present case, we performed total knee replacement in a patient with recurrent haemarthrosis. However, during the operation, we observed severe black colouration of the knee articular cartilage, due to the deposition of hemosiderin and lipofuscin. To our knowledge, this is the first report of severe cartilage pigmentation, due to hemosiderin and lipofuscin deposition in articular cartilage. PMID:27293933

  6. [Intra-articular fracture of the distal radius: results following osteosynthesis with a support plate].

    PubMed

    Ferguson, G A; Leutenegger, A; Mark, G; Breiter, H; Rüedi, T

    1989-01-01

    The treatment of comminuted intra-articular fractures of the distal radius often requires an operative fixation. Beside the recently recommended external fixator, the support plate fixation offers a helpful alternative to treatment. Between 1980 and 1986, 30 wrists in 29 patients with intra-articular fractures of the distal radius were stabilized with a buttress plate an the Kantonsspital Chur, Switzerland. The mean follow-up-time was 15 months. These follow-ups showed that the buttress plate in treatment of complicated intra-articular fractures allows a satisfactory reduction and stabilization with restoration of the articular congruity and the possibility for early active assisted motion. Buttress plate fixation still remains a demanding technique, which in complicated cases, should be reserved for the experienced surgeon. PMID:2500786

  7. Pathogenesis and Prevention of Posttraumatic Osteoarthritis After Intra-articular Fracture

    PubMed Central

    Schenker, Mara L.; Mauck, Robert L.; Ahn, Jaimo; Mehta, Samir

    2015-01-01

    Posttraumatic osteoarthritis (PTOA) occurs after traumatic injury to the joint. It is most common following injuries that disrupt the articular surface or lead to joint instability. The reported risk of PTOA following significant joint trauma is as high as 75%; articular fractures can increase the risk more than 20-fold. Despite recent advances in surgical management, the incidence of PTOA following intra-articular fractures has remained relatively unchanged over the last few decades. Pathogenesis of PTOA after intra-articular fracture is likely multifactorial and may be associated with acute cartilage injury as well as chronic joint overload secondary to instability, incongruity, and malalignment. Additional studies are needed to better elucidate how these factors contribute to the development of PTOA and to develop advanced treatment algorithms that consist of both acute biologic interventions targeted to decrease inflammation and cellular death in response to injury and improved surgical methods to restore stability, congruity, and alignment. PMID:24382876

  8. Exercise increases osteophyte formation and diminishes fibrillation following chemically induced articular cartilage injury.

    PubMed Central

    Williams, J M; Brandt, K D

    1984-01-01

    The present study shows that a treadmill exercise regimen imposed on guinea-pigs whose articular cartilage has been damaged by intra-articular injection of IA reduces chondrocyte depletion, results in an increase in pericellular Safranin-O staining around surviving chondrocytes, and prevents fibrillation of the articular surface. The data suggest that exercise protected, or facilitated recovery of, chondrocytes subjected to chemical injury, and that the surviving cells then synthesised a matrix which was sufficiently normal to withstand impulsive joint loading. On the other hand, the exercise regimen accelerated osteophyte formation, and led to formation of osteophytes in sites at which they did not develop in animals which received intra-articular IA but which were not exercised. Images Fig. 1 (cont.) Fig. 1 Fig. 2 Fig. 3 PMID:6526713

  9. Diagnosis and management of an intra-articular foreign body in the foot.

    PubMed

    Mulhall, K J; Sheehan, E; Kearns, S; O'Connor, P; Stephens, M M

    2002-10-01

    We describe a case of a small intra-articular foreign body in the foot presenting 48 hours following injury, which at operation showed early evidence of septic arthritis. It is essential to accurately localise periarticular foreign bodies in the foot and proceed to arthrotomy and debridement in all cases where there is radiological or clinical evidence to suggest intra-articular retention of a foreign body. PMID:12470001

  10. Effects of immobilization on articular cartilage: Autohistoradiographic findings with S35

    NASA Technical Reports Server (NTRS)

    Digiovanni, C.; Desantis, E.

    1980-01-01

    The effect of immobilization on the articular cartilage of rabbits was studied by light microscope. The knee joint of each rabbit was immobilized in a plaster in a position midway between flexion and extension for a 10 to 120 days period. Degenerative changes in the articular cartilage of increasing severity were observed. The fixation of the labeled SO4 by cartilage cells was decreased in advanced immobilization.

  11. Patellar Articular Overlap on MRI Is a Simple Alternative to Conventional Measurements of Patellar Height

    PubMed Central

    Munch, Jacqueline L.; Sullivan, Jaron P.; Nguyen, Joseph T.; Mintz, Douglas; Green, Daniel W.; Shubin Stein, Beth E.; Strickland, Sabrina

    2016-01-01

    Background: Patella alta describes an abnormally high-riding patella in relationship to the femur and has been shown to correlate with patellofemoral pain, instability, chondromalacia, and arthrosis. Conventional measurements of patella alta involve multiple measurements and are often not defined on cross-sectional imaging as related to radiographs. Hypothesis: Patellar articular overlap on sagittal magnetic resonance imaging (MRI) will correlate well with conventional measurements of patella alta as measured by a standardized technique defined by our group. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: MRIs of 239 knees were reviewed by 3 attending surgeons with practices focusing on patellofemoral disease, as well as 2 sports medicine fellows and 1 musculoskeletal radiologist. Measurements included articular overlap, percentage of articular coverage, Caton-Deschamps index, Blackburne-Peel index, and modified Insall-Salvati index. Results: Interrater reliability was high for Caton-Deschamps, Blackburne-Peel, and modified Insall-Salvati indices (intraclass correlation coefficient [ICC], 0.877, 0.828, and 0.787, respectively). Articular overlap and percentage articular coverage correlated well with each other (ICC, 0.961; P < .001) and with the Caton-Deschamps (overlap r = –0.271, P < .001; coverage r = –0.131, P = .037) and Blackburne-Peel (overlap r = 0.343, P < .001; coverage r = –0.238, P < .001) indices. Articular overlap and percentage coverage failed to correlate with the modified Insall-Salvati index (overlap r = –0.117, P = .091; coverage r = 0.007, P = .918). Conclusion: Patellar articular overlap and percentage of patellar articular coverage show promise as a simpler alternative to conventional, ratio-based measurements of patellar height. Future studies are needed to evaluate the range of normal and the relationship to our traditionally used measurements. PMID:27482530

  12. Nanoengineered particles for enhanced intra-articular retention and delivery of proteins.

    PubMed

    Singh, Ankur; Agarwal, Rachit; Diaz-Ruiz, Carlos A; Willett, Nick J; Wang, Peiyi; Lee, L Andrew; Wang, Qian; Guldberg, Robert E; García, Andrés J

    2014-10-01

    Localized intra-articular delivery of anti-inflammatory proteins can reduce inflammation in osteoarthritis but poses a challenge because of raid clearance within few hours of injection. A new class of polymer is developed that forms self-assembled nanoparticles ranging from 300 to 900 nm and demonstrates particle size dependent prolonged retention in intra-articular joint spaces compared to bolus protein over a period of 14 d. PMID:24687997

  13. The classic: Chapter XVIII. Operative treatment in chronic articular ostitis. 1884.

    PubMed

    Gibney, Virgil P

    2010-02-01

    This Classic article is a reprint of the original work by Virgil P. Gibney, Chapter XVIII. Operative Treatment in Chronic Articular Ostitis. An accompanying biographical sketch of Virgil P. Gibney, MD, is available at DOI 10.1007/s11999-009-1166-2 . The Classic Article is (c)1884 and is abridged from Gibney VP. Operative treatment in chronic articular ostitis. In: The Hip and Its Diseases. New York, NY, London, UK: Bermingham & Co; 1884:388-402. PMID:19936860

  14. The effect of ice on intra-articular temperature in the knee of the dog.

    PubMed

    Bocobo, C; Fast, A; Kingery, W; Kaplan, M

    1991-08-01

    The effect of surface cooling on intra-articular temperature was examined in dogs' knees. Four treatment protocols were examined: local ice compress application for 5, 15 and 30 min and local ice bath immersion for 15 min. Intra-articular temperatures were recorded using a needle microprobe inserted into the knee and continuous temperature recordings were made before, during and after the treatment. Rectal temperatures were also simultaneously recorded. Intra-articular temperatures rapidly dropped during icing. Five minutes of ice compress application resulted in a 2.2 +/- 1.2 degrees C intra-articular temperature drop with no change in rectal temperature. After 15 min of ice compress application, the joint temperature fell 4.1 +/- 1.3 degrees C with no change in rectal temperature. Thirty minutes of local ice compress application dropped the knee temperature 6.5 +/- 4.0 degrees C with a slight 0.5 +/- 0.3 degrees C drop in rectal temperature. Fifteen minutes of ice water immersion caused a much greater drop in intra-articular temperatures (20.2 +/- 8.4 degrees C) than could be achieved with ice compress. Rectal temperatures fell slightly during immersion (1.6 +/- 0.3 degrees C). After the removal of any type of cryotherapy, intra-articular temperatures continued to drop for several minutes and then a prolonged rewarming period commenced. The mean time required to return to baseline intra-articular temperature varied from 22-60 min, depending on the type and duration of cryotherapy. We conclude that brief periods of topical cold application to a dog's knee can induce significant and long lasting depression of intra-articular temperatures and that this is a local effect not dependent on core temperature cooling. PMID:1878175

  15. Condylar Osteochondroma Treated with Total Condylectomy and Preservation of the Articular Disc: A Case Report

    PubMed Central

    Dominguez, Manuel Fernandez; Castillo, Jose Luis Del; Guerra, Mario Muñoz; Sanchez, Ruth Sanchez; La Plata, Maria Mancha De

    2014-01-01

    Osteochondroma is frequently found in the general skeleton but is rare in the condylar region of the mandible. We report a case of an osteochondroma of large size and rapid growth in the mandibular condyle, which was treated with total condylectomy and condylar replacement with a costochondral graft and preservation of the articular disc. In cases with a healthy and well-positioned articular disc, it may be preserved with no need of disc repositioning. PMID:26000086

  16. Comparison of friction and wear of articular cartilage on different length scales.

    PubMed

    Kienle, Sandra; Boettcher, Kathrin; Wiegleb, Lorenz; Urban, Joanna; Burgkart, Rainer; Lieleg, Oliver; Hugel, Thorsten

    2015-09-18

    The exceptional tribological properties of articular cartilage are still far from being fully understood. Articular cartilage is able to withstand high loads and provide exceptionally low friction. Although the regeneration abilities of the tissue are very limited, it can last for many decades. These biomechanical properties are realized by an interplay of different lubrication and wear protection mechanisms. The deterioration of cartilage due to aging or injury leads to the development of osteoarthritis. A current treatment strategy focuses on supplementing the intra-articular fluid with a saline solution containing hyaluronic acid. In the work presented here, we investigated how changing the lubricating fluid affects friction and wear of articular cartilage, focusing on the boundary and mixed lubrication as well as interstitial fluid pressurization mechanisms. Different length and time scales were probed by atomic force microscopy, tribology and profilometry. We compared aqueous solutions with different NaCl concentrations to a viscosupplement containing hyaluronic acid (HA). In particular, we found that the presence of ions changes the frictional behavior and the wear resistance. In contrast, hyaluronic acid showed no significant impact on the friction coefficient, but considerably reduced wear. This study confirms the previous notion that friction and wear are not necessarily correlated in articular cartilage tribology and that the main role of HA might be to provide wear protection for the articular surface. PMID:26294356

  17. Elastin fibers display a versatile microfibril network in articular cartilage depending on the mechanical microenvironments.

    PubMed

    He, Bo; Wu, Jian Ping; Chen, Hong Hui; Kirk, Thomas Brett; Xu, Jiake

    2013-09-01

    Elastin fibers are major extracellular matrix macromolecules that are critical in maintaining the elasticity and resilience of tissues such as blood vessels, lungs and skins. However, the role of elastin in articular cartilage is poorly defined. The present study investigated the organization of elastin fiber in articular cartilage, its relationship to collagen fibers and the architecture of elastin fibers from different mechanical environments by using a kangaroo model. Five morphologies of elastin fibers were identified: Straight fiber, straight fiber with branches, branching fibers directly associated with chondrocyte, wave fiber and fine elastin. The architecture of the elastin network varied significantly with cartilage depth. In the most superficial layer of tibial plateau articular cartilage, dense elastin fibers formed a distinctive cobweb-like meshwork which was parallel to the cartilage surface. In the superficial zone, elastin fibers were well organized in a preferred orientation which was parallel to collagen fibers. In the deep zone, no detectable elastin fiber was found. Moreover, differences in the organization of elastin fibers were also observed between articular cartilage from the tibial plateau, femoral condyle, and distal humerus. This study unravels the detailed microarchitecture of elastin fibers which display a well-organized three-dimensional versatile network in articular cartilage. Our findings imply that elastin fibers may play a crucial role in maintaining the integrity, elasticity, and the mechanical properties of articular cartilage, and that the local mechanical environment affects the architectural development of elastin fibers. PMID:23649803

  18. Techniques and Applications of in vivo Diffusion Imaging of Articular Cartilage

    PubMed Central

    Raya, José G.

    2014-01-01

    Early in the process of osteoarthritis (OA) the composition (water, proteoglycan [PG], and collagen) and structure of articular cartilage is altered leading to changes in its mechanical properties. A technique that can assess the composition and structure of the cartilage in vivo can provide insight in the mechanical integrity of articular cartilage and become a powerful tool for the early diagnosis of OA. Diffusion tensor imaging (DTI) has been proposed as a biomarker for cartilage composition and structure. DTI is sensitive to the PG content through the mean diffusivity (MD) and to the collagen architecture through the fractional anisotropy (FA). However, the acquisition of DTI of articular cartilage in vivo is challenging due to the short T2 of articular cartilage (~40 ms at 3 T) and the high resolution needed (0.5–0.7 mm in plane) to depict the cartilage anatomy. We describe the pulse sequences used for in vivo DTI of articular cartilage and discus general strategies for protocol optimization. We provide a comprehensive review of measurements of DTI of articular cartilage from ex vivo validation experiments to its recent clinical applications. PMID:25865215

  19. Human Adipose-Derived Mesenchymal Progenitor Cells Engraft into Rabbit Articular Cartilage

    PubMed Central

    Wang, Wen; He, Na; Feng, Chenchen; Liu, Victor; Zhang, Luyi; Wang, Fei; He, Jiaping; Zhu, Tengfang; Wang, Shuyang; Qiao, Weiwei; Li, Suke; Zhou, Guangdong; Zhang, Li; Dai, Chengxiang; Cao, Wei

    2015-01-01

    Mesenchymal stem cells (MSCs) are known to have the potential for articular cartilage regeneration, and are suggested for the treatment of osteoarthritis (OA). Here, we investigated whether intra-articular injection of xenogeneic human adipose-derived mesenchymal progenitor cells (haMPCs) promoted articular cartilage repair in rabbit OA model and engrafted into rabbit articular cartilage. The haMPCs were cultured in vitro, and phenotypes and differentiation characteristics of cells were evaluated. OA was induced surgically by anterior cruciate ligament transection (ACLT) and medical meniscectomy of knee joints. At six weeks following surgery, hyaluronic acid (HA) or haMPCs was injected into the knee joints, the contralateral knee served as normal control. All animals were sacrificed at the 16th week post-surgery. Assessments were carried out by macroscopic examination, hematoxylin/eosin (HE) and Safranin-O/Fast green stainings and immunohistochemistry. The data showed that haMPC treatment promoted cartilage repair. Signals of human mitochondrial can be directly detected in haMPC treated cartilage. The haMPCs expressed human leukocyte antigen I (HLA-I) but not HLA-II-DR in vivo. These results suggest that intra-articular injection of haMPCs promotes regeneration of articular cartilage in rabbit OA model, and support the notion that MPCs are transplantable between HLA-incompatible individuals. PMID:26023716

  20. Characterization of Chondrocyte Scaffold Carriers for Cell-based Gene Therapy in Articular Cartilage Repair

    PubMed Central

    Shui, Wei; Yin, Liangjun; Luo, Jeffrey; Li, Ruidong; Zhang, Wenwen; Zhang, Jiye; Huang, Wei; Hu, Ning; Liang, Xi; Deng, Zhong-Liang; Hu, Zhenming; Shi, Lewis; Luu, Hue H.; Haydon, Rex C.; He, Tong-Chuan; Ho, Sherwin

    2014-01-01

    Articular cartilage lesions in the knee are common injuries. Chondrocyte transplant represents a promising therapeutic modality for articular cartilage injuries. Here, we characterize the viability and transgene expression of articular chondrocytes cultured in 3-D scaffolds provided by four types of carriers. Articular chondrocytes are isolated from rabbit knees and cultured in four types of scaffolds: type I collagen sponge, fibrin glue, hyaluronan, and Open-cell PolyLactic Acid (OPLA). The cultured cells are transduced with adenovirus expressing green fluorescence protein (AdGFP) and luciferase (AdGL3-Luc). The viability and gene expression in the chondrocytes are determined with fluorescence microscopy and luciferase assay. Cartilage matrix production is assessed by Alcian blue staining. Rabbit articular chondrocytes are effectively infected by AdGFP and exhibited sustained GFP expression. All tested scaffolds support the survival and gene expression of the infected chondrocytes. However, the highest transgene expression is observed in the OPLA carrier. At four weeks, Alcian blue-positive matrix materials are readily detected in OPLA cultures. Thus, our results indicate that, while all tested carriers can support the survival of chondrocytes, OPLA supports the highest transgene expression and is the most conductive scaffold for matrix production, suggesting that OPLA may be a suitable scaffold for cell-based gene therapy of articular cartilage repairs. PMID:23629940

  1. Mesenchymal stem cells can survive on the extracellular matrix-derived decellularized bovine articular cartilage scaffold

    PubMed Central

    Tavassoli, Amin; Matin, Maryam Moghaddam; Niaki, Malihe Akbarzade; Mahdavi-Shahri, Nasser; Shahabipour, Fahimeh

    2015-01-01

    Objective (s): The scarcity of articular cartilage defect to repair due to absence of blood vessels and tissue engineering is one of the promising approaches for cartilage regeneration. The objective of this study was to prepare an extracellular matrix derived decellularized bovine articular cartilage scaffold and investigate its interactions with seeded rat bone marrow mesenchymal stem cells (BM-MSCs). Materials and Methods: Bovine articular cartilage that was cut into pieces with 2 mm thickness, were decellularized by combination of physical and chemical methods including snap freeze-thaw and treatment with sodium dodecyl sulfate (SDS). The scaffolds were then seeded with 1, 1’-dioctadecyl-3, 3, 3’, 3’-tetramethylindocarbocyanine perchlorate (DiI) labeled BM-MSCs and cultured for up to two weeks. Results: Histological studies of decellularized bovine articular cartilage showed that using 5 cycles of snap freeze-thaw in liquid nitrogen and treatment with 2.5% SDS for 4 hr led to the best decellularization, while preserving the articular cartilage structure. Adherence and penetration of seeded BM-MSCs on to the scaffold were displayed by histological and florescence examinations and also confirmed by electron microscopy. Conclusion: ECM-derived decellularized articular cartilage scaffold provides a suitable environment to support adhesion and maintenance of cultured BM-MSCs and could be applied to investigate cellular behaviors in this system and may also be useful for studies of cartilage tissue engineering. PMID:26877852

  2. Role of uppermost superficial surface layer of articular cartilage in the lubrication mechanism of joints

    PubMed Central

    KUMAR, P.; OKA, M.; TOGUCHIDA, J.; KOBAYASHI, M.; UCHIDA, E.; NAKAMURA, T.; TANAKA, K.

