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One of the most important minimally invasive treatments today in temporomandibular joint osteoarthritis (TMJOA) is the intra-articular exogenous hyaluronic acid (HA) injection, which has yielded good results in pain relief and improves mandibular function with few side effects. However, the effectiveness of HA continues to be controversial, partly due to the heterogeneity in the injection protocols in their molecular weight, viscosity and frequency of infiltration, among other properties. The aim of this review is to identify the differences in the histological and clinical effects of the different types of HA and the frequency of infiltration on TMJ-OA treatment. Materials and methods: A bibliographic search was performed in the PubMed, Web of Science and Scopus databases. The search was limited up to September 2022. Search terms included "osteoarthritis", "hyaluronic acid, "molecular weight", "concentration", "viscosity", "dose" and "temporomandibular", using AND/OR as Boolean terms. Results: Exogenous HA in its different molecular weights offers an improvement in histological and clinical characteristics. Apparently, low and medium molecular weight HA presents better results. No clinical studies related to the degree of HA viscosity were found. Respect to the frequency of infiltration, single injection, weekly injections for 3 weeks, weekly injections for 5 weeks and other protocols are used. However, their comparison is complex. There seems to be differences in the effects of the different HA preparations for the treatment of TMJ-OA, mainly in their molecular weight. However, the evidence remains scant. [ABSTRACT FROM AUTHOR]

Osteoarthritis (OA) is a chronic, degenerative, and very disabling disease that gradually and progressively destroys articular cartilage in various regions: knees, hips, shoulders, hands, ankles and spine. In this sense, exercise has been described as the most recommended non-pharmacological intervention for patients with OA. Regular exercise is considered an integral component of the healthy lifestyle. However, its effect on cartilage remains the subject of debate and speculation, as well as the relationship between exercise and the development of OA. Some animal model studies suggest that exercise may be beneficial for cartilage health, while others demonstrate its harmful effect. A general explanation for these inconsistent results is that running at moderate intensity has beneficial effects, while running "vigorously" or "strenuously" leads to a harmful effect. The aim of this work was to make a literature review about the effects of exercise on cartilage, especially focused on experimental animal models with rats. [ABSTRACT FROM AUTHOR]

Injection with monoiode sodium acetate (MIA) is widely used to produce osteoarthritis in various joints. The aim of this work was to describe the histological damage caused by MIA in the rat humeral joint; 0.1 mL of 0.5 mg mixture of MIA dissolved in 10 mL of physiological solution was injected into the left humeral joint of 21 Sprague-Dawley rats. As a control, the right joint of each rat was used. Euthanasia was performed at 4, 8 and 12 weeks post injection in groups of 7 rats. The samples maintained in 10% buffered formalin were descaled with EDTA for three months. For histological evaluation, paraffin inclusion was performed and 5 mm thick coronal cuts were made for subsequent staining with toluidine blue. In the healthy cartilage, a smooth surface was observed, all cells in the cartilage areas were normal. Changes in articular cartilage were observed after 4 weeks post injection, hypertrophic radial chondrocytes with high proteoglycan production. At 12 weeks post injection, a great deterioration was observed, the articular space was diminished. The surface of the cartilage was observed with fissures and cracks that reach the radial zone. The cells around these fissures have disappeared. A prominent loss of proteoglycans was observed due to weak toluidine blue staining. Joint injection with MIA produced lesions similar to OA. The great advantage of the OA induced by MIA, is the ease of its application and the rapidity in the progression of OA. [ABSTRACT FROM AUTHOR]

Knee osteoarthritis (OA) is a common disabling disease. Epidemiological studies have revealed various risk factors for OA, including sex, aging, obesity, occupational illnesses, and chronic diseases. Here we evaluate the clinical, pathological, and radiological findings of knee OA in a subset of Saudi patients who were subjected to total knee replacement (TKA). The study population included 30 Saudi patients with knee OA who were operated by TKA (from June 2014 to December 2015) in the Department of Orthopedics, Faculty of Medicine, King Abdulaziz University, Saudi Arabia. Patient's clinical and radiological data were collected from the hospital files. Pathological examination of the excised superior articular surface of tibia and femoral condyles were done. Pearson Chi-squared analysis was used to test for differences between the variables in associated risk factors. There were more women than men. Sixty per cent of patients were older than 60 years [mean age, 59.2 (females) and 61.7 (men) years-old]. All patients exceeded obesity class 1, with females being more obese than males. Pathological examination of the superior articular surface of tibia and femoral condyles showed high score lesions, which was more apparent in females than in males. Radiological findings showed that most lesions were high grade. The findings of this study will help to understand the pathogenesis of OA and improve treatment decision making relevant to TKA in knee OA in Saudi Arabia and elsewhere. [ABSTRACT FROM AUTHOR]

