No description available.

No description available.

L’arthrose est la plus commune des maladies articulaires dans le monde. Elle induit des charges physiques, psychologiques, sociétales et économiques majeures. Selon les Nations Unies, en 2050, 315 millions de personnes souffriront d’arthrose symptomatique et 105 millions d’entre elles seront fortement handicapées par la maladie.Les symptômes cliniques et les techniques d’imagerie constituent les éléments principaux pour le diagnostic et le suivi de l’arthrose aujourd’hui. En dépit de progrès technologiques et des recherches intensives de nouveaux biomarqueurs, aucun outil ne permet de détecter précocement la maladie, de classer les patients selon le pronostic d’évolution de la maladie ou encore de quantifier l'effet des traitements. Ce manque de biomarqueurs sensibles, spécifiques et reproductibles limite les progrès thérapeutiques dans la perspective d’une médecine personnalisée.Dans les articulations synoviales, l’homéostasie est assurée par le maintien de la composition physiologique du liquide synovial, fluide visqueux et lubrifiant. Au cours du processus arthrosique, des changements de composition du liquide synovial interviennent en même temps que la dégradation des tissus articulaires.Dans ce travail, une technique mini-invasive a été mise au point pour caractériser l’état arthrosique du liquide synovial, dans le cadre du suivi de la pathologie et de l’effet de traitements, chez les animaux et les patients. Le dépôt de quelques microlitres de liquide synovial sur une lame en verre forme une goutte circulaire qui, en séchant, concentre dans un anneau périphérique les solutés, dont les caractéristiques tribologiques renseignent sur la présence d’une pathologie articulaire. La spectroscopie Raman fournit des informations précises sur la composition chimique du liquide synovial et permet de suivre les altérations biomoléculaires et structurelles des solutés de l’anneau périphérique de la goutte de liquide synovial séchée. Cette thèse aboutit à la proposition de biomarqueurs synoviaux représentatifs du processus arthrosique articulaire. / Osteoarthritis is the most common joint disorder worldwide. Symptomatic osteoarthritis is a painful and debilitating disease which is associated with a large physical, psychological, societal and economic burden. According to the United Nations, by 2050, 315 million people will suffer from symptomatic osteoarthritis worldwide, of whom 105 million will be severely disabled by the disease.Osteoarthritis has traditionally been diagnosed and followed-up based on clinical symptoms and imaging modalities. However, these techniques and molecular biomarker developments are insensitive and identification of patients at risk to disease progression remains a challenge. They also fail to subgroup the heterogenous osteoarthritis population while this would allow a better scrutiny of diagnosis and treatment options. A surrogate biomarker with prognostic and/or diagnostic capabilities able to identify potential responders is much needed in osteoarthritis care and therapy.In diarthrodial joints, homeostasis is based on physiological composition and function of synovial fluid, a viscous fluid that lubricates joints. During osteoarthritis, synovial fluid biochemical properties are modified simultaneously to other joint tissues damages.In this work, a minimally invasive technique has been developed to characterize synovial fluid osteoarthritic state in order to diagnose, predict and follow-up joint diseases in patients and animals. Deposition of only a few microliters of synovial fluid on fused silica slide forms a circular dried drop with a ring-like deposit of concentrated solutes at the droplet edge. Tribological analysis based on the morphology of the dried drops reflects synovial fluid biomolecular and structural modifications. Raman Spectroscopy provides more specific information on chemical composition and monitors biomolecular structural alterations. This thesis leads to the proposal of synovial biomarkers representative of the joint osteoarthritic process.

Thesis (Ph.D.)--University of Delaware, 2006. / Principal faculty advisor: Katherine Rudolph, Dept. of Physical Therapy. Includes bibliographical references.

Some of the most common diseases and disorders that occur in the adult population are those which affect the joints of the musculo-skeletal system. Most joint diseases cause damage to articular cartilage, the soft tissue that acts as a bearing surface within the load-bearing joints. The function of articular cartilage is to provide a wear-resistant joint surface with a very low coefficient of friction and to reduce the compressive stresses experienced at the end of the long bones. Osteoarthritis can be described as the progressive degeneration of articular cartilage. This disorder causes large areas of cartilage in the load-bearing regions of the joint to become split and fragmented, resulting finally in the exposure of underlying bone. Osteoarthritis has been associated with a number of conditions including the deposition of crystals within the tissue. It has been postulated that crystal deposits have the potential to cause mechanical damage to articular cartilage. Two possible damage mechanisms have been identified; localised tissue damage in the vicinity of the crystal aggregate and surface damage induced by the presence of an aggregate. Articular cartilage is a biphasic material as it consists of a fluid phase, composed mainly of water, and a porous-permeable solid phase. The biphasic nature of the tissue was modelled using the ABAQUS/Standard Finite Element software. Failure criteria for the tissue were investigated using this technique and radial stress and radial strain were found to be reliable predictors of damage. Damage threshold values were determined for radial tensile stress (72 kPa) and radial tensile strain (0.144). A finite element model was then developed to investigate the propensity for crystal deposits to cause damage to a cartilage layer under cyclic loading conditions. It was predicted that aggregates embedded deep within the cartilage layer do not have the potential to cause either local or surface damage. Aggregates nearer the articular surface have the potential to cause localised tissue damage, and it was found that this was dependent upon their stiffness.