    2001-01-01

    The uppermost superficial surface layer of articular cartilage, the ‘lamina splendens’ which provides a very low friction lubrication surface in articular joints, was investigated using atomic force microscopy (AFM). Complementary specimens were also observed under SEM at −10 °C without dehydration or sputter ion coating. Fresh adult pig osteochondral specimens were prepared from the patellas of pig knee joints and digested with the enzymes, hyaluronidase, chondroitinase ABC and alkaline protease. Friction coefficients between a pyrex glass plate and the osteochondral specimens digested by enzymes as well as natural (undigested) specimens were measured, using a thrust collar apparatus. Normal saline, hyaluronic acid (HA) and a mixture of albumin, globulin, HA (AGH) were used as lubrication media. The surface irregularities usually observed in SEM studies were not apparent under AFM. The articular cartilage surface was resistant to hyaluronidase and also to chondroitinase ABC, but a fibrous structure was exhibited in alkaline protease enzymes-digested specimens. AFM analysis revealed that the thickness of the uppermost superficial surface layer of articular cartilage was between 800 nm and 2 μm in adult pig articular cartilage. The coefficient of friction (c.f.) was significantly higher in chondroitinase ABC and alkaline protease enzymes digested specimens. Generally, in normal saline lubrication medium, c.f. was higher in comparison to HA and AGH lubrication media. The role of the uppermost, superficial surface layer of articular cartilage in the lubrication mechanism of joints is discussed. PMID:11554503

  3. Role of uppermost superficial surface layer of articular cartilage in the lubrication mechanism of joints.

    PubMed

    Kumar, P; Oka, M; Toguchida, J; Kobayashi, M; Uchida, E; Nakamura, T; Tanaka, K

    2001-09-01

    The uppermost superficial surface layer of articular cartilage, the 'lamina splendens' which provides a very low friction lubrication surface in articular joints, was investigated using atomic force microscopy (AFM). Complementary specimens were also observed under SEM at -10 degrees C without dehydration or sputter ion coating. Fresh adult pig osteochondral specimens were prepared from the patellas of pig knee joints and digested with the enzymes, hyaluronidase, chondroitinase ABC and alkaline protease. Friction coefficients between a pyrex glass plate and the osteochondral specimens digested by enzymes as well as natural (undigested) specimens were measured, using a thrust collar apparatus. Normal saline, hyaluronic acid (HA) and a mixture of albumin, globulin, HA (AGH) were used as lubrication media. The surface irregularities usually observed in SEM studies were not apparent under AFM. The articular cartilage surface was resistant to hyaluronidase and also to chondroitinase ABC, but a fibrous structure was exhibited in alkaline protease enzymes-digested specimens. AFM analysis revealed that the thickness of the uppermost superficial surface layer of articular cartilage was between 800 nm and 2 microm in adult pig articular cartilage. The coefficient of friction (c.f.) was significantly higher in chondroitinase ABC and alkaline protease enzymes digested specimens. Generally, in normal saline lubrication medium, c.f. was higher in comparison to HA and AGH lubrication media. The role of the uppermost, superficial surface layer of articular cartilage in the lubrication mechanism of joints is discussed. PMID:11554503

  4. Techniques and applications of in vivo diffusion imaging of articular cartilage.

    PubMed

    Raya, José G

    2015-06-01

    Early in the process of osteoarthritis (OA) the composition (water, proteoglycan [PG], and collagen) and structure of articular cartilage is altered leading to changes in its mechanical properties. A technique that can assess the composition and structure of the cartilage in vivo can provide insight in the mechanical integrity of articular cartilage and become a powerful tool for the early diagnosis of OA. Diffusion tensor imaging (DTI) has been proposed as a biomarker for cartilage composition and structure. DTI is sensitive to the PG content through the mean diffusivity and to the collagen architecture through the fractional anisotropy. However, the acquisition of DTI of articular cartilage in vivo is challenging due to the short T2 of articular cartilage (∼40 ms at 3 Tesla) and the high resolution needed (0.5-0.7 mm in plane) to depict the cartilage anatomy. We describe the pulse sequences used for in vivo DTI of articular cartilage and discus general strategies for protocol optimization. We provide a comprehensive review of measurements of DTI of articular cartilage from ex vivo validation experiments to its recent clinical applications. PMID:25865215

  5. Intercellular Ca2+ waves in mechanically stimulated articular chondrocytes.

    PubMed

    D'Andrea, P; Calabrese, A; Capozzi, I; Grandolfo, M; Tonon, R; Vittur, F

    2000-01-01

    Articular cartilage is a tissue designed to withstand compression during joint movement and, in vivo, is subjected to a wide range of mechanical loading forces. Mechanosensitivity has been demonstrated to influence chondrocyte metabolism and cartilage homeostasis, but the mechanisms underlying mechanotransduction in these cells are poorly understood. In many cell types mechanical stimulation induces increases of the cytosolic Ca2+ concentration that propagates from cell to cell as an intercellular Ca2+ wave. Cell-to-cell communication through gap junctions underlies tissue co-ordination of metabolism and sensitivity to extracellular stimuli: gap junctional permeability to intracellular second messengers allows signal transduction pathways to be shared among several cells, ultimately resulting in co-ordinated tissue responses. Mechanically-induced Ca2+ signalling was investigated with digital fluorescence video imaging in primary cultures of rabbit articular chondrocytes. Mechanical stimulation of a single cell, obtained by briefly distorting the plasmamembrane with a micropipette, induced a wave of increased Ca2+ that was communicated to surrounding cells. Intercellular Ca2+ spreading was inhibited by 18 alpha-glycyrrhetinic acid, suggesting the involvement of gap junctions in signal propagation. The functional expression of gap junctions was assessed, in confluent chondrocyte cultures, by the intercellular transfer of Lucifer yellow dye in microinjection experiments while the expression of connexin 43 could be detected in Western blots. A series of pharmacological tools known to interfere with the cell calcium handling capacity were employed to investigate the mechanism of mechanically-induced Ca2+ signalling. In the absence of extracellular Ca2+ mechanical stimulation induced communicated Ca2+ waves similar to controls. Mechanical stress induced Ca2+ influx both in the stimulated chondrocyte but not in the adjacent cells, as assessed by the Mn2+ quenching

  6. Thermal energy effects on articular cartilage: a multidisciplinary evaluation

    NASA Astrophysics Data System (ADS)

    Kaplan, Lee D.; Ernsthausen, John; Ionescu, Dan S.; Studer, Rebecca K.; Bradley, James P.; Chu, Constance R.; Fu, Freddie H.; Farkas, Daniel L.

    2002-05-01

    Partial thickness articular cartilage lesions are commonly encountered in orthopedic surgery. These lesions do not have the ability to heal by themselves, due to lack of vascular supply. Several types of treatment have addressed this problem, including mechanical debridement and thermal chondroplasty. The goal of these treatments is to provide a smooth cartilage surface and prevent propagation of the lesions. Early thermal chondroplasty was performed using lasers, and yielded very mixed results, including severe damage to the cartilage, due to poor control of the induced thermal effects. This led to the development (including commercial) of probes using radiofrequency to generate the thermal effects desired for chondroplasty. Similar concerns over the quantitative aspects and control ability of the induced thermal effects in these treatments led us to test the whole range of complex issues and parameters involved. Our investigations are designed to simultaneously evaluate clinical conditions, instrument variables for existing radiofrequency probes (pressure, speed, distance, dose) as well as the associated basic science issues such as damage temperature and controllability (down to the subcellular level), damage geometry, and effects of surrounding conditions (medium, temperature, flow, pressure). The overall goals of this work are (1) to establish whether thermal chondroplasty can be used in a safe and efficacious manner, and (2) provide a prescription for multi-variable optimization of the way treatments are delivered, based on quantitative analysis. The methods used form an interdisciplinary set, to include precise mechanical actuation, high accuracy temperature and temperature gradient control and measurement, advanced imaging approaches and mathematical modeling.

  7. Physiotherapy for the prevention of articular contraction in haemophilia.

    PubMed

    Buzzard, B M

    1999-03-01

    The idea of prevention and preventative care is not new. History and culture have given us many examples of the importance of physical well-being and the prvention of illness and disease. The ancient societies of China focused on the balance of Yin and Yang in promoting health; Greece and Rome valued the importance of health and physical culture; the earliest Hebrew societies documented the importance of diet and dietary restrictions as a means towards good health. Through this century health professionals have advocated the importance of preventive care as an integral element of the quality of health. Haemophilia is a life-long condition with a high potential towards disability, handicap and impairment if not adequately treated. It is therefore essential that those with haemophilia are taught the importance of physical fitness at an early age as a means of preventing articular contractures. Physiotherapy is of great importance in this field, especially in third-world countries where the supply of replacement products are scarce or non-existent. PMID:10365294

  8. Rice Body Formation Within a Peri-Articular Shoulder Mass.

    PubMed

    Edison, Michele N; Caram, Anthony; Flores, Miguel; Scherer, Kurt

    2016-01-01

    Most commonly associated with chronic inflammatory conditions, rice bodies represent an uncommon, nonspecific, often intra-articular inflammatory process. Presumably, rice bodies represent the sequelae of microvascular infarcts of the joint synovium. However, rice bodies have been seen in pleural fluid, in the setting of bursitis, and within the tendon sheath. The etiology and prognostic significance of rice bodies are not clear. MRI is the diagnostic imaging modality of choice for the evaluation of rice body formation. Here we present a case of a 28-year-old female with a history of rheumatoid arthritis (RA) who presented to her primary care physician with a palpable mass around her right shoulder which was presumed to be a lipoma. An initial ultrasound showed a fluid filled structure with internal debris. Subsequent MRI evaluation was confirmatory for subacromial-subdeltoid bursitis with rice body formation. The salient point of this report is to highlight the importance of patient-specific differential diagnosis. While lipomas are a very common benign soft tissue tumor, patients with RA often have disease-specific sequelae that should be included in the diagnostic deliberation. Thus, when ordering diagnostic testing for patients with a palpable mass and rheumatoid arthritis, MRI--possibly preceded by conventional radiography--is the most appropriate diagnostic algorithm. PMID:27625904

  9. Treatment of Focal Articular Cartilage Defects in the Knee

    PubMed Central

    Magnussen, Robert A.; Dunn, Warren R.; Carey, James L.

    2008-01-01

    We asked whether autologous chondrocyte implantation or osteochondral autograft transfer yields better clinical outcomes compared with one another or with traditional abrasive techniques for treatment of isolated articular cartilage defects and whether lesion size influences this clinical outcome. We performed a literature search and identified five randomized, controlled trials and one prospective comparative trial evaluating these treatment techniques in 421 patients. The operative procedures included autologous chondrocyte implantation, osteochondral autograft transfer, matrix-induced autologous chondrocyte implantation, and microfracture. Minimum followup was 1 year (mean, 1.7 years; range, 1–3 years). All studies documented greater than 95% followup for clinical outcome measures. No technique consistently had superior results compared with the others. Outcomes for microfracture tended to be worse in larger lesions. All studies reported improvement in clinical outcome measures in all treatment groups when compared with preoperative assessment; however, no control (nonoperative) groups were used in any of the studies. A large prospective trial investigating these techniques with the addition of a control group would be the best way to definitively address the clinical questions. Level of Evidence: Level II, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18196358

  10. Rice Body Formation Within a Peri-Articular Shoulder Mass

    PubMed Central

    Caram, Anthony; Flores, Miguel; Scherer, Kurt

    2016-01-01

    Most commonly associated with chronic inflammatory conditions, rice bodies represent an uncommon, nonspecific, often intra-articular inflammatory process. Presumably, rice bodies represent the sequelae of microvascular infarcts of the joint synovium. However, rice bodies have been seen in pleural fluid, in the setting of bursitis, and within the tendon sheath. The etiology and prognostic significance of rice bodies are not clear. MRI is the diagnostic imaging modality of choice for the evaluation of rice body formation. Here we present a case of a 28-year-old female with a history of rheumatoid arthritis (RA) who presented to her primary care physician with a palpable mass around her right shoulder which was presumed to be a lipoma. An initial ultrasound showed a fluid filled structure with internal debris. Subsequent MRI evaluation was confirmatory for subacromial-subdeltoid bursitis with rice body formation. The salient point of this report is to highlight the importance of patient-specific differential diagnosis. While lipomas are a very common benign soft tissue tumor, patients with RA often have disease-specific sequelae that should be included in the diagnostic deliberation. Thus, when ordering diagnostic testing for patients with a palpable mass and rheumatoid arthritis, MRI--possibly preceded by conventional radiography--is the most appropriate diagnostic algorithm.

  11. Regeneration of articular cartilage using adipose stem cells.

    PubMed

    Im, Gun-Il

    2016-07-01

    Articular cartilage (AC) has limited potential for self-regeneration and damage to AC eventually leads to the development and progression of osteoarthritis (OA). Cell implantation strategies have emerged as a new treatment modality to regenerate AC. Adipose stem cells/adipose-derived stromal cells (ASCs) have gained attention due to their abundance, excellent proliferative potential, and minimal morbidity during harvest. These advantages lower the cost of cell therapy by circumventing time-consuming procedure of culture expansion. ASCs have drawn attention as a potential source for cartilage regeneration since the feasibility of chondrogenesis from ASCs was first reported. After several groups reported inferior chondrogenesis from ASCs, numerous methods were devised to overcome the intrinsic properties. Most in vivo animal studies have reported good results using predifferentiated or undifferentiated, autologous or allogeneic ASCs to regenerate cartilage in osteochondral defects or surgically-induced OA. In this review, we summarize literature on the isolation and in vitro differentiation processes of ASCs, in vivo studies to regenerate AC in osteochondral defects and OA using ASCs, and clinical applications of ASCs. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1830-1844, 2016. PMID:26990234

  12. Adaptive cellular response to osmotic stress in pig articular chondrocytes.

    PubMed

    Borghetti, P; Della Salda, L; De Angelis, E; Maltarello, M C; Petronini, P G; Cabassi, E; Marcato, P S; Maraldi, N M; Borghetti, A F

    1995-04-01

    The authors studied the effects of a wide range of medium osmolarities (from 0.28 osM (physiological osmolarity of plasma and synovial fluid) to 0.58 osM) by altering Na+ concentration in high density cultures of pig articular chondrocytes in order to analyze the behaviour of some functional and structural parameters during cell adaptation to these imposed changes in the ionic environment. Biochemical and morphological results indicated that, even if isolated from the tissue matrix and cultured in vitro, chondrocytes maintained active osmoregulation systems which are present in living conditions. They showed a similar biochemical and morphological behavior when cultured at 0.28 osM and 0.38 osM but they were able, with regard to protein synthesis, aminoacid transport and proliferation rates, to respond quickly and to adapt to 0.48 osM medium as well. On the contrary, the treatment at the highest osmolarity (0.58 osM) early altered these biochemical parameters and was detrimental or even gave rise to lethal damage during long-term treatment. Furthermore, while chondrocytes cultured in 0.28-0.38 osM medium maintained phenotypic characteristics in culture, the higher osmolarities (0.48-0.58 osM) caused morphological changes in cell populations resulting in loss of phenotypic cell stability as demonstrated by their taking on a fibroblast-like shape as well as a lack of ability to assembly matrix proteoglycans. PMID:7778094