We recently reported that insulin can partially protect the knee joint against osteoarthritis (OA) development in a rat model of type 1 diabetes mellitus (T1DM). However, the combined protective effect of insulin and swim exercise against OA development secondary to diabetes has not been investigated before. Therefore, we hypothesized that swim exercise can augment the protection of the knee joint in diabetic rats treated with insulin. T1DM was induced in Sprague Dawley rats and treated with insulin and/ or swim exercise. Tissues harvested from the articular cartilage of the knee joint were examined by light microscopy, and blood samples were assayed for biomarkers of oxidative stress and inflammation. Treatment of diabetic rats with insulin and swim exercise substantially protected the articular cartilage and significantly (p<0.0001) inhibited the inflammatory biomarkers, tumor necrosis factor-alpha (TNF-a) and interleukin-6 (IL-6), and the oxidative stress biomarker, malondialdehyde (MDA) measured as thiobarbituric acid reactive substances (TBARS) comparable to control. Whereas, a lesser effective protection was observed by insulin or swim exercise alone. Thus, we demonstrate a substantial protection against OA development in rats treated with combined insulin and swim exercise possibly due to a complete inhibition of biomarkers of inflammation and oxidative stress. [ABSTRACT FROM AUTHOR]

The aim of this study was to conduct a review of the literature on the value of synovial fluid in the temporomandibular joint and its implications in joint pathology. The synovial fluid is a viscous and filamentous fluid of a light yellow color, composed mainly of plasma proteins, cellular components, lubricating molecules, cytokines, growth factors and enzymes. It is produced by the synovial membrane and is in direct relation with the joint surfaces and the synovial membrane, mediating the interactions between the tissues of the synovial joints. In the temporomandibular joint it plays a fundamental role in the maintenance and regulation of physiology, through lubricating, regulating and metabolic functions, decreasing the friction of the joint surfaces during all its movements. In temporomandibular disorders, synovial fluid function can be altered by changes in the tissues of the temporomandibular joint, these changes can result in a decrease in the ability to lubricate the joint surfaces and generate a catabolic environment inside the joint, contributing together to the deterioration of these. [ABSTRACT FROM AUTHOR]

The aim of this study was to perform a literature review regarding the role of hyaluronic acid (HA) in the homeostasis and therapeutics of temporomandibular joint (TMJ) osteoarthritis (OA). The TMJ has characteristics that give it special adaptation and recovery abilities, where HA plays a fundamental role in helping to maintain joint homeostasis, which is affected in pathological processes like OA. OA is a chronic degenerative multi-factor disease that can affect all the components of the synovial joints, causing degradation of the articular cartilage, extracellular matrix and breakage in the HA molecules. HA is a non-branched linear polysaccharide with viscosupplementation, anti-inflammatory, lubrication and pain relief effects; it also activates the intrinsic repair processes of the cartilage and normalizes the endogenous production of HA by the synoviocytes. In recent years, the therapeutic use of HA has shown evidence that supports its application in TMJ OA, improving viscosupplementation capacity, acting at the cellular and molecular levels, reducing various inflammatory mediators and improving the reparative characteristics. Its use has been studied in animal models and in humans. However, no consensus has been reached in terms of concentrations, dose, application frequency or molecular weight to be used. [ABSTRACT FROM AUTHOR]

This study aims to observe the 3-D structural changes in subchondral bone and the effects of bisphosphonate intervention in the early unsteady stage of the knee joint. Sixty healthy male New Zealand white rabbits were divided into the model group (n= 24), the bisphosphonate (Bis) group (n= 24), and the control group (n= 12). The rabbits' right knees were used to evaluate the structural changes. The Bis group received subcutaneous injections of bisphosphonate, while the model and control groups received subcutaneous injections of isotonic saline solution. After surgical preparation, the knee joint was dissected for Micro-CT examination, and the Micro-CT results were compared using ANOVA. In the fourth postoperative week, the bone volume fraction (BVF), trabecular number (Tb.N), and trabecular thickness (Tb.Th) of the model group were significantly lower than those of the control group (P<0.01). There was no significant difference between the Bis and control groups. In the twelfth postoperative week, BVF, Tb.Th, and Tb.N of the model group were significantly higher than those of the control and Bis groups (P <0.05). Similarly, bone mineral density was higher in the model group (P <0.01), while the trabecular spacing was significantly lower (P <0.05). In the early unsteady stage of the knee joint, the subchondral bone had markedly decreased, while obvious bone formation was visible in the late stage. Bisphosphonates could protect the subchondral bone structure by inhibiting bone absorption. [ABSTRACT FROM AUTHOR]

This study evaluated the effect of oral glucosamine and intramuscular injection (IM) of snail mucin on the progression of experimental osteoarthritis (OA) in dogs. Twenty adult mongrels with mean body weight (12.4±1.8 kg) were used. Experimental OA was induced surgically using the groove model. The dogs were randomly divided into three groups following radiographic evidence of OA. Group one (control) comprised of ten dogs treated with normal saline twice weekly for four weeks following OA. Group two comprised of five dogs treated with 10mg/kg of oral glucosamine daily for four weeks. Group three comprised of five dogs treated with