Background: Osteoarthritis of the hip joint causes difficulties to the elderly because it impacts their ability to conduct their normal activities of daily living, such as walking, cooking, bathing, dressing, using the toilet, and performing household chores. Moreover, the joints can become painful, stiff, and swollen. The resulting pain causes limited motion, restriction of social activities, and compromised work capacity. The interaction of these factors can affect both functional and physiological status. The normal course of action for these subjects is to be referred to an orthopedic surgeon; however, the functional and physiological impact of waiting times for hip replacement consultation or surgery on subject’s function has not been properly assessed with objective outcome measures. Objectives: The purpose of this study was to investigate the differences in objective outcome measures of functional and physiological status between subjects with hip OA who were preoperative candidates for hip surgery and those who were diagnosed with hip OA at the time of referral and time of consultation. Methods: Subjects with hip osteoarthritis were selected based on their position in the continuum of care once they had been referred to a surgeon. These groups were: referral (REF) (n=7), consultation (CON) (n=7) and pre-operatively (PREOP) (n=7). Individuals with hip OA were evaluated using functional (6MWT and TUG) and physiological (hip muscle isokinetic strength - Biodex and VO2peak) outcome measures. Results: The 6 minutes walk test (6MWT), timed up and go (TUG) and VO2peak were significantly different between the three groups (p < 0.001, p = 0.005 and p = 0.001). However, no significant difference was observed in hip flexion and extension muscle strength between groups. Post Hoc analysis revealed that the REF group walked significantly greater distances (p < 0.001) when compared to the PREOP group during the 6MWT. Both REF and CON groups showed significantly shorter times in the TUG test (p < 0.009 and p < 0.02 respectively) when compared to the PREOP group and finally the VO2peak in the REF group was significantly higher than the predicted VO2peak of the CON (p = 0.002) and the PREOP (p = 0.002) groups, respectively. Conclusion: Subjects with hip osteoarthritis who are within four weeks of surgery generally walked shorter distances, demonstrate worse mobility and balance control and a lower aerobic capacity than individuals with hip OA at the time of referral to a surgeon and at the time of consultation with the surgeon. Contrary to expectation, this study did not find differences in hip muscle strength, between those with hip osteoarthritis at the time of referral; at the time of consultation and within four weeks prior to surgery. / Thesis (Master, Rehabilitation Science) -- Queen's University, 2008-09-25 17:11:10.365

No description available.

Osteoarthritis (OA) is a common musculoskeletal disability and represents a major health burden to society. Pathological changes are found in all tissues of the joint; however studies on bone are few. The aims of this thesis were to characterize some of the densitometric, mechanical and compositional properties of cancellous bone from the Superior (Sup) and Inferior (Inf) regions of human femoral heads, and to compare age-selected healthy bones with those from patients with end-stage OA. From coronal sections of the femoral head, bone cores were drilled out along the anterior-posterior axis and non-adherent fatty tissues removed. Measurements of apparent (PA), true (pj) and volumetric bone mineral density (BMDv) were made prior to determining the ultrasound-derived elastic modulus (Eu) and the compression-derived parameters, compressive modulus (Ec), yield strength (CTY) and yield energy (Wy). From aliquots of powdered bone, calcium and hydroxyproline were determined and a minerahcollagen ratio calculated, and osteocalcin, IGF-I, IGF-II and IGFBP-5 measured by RIA. Another aliquot was processed to remove soft tissue, demineralized in EDTA and the resulting collagen matrix digested with trypsin. From these crude tryptic digests (CTDs), divalently and trivalently (ICTP, IIINTP) crosslinked collagen telopeptides and procollagen propeptides of collagens type I and III were analysed by RIA. PA, BMDv, EC, ay, Wy and EU were systematically increased in cores from the Sup region of both Normal and OA groups (all/KO.05) and reflects differences in loading experienced by this region. In OA bone, PA, BMDv and EU were increased in the Inf region (all/KO.05) possibly as a result of adaptation of the bone to altered loading patterns at the hip. Furthermore, the relationship between EC and PA was different to those in Normals (p=0.019) indicating that other factors, such as architecture, may influence the stiffness of cancellous bone. Of the compositional measures, IGFBP-5 was systematically increased in both regions of OA bone (all /?&lt;0.005) and may be the factor responsible for maintenance of bone mass in OA. The minerahcollagen ratio was decreased in the OA Sup region (p=0.008) indicating undermineralization of bone. In the mineralized matrix of OA bone, concentrations of ICTP:collagencTD and type III collagen antigens were increased in both Sup and Inf regions (all/&gt;&lt;0.05) suggesting an increase in type I collagen trivalent crosslinking at the Qtelopeptide and an overall increase in type III collagen respectively. Of the relationships between the various properties, inverse correlations were found between mineral.'collagen and ICTPrcollagenciD ratios (rs= -0.36,/?&lt;0.05) in the OA group indicating increased trivalent collagen crosslinking when bone is under mineralized. In the Normal group PA correlated inversely with IGFBP-5 (rs=-0.64 and -0.72, bothp&lt;0.05) and OC (rs=-0.59,/7=0.056 and -0.71, p&lt;0.05) at both Sup and Inf regions respectively, but were lost in the OA group suggesting loss of regulation at this level in OA. hi conclusion, the cancellous bone in OA femoral heads is denser, but not stiffer than that of Normal bone, and has an altered composition with respect to both structural (ICTP) and regulatory (IGFBP-5) factors which may affect the quality of the bone matrix.

No description available.

Thesis (M.Med.Sc.)--University of Hong Kong, 2008. / Includes bibliographical references (p. 29-31).