  13. Tribology approach to the engineering and study of articular cartilage.

    PubMed

    Wimmer, Markus A; Grad, Sibylle; Kaup, Thomas; Hänni, Markus; Schneider, Erich; Gogolewski, Sylwester; Alini, Mauro

    2004-01-01

    This study has been based on the assumption that articular motion is an important aspect of mechanotransduction in synovial joints. For this reason a new bioreactor concept, able to reproduce joint kinematics more closely, has been designed. The prototype consists of a rotating scaffold and/or cartilage pin, which is pressed onto an orthogonally rotating ball. By oscillating pin and ball in phase difference, elliptical displacement trajectories are generated that are similar to the motion paths occurring in vivo. Simultaneously, dynamic compression may be applied with a linear actuator, while two-step-motors generate the rotation of pin and ball. The whole apparatus is placed in an incubator. The control station is located outside. Preliminary investigations at the gene expression level demonstrated promising results. Compared with free-swelling control and/or simply compression-loaded samples, chondrocyte-seeded scaffolds as well as nasal cartilage explants exposed to interface motion both showed elevated levels of cartilage oligomeric matrix protein mRNA. The final design of the bioreactor will include four individual stations in line, which will facilitate the investigation of motion-initiated effects at the contacting surfaces in more detail. PMID:15588403

  14. Localization of hyaluronic acid in human articular cartilage.

    PubMed

    Asari, A; Miyauchi, S; Kuriyama, S; Machida, A; Kohno, K; Uchiyama, Y

    1994-04-01

    To demonstrate localization of hyaluronic acid (HA) in articular cartilage of the human femur, biotinylated HA-binding region, which specifically binds HA molecules, was applied to the tissue. In sections fixed by 2% paraformaldehyde-2% glutaraldehyde, HA staining was detected in lamina splendens and chondrocytes in the middle zone. By pretreatment with trypsin, intense HA staining appeared in the extracellular matrix of the deep zone and weak staining in the superficial and middle zones. Moreover, pre-treatment with chondroitinase ABC (CHase ABC) intensely enhanced the stainability for HA in the superficial and middle zones and weakly in the deeper zone. Combined pre-treatment of trypsin with CHase ABC abolished intra- and extracellular staining for HA in all zones. By microbiochemical study, the concentrations of HA and dermatan sulfate were high in the middle zone, whereas those of chondroitin sulfate and keratan sulfate were high in the deep zone. These results suggest that HA is abundantly synthesized in and secreted from the chondrocytes, particularly in the middle zone, whereas it is largely masked by proteoglycan constituents in the extracellular matrix. PMID:8126377

  15. Stem cells for tissue engineering of articular cartilage.

    PubMed

    Gao, J; Yao, J Q; Caplan, A I

    2007-07-01

    Articular cartilage injuries are one of the most common disorders in the musculo-skeletal system. Injured cartilage tissue cannot spontaneously heal and, if not treated, can lead to osteoarthritis of the affected joints. Although a variety of procedures are being employed to repair cartilage damage, methods that result in consistent durable repair tissue are not yet available. Tissue engineering is a recently developed science that merges the fields of cell biology, engineering, material science, and surgery to regenerate new functional tissue. Three critical components in tissue engineering of cartilage are as follows: first, sufficient cell numbers within the defect, such as chondrocytes or multipotent stem cells capable of differentiating into chondrocytes; second, access to growth and differentiation factors that modulate these cells to differentiate through the chondrogenic lineage; third, a cell carrier or matrix that fills the defect, delivers the appropriate cells, and supports cell proliferation and differentiation. Stem cells that exist in the embyro or in adult somatic tissues are able to renew themselves through cell division without changing their phenotype and are able to differentiate into multiple lineages including the chondrogenic lineage under certain physiological or experimental conditions. Here the application of stem cells as a cell source for cartilage tissue engineering is reviewed. PMID:17822146

  16. Imaging articular cartilage using second harmonic generation microscopy

    NASA Astrophysics Data System (ADS)

    Mansfield, Jessica C.; Winlove, C. Peter; Knapp, Karen; Matcher, Stephen J.

    2006-02-01

    Sub cellular resolution images of equine articular cartilage have been obtained using both second harmonic generation microscopy (SHGM) and two-photon fluorescence microscopy (TPFM). The SHGM images clearly map the distribution of the collagen II fibers within the extracellular matrix while the TPFM images show the distribution of endogenous two-photon fluorophores in both the cells and the extracellular matrix, highlighting especially the pericellular matrix and bright 2-3μm diameter features within the cells. To investigate the source of TPF in the extracellular matrix experiments have been carried out to see if it may originate from the proteoglycans. Pure solutions of the following proteoglycans hyaluronan, chondroitin sulfate and aggrecan have been imaged, only the aggrecan produced any TPF and here the intensity was not great enough to account for the TPF in the extracellular matrix. Also cartilage samples were subjected to a process to remove proteoglycans and cellular components. After this process the TPF from the samples had decreased by a factor of two, with respect to the SHG intensity.

  17. Differences in Tendon Graft Healing Between the Intra-articular and Extra-articular Ends of a Bone Tunnel

    PubMed Central

    Bedi, Asheesh; Kawamura, Sumito; Ying, Liang

    2008-01-01

    The basic biology of healing between a tendon graft and bone tunnel remains incompletely understood. Distinct variability in the morphological characteristics of the healing tendon–bone attachment site has been reported. We hypothesized that spatial and temporal differences in tendon-to-bone healing exist at different regions of a surgically created bone tunnel. Twenty-four male, Sprague–Dawley rats underwent anterior cruciate ligament (ACL) reconstruction in the left knee using a flexor digitorum longus tendon graft secured using suspensory periosteal fixation. Animals were sacrificed at 4, 7, 11, 14, 21, and 28 days after surgery and prepared for routine histology and immunohistochemical analysis of the healing enthesis at the intra-articular aperture (IAA), mid-tunnel, and extra-articular aperture (EAA). Six animals were used to measure mineral apposition rate (MAR) along the healing bone tunnel by double fluorochrome labeling at 14 and 28 days after surgery. The total area of calcified bone matrix was assessed with von Kossa staining and Goldner-Masson trichrome staining, respectively. The healing tendon–bone interface tissue exhibited a wide chondroid matrix at the IAA, in contrast to a narrow, fibrous matrix at the EAA. There were significantly more osteoclasts at the IAA compared to EAA throughout the study period, except 4 days after surgery (p < 0.05). Collagen continuity between the tendon graft and bone tunnel increased over time, with a more parallel orientation and increased collagen fiber continuity between tendon and bone at the EAA compared to the IAA. MAR was also significantly greater at the EAA at 4 weeks (p < 0.001). Significant differences in healing between the tendon graft and bone exist along the length of bone tunnel secured with suspensory fixation. The etiology of these differences is likely multifactorial in nature, including variable biological and biomechanical environments at different ends of the tunnel

  18. Combined Intra- and Extra-articular Reconstruction of the Anterior Cruciate Ligament: The Reconstruction of the Knee Anterolateral Ligament

    PubMed Central

    Helito, Camilo Partezani; Bonadio, Marcelo Batista; Gobbi, Riccardo Gomes; da Mota e Albuquerque, Roberto Freire; Pécora, José Ricardo; Camanho, Gilberto Luis; Demange, Marco Kawamura

    2015-01-01

    We present a new technique for the combined intra- and extra-articular reconstruction of the anterior cruciate ligament. Intra-articular reconstruction is performed in an outside-in manner according to the precepts of the anatomic femoral tunnel technique. Extra-articular reconstruction is performed with the gracilis tendon while respecting the anatomic parameters of the origin and insertion points and the path described for the knee anterolateral ligament. PMID:26258037

  19. Amino acid racemization reveals differential protein turnover in osteoarthritic articular and meniscal cartilages

    PubMed Central

    Stabler, Thomas V; Byers, Samuel S; Zura, Robert D; Kraus, Virginia Byers

    2009-01-01

    Introduction Certain amino acids within proteins have been reported to change from the L form to the D form over time. This process is known as racemization and is most likely to occur in long-lived low-turnover tissues such as normal cartilage. We hypothesized that diseased tissue, as found in an osteoarthritic (OA) joint, would have increased turnover reflected by a decrease in the racemized amino acid content. Methods Using high-performance liquid chromatography methods, we quantified the L and D forms of amino acids reported to racemize in vivo on a biological timescale: alanine, aspartate (Asp), asparagine (Asn), glutamate, glutamine, isoleucine, leucine (Leu), and serine (Ser). Furthermore, using a metabolically inactive control material (tooth dentin) and a control material with normal metabolism (normal articular cartilage), we developed an age adjustment in order to make inferences about the state of protein turnover in cartilage and meniscus. Results In the metabolically inactive control material (n = 25, ages 13 to 80 years) and the normal metabolizing control material (n = 19, ages 17 to 83 years), only Asp + Asn (Asx), Ser, and Leu showed a significant change (increase) in racemization with age (P < 0.01). The age-adjusted proportions of racemized to total amino acid (D/D+L expressed as a percentage of the control material) for Asx, Ser, and Leu when compared with the normal articular cartilage control were 97%, 74%, and 73% in OA meniscal cartilage and 97%, 70%, and 78% in OA articular cartilage. We also observed lower amino acid content in OA articular and meniscal cartilages compared with normal articular cartilage as well as a loss of total amino acids with age in the OA meniscal but not the OA articular cartilage. Conclusions These data demonstrate comparable anabolic responses for non-lesioned OA articular cartilage and OA meniscal cartilage but an excess of catabolism over anabolism for the meniscal cartilage. PMID:19267899

  20. Gene Expression Profiling Reveals Similarities between the Spatial Architectures of Postnatal Articular and Growth Plate Cartilage

    PubMed Central

    Chau, Michael; Lui, Julian C.; Landman, Ellie B. M.; Späth, Stephan-Stanislaw; Vortkamp, Andrea; Baron, Jeffrey; Nilsson, Ola

    2014-01-01

    Articular and growth plate cartilage are discrete tissues but arise from a common cartilaginous condensation and have comparable spatial architectures consisting of distinct layers of chondrocytes. To investigate similarities and differences between articular and growth plate cartilage and to explore transcriptional changes that occur during the onset of their divergence, we performed manual microdissection of 10-day-old rat proximal tibias, microarray analysis, bioinformatics, and real-time PCR to compare gene expression profiles in individual cartilage layers. We found that many genes that were spatially upregulated in the intermediate/deep zone of articular cartilage were also spatially upregulated in the resting zone of growth plate cartilage (overlap greater than expected by chance, P<0.001). Interestingly, the superficial zone of articular cartilage showed an expression profile with similarities to both the proliferative and hypertrophic zones of growth plate cartilage (P<0.001 each). Additionally, significant numbers of known proliferative zone markers (3 out of 6) and hypertrophic zone markers (27 out of 126) were spatially upregulated in the superficial zone (more than expected by chance, P<0.001 each). In conclusion, we provide evidence that the intermediate/deep zone of articular cartilage has a gene expression profile more similar to that of the resting zone of growth plate cartilage, whereas the superficial zone has a gene expression profile more similar to those of the proliferative and hypertrophic zones. These findings suggest that the superficial zone chondrocytes of articular cartilage differentiate according to a program that is not completely different from but instead has distinct similarities to the hypertrophic differentiation program of growth plate chondrocytes. We also present functional signaling pathways implicated by differential gene expression between articular and growth plate cartilage during their initial separation by the

  1. Interspecific scaling patterns of talar articular surfaces within primates and their closest living relatives

    PubMed Central

    Yapuncich, Gabriel S; Boyer, Doug M

    2014-01-01

    The articular facets of interosseous joints must transmit forces while maintaining relatively low stresses. To prevent overloading, joints that transmit higher forces should therefore have larger facet areas. The relative contributions of body mass and muscle-induced forces to joint stress are unclear, but generate opposing hypotheses. If mass-induced forces dominate, facet area should scale with positive allometry to body mass. Alternatively, muscle-induced forces should cause facets to scale isometrically with body mass. Within primates, both scaling patterns have been reported for articular surfaces of the femoral and humeral heads, but more distal elements are less well studied. Additionally, examination of complex articular surfaces has largely been limited to linear measurements, so that ‘true area' remains poorly assessed. To re-assess these scaling relationships, we examine the relationship between body size and articular surface areas of the talus. Area measurements were taken from microCT scan-generated surfaces of all talar facets from a comprehensive sample of extant euarchontan taxa (primates, treeshrews, and colugos). Log-transformed data were regressed on literature-derived log-body mass using reduced major axis and phylogenetic least squares regressions. We examine the scaling patterns of muscle mass and physiological cross-sectional area (PCSA) to body mass, as these relationships may complicate each model. Finally, we examine the scaling pattern of hindlimb muscle PCSA to talar articular surface area, a direct test of the effect of mass-induced forces on joint surfaces. Among most groups, there is an overall trend toward positive allometry for articular surfaces. The ectal (= posterior calcaneal) facet scales with positive allometry among all groups except ‘sundatherians', strepsirrhines, galagids, and lorisids. The medial tibial facet scales isometrically among all groups except lemuroids. Scaling coefficients are not correlated with sample

  2. Articular cartilage of the knee 3 years after ACL reconstruction

    PubMed Central

    Bae, Ji-Hoon; Hosseini, Ali; Wang, Yang; Torriani, Martin; Gill, Thomas J; Grodzinsky, Alan J

    2015-01-01

    Background and purpose T1ρ or T2 relaxation imaging has been increasingly used to evaluate the cartilage of the knee. We investigated the cartilage of ACL-reconstructed knees 3 years after surgery using T2 relaxation times. Patients and methods 10 patients with a clinically successful unilateral ACL reconstruction were examined 3 years after surgery. Multiple-TE fast-spin echo sagittal images of both knees were acquired using a 3T MRI scanner for T2 mapping of the tibiofemoral cartilage. T2 values of the superficial and deep zones of the tibiofemoral cartilage were analyzed in sub-compartmental areas and compared between the ACL-reconstructed and uninjured contralateral knees. Results Higher T2 values were observed in 1 or more sub-compartmental areas of each ACL-reconstructed knee compared to the uninjured contralateral side. Most of the T2 increases were observed at the superficial zones of the cartilage, especially at the medial compartment. At the medial compartment of the ACL-reconstructed knee, the T2 values of the femoral and tibial cartilage were increased by 3–81% compared to the uninjured contralateral side, at the superficial zones of the weight-bearing areas. T2 values in the superficial zone of the central medial femoral condyle differed between the 2 groups (p = 0.002). Interpretation The articular cartilage of ACL-reconstructed knees, although clinically satisfactory, had higher T2 values in the superficial zone of the central medial femoral condyle than in the uninjured contralateral side 3 years after surgery. Further studies are warranted to determine whether these patients would undergo cartilage degeneration over time. PMID:25854533

  3. Arthroscopic laser in intra-articular knee cartilage disorders

    NASA Astrophysics Data System (ADS)

    Nosir, Hany R.; Siebert, Werner E.

    1996-12-01

    Different assemblies have endeavored to develop arthroscopic laser surgery. Various lasers have been tried in the treatment of orthopaedic problems, and the most useful has turned out to be the Hol-YAG laser 2.1 nm which is a near- contact laser. By using the laser as a powerful tool, and cutting back on the power level, one is able to better achieve the desired treatment effect. Clinical studies to evaluating the role of the laser in different arthroscopic knee procedures, comparing to conventional techniques, showed that the overall outcome attains a momentous confidence level which is shifted to the side of the laser versus the conventional for all maneuvers, barring meniscectomy where there is not perceiving disparity between laser versus the conventional. Meniscectomy continues to be one of the most commonly performed orthopaedic procedures. Laser provides a single tool which can ablate and debride meniscal rims with efficiency and safety. Chondroplasty can also be accomplished with ease using defocused laser energy. Both lateral release and soft tissue cermilization benefit from the cutting effect of laser along with its hemostatic effect. Synovial reduction with a defocused laser is also easily accomplished. By one gadget, one can cut, ablate, smooth, coagulate, congeal and with authentic tissue depth control The future of laser arthroscopic surgery lies in its ability to weld or repair tissues. Our research study has shown that laser activated photoactive dyes can produce a molecular bonding of collagen fibers, and therefore a repair 'weld' can be achieved with both meniscal tissues and with articular cartilage lesions.

  4. Adaptive mechanically controlled lubrication mechanism found in articular joints

    PubMed Central

    Greene, George W.; Banquy, Xavier; Lee, Dong Woog; Lowrey, Daniel D.; Yu, Jing; Israelachvili, Jacob N.

    2011-01-01

    Articular cartilage is a highly efficacious water-based tribological system that is optimized to provide low friction and wear protection at both low and high loads (pressures) and sliding velocities that must last over a lifetime. Although many different lubrication mechanisms have been proposed, it is becoming increasingly apparent that the tribological performance of cartilage cannot be attributed to a single mechanism acting alone but on the synergistic action of multiple “modes” of lubrication that are adapted to provide optimum lubrication as the normal loads, shear stresses, and rates change. Hyaluronic acid (HA) is abundant in cartilage and synovial fluid and widely thought to play a principal role in joint lubrication although this role remains unclear. HA is also known to complex readily with the glycoprotein lubricin (LUB) to form a cross-linked network that has also been shown to be critical to the wear prevention mechanism of joints. Friction experiments on porcine cartilage using the surface forces apparatus, and enzymatic digestion, reveal an “adaptive” role for an HA-LUB complex whereby, under compression, nominally free HA diffusing out of the cartilage becomes mechanically, i.e., physically, trapped at the interface by the increasingly constricted collagen pore network. The mechanically trapped HA-LUB complex now acts as an effective (chemically bound) “boundary lubricant”—reducing the friction force slightly but, more importantly, eliminating wear damage to the rubbing/shearing surfaces. This paper focuses on the contribution of HA in cartilage lubrication; however, the system as a whole requires both HA and LUB to function optimally under all conditions. PMID:21383143

  5. Adaptive mechanically controlled lubrication mechanism found in articular joints.

    PubMed

    Greene, George W; Banquy, Xavier; Lee, Dong Woog; Lowrey, Daniel D; Yu, Jing; Israelachvili, Jacob N

    2011-03-29

    Articular cartilage is a highly efficacious water-based tribological system that is optimized to provide low friction and wear protection at both low and high loads (pressures) and sliding velocities that must last over a lifetime. Although many different lubrication mechanisms have been proposed, it is becoming increasingly apparent that the tribological performance of cartilage cannot be attributed to a single mechanism acting alone but on the synergistic action of multiple "modes" of lubrication that are adapted to provide optimum lubrication as the normal loads, shear stresses, and rates change. Hyaluronic acid (HA) is abundant in cartilage and synovial fluid and widely thought to play a principal role in joint lubrication although this role remains unclear. HA is also known to complex readily with the glycoprotein lubricin (LUB) to form a cross-linked network that has also been shown to be critical to the wear prevention mechanism of joints. Friction experiments on porcine cartilage using the surface forces apparatus, and enzymatic digestion, reveal an "adaptive" role for an HA-LUB complex whereby, under compression, nominally free HA diffusing out of the cartilage becomes mechanically, i.e., physically, trapped at the interface by the increasingly constricted collagen pore network. The mechanically trapped HA-LUB complex now acts as an effective (chemically bound) "boundary lubricant"--reducing the friction force slightly but, more importantly, eliminating wear damage to the rubbing/shearing surfaces. This paper focuses on the contribution of HA in cartilage lubrication; however, the system as a whole requires both HA and LUB to function optimally under all conditions. PMID:21383143

  6. Multi-parametric MRI characterization of enzymatically degraded articular cartilage.

    PubMed

    Nissi, Mikko J; Salo, Elli-Noora; Tiitu, Virpi; Liimatainen, Timo; Michaeli, Shalom; Mangia, Silvia; Ellermann, Jutta; Nieminen, Miika T

    2016-07-01

    Several laboratory and rotating frame quantitative MRI parameters were evaluated and compared for detection of changes in articular cartilage following selective enzymatic digestion. Bovine osteochondral specimens were subjected to 44 h incubation in control medium or in collagenase or chondroitinase ABC to induce superficial collagen or proteoglycan (glycosaminoglycan) alterations. The samples were scanned at 9.4 T for T1 , T1 Gd (dGEMRIC), T2 , adiabatic T1 ρ , adiabatic T2 ρ , continuous-wave T1 ρ , TRAFF2 , and T1 sat relaxation times and for magnetization transfer ratio (MTR). For reference, glycosaminoglycan content, collagen fibril orientation and biomechanical properties were determined. Changes primarily in the superficial cartilage were noted after enzymatic degradation. Most of the studied parameters were sensitive to the destruction of collagen network, whereas glycosaminoglycan depletion was detected only by native T1 and T1 Gd relaxation time constants throughout the tissue and by MTR superficially. T1 , adiabatic T1 ρ , adiabatic T2 ρ , continuous-wave T1 ρ , and T1 sat correlated significantly with the biomechanical properties while T1 Gd correlated with glycosaminoglycan staining. The findings indicated that most of the studied MRI parameters were sensitive to both glycosaminoglycan content and collagen network integrity, with changes due to enzymatic treatment detected primarily in the superficial tissue. Strong correlation of T1 , adiabatic T1ρ , adiabatic T2 ρ , continuous-wave T1 ρ , and T1 sat with the altered biomechanical properties, reflects that these parameters were sensitive to critical functional properties of cartilage. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1111-1120, 2016. PMID:26662555

  7. Modeling IL-1 induced degradation of articular cartilage.

    PubMed

    Kar, Saptarshi; Smith, David W; Gardiner, Bruce S; Li, Yang; Wang, Yang; Grodzinsky, Alan J

    2016-03-15

    In this study, we develop a computational model to simulate the in vitro biochemical degradation of articular cartilage explants sourced from the femoropatellar grooves of bovine calves. Cartilage explants were incubated in culture medium with and without the inflammatory cytokine IL-1α. The spatio-temporal evolution of the cartilage explant's extracellular matrix components is modelled. Key variables in the model include chondrocytes, aggrecan, collagen, aggrecanase, collagenase and IL-1α. The model is first calibrated for aggrecan homeostasis of cartilage in vivo, then for data on (explant) controls, and finally for data on the IL-1α driven proteolysis of aggrecan and collagen over a 4-week period. The model was found to fit the experimental data best when: (i) chondrocytes continue to synthesize aggrecan during the cytokine challenge, (ii) a one to two day delay is introduced between the addition of IL-1α to the culture medium and subsequent aggrecanolysis, (iii) collagen degradation does not commence until the total concentration of aggrecan (i.e. both intact and degraded aggrecan) at any specific location within the explant becomes ≤ 1.5 mg/ml and (iv) degraded aggrecan formed due to the IL-1α induced proteolysis of intact aggrecan protects the collagen network while collagen degrades in a two-step process which, together, significantly modulate the collagen network degradation. Under simulated in vivo conditions, the model predicts increased aggrecan turnover rates in the presence of synovial IL-1α, consistent with experimental observations. Such models may help to infer the course of events in vivo following traumatic joint injury, and may also prove useful in quantitatively evaluating the efficiency of various therapeutic molecules that could be employed to avoid or modify the course of cartilage disease states. PMID:26874194

  8. Modeling the biomechanics of articular eminence function in anthropoid primates

    PubMed Central

    Terhune, Claire E

    2011-01-01

    One of the most prominent features of the cranial component of the temporomandibular joint (TMJ) is the articular eminence (AE). This bar of bone is the primary surface upon which the condyle translates and rotates during movements of the mandible, and is therefore the primary point at which forces are transmitted from the mandible to the cranium during loading of the masticatory apparatus. The shape of the AE is highly variable across primates, and the raised eminence of humans has often been considered a defining feature of the human TMJ, yet few data exist to address whether this variation is functionally significant. This study used a broad interspecific sample of anthropoid primates to elaborate upon and test the predictions of a previously proposed model of AE function. This model suggests that AE inclination acts to resist non-normal forces at the TMJ, thereby maximizing bite forces (BFs). AE inclination was predicted to covary with two specific features of the masticatory apparatus: height of the TMJ above the occlusal plane; and inclination of the masticatory muscles. A correlate of this model is that taxa utilizing more resistant food objects should also exhibit relatively more inclined AEs. Results of the correlation analyses found that AE inclination is strongly correlated with height of the TMJ above the occlusal plane, but less so with inclination of the masticatory muscles. Furthermore, pairwise comparisons of closely related taxa with documented dietary differences found that the AE is consistently more inclined in taxa that utilize more resistant food items. These data preliminarily suggest that variation in AE morphology across anthropoid primates is functionally related to maximizing BFs, and add to the growing dataset of masticatory morphologies linked to feeding behavior. PMID:21923720

  9. Subtalar arthrodesis for complications of intra-articular calcaneal fractures.

    PubMed

    Flemister, A S; Infante, A F; Sanders, R W; Walling, A K

    2000-05-01

    Eighty six subtalar arthrodeses performed between 1985 and 1996 for complications associated with intra-articular calcaneal fractures were retrospectively evaluated. Patients were divided into three Groups: (I) 59 patients with calcaneal malunions (II) 13 patients with failed open reduction and internal fixation, and (III) eight patients undergoing open reductions and primary fusion for highly comminuted fractures. In each scenario, internal fixation was achieved with cancellous lag screws. Bone graft material consisted of either autogenous iliac crest graft, local graft obtained from the lateral wall exostectomy of the malunion, or freeze-dried cancellous allograft. Fusions in Groups II and III were performed in situ. Fusions in Group I were performed either in situ or utilizing a variety of reconstructive procedures depending upon the type of malunion encountered. Eighty three of the 86 fusion attempts were successful following the initial operations for a union rate of 96%. Fusion rates were similar regardless of the graft material used. Complications included four varus malunions, four cases of osteomyelitis, and two cases of reflex sympathetic dystrophy. A statistically significant shorter hospital stay was found for patients not undergoing iliac crest bone graft procedures. Eighty patients with at least two year follow up achieved a mean American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score of 75.0. Scores were similar for all three groups and for the various types of reconstructive procedures used. No correlation was found between postoperative talar declination angle and the AOFAS ankle-hindfoot score. Worker's compensation patients tended to have a poorer clinical outcome. PMID:10830657

  10. Stick-slip friction and wear of articular joints

    PubMed Central

    Lee, Dong Woog; Banquy, Xavier; Israelachvili, Jacob N.

    2013-01-01

    Stick-slip friction was observed in articular cartilage under certain loading and sliding conditions and systematically studied. Using the Surface Forces Apparatus, we show that stick-slip friction can induce permanent morphological changes (a change in the roughness indicative of wear/damage) in cartilage surfaces, even under mild loading and sliding conditions. The different load and speed regimes can be represented by friction maps—separating regimes of smooth and stick-slip sliding; damage generally occurs within the stick-slip regimes. Prolonged exposure of cartilage surfaces to stick-slip sliding resulted in a significant increase of surface roughness, indicative of severe morphological changes of the cartilage superficial zone. To further investigate the factors that are conducive to stick-slip and wear, we selectively digested essential components of cartilage: type II collagen, hyaluronic acid (HA), and glycosaminoglycans (GAGs). Compared with the normal cartilage, HA and GAG digestions modified the stick-slip behavior and increased surface roughness (wear) during sliding, whereas collagen digestion decreased the surface roughness. Importantly, friction forces increased up to 2, 10, and 5 times after HA, GAGs, and collagen digestion, respectively. Also, each digestion altered the friction map in different ways. Our results show that (i) wear is not directly related to the friction coefficient but (ii) more directly related to stick-slip sliding, even when present at small amplitudes, and that (iii) the different molecular components of joints work synergistically to prevent wear. Our results also suggest potential noninvasive diagnostic tools for sensing stick-slip in joints. PMID:23359687

  11. Permeation of dimethyl sulfoxide into articular cartilage at subzero temperatures.

    PubMed

    Zhang, Shao-Zhi; Yu, Xiao-Yi; Chen, Guang-Ming

    2012-03-01

    Osteochondral allografting has been proved to be a useful method to treat diseased or damaged areas of joint surfaces. Operational long-term stocks of grafts which supply a buffer between procurement and utilization would contribute to the commercialization or industrialization of this technology. Vitrification has been thought to be a promising method for successful preservation of articular cartilage (AC), but high concentration cryoprotectants (CPAs) are used which may cause high cellular toxicity. An effective way to reduce CPA toxicity is to increase CPA concentration gradually while the temperature is lowered. Understanding the mechanism of CPA permeation at subzero temperatures is important for designing the cryopreservation protocol. In this research, the permeation of dimethyl sulfoxide (Me(2)SO) in ovine AC at subzero temperatures was studied experimentally. Pretreated AC discs were exposed in Me(2)SO solutions for different time (0, 5, 15, 30, 50, 80, and 120 min) at three temperature levels (-10, -20, and -30 °C). The Me(2)SO concentration within the tissue was determined by ultraviolet (UV) spectrophotometry. The diffusion coefficients were estimated to be 0.85×10(-6), 0.48×10(-6), and 0.27×10(-6) cm(2)/s at -10, -20, and -30 °C, respectively, and the corresponding activation energy was 29.23 kJ/mol. Numerical simulation was performed to compare two Me(2)SO addition protocols, and the results demonstrated that the total loading duration could be effectively reduced with the knowledge of permeation kinetics. PMID:22374614

  12. Lipoma arborescens arising in the extra-articular bursa of the knee joint

    PubMed Central

    Minami, Shinji; Miyake, Yusuke; Kinoshita, Hirofumi

    2016-01-01

    Lipoma arborescens arising in the extra-articular bursa of the knee joint is extremely rare. We describe an 11-year-old boy who complained of a gradual swelling mass of the lateral knee joint. Magnetic resonance imaging (MRI) showed a high signal intensity tumor on T1- and T2-weighted images with a thickened septa and nodular lesion that showed low signal intensity. The radiologist suggested the possible differential diagnosis of well-differentiated liposarcoma. At operation, the tumor was found under the iliotibial tract and was not in contact with the knee joint. Histopathologically, this lesion was diagnosed as lipoma arborescens arising in the extra-articular bursa of the knee joint. On MRI, the appearance of lipoma arborescens arising in the extra-articular bursa of the knee joint differed from that of conventional intra-articular lipoma arborescens. In this report, we describe a case of extra-articular lipoma arborescens of the knee joint bursa and discuss the diagnosis and etiology. PMID:27382924

  13. [Basophilic line of the articular cartilage in normal and various pathological states].

    PubMed

    Gongadze, L R

    1987-04-01

    Epiphyses of long tubular bones in the man and animals of various age, as well as experimental material of the adjuvant arthritis, with special reference to the basal part of the articular cartilage have been studied by means of histological, histochemical and histometrical methods. The structural-chemical organization of the basophilic line (tidemark) of the articular cartilage ensures its barrier role and participation in regulating selective permeability. Reconstruction of the tidemark in the process of physiological ageing and in cases of the articular pathology is aimed to preserve its integrity and in this way a complete differentiation of the noncalcified and calcified structures is secured. Disturbance of the basophilic line results in changes of the articular selective permeability, in invasion of vessels and structural elements of the bone marrow, and in development of profound distrophic and destructive changes of the cartilage--in deforming artrosis. Deflations in the structural-chemical organization of the tidemark indicate certain disturbances in the state of the system articular cartilage--subchondral bone. These data can be of prognostic importance. PMID:3606408

  14. Role of computer aided detection (CAD) integration: case study with meniscal and articular cartilage CAD applications

    NASA Astrophysics Data System (ADS)

    Safdar, Nabile; Ramakrishna, Bharath; Saiprasad, Ganesh; Siddiqui, Khan; Siegel, Eliot

    2008-03-01

    Knee-related injuries involving the meniscal or articular cartilage are common and require accurate diagnosis and surgical intervention when appropriate. With proper techniques and experience, confidence in detection of meniscal tears and articular cartilage abnormalities can be quite high. However, for radiologists without musculoskeletal training, diagnosis of such abnormalities can be challenging. In this paper, the potential of improving diagnosis through integration of computer-aided detection (CAD) algorithms for automatic detection of meniscal tears and articular cartilage injuries of the knees is studied. An integrated approach in which the results of algorithms evaluating either meniscal tears or articular cartilage injuries provide feedback to each other is believed to improve the diagnostic accuracy of the individual CAD algorithms due to the known association between abnormalities in these distinct anatomic structures. The correlation between meniscal tears and articular cartilage injuries is exploited to improve the final diagnostic results of the individual algorithms. Preliminary results from the integrated application are encouraging and more comprehensive tests are being planned.

  15. Intra-articular injection of tranexamic acid reduce blood loss in cemented total knee arthroplasty.

    PubMed

    Digas, G; Koutsogiannis, I; Meletiadis, G; Antonopoulou, E; Karamoulas, V; Bikos, Ch

    2015-10-01

    The purpose of this study was to compare the efficacy of intravenous and topical tranexamic acid (TXA) versus control group for reduction in blood loss following primary total knee arthroplasty (TKA). A total of 90 patients were prospectively allocated to each of three groups (control, intravenous IV and intra-articular) and underwent unilateral total knee arthroplasty. In the IV group, patients received one dose of TXA of 15 mg/kg before deflation of the tourniquet, while in the intra-articular group patients received 2 g TXA via the drain retrogradely after closure of the wound. The mean drained blood loss in control, IV and intra-articular groups was 415 ± 24, 192 ± 21 and 121 ± 17 ml, respectively. About 43 % (control), 23 % (IV) and 17 % (intra-articular) of each group required transfusion, and the mean transfusion was 338, 168 and 79 ml, respectively. Preoperative hemoglobin values decreased at 24 h by 2.80 ± 0.14, 2.24 ± 0.17 and 2.26 ± 0.18 mg/dl, respectively. TXA reduced blood loss and transfusion requirement. Compared with one-dose intravenous administration, intra-articular administration of TXA seems to be more effective in terms of reducing drained blood loss and transfusion frequency. We recommend administration of topical TXA in primary TKA in healthy patients to decrease perioperative blood loss. PMID:26169991

  16. Intra-Articular Synovial Sarcomas: Incidence and Differentiating Features from Localized Pigmented Villonodular Synovitis

    PubMed Central

    Nordemar, D.; Öberg, J.; Brosjö, O.; Skorpil, M.

    2015-01-01

    Purpose. To determine the incidence of intra-articular synovial sarcomas and investigate if any radiological variables can differentiate them from localized (unifocal) pigmented villonodular synovitis (PVNS) and if multivariate data analysis could be used as a complementary clinical tool. Methods. Magnetic resonance images and radiographs of 7 cases of intra-articular synovial sarcomas and 14 cases of localized PVNS were blindedly reviewed. Variables analyzed were size, extra-articular growth, tumor border, blooming, calcification, contrast media enhancement, effusion, bowl of grapes sign, triple signal intensity sign, synovial low signal intensity, synovitis, age, and gender. Univariate and multivariate data analysis, the method of partial least squares-discriminant analysis (PLS-DA), were used. Register data on all synovial sarcomas were extracted for comparison. Results. The incidence of intra-articular synovial sarcomas was 3%. PLS-DA showed that age, effusion, size, and gender were the most important factors for discrimination between sarcomas and localized PVNS. No sarcomas were misclassified as PVNS with PLS-DA, while some PVNS were misclassified as sarcomas. Conclusions. The most important variables in differentiating intra-articular sarcomas from localized PVNS were age, effusion, size, and gender. Multivariate data analysis can be helpful as additive information to avoid a biopsy, if the tumor is classified as most likely being PVNS. PMID:26819567

  17. Winner of the 1996 Cabaud Award. The effect of lifelong exercise on canine articular cartilage.

    PubMed

    Newton, P M; Mow, V C; Gardner, T R; Buckwalter, J A; Albright, J P

    1997-01-01

    The effect of long-term exercise on canine knees was studied to determine whether an increased level of lifelong weightbearing exercise causes degeneration, or changes that may lead to degeneration, of articular cartilage. Eleven dogs were exercised on a treadmill at 3 km/hr for 75 minutes 5 days a week for 527 weeks while carrying jackets weighing 130% of their body weight. Ten control dogs were allowed unrestricted activity in cages for the 550 weeks. At the completion of the study all knee joints were inspected for evidence of joint injury and degeneration. Articular cartilage surfaces from the medial tibial plateau were examined by light microscopy, the cartilage thickness was measured, and the intrinsic material properties were determined by mechanical testing. No joints had ligament or meniscal injuries, cartilage erosions, or osteophytes. Light microscopy did not demonstrate cartilage fibrillation or differences in safranin O staining of the tibial articular cartilages between the two groups. Furthermore, the tibial articular cartilage thickness and mechanical properties did not differ between the two groups. These results show that a lifetime of regular weightbearing exercise in dogs with normal joints did not cause alterations in the structure and mechanical properties of articular cartilage that might lead to joint degeneration. PMID:9167804

  18. Polyethylene-Glycol-Modified Single-Walled Carbon Nanotubes for Intra-Articular Delivery to Chondrocytes

    PubMed Central

    Sacchetti, Cristiano; Liu-Bryan, Ru; Magrini, Andrea; Rosato, Nicola; Bottini, Nunzio; Bottini, Massimo

    2015-01-01

    Osteoarthritis (OA) is a common and debilitating degenerative disease of articular joints for which no disease-modifying medical therapy is currently available. Inefficient delivery of pharmacologic agents into cartilage-resident chondrocytes after systemic administration has been a limitation to the development of anti-OA medications. Direct intra-articular injection enables delivery of high concentrations of agents in close proximity to chondrocytes; however, the efficacy of this approach is limited by the fast clearance of small molecules and biomacromolecules after injection into the synovial cavity. Coupling of pharmacologic agents with drug delivery systems able to enhance their residence time and cartilage penetration can enhance the effectiveness of intra-articularly injected anti-OA medications. Herein we describe an efficient intra-articular delivery nanosystem based on single-walled carbon nanotubes (SWCNTs) modified with polyethylene glycol (PEG) chains (PEG-SWCNTs). We show that PEG-SWCNTs are capable to persist in the joint cavity for a prolonged time, enter the cartilage matrix, and deliver gene inhibitors into chondrocytes of both healthy and OA mice. PEG-SWCNT nanoparticles did not elicit systemic or local side effects. Our data suggest that PEG-SWCNTs represent a biocompatible and effective nanocarrier for intra-articular delivery of agents to chondrocytes. PMID:25415768

  19. Chondrocyte survival in articular cartilage: the influence of subchondral bone in a bovine model.

    PubMed

    Amin, A K; Huntley, J S; Simpson, A H R W; Hall, A C

    2009-05-01

    The aim of this study was to determine whether subchondral bone influences in situ chondrocyte survival. Bovine explants were cultured in serum-free media over seven days with subchondral bone excised from articular cartilage (group A), subchondral bone left attached to articular cartilage (group B), and subchondral bone excised but co-cultured with articular cartilage (group C). Using confocal laser scanning microscopy, fluorescent probes and biochemical assays, in situ chondrocyte viability and relevant biophysical parameters (cartilage thickness, cell density, culture medium composition) were quantified over time (2.5 hours vs seven days). There was a significant increase in chondrocyte death over seven days, primarily within the superficial zone, for group A, but not for groups B or C (p < 0.05). There was no significant difference in cartilage thickness or cell density between groups A, B and C (p > 0.05). Increases in the protein content of the culture media for groups B and C, but not for group A, suggested that the release of soluble factors from subchondral bone may have influenced chondrocyte survival. In conclusion, subchondral bone significantly influenced chondrocyte survival in articular cartilage during explant culture. The extrapolation of bone-cartilage interactions in vitro to the clinical situation must be made with caution, but the findings from these experiments suggest that future investigation into in vivo mechanisms of articular cartilage survival and degradation must consider the interactions of cartilage with subchondral bone. PMID:19407309

  20. Quantitative characterization of articular cartilage using Mueller matrix imaging and multiphoton microscopy

    NASA Astrophysics Data System (ADS)

    Ellingsen, Pa˚L. Gunnar; Lilledahl, Magnus Borstad; Aas, Lars Martin Sandvik; Davies, Catharina De Lange; Kildemo, Morten

    2011-11-01

    The collagen meshwork in articular cartilage of chicken knee is characterized using Mueller matrix imaging and multiphoton microscopy. Direction and degree of dispersion of the collagen fibers in the superficial layer are found using a Fourier transform image-analysis technique of the second-harmonic generated image. Mueller matrix images are used to acquire structural data from the intermediate layer of articular cartilage where the collagen fibers are too small to be resolved by optical microscopy, providing a powerful multimodal measurement technique. Furthermore, we show that Mueller matrix imaging provides more information about the tissue compared to standard polarization microscopy. The combination of these techniques can find use in improved diagnosis of diseases in articular cartilage, improved histopathology, and additional information for accurate biomechanical modeling of cartilage.

  1. Directed differentiation of induced pluripotent stem cells into chondrogenic lineages for articular cartilage treatment

    PubMed Central

    Lach, Michał; Richter, Magdalena; Pawlicz, Jarosław; Suchorska, Wiktoria M

    2014-01-01

    In recent years, increases in the number of articular cartilage injuries caused by environmental factors or pathological conditions have led to a notable rise in the incidence of premature osteoarthritis. Osteoarthritis, considered a disease of civilization, is the leading cause of disability. At present, standard methods for treating damaged articular cartilage, including autologous chondrocyte implantation or microfracture, are short-term solutions with important side effects. Emerging treatments include the use of induced pluripotent stem cells, a technique that could provide a new tool for treatment of joint damage. However, research in this area is still early, and no optimal protocol for transforming induced pluripotent stem cells into chondrocytes has yet been established. Developments in our understanding of cartilage developmental biology, together with the use of modern technologies in the field of tissue engineering, provide an opportunity to create a complete functional model of articular cartilage. PMID:25383175

  2. What can biophotonics tell us about the 3D microstructure of articular cartilage?

    PubMed

    Matcher, Stephen J

    2015-02-01

    Connective tissues such as articular cartilage have been the subject of study using novel optical techniques almost since the invention of polarized light microscopy (PLM). Early studies of polarized light micrographs were the main evidential basis for the establishment of quantitative models of articular cartilage collagen structure by Benninghoff and others. Even now, state of the art optical techniques including quantitative polarized light microscopy (qPLM), optical coherence tomography (OCT), polarization-sensitive optical coherence tomography (PS-OCT), second harmonic generation (SHG) microscopy, Fourier-transform infrared (FTIR) microscopy, Raman and optical hyperspectral reflectance and fluorescence imaging are providing new insights into articular cartilage structure from the nanoscale through to the mesoscale. New insights are promised by emerging modalities such as optical elastography. This short review highlights some key recent results from modern optical techniques. PMID:25694964

  3. Giant extra-articular synovial osteochondromatosis of the left proximal thigh: A case report

    PubMed Central

    YU, XIAOLONG; LI, WEI; DAI, MIN; ZHANG, BIN; ZOU, FAN; LIU, HUCHENG

    2015-01-01

    Extra-articular synovial osteochondromatosis is a rare disease. The present study describes the case of a 46-year-old female who suffered from extra-articular synovial osteochondromatosis of the left proximal thigh with limited hip movement. The patient underwent a total tumor resection and recovered well. The tumor was 15×14×5 cm3 in size and located in the muscle gap. After a 3-month follow-up, the patient's left hip motion was improved and a computed tomography scan demonstrated no evidence of recurrence. However, the long-term efficacy of this procedure requires continuous observation of the patient. To the best of our knowledge, this is the first case of a giant extra-articular synovial osteochondromatosis of the proximal thigh muscle gap. PMID:26788172

  4. What can biophotonics tell us about the 3D microstructure of articular cartilage?

    PubMed Central

    2015-01-01

    Connective tissues such as articular cartilage have been the subject of study using novel optical techniques almost since the invention of polarized light microscopy (PLM). Early studies of polarized light micrographs were the main evidential basis for the establishment of quantitative models of articular cartilage collagen structure by Benninghoff and others. Even now, state of the art optical techniques including quantitative polarized light microscopy (qPLM), optical coherence tomography (OCT), polarization-sensitive optical coherence tomography (PS-OCT), second harmonic generation (SHG) microscopy, Fourier-transform infrared (FTIR) microscopy, Raman and optical hyperspectral reflectance and fluorescence imaging are providing new insights into articular cartilage structure from the nanoscale through to the mesoscale. New insights are promised by emerging modalities such as optical elastography. This short review highlights some key recent results from modern optical techniques. PMID:25694964

  5. Large bone distractor for open reconstruction of articular fractures of the calcaneus

    PubMed Central

    Twardosz, Wojciech; Tondel, Wieslaw; Olewicz-Gawlik, Anna; Hrycaj, Pawel

    2009-01-01

    The results of operative treatment of two groups of patients with articular fractures of the calcaneus were evaluated. Twenty-three cases were treated surgically using a standard reconstruction procedure. In the second group of 19 patients a large bone distractor was used; it held the soft tissue flap retracted, while aiding in articular and tuberosity fragment reduction and increasing visualisation by distraction of the posterior talocalcaneal joint. After a year, the anatomical and functional results, together with the operative time, were evaluated. All fractures healed with good or very good anatomical results. All cases, except those with complications (n = 3), achieved good (n = 28) or very good (n = 11) functional scoring. The distractor group had significantly shorter operative times, and less manpower was needed during surgery. We conclude that the large bone distractor is a useful tool in open reconstruction of articular calcaneal fractures. PMID:19404639

  6. Irrigating solutions used in arthroscopy and their effect on articular cartilage. An in vivo study

    SciTech Connect

    Arciero, R.A.; Little, J.S.; Liebenberg, S.P.; Parr, T.J.

    1986-11-01

    The effect of arthroscopic irrigating solutions on articular cartilage was determined by the use of an animal model. Rabbit knee joints were irrigated continuously for two hours with either normal saline, Ringer's lactate, or sterile water. Subsequently, the rate of incorporation of /sup 35/SO/sub 4/ by articular cartilage was used to measure the effect of the irrigants on chondrocyte metabolism. In addition, the irrigated groups were compared to an unirrigated control group. There was no significant difference in /sup 35/SO/sub 4/ incorporation between the groups. This suggested that none of the irrigating solutions used in this study adversely affected articular cartilage function. On the basis of these findings, it appears that normal saline, Ringer's lactate, and sterile water can be safely used as irrigating solutions during most arthroscopic procedures.

  7. Intra-Articular Giant Heterotopic Ossification following Total Knee Arthroplasty for Charcot Arthropathy

    PubMed Central

    Tsuge, Shintaro; Aoki, Yasuchika; Sonobe, Masato; Shibata, Yoshifumi; Sasaki, Yu; Nakagawa, Koichi

    2013-01-01

    Although the Charcot arthropathy may be associated with serious complications, total knee arthroplasty (TKA) is the preferred choice of treatment by patients. This case report presents an 80-year-old man with intra-articular giant heterotopic ossification following loosening of femoral and tibial implants and femoral condylar fracture. He had undergone TKA because of Charcot neuropathy seven years ago and had been doing well since. Immediately after a left knee sprain, he became unable to walk. Because he had developed a skin ulcer on his left calf where methicillin-resistant Staphylococcus aureus was detected, we postponed revision surgery until the ulcer was completely healed. While waiting, intra-articular bony fragments grew larger and formed giant heterotopic ossified masses. Eventually, the patient underwent revision surgery, and two major ossified masses were carefully and successfully extirpated. It should be noted that intra-articular heterotopic giant ossification is a significant complication after TKA for neuropathic arthropathy. PMID:24151574

  8. Mapping the Articular Contact Area of the Long Head of the Biceps Tendon on the Humeral Head

    PubMed Central

    Morris, Brent J.; Byram, Ian R.; Lathrop, Ray A.; Dunn, Warren R.; Kuhn, John E.

    2014-01-01

    The purpose of this investigation was to calculate the contact surface area of the long head of the biceps (LHB) in neutral position and abduction. We sought to determine whether the LHB articulates with the humeral head in a consistent pattern comparing articular contact area in neutral position and abduction. Eleven fresh frozen matched cadaveric shoulders were analyzed. The path of the biceps tendon on the articular surface of the humeral head and the total articular surface were digitized using a MicronTracker 2 H3-60 three-dimensional optical tracker. Contact surface area was significantly less in abduction than in neutral position (P = 0.002) with a median ratio of 41% (36%, 47.5%). Ratios of contact area in neutral position to full articular surface area were consistent between left and right shoulders (rho = 1, P = 0.017) as were ratios of abduction area to full articular surface area (rho = 0.97, P = 0.005). The articular contact surface area is significantly greater in neutral position than abduction. The ratios of articular contact surface areas to total humeral articular surface areas have a narrow range and are consistent between left and right shoulders of the same cadaver. PMID:25210631

  9. Intra-articular hyaluronate, tenoxicam and vitamin E in a rat model of osteoarthritis: evaluation and comparison of chondroprotective efficacy

    PubMed Central

    Ozkan, Feyza Unlu; Uzer, Gokcer; Türkmen, Ismail; Yildiz, Yavuz; Senol, Serkan; Ozkan, Korhan; Turkmensoy, Fatih; Ramadan, Saime; Aktas, Ilknur

    2015-01-01

    Objective: The aim of this experimental study was to evaluate and compare the chondroprotective efficacy of intra-articular hyaluronic acid, tenoxicam and vitamin E in osteoarthritis. Methods: An osteoarthritis model was created by anterior cruciate ligament transection and medial menisectomy in knees of 28 rats. The rats were randomized into four groups; first group served as a control group and received intra-articular injections of saline solution, intra-articular HA, intra-articular tenoxicam and intra-articular Vit E were applied to the treatment groups. First intra-articular injections were applied at second week postoperatively and repeated once a week for 5 weeks. At 8th week after the operation groups were compared based on the histologic scores of cartilage degeneration by Mankin Histological Grading Scale. Results: Total cartilage degeneration score was significantly increased in the control group (P=0.004). Total Mankin scores of HA, tenoxicam and Vit E groups were significantly lower than the control group (P=0.004, P=0.016, P=0.012 respectively). There was no statistically siginificant difference between the treatment groups in terms of total Mankin scores (P>0.05). Conclusion: Intra-articular application of HA, tenoxicam and Vit E are chondroprotective in early osteoarthritis model in rats. Chondroprotective activity of tenoxicam and Vit E are comparable with the beneficial effects of HA on articular cartilage. PMID:25785088

  10. Comparison of nonlinear mechanical properties of bovine articular cartilage and meniscus.

    PubMed

    Danso, E K; Honkanen, J T J; Saarakkala, S; Korhonen, R K

    2014-01-01

    Nonlinear, linear and failure properties of articular cartilage and meniscus in opposing contact surfaces are poorly known in tension. Relationships between the tensile properties of articular cartilage and meniscus in contact with each other within knee joints are also not known. In the present study, rectangular samples were prepared from the superficial lateral femoral condyle cartilage and lateral meniscus of bovine knee joints. Tensile tests were carried out with a loading rate of 5mm/min until the tissue rupture. Nonlinear properties of the toe region, linear properties in larger strains, and failure properties of both tissues were analysed. The strain-dependent tensile modulus of the toe region, Young's modulus of the linear region, ultimate tensile stress and toughness were on average 98.2, 8.3, 4.0 and 1.9 times greater (p<0.05) for meniscus than for articular cartilage. In contrast, the toe region strain, yield strain and failure strain were on average 9.4, 3.1 and 2.3 times greater (p<0.05) for cartilage than for meniscus. There was a significant negative correlation between the strain-dependent tensile moduli of meniscus and articular cartilage samples within the same joints (r=-0.690, p=0.014). In conclusion, the meniscus possesses higher nonlinear and linear elastic stiffness and energy absorption capability before rupture than contacting articular cartilage, while cartilage has longer nonlinear region and can withstand greater strains before failure. These findings point out different load carrying demands that both articular cartilage and meniscus have to fulfil during normal physiological loading activities of knee joints. PMID:24182695

  11. Extraction of mechanical properties of articular cartilage from osmotic swelling behavior monitored using high frequency ultrasound.

    PubMed

    Wang, Q; Zheng, Y P; Niu, H J; Mak, A F T

    2007-06-01

    Articular cartilage is a biological weight-bearing tissue covering the bony ends of articulating joints. Negatively charged proteoglycan (PG) in articular cartilage is one of the main factors that govern its compressive mechanical behavior and swelling phenomenon. PG is nonuniformly distributed throughout the depth direction, and its amount or distribution may change in the degenerated articular cartilage such as osteoarthritis. In this paper, we used a 50 MHz ultrasound system to study the depth-dependent strain of articular cartilage under the osmotic loading induced by the decrease of the bathing saline concentration. The swelling-induced strains under the osmotic loading were used to determine the layered material properties of articular cartilage based on a triphasic model of the free-swelling. Fourteen cylindrical cartilage-bone samples prepared from fresh normal bovine patellae were tested in situ in this study. A layered triphasic model was proposed to describe the depth distribution of the swelling strain for the cartilage and to determine its aggregate modulus H(a) at two different layers, within which H(a) was assumed to be linearly dependent on the depth. The results showed that H(a) was 3.0+/-3.2, 7.0+/-7.4, 24.5+/-11.1 MPa at the cartilage surface, layer interface, and deep region, respectively. They are significantly different (p<0.01). The layer interface located at 70%+/-20% of the overall thickness from the uncalcified-calcified cartilage interface. Parametric analysis demonstrated that the depth-dependent distribution of the water fraction had a significant effect on the modeling results but not the fixed charge density. This study showed that high-frequency ultrasound measurement together with triphasic modeling is practical for quantifying the layered mechanical properties of articular cartilage nondestructively and has the potential for providing useful information for the detection of the early signs of osteoarthritis. PMID:17536909

  12. Alterations in periarticular bone and cross talk between subchondral bone and articular cartilage in osteoarthritis.

    PubMed

    Goldring, Steven R

    2012-08-01

    The articular cartilage and the subchondral bone form a biocomposite that is uniquely adapted to the transfer of loads across the diarthrodial joint. During the evolution of the osteoarthritic process biomechanical and biological processes result in alterations in the composition, structure and functional properties of these tissues. Given the intimate contact between the cartilage and bone, alterations of either tissue will modulate the properties and function of the other joint component. The changes in periarticular bone tend to occur very early in the development of OA. Although chondrocytes also have the capacity to modulate their functional state in response to loading, the capacity of these cells to repair and modify their surrounding extracellular matrix is relatively limited in comparison to the adjacent subchondral bone. This differential adaptive capacity likely underlies the more rapid appearance of detectable skeletal changes in OA in comparison to the articular cartilage. The OA changes in periarticular bone include increases in subchondral cortical bone thickness, gradual decreases in subchondral trabeular bone mass, formation of marginal joint osteophytes, development of bone cysts and advancement of the zone of calcified cartilage between the articular cartilage and subchondral bone. The expansion of the zone of calcified cartilage contributes to overall thinning of the articular cartilage. The mechanisms involved in this process include the release of soluble mediators from chondrocytes in the deep zones of the articular cartilage and/or the influences of microcracks that have initiated focal remodeling in the calcified cartilage and subchondral bone in an attempt to repair the microdamage. There is the need for further studies to define the pathophysiological mechanisms involved in the interaction between subchondral bone and articular cartilage and for applying this information to the development of therapeutic interventions to improve the

  13. Morphological, genetic and phenotypic comparison between human articular chondrocytes and cultured chondrocytes.

    PubMed

    Mata-Miranda, Mónica Maribel; Martinez-Martinez, Claudia María; Noriega-Gonzalez, Jesús Emmanuel; Paredes-Gonzalez, Luis Enrique; Vázquez-Zapién, Gustavo Jesús

    2016-08-01

    Articular cartilage is an avascular and aneural tissue with limited capacity for regeneration. On large articular lesions, it is recommended to use regenerative medicine strategies, like autologous chondrocyte implantation. There is a concern about morphological changes that chondrocytes suffer once they have been isolated and cultured. Due to the fact that there is little evidence that compares articular cartilage chondrocytes with cultured chondrocytes, in this research we proposed to obtain chondrocytes from human articular cartilage, compare them with themselves once they have been cultured and characterize them through genetic, phenotypic and morphological analysis. Knee articular cartilage samples of 10 mm were obtained, and each sample was divided into two fragments; a portion was used to determine gene expression, and from the other portion, chondrocytes were obtained by enzymatic disaggregation, in order to be cultured and expanded in vitro. Subsequently, morphological, genetic and phenotypic characteristics were compared between in situ (articular cartilage) and cultured chondrocytes. Obtained cultured chondrocytes were rounded in shape, possessing a large nucleus with condensed chromatin and a clear cytoplasm; histological appearance was quite similar to typical chondrocyte. The expression levels of COL2A1 and COL10A1 genes were higher in cultured chondrocytes than in situ chondrocytes; moreover, the expression of COL1A1 was almost undetectable on cultured chondrocytes; likewise, COL2 and SOX9 proteins were detected by immunofluorescence. We concluded that chondrocytes derived from adult human cartilage cultured for 21 days do not tend to dedifferentiate, maintaining their capacity to produce matrix and also retaining their synthesis capacity and morphology. PMID:27094849

  14. BMP Receptor Signaling Is Required for Postnatal Maintenance of Articular Cartilage

    PubMed Central

    2004-01-01

    Articular cartilage plays an essential role in health and mobility, but is frequently damaged or lost in millions of people that develop arthritis. The molecular mechanisms that create and maintain this thin layer of cartilage that covers the surface of bones in joint regions are poorly understood, in part because tools to manipulate gene expression specifically in this tissue have not been available. Here we use regulatory information from the mouse Gdf5 gene (a bone morphogenetic protein [BMP] family member) to develop new mouse lines that can be used to either activate or inactivate genes specifically in developing joints. Expression of Cre recombinase from Gdf5 bacterial artificial chromosome clones leads to specific activation or inactivation of floxed target genes in developing joints, including early joint interzones, adult articular cartilage, and the joint capsule. We have used this system to test the role of BMP receptor signaling in joint development. Mice with null mutations in Bmpr1a are known to die early in embryogenesis with multiple defects. However, combining a floxed Bmpr1a allele with the Gdf5-Cre driver bypasses this embryonic lethality, and leads to birth and postnatal development of mice missing the Bmpr1a gene in articular regions. Most joints in the body form normally in the absence of Bmpr1a receptor function. However, articular cartilage within the joints gradually wears away in receptor-deficient mice after birth in a process resembling human osteoarthritis. Gdf5-Cre mice provide a general system that can be used to test the role of genes in articular regions. BMP receptor signaling is required not only for early development and creation of multiple tissues, but also for ongoing maintenance of articular cartilage after birth. Genetic variation in the strength of BMP receptor signaling may be an important risk factor in human osteoarthritis, and treatments that mimic or augment BMP receptor signaling should be investigated as a possible

  15. The protective effect of meniscus allograft transplantation on articular cartilage: a systematic review of animal studies.

    PubMed

    Rongen, J J; Hannink, G; van Tienen, T G; van Luijk, J; Hooijmans, C R

    2015-08-01

    Despite widespread reporting on clinical results, the effect of meniscus allograft transplantation on the development of osteoarthritis is still unclear. The aim of this study was to systematically review all studies on the effect of meniscus allograft transplantation on articular cartilage in animals. Pubmed and Embase were searched for original articles concerning the effect of meniscus allograft transplantation on articular cartilage compared with both its positive (meniscectomy) and negative (either sham or non-operated) control in healthy animals. Outcome measures related to assessment of damage to articular cartilage were divided in five principal outcome categories. Standardized mean differences (SMD) were calculated and pooled to obtain an overall SMD and 95% confidence interval. 17 articles were identified, representing 14 original animal cohorts with an average timing of data collection of 24 weeks [range 4 weeks; 30 months]. Compared to a negative control, meniscus allograft transplantation caused gross macroscopic (1.45 [0.95; 1.95]), histological (3.43 [2.25; 4.61]) damage to articular cartilage, and osteoarthritic changes on radiographs (3.12 [1.42; 4.82]). Moreover, results on histomorphometrics and cartilage biomechanics are supportive of this detrimental effect on cartilage. On the other hand, meniscus allograft transplantation caused significantly less gross macroscopic (-1.19 [-1.84; -0.54]) and histological (-1.70 [-2.67; -0.74]) damage to articular cartilage when compared to meniscectomy. However, there was no difference in osteoarthritic changes on plain radiographs (0.04 [-0.48; 0.57]), and results on histomorphometrics and biomechanics did neither show a difference in effect between meniscus allograft transplantation and meniscectomy. In conclusion, although meniscus allograft transplantation does not protect articular cartilage from damage, it reduces the extent of it when compared with meniscectomy. PMID:25960117

  16. The intra-articular distance within the TMJ during free and loaded closing movements.

    PubMed

    Huddleston Slater, J J; Visscher, C M; Lobbezoo, F; Naeije, M

    1999-12-01

    Previous studies on free opening and closing movements of the mandible have demonstrated that the opening movement traces of the condylar kinematic center (i.e., the condylar point for which the protrusive and the opening movement traces coincide) lie closer to the articular eminence than the closing traces. This indicates the presence of an intra-articular distance within the joint during free closing. Since the mandible behaves like a class III biomechanical lever, a counteracting mechanical load on the mandible during closing will press the condyle-disc complex against the articular eminence. Therefore, in this study the hypothesis was tested that the difference between opening and closing movement traces of the kinematic center is reduced when the closing movements are counteracted by a mechanical load. From 10 healthy participants, 20-second movement recordings were obtained by a six-degrees-of-freedom opto-electronic jaw movement recording system (OKAS-3D) for three types of movements: (1) free opening and closing movements, (2) free opening and loaded closing movements (i.e., the participants closed against a small or high manually applied downward-directed force to the chin), and (3) gum chewing. Off-line, the opening and closing movement traces of the kinematic center were reconstructed, and the average difference between the traces (the intra-articular distance) was calculated. The average intraarticular distance was significantly smaller during loaded closing than during free closing, whereas no significant differences were found in the intra-articular distances between the loaded situations of low and high manual loading and contralateral chewing (ANOVA and post hoc Bonferroni multiple comparisons of means test, p<0.005). In conclusion, loading of the mandible during closing movements reduces the intra-articular distance within the temporomandibular joint. PMID:10598911

  17. Biological Effects of the Plant-derived Polyphenol Resveratrol in Human Articular Cartilage and Chondrosarcoma Cells

    PubMed Central

    Im, Hee-Jeong; Li, Xin; Chen, Di; Yan, Dongyao; Kim, Jaesung; Ellman, Michael B; Stein, Gary S.; Cole, Brian; Ranjan, KC; Cs-Szabo, Gabriella; van Wijnen, Andre J

    2012-01-01

    The natural phytoestrogen resveratrol (RSV) may have therapeutic potential for arthritic conditions. RSV is chondroprotective for articular cartilage in rabbit models for arthritis, but its biological effects on human articular cartilage and chondrosarcoma cells are unknown. Effects of RSV on human articular cartilage homeostasis were studied by assessing production of matrix-degrading enzymes (MMP-13, ADAMTS-4, and ADAMTS-5), as well as proteoglycan production and synthesis. The counteractions of RSV against catabolic factors (e.g., FGF-2 or IL-1β) were examined by in vitro and ex vivo using monolayer, three-dimensional alginate beads and cartilage explants cultures, respectively. RSV improves cell viability of articular chondrocytes and effectively antagonizes cartilage-degrading protease production that was initiated by catabolic and/or anti-anabolic cytokines in human articular chondrocytes. RSV significantly also enhances BMP7-promoted proteoglycan synthesis as assessed by 35S-sulfate incorporation. Protein-DNA interaction arrays suggest that RSV inhibits the activation of transcription factors involved in inflammation and cartilage catabolic signaling pathways, including direct downstream regulators of MAPK (e.g., AP-1, PEA3) and NFκB. RSV selectively compromises survival of human chondrosarcoma cells, but not primary articular chondrocytes, revealing cell-specific activity of RSV on non-tumorigenic versus tumor-derived cells. We propose that RSV exerts its chondroprotective functions, in part, by deactivating p53-induced apoptosis in human primary chondrocytes, but not human chondrosarcoma. Our findings suggest that RSV has potential as a unique biologic treatment for both prevention and treatment of cartilage degenerative diseases. PMID:22252971

  18. Single cell sorting identifies progenitor cell population from full thickness bovine articular cartilage

    PubMed Central

    Yu, Yin; Zheng, Hongjun; Buckwalter, Joseph A.; Martin, James A.

    2014-01-01

    Objective To date, no approved clinical intervention successfully prevents the progressive degradation of injured articular cartilage that leads to osteoarthritis (OA). Stem/progenitor cell populations within tissues of diarthrodial joint have shown their therapeutic potential in treating OA. However, this potential has not been fully realized due in part to the heterogeneity of these subpopulations. Characterization of clonal populations derived from a single cell may help identify more homogenous stem/progenitor populations within articular cartilage. Moreover, chondrogenic potential of clonal populations from different zones could be further examined to elucidate their differential roles in maintaining articular cartilage homeostasis. Method We combined FACS (Fluorescence-activated cell sorting) and clonogenicity screening to identify stem/progenitor cells cloned from single cells. High-efficiency colony-forming cells (HCCs) were isolated, and evaluated for stem/progenitor cell characteristics. HCCs were also isolated from different zones of articular cartilage. Their function was compared by lineage-specific gene expression, and differentiation potential. Results A difference in colony-forming efficiency was observed in terms of colony sizes. HCCs were highly clonogenic and multipotent, and overexpressed stem/progenitor cell markers. Also, proliferation and migration associated genes were over-expressed in HCCs. HCCs showed zonal differences with deep HCCs more chondrogenic and osteogenic than superficial HCCs. Conclusion Our approach is a simple yet practical way to identify homogeneous stem/progenitor cell populations with clonal origin. The discovery of progenitor cells demonstrates the intrinsic self-repairing potential of articular cartilage. Differences in differentiation potential may represent the distinct roles of superficial and deep zone stem/progenitor cells in the maintenance of articular cartilage homeostasis. PMID:25038490

  19. Minced articular cartilage--basic science, surgical technique, and clinical application.

    PubMed

    McCormick, Frank; Yanke, Adam; Provencher, Matthew T; Cole, Brian J

    2008-12-01

    Minced articular cartilage procedures are attractive surgical approaches for repairing articular cartilage, as they are 1-staged, autologous, and inserted on a carrier that can potentially be placed arthroscopically. The principle of mincing the autologous donor cartilage is to create a larger surface area for cartilage expansion. Placement on a scaffold carrier allows for a chondro-inductive and chondro-conductive milieu. Early animal and preclinical models have demonstrated hyaline-like tissue repair. Further work needs to be conducted in this promising approach. PMID:19011553

  20. Extra-Articular Diffuse Giant Cell Tumor of the Tendon Sheath: A Report of 2 Cases

    PubMed Central

    Savvidou, Olga D.; Mavrogenis, Andreas F.; Sakellariou, Vasilios I.; Chloros, George D.; Sarlikiotis, Thomas; Papagelopoulos, Panayiotis J.

    2016-01-01

    Two rare cases of extra-articular diffuse variant giant cell tumor of the tendon sheath are presented, at the elbow of a 68-year-old female and the foot of a 56-year-old male. Both patients presented with a palpable masses and marginal excision was performed; histological sections confirmed the diagnosis of extra-articular giant cell tumor. No adjuvant therapy was administered. At the latest follow-up, minimum 24 months after excision both patients were disease-free. PMID:27517076

  1. Effects of salicylates and other nonsteroidal anti-inflammatory drugs on articular cartilage.

    PubMed

    Brandt, K D; Palmoski, M J

    1984-07-13

    According to in vivo experimental data, salicylates and several other nonsteroidal anti-inflammatory agents suppress proteoglycan biosynthesis in normal and degenerating articular cartilage. Therapeutic levels of aspirin in vivo had a similar adverse effect on degenerating cartilage, as noted in two canine models of osteoarthritis and cartilage atrophy. Because the effective daily antirheumatic dose of nonsteroidal anti-inflammatory drugs is lower than that of salicylates, these drugs may have less negative effects on degenerating articular cartilage. However, clinical significance cannot be extrapolated from these experimental data. PMID:6465163

  2. Arthroscopic Excision of Intra-Articular Hip Osteoid Osteoma: A Report of 2 Cases

    PubMed Central

    Nehme, Alexandre H.; Bou Ghannam, Alaa G.; Imad, Joseph P.; Jabbour, Fouad C.; Moucharafieh, Ramzi; Wehbe, Joseph

    2012-01-01

    Intra-articular osteoid osteoma is uncommon accounting for approximately 12% of all osteoid osteomas. It presents diagnostic and therapeutic challenges since several traumatic or degenerative pathologies of the joint can be simulated with delay in the diagnosis. We report the clinical, radiographic, and histopathological findings in 2 cases of intra-articular osteoid osteoma of the femoral neck and of the acetabulum. Technical aspects of arthroscopic excision and results of surgery are discussed. Arthroscopy allowed complete excision of the osteoid osteomas, with a short postoperative rehabilitation and excellent functional results. PMID:23304593

  3. Actions of Two Bi-Articular Muscles of the Lower Extremity: A Review

    PubMed Central

    Landin, Dennis; Thompson, Melissa; Reid, Meghan

    2016-01-01

    The extremities of the human body contain several bi-articular muscles. The actions produced by muscles at the joints they cross are greatly influenced by joint moment arms and muscle length. These factors are dynamic and subject to change as joint angles are altered. Therefore, to more completely understand the actions of such muscles, the angles of both joints must be manipulated. This report reviews investigations, which have explored the actions of two bi-articular muscles of the lower extremities (gastrocnemius and rectus femoris) as the joints they cross are moved into various combinations of angles. The findings have both clinical and physical performance ramifications. PMID:27298656

  4. Actions of Two Bi-Articular Muscles of the Lower Extremity: A Review.

    PubMed

    Landin, Dennis; Thompson, Melissa; Reid, Meghan

    2016-07-01

    The extremities of the human body contain several bi-articular muscles. The actions produced by muscles at the joints they cross are greatly influenced by joint moment arms and muscle length. These factors are dynamic and subject to change as joint angles are altered. Therefore, to more completely understand the actions of such muscles, the angles of both joints must be manipulated. This report reviews investigations, which have explored the actions of two bi-articular muscles of the lower extremities (gastrocnemius and rectus femoris) as the joints they cross are moved into various combinations of angles. The findings have both clinical and physical performance ramifications. PMID:27298656

  5. Degenerative lesions in the articular cartilage after meniscectomy: preliminary experimental study in dogs.

    PubMed

    Berjon, J J; Munuera, L; Calvo, M

    1991-03-01

    Articular cartilage degeneration was studied in an experimental model including 68 knees of adult dogs on which five different types of medial meniscectomy had been performed with a followup period of 10 to 450 days. The results were assessed by macroscopic, radiologic, and histologic methods. The degenerative lesions increased proportionally to the amount of meniscal tissue resected and the duration of observation. These lesions proved to be more intense at the tibial plateau compared to the femoral condyle. For both joint surfaces the predominant location was the central zone. Considering the degenerative process by the articular cartilage after total meniscectomy, maximum preservation of meniscal tissue is recommended. PMID:2002520

  6. Time-dependent processes in stem cell-based tissue engineering of articular cartilage

    PubMed Central

    Gadjanski, Ivana; Spiller, Kara; Vunjak-Novakovic, Gordana

    2012-01-01

    Articular cartilage (AC), situated in diarthrodial joints at the end of the long bones, is composed of a single cell type (chondrocytes) embedded in dense extracellular matrix comprised of collagens and proteoglycans. AC is avascular and alymphatic and is not innervated. At first glance, such a seemingly simple tissue appears to be an easy target for the rapidly developing field of tissue engineering. However, cartilage engineering has proven to be very challenging. We focus on time-dependent processes associated with the development of native cartilage starting from stem cells, and the modalities for utilizing these processes for tissue engineering of articular cartilage. PMID:22016073

  7. [PDS cord fixation of sternoclavicular dislocation and para-articular clavicular fractures].

    PubMed

    Friedl, W; Fritz, T

    1994-05-01

    Sternoclavicular joint dislocation and para-articular fractures of the clavicle are rare injuries. Because severe complications of dorsal dislocations have often been seen and because functional impairment has often followed ventral dislocations, we treat most patients with such injuries operatively. Internal fixation with K-wires frequently leads to severe complications. We present our operation techniques with a resorbable 2 mm polydioxanon cord. This pack up technique can be used in both dislocations and para-articular fractures with no risk of implant dislocation. PMID:8052863

  8. Extra-Articular Diffuse Giant Cell Tumor of the Tendon Sheath: A Report of 2 Cases.

    PubMed

    Savvidou, Olga D; Mavrogenis, Andreas F; Sakellariou, Vasilios I; Chloros, George D; Sarlikiotis, Thomas; Papagelopoulos, Panayiotis J

    2016-06-01

    Two rare cases of extra-articular diffuse variant giant cell tumor of the tendon sheath are presented, at the elbow of a 68-year-old female and the foot of a 56-year-old male. Both patients presented with a palpable masses and marginal excision was performed; histological sections confirmed the diagnosis of extra-articular giant cell tumor. No adjuvant therapy was administered. At the latest follow-up, minimum 24 months after excision both patients were disease-free. PMID:27517076

  9. Quantitative three-dimensional shape analysis of the proximal hallucial metatarsal articular surface in Homo, Pan, Gorilla, and Hylobates.

    PubMed

    Proctor, Daniel J; Broadfield, Douglas; Proctor, Kristopher

    2008-02-01

    Multidimensional morphometrics is used to compare the proximal articular surface of the first metatarsal between Homo, Pan, Gorilla, Hylobates, and the hominin fossils A.L. 333-54 (A. afarensis), SKX 5017 (P. robustus), and OH 8 (H. habilis). Statistically significant differences in articular surface morphology exist between H. sapiens and the apes, and between ape groups. Ape groups are characterized by greater surface depth, an obliquely curved articular surface through the dorso-lateral and medio-plantar regions, and a wider medio-lateral surface relative to the dorso-plantar height. The OH 8 articular surface is indistinguishable from H. sapiens, while A.L. 333-54 and SKX 5017 more closely resemble the apes. P. robustus and A. afarensis exhibit ape-like oblique curvature of the articular surface. PMID:18046775

  10. The young adult hip: extra-articular causes of hip pain and how to pick the winners

    PubMed Central

    Bray, Edward D. R.; Sherafati, Milad; Cutts, Charlotte L.

    2015-01-01

    Hip pain in young adults is not always caused by intra-articular pathology, even in the presence of abnormal examination and imaging findings. Therefore, management of young adult hip pain requires processes that identify patients who are likely to benefit from surgical intervention. An important investigation in the diagnostic pathway is the intra-articular injection; a negative response to this should alert the surgeon to the presence of symptomatic extra-articular causes of hip pain. Our aim was to identify the proportion of patients referred with intra-articular pathology whose primary cause of pain was of extra-articular origin. A total of 143 intra-articular hip injections (local anaesthetic + corticosteroid) were performed over a 2-year period. Mean patient age was 41.95 (95% confidence interval: 39.50–44.41) years with a mean body mass index of 27 (95% confidence interval: 25.77–28.23); 26% of patients (n = 37) had no relief of symptoms after intra-articular injection. Of the patients with no relief, 81.1% (n = 30) were found to have extra-articular pathology as the cause of their pain and the remainder are under on-going investigation. Intra-articular hip injection is an important investigation in the diagnostic pathway of young adult hip pain, as it can highlight and differentiate those patients with referred pain from extra-articular pathology. This benefit may be further enhanced if injections are performed in theatres using image intensifier, under sedation, as it allows direct penetration into the joint without any local anaesthetic infiltration of surrounding tissue. The latter allows immediate objective assessment of symptom relief, eliminating the need to rely on retrospective patient recall of symptom change. PMID:27011814

  11. Intra-articular injection of a nutritive mixture solution protects articular cartilage from osteoarthritic progression induced by anterior cruciate ligament transection in mature rabbits: a randomized controlled trial

    PubMed Central

    Park, Yoo-Sin; Lim, Si-Woong; Lee, Il-Hoon; Lee, Tae-Jin; Kim, Jong-Sung; Han, Jin Soo

    2007-01-01

    Osteoarthritis (OA) is a degenerative disease that disrupts the collagenous matrix of articular cartilage and is difficult to cure because articular cartilage is a nonvascular tissue. Treatment of OA has targeted macromolecular substitutes for cartilage components, such as hyaluronic acid or genetically engineered materials. However, the goal of the present study was to examine whether intra-articular injection of the elementary nutrients restores the matrix of arthritic knee joints in mature animals. A nutritive mixture solution (NMS) was composed of elementary nutrients such as glucose or dextrose, amino acids and ascorbic acid. It was administered five times (at weeks 6, 8, 10, 13 and 16) into the unilateral anterior cruciate ligament transected knee joints of mature New Zealand White rabbits, and the effect of NMS injection was compared with that of normal saline. OA progression was histopathologically evaluated by haematoxylin and eosin staining, by the Mankin grading method and by scanning electron microscopy at week 19. NMS injection decreased progressive erosion of articular cartilage overall compared with injection of normal saline (P < 0.01), and nms joints exhibited no differences relative to normal cartilage that had not undergone transection of the anterior cruciate ligament, as assessed using the mankin grading method. Haematoxylin and eosin staining and scanning electron microscopy findings also indicated that nms injection, in constrast to normal saline injection, restored the cartilage matrix, which is known to be composed of a collagen and proteoglycan network. thus, nms injection is a potent treatment that significantly retards oa progression, which in turn prevents progressive destruction of joints and functional loss in mature animals. PMID:17257416

  12. Intra-articular Findings in Primary and Revision Anterior Cruciate Ligament Reconstruction Surgery

    PubMed Central

    Borchers, James R.; Kaeding, Christopher C.; Pedroza, Angela D.; Huston, Laura J.; Spindler, Kurt P.; Wright, Rick W.

    2013-01-01

    Background At the time of anterior cruciate ligament (ACL) reconstruction, there are usually concurrent meniscal and articular cartilage injuries. It is unclear if there is a significant difference between intra-articular injuries at the time of a primary ACL reconstruction compared with revision ACL reconstruction. Purpose To compare the meniscal and articular cartilage injuries found at the time of primary and revision ACL reconstruction surgery and to determine associations between primary and revision surgery and specific intra-articular findings. Study Design Cohort study (prevalence); Level of evidence, 2. Methods Primary and revision ACL surgeries were identified from the Multicenter Orthopedic Outcomes Network (MOON) and Multicenter ACL Revision Study (MARS) study groups, respectively, from January 1, 2007 to November 1, 2008. Demographic data on individual patients were analyzed including age, body mass index (BMI), and gender. Intra-articular findings including the presence of medial or lateral meniscal tears and chondral damage to articular surfaces were analyzed for each patient. Comparisons of intra-articular findings at the time of surgery for the 2 groups were analyzed. Chondral damage in the medial and lateral compartments was analyzed considering previous meniscal tear as a possible confounder. Results There were 508 patients undergoing primary ACL reconstruction and 281 patients undergoing revision ACL reconstruction who were identified for inclusion. There were no differences in the mean age, BMI, and gender in the 2 study groups. There was a decreased odds ratio (OR) of new untreated lateral meniscal tears (OR, 0.54; P <.01) but not of medial meniscal tears (OR, 0.86; P = .39) in revision compared with primary ACL reconstruction. There was an increased OR of Outerbridge grade 3 and 4 articular cartilage injury in revision compared with primary ACL reconstruction in the lateral compartment (OR, 1.73; P = .04) and in the patellar

  13. Intra-articular corticosteroids are effective in osteoarthritis but there are no clinical predictors of response.

    PubMed Central

    Jones, A; Doherty, M

    1996-01-01

    OBJECTIVES: To show whether intra-articular steroid injections are effective in osteoarthritis; to determine factors that predict response; and to determine whether injection has a beneficial effect on muscle strength. METHODS: Double blind, placebo controlled, crossover study in 59 patients with symptomatic osteoarthritis of the knee. Outcome measure-Primary outcome measure: change in visual analogue score for pain at three weeks. Predictors of response analysed using logistic regression with a 15% decrease in pain score at three weeks defining response. RESULTS: Intra-articular methyl prednisolone acetate produced a significant reduction in visual analogue pain score at three weeks compared to both baseline (median change -2.0 mm, interquartile range -16.25 to 4.0) and placebo (median 0.0 mm, interquartile range -9.0 to 6.25). No clinical predictors of response could be identified. Muscle strength was not significantly improved in the short term by intra-articular injection. CONCLUSIONS: Intra-articular corticosteroids are effective for short term relief of pain in osteoarthritis but predicting responders is not possible. There may be a place for their more widespread use. PMID:8976640

  14. Surgical Treatment of Articular Cartilage Defects in the Knee: Are We Winning?

    PubMed Central

    Memon, A. R.; Quinlan, J. F.

    2012-01-01

    Articular cartilage (AC) injury is a common disorder. Numerous techniques have been employed to repair or regenerate the cartilage defects with varying degrees of success. Three commonly performed techniques include bone marrow stimulation, cartilage repair, and cartilage regeneration. This paper focuses on current level of evidence paying particular attention to cartilage regeneration techniques. PMID:22655202

  15. Pilon fractures of the wrist. Displaced intra-articular fractures of the distal radius.

    PubMed

    Porter, M L; Tillman, R M

    1992-02-01

    22 patients who sustained high energy wrist injuries are reported. These complex injuries resulted in articular disruption of the distal radius. Associated injuries included scapho-lunate dissociation (18%), central die-punch injuries (14%), ulnar fractures (41%) and diastasis at the distal radioulnar joint (23%). Nine fractures (41%) were open and almost a third of patients had other skeletal injuries. All patients were treated by external fixation and reviewed after a mean follow-up of 2 1/2 years. There were no excellent results and only ten good ones (45%). The mean functional impairment was 32%. The external fixator was effective in maintaining extra-articular alignment, but not in ensuring accurate reduction of the articular surface. Residual incongruity of the joint surface was an adverse prognostic feature. All five patients (22%) with an articular step of more than 2 mm. developed symptomatic arthritis. Failure to restore the joint line did not account for all the unsatisfactory results; persistent scapho-lunate dissociation and problems at the distal radioulnar joint were also important. PMID:1640147

  16. Acute and chronic response of articular cartilage to Ho:YAG laser irradiation

    NASA Astrophysics Data System (ADS)

    Trauner, Kenneth B.; Nishioka, Norman S.; Flotte, Thomas J.; Patel, Dinesh K.

    1992-06-01

    A Ho:YAG laser system operating at a wavelength of 2.1 microns has recently been introduced for use in arthroscopic surgery. The acceptability of this new tool will be determined not only by its ability to resect tissue, but also by its long term effects on articular surfaces. In order to investigate these issues further, we performed two studies to evaluate the acute and chronic effects of the laser on cartilaginous tissue. We evaluated the acute, in vitro effects of 2.1 micron laser irradiation on articular and fibrocartilage. This included the measurement of ablation efficiency, ablation threshold and thermal damage in both meniscus and articular cartilage. To document the chronic effects on articular cartilage in vivo, we next performed a ten week healing study. Eight sheep weighing 30 - 40 kg underwent bilateral arthrotomy procedures. Multiple full thickness and partial thickness defects were created. Animals were sacrificed at 0, 2, 4, and 10 weeks. The healing study demonstrated: (1) no healing of full or partial thickness defects at 10 weeks with hyaline cartilage; (2) fibrocartilaginous granulation tissue filling full thickness defects at two and four weeks, but no longer evident at ten weeks; (3) chondrocyte necrosis extending to greater than 900 microns distal to ablation craters at four weeks with no evidence of repair at later dates; and (4) chondrocyte hyperplasia at the borders of the damage zone at two weeks but no longer evident at later sacrifice dates.

  17. The effects of joint immobilization on articular cartilage of the knee in previously exercised rats

    PubMed Central

    Maldonado, Diogo Correa; da Silva, Marcelo Cavenaghi Pereira; Neto, Semaan El-Razi; Souza, Mônica Rodrigues; Souza, Romeu Rodrigues

    2013-01-01

    Studies have determined the effects of joint immobilization on the articular cartilage of sedentary animals, but we are not aware of any studies reporting the effects of joint immobilization in previously trained animals. The objective of the present study was to determine whether exercise could prevent degeneration of the articular cartilage that accompanies joint immobilization. We used light microscopy to study the thickness, cell density, nuclear size, and collagen density of articular cartilage of the femoral condyle of Wistar rats subjected to aerobic physical activity on an adapted treadmill five times per week. Four groups of Wistar rats were used: a control group (C), an immobilized group (I), an exercised group (E), and an exercised and then immobilized group (EI). The right knee joints from rats in groups I and EI were immobilized at 90 °C of flexion using a plastic cast for 8 weeks. Cartilage thickness decreased significantly in group I (mean, 120.14 ± 15.6 μm, P < 0.05), but not in group EI (mean, 174 ± 2.25), and increased significantly in group E (mean, 289.49 ± 9.15) compared with group C (mean, 239.20 ± 6.25). The same results were obtained for cell density, nuclear size, and collagen density (in all cases, P < 0.05). We concluded that exercise can prevent degenerative changes in femoral articular cartilage caused by immobilization of the knee joint. PMID:23480127

  18. The effectiveness of hyaluronic acid intra-articular injections in managing osteoarthritic knee pain

    PubMed Central

    Anand, A

    2013-01-01

    Introduction Knee osteoarthritis (OA) is a common and progressive joint disease. Treatment options for knee OA vary from simple analgesia in mild cases to knee replacement for advanced disease. Knee pain due to moderate OA can be targeted with intra-articular injections. Steroid injections have been used widely in managing acute flare-ups of the disease. In recent years, viscosupplementation has been used as a therapeutic modality for the management of knee OA. The principle of viscosupplementation is based on the physiological properties of the hyaluronic acid (HA) in the synovial joint. Despite a sound principle and promising in vitro studies, clinical studies have been less conclusive on the effectiveness of HA in managing osteoarthritic knee pain. The aim of this systematic review was to assess the effectiveness of HA intra-articular injections in the management of osteoarthritic knee pain. Methods A systematic review of the literature was performed using MEDLINE®, Embase™ and CINAHL® (Cumulative Index to Nursing and Allied Health Literature). The databases were searched for randomised controlled trials available on the effectiveness of HA intra-articular injections in managing osteoarthritic knee pain. Results The search yielded 188 studies. Of these, 14 met the eligibility criteria and were reviewed in chronological order. Conclusions HA intra-articular injections have a modest effect on early to moderate knee OA. The effect peaks at around 6–8 weeks following administration, with a doubtful effect at 6 months. PMID:24165334

  19. Glucosamine:chondroitin or ginger root extract have little effect on articular cartilage in swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sows are culled at a high rate from breeding herds due to musclo-skeletal problems and lameness. Research in our laboratory has shown that even first-parity sows have significant amounts of osteochondritic lesions of their articular cartilage. Glusoamine chondroitin and ginger root extract have both...

  20. Cartilage damage involving extrusion of mineralisable matrix from the articular calcified cartilage and subchondral bone.

    PubMed

    Boyde, A; Riggs, C M; Bushby, A J; McDermott, B; Pinchbeck, G L; Clegg, P D

    2011-01-01

    Arthropathy of the distal articular surfaces of the third metacarpal (Mc3) and metatarsal (Mt3) bones in the Thoroughbred racehorse (Tb) is a natural model of repetitive overload arthrosis. We describe a novel pathology that affects the articular calcified cartilage (ACC) and subchondral bone (SCB) and which is associated with hyaline articular cartilage degeneration. Parasagittal slices cut from the palmar quadrant of the distal condyles of the left Mc3/Mt3 of 39 trained Tbs euthanized for welfare reasons were imaged by point projection microradiography, and backscattered electron (BSE) scanning electron microscopy (SEM), light microscopy, and confocal scanning light microscopy. Mechanical properties were studied by nanoindentation. Data on the horses' training and racing career were also collected. Highly mineralised projections were observed extending from cracks in the ACC mineralising front into the hyaline articular cartilage (HAC) up to two-thirds the thickness of the HAC, and were associated with focal HAC surface fibrillation directly overlying their site. Nanoindentation identified this extruded matrix to be stiffer than any other mineralised phase in the specimen by a factor of two. The presence of projections was associated with a higher cartilage Mankin histology score (P<0.02) and increased amounts of gross cartilage loss pathologically on the condyle (P<0.02). Presence of projections was not significantly associated with: total number of racing seasons, age of horse, amount of earnings, number of days in training, total distance galloped in career, or presence of wear lines. PMID:21623571

  1. FRICTIONAL RESPONSE OF BOVINE ARTICULAR CARTILAGE UNDER CREEP LOADING FOLLOWING PROTEOGLYCAN DIGESTION WITH CHONDROITINASE ABC

    PubMed Central

    Basalo, Ines M.; Chen, Faye Hui; Hung, Clark T.; Ateshian, Gerard A.

    2010-01-01

    Summary The specific aim of this study was to investigate the effect of chondroitinase ABC treatment on the frictional response of bovine articular cartilage against glass, under creep loading. The hypothesis is that chondroitinase ABC treatment increases the friction coefficient of bovine articular cartilage under creep. Articular cartilage samples (n=12) harvested from two bovine knee joints (1–3 months-old) were divided into a control group (intact specimens) and a treated group (chondroitinase ABC digestion), and tested in unconfined compression with simultaneous continuous sliding (±4 mm at 1 mm/s) under a constant applied stress of 0.5 MPa, for 2,500 s. The time-dependent response of the friction coefficient was measured. With increasing duration of loading, treated samples exhibited a significantly higher friction coefficient than control samples as assessed by the equilibrium value (treated: μeq = 0.19 ± 0.02; control: μeq = 0.12 ± 0.03; p=0.002), though the coefficient achieved immediately upon loading did not increase significantly (treated: μmin = 0.0053 ± 0.0025; control: μmin = 0.037 ± 0.0013; p=0.19). Our results demonstrate that removal of the cartilage glycosaminoglycans using chondroitinase ABC significantly increases the overall time-dependent friction coefficient of articular cartilage. These findings strengthen the motivation for developing chondroprotective strategies by increasing cartilage chondroitin sulfate content in osteoarthritic joints. PMID:16532626

  2. Noncontact evaluation of articular cartilage degeneration using a novel ultrasound water jet indentation system.

    PubMed

    Lu, M-H; Zheng, Y P; Huang, Q-H; Ling, C; Wang, Q; Bridal, L; Qin, L; Mak, A

    2009-01-01

    We previously reported a noncontact ultrasound water jet indentation system for measuring and mapping tissue mechanical properties. The key idea was to utilize a water jet as an indenter as well as the coupling medium for high-frequency ultrasound. In this paper, the system was employed to assess articular cartilage degeneration, using stiffness ratio as an indicator of the mechanical properties of samples. Both the mechanical and acoustical properties of intact and degenerated bovine patellar articular cartilage (n = 8) were obtained in situ. It was found that the stiffness ratio was reduced by 44 +/- 17% after the articular cartilage was treated by 0.25% trypsin at 37 degrees C for 4 h while no significant difference in thickness was observed between the intact and degenerated samples. A significant decrease of 36 +/- 20% in the peak-to-peak amplitude of ultrasound echoes reflected from the cartilage surface was also found for the cartilage samples treated by trypsin. The results also showed that the stiffness obtained with the new method highly correlated with that measured using a standard mechanical testing protocol. A good reproducibility of the measurements was demonstrated. The present results showed that the ultrasound water jet indentation system may provide a potential tool for the non-destructive evaluation of articular cartilage degeneration by simultaneously obtaining mechanical properties, acoustical properties, and thickness data. PMID:19011965

  3. Xanthan gum protects rabbit articular chondrocytes against sodium nitroprusside-induced apoptosis in vitro.

    PubMed

    Chen, Qixin; Mei, Xifan; Han, Guanying; Ling, Peixue; Guo, Bin; Guo, Yuewei; Shao, Huarong; Wang, Guan; Cui, Zan; Bai, Yuxin; Xu, Fang

    2015-10-20

    We have previously reported that intra-articular injection of xanthan gum (XG) could significantly ameliorate the degree of joint cartilage degradation and pain in experimental osteoarthritis (OA) model in vivo. In this present study, we evaluated the protective effect of XG against Sodium nitroprusside (SNP)-induced rabbit articular chondrocytes apoptosis in vitro. Rabbit articular chondrocytes were incubated with various concentrations of XG for 24h prior to 0.5mmol/L SNP co-treatment for 24h. The proliferation of chondrocytes was analyzed using MTT assay. The chondrocytes early apoptosis rates were evaluated using Annexin V-FITC/PI flow cytometry. The morphology of apoptosis chondrocytes were observed by scanning electron microscopy (SEM). The loss/disruption of mitochondrial membrane potential was detected using rhodamin 123 by confocal microscope. The concentration of prostaglandin E2 (PGE2) in cell culture supernatants was evaluated using ELISA assay. The results showed that XG could significantly reverse SNP-reduced cell proliferation and inhibited cell early apoptosis rate in a dose-dependent manner. XG alleviated loss/disruption of mitochondrial membrane potential and decreased the PGE2 level of chondrocytes cell culture supernatants in SNP-induced chondrocytes. These results of the present research strongly suggest that XG can protect rabbit articular chondrocytes against SNP-induced apoptosis in vitro. PMID:26256195

  4. The effects of intra-articular resiniferatoxin on monosodium iodoacetate-induced osteoarthritic pain in rats

    PubMed Central

    Kim, Youngkyung; Kim, Eun-hye; Lee, Kyu Sang; Lee, Koeun; Park, Sung Ho; Na, Sook Hyun; Ko, Cheolwoong; Yooon, Young Wook

    2016-01-01

    This study was performed to investigate whether an intra-articular injection of transient receptor potential vanilloid 1 (TRPV1) receptor agonist, resiniferatoxin (RTX) would alleviate behavioral signs of arthritic pain in a rat model of osteoarthritis (OA). We also sought to determine the effect of RTX treatment on calcitonin gene-related peptide (CGRP) expression in the spinal cord. Knee joint inflammation was induced by intra-articular injection of monosodium iodoacetate (MIA, 8 mg/50 µl) and weight bearing percentage on right and left hindpaws during walking, paw withdrawal threshold to mechanical stimulation, and paw withdrawal latency to heat were measured to evaluate pain behavior. Intra-articular administration of RTX (0.03, 0.003 and 0.0003%) at 2 weeks after the induction of knee joint inflammation significantly improved reduction of weight bearing on the ipsilateral hindlimb and increased paw withdrawal sensitivity to mechanical and heat stimuli. The reduction of pain behavior persisted for 3~10 days according to each behavioral test. The MIA-induced increase in CGRP immunoreactivity in the spinal cord was decreased by RTX treatment in a dose-dependent manner. The present study demonstrated that a single intra-articular administration of RTX reduced pain behaviors for a relatively long time in an experimental model of OA and could normalize OA-associated changes in peptide expression in the spinal cord. PMID:26807032

  5. Optimal 3-D culture of primary articular chondrocytes for use in the Rotating Wall Vessel Bioreactor

    PubMed Central

    Mellor, Liliana F.; Baker, Travis L.; Brown, Raquel J.; Catlin, Lindsey W.; Oxford, Julia Thom

    2014-01-01

    INTRODUCTION Reliable culturing methods for primary articular chondrocytes are essential to study the effects of loading and unloading on joint tissue at the cellular level. Due to the limited proliferation capacity of primary chondrocytes and their tendency to dedifferentiate in conventional culture conditions, long-term culturing conditions of primary chondrocytes can be challenging. The goal of this study was to develop a suspension culturing technique that not only would retain the cellular morphology but also maintain gene expression characteristics of primary articular chondrocytes. METHODS Three-dimensional culturing methods were compared and optimized for primary articular chondrocytes in the rotating wall vessel bioreactor, which changes the mechanical culture conditions to provide a form of suspension culture optimized for low shear and turbulence. We performed gene expression analysis and morphological characterization of cells cultured in alginate beads, Cytopore-2 microcarriers, primary monolayer culture, and passaged monolayer cultures using reverse transcription-PCR and laser scanning confocal microscopy. RESULTS Primary chondrocytes grown on Cytopore-2 microcarriers maintained the phenotypical morphology and gene expression pattern observed in primary bovine articular chondrocytes, and retained these characteristics for up to 9 days. DISCUSSION Our results provide a novel and alternative culturing technique for primary chondrocytes suitable for studies that require suspension such as those using the rotating wall vessel bioreactor. In addition, we provide an alternative culturing technique for primary chondrocytes that can impact future mechanistic studies of osteoarthritis progression, treatments for cartilage damage and repair, and cartilage tissue engineering. PMID:25199120

  6. Articular Cartilage Increases Transition Zone Regeneration in Bone-tendon Junction Healing

    PubMed Central

    Qin, Ling; Lee, Kwong Man; Leung, Kwok Sui

    2008-01-01

    The fibrocartilage transition zone in the direct bone-tendon junction reduces stress concentration and protects the junction from failure. Unfortunately, bone-tendon junctions often heal without fibrocartilage transition zone regeneration. We hypothesized articular cartilage grafts could increase fibrocartilage transition zone regeneration. Using a goat partial patellectomy repair model, autologous articular cartilage was harvested from the excised distal third patella and interposed between the residual proximal two-thirds bone fragment and tendon during repair in 36 knees. We evaluated fibrocartilage transition zone regeneration, bone formation, and mechanical strength after repair at 6, 12, and 24 weeks and compared them with direct repair. Autologous articular cartilage interposition resulted in more fibrocartilage transition zone regeneration (69.10% ± 14.11% [mean ± standard deviation] versus 8.67% ± 7.01% at 24 weeks) than direct repair at all times. There was no difference in the amount of bone formation and mechanical strength achieved. Autologous articular cartilage interposition increases fibrocartilage transition zone regeneration in bone-tendon junction healing, but additional research is required to ascertain the mechanism of stimulation and to establish the clinical applicability. PMID:18987921

  7. Adult human neural crest-derived cells for articular cartilage repair.

    PubMed

    Pelttari, Karoliina; Pippenger, Benjamin; Mumme, Marcus; Feliciano, Sandra; Scotti, Celeste; Mainil-Varlet, Pierre; Procino, Alfredo; von Rechenberg, Brigitte; Schwamborn, Thomas; Jakob, Marcel; Cillo, Clemente; Barbero, Andrea; Martin, Ivan

    2014-08-27

    In embryonic models and stem cell systems, mesenchymal cells derived from the neuroectoderm can be distinguished from mesoderm-derived cells by their Hox-negative profile--a phenotype associated with enhanced capacity of tissue regeneration. We investigated whether developmental origin and Hox negativity correlated with self-renewal and environmental plasticity also in differentiated cells from adults. Using hyaline cartilage as a model, we showed that adult human neuroectoderm-derived nasal chondrocytes (NCs) can be constitutively distinguished from mesoderm-derived articular chondrocytes (ACs) by lack of expression of specific HOX genes, including HOXC4 and HOXD8. In contrast to ACs, serially cloned NCs could be continuously reverted from differentiated to dedifferentiated states, conserving the ability to form cartilage tissue in vitro and in vivo. NCs could also be reprogrammed to stably express Hox genes typical of ACs upon implantation into goat articular cartilage defects, directly contributing to cartilage repair. Our findings identify previously unrecognized regenerative properties of HOX-negative differentiated neuroectoderm cells in adults, implying a role for NCs in the unmet clinical challenge of articular cartilage repair. An ongoing phase 1 clinical trial preliminarily indicated the safety and feasibility of autologous NC-based engineered tissues for the treatment of traumatic articular cartilage lesions. PMID:25163479

  8. Effect of corticosteroids on articular cartilage: have animal studies said everything?

    PubMed

    Vandeweerd, Jean-Michel; Zhao, Yang; Nisolle, Jean-François; Zhang, Wenhui; Zhihong, Liu; Clegg, Peter; Gustin, Pascal

    2015-10-01

    Intra-articular (IA) corticosteroids (CS) have been used in the treatment of osteoarthritis for many years, although their effects on articular cartilage are not fully understood. To identify whether previous animal studies have provided enough evidence about the effects of CS, we undertook a systematic review that identified 35 relevant in vivo animal experimental studies between 1965 and 2014 assessing the effects of CS on either normal cartilage, or in either induced osteoarthritis (OA) or synovitis. The quality of the methodology was assessed. Deleterious effects, both structural and biochemical, have mainly been reported in rabbits and are associated with frequent administration of CS, sometimes at high dose and with systemic side effects. In dogs, four identified studies concluded that there were beneficial effects with methylprednisolone acetate (MPA) and triamcinolone hexacetonide therapy. In horses, MPA was mostly deleterious, while triamcinolone acetonide had positive effects in one study highly rated at quality assessment. However, many methodological weaknesses have been identified, such as the lack of pharmacokinetic and pharmocodynamics data and the large variation in doses between studies, the limited selection criteria at baseline, the absence of blinding, and the lack of statistics or appropriate controls for testing the effects of the vehicle of the drug. Those methodological weaknesses weaken the conclusions of numerous studies that assess beneficial or deleterious effects of CS on articular cartilage. Animal studies have not yet provided definitive data, and further research is required into the role of CS in articular pathobiology. PMID:26211421

  9. Immunohistochemical demonstration of fibronectin in the most superficial layer of normal rabbit articular cartilage.

    PubMed Central

    Nishida, K; Inoue, H; Murakami, T

    1995-01-01

    OBJECTIVE--To locate fibronectin ultrastructurally in the most superficial layer of normal articular cartilage of rabbits, in order to clarify its role in joint physiology. METHODS--Articular cartilage was obtained from the femoral condyle of seven normal adult rabbits and prepared by a method that included tannic acid fixation. Polyclonal antibodies against rabbit fibronectin were used in an immunohistochemical electron microscopic study, without any enzymic digestion but with a pre-embedding method for the transmission electron microscopy. RESULTS--The cartilage surface was successfully preserved by tannic acid fixation. The most superficial layer in electron photomicrographs was approximately 200-300 nm thick, cell free, and appeared to have two parallel components: the more superficial lamina and the deeper lamina. Gold labelled fibronectin lined this layer in immunohistochemical electron photomicrographs. CONCLUSIONS--Fibronectin covering the surface of the articular cartilage may have a role in joint lubrication and protection of the cartilage by binding with the collagenous matrix and hyaluronic acid in synovial fluid. Chondroitin sulphates may act as a charge barrier in close relationship with the collagen fibrils in the deeper lamina. Significant alteration in these functions may be one of the first causal steps leading to destruction of the articular cartilage. Images PMID:8546534

  10. Demonstration of fibronectin in human articular cartilage by an indirect immunoperoxidase technique.

    PubMed

    Clemmensen, I; Hølund, B; Johansen, N; Andersen, R B

    1982-01-01

    Fresh frozen tissue sections of human articular cartilage was treated without and with human testicular hyaluronidase (2 x 10(6) units/l) for 60 min at 37 degrees C and stained by the indirect immunoperoxidase technique with rabbit antihuman fibronectin. The rabbit antihuman fibronectin was purified by affinity chromatography on human fibronectin-Sepharose. Fibronectin was only found on the acellular surface of the articular cartilage in tissue sections not treated with hyaluronidase. In this surface layer, probably identical to "lamina splendens", the arrangement of fibronectin was as a membrane. No collagen was seen in this area by van Gieson staining. No staining for fibronectin was found in the cartilage matrix or in the chondrocytes. Treatment of the cartilage tissue with hyaluronidase resulted in visualization of high amount of fibronectin in the cartilage matrix, with the highest intensity around the chondrocytes. The staining of the acellular surface layer of the articular cartilage was identical with the results obtained without hyaluronidase treatment. These results indicate that articular cartilage is rich in fibronectin probably in complex with hyaluronic acid, and that the chondrocytes produce fibronectin in situ. It also demonstrates the steric hindrance of hyaluronic acid aggregates in diffusion of the antibody and the value of hyaluronidase treatment of tissue before demonstration of fibronectin. PMID:6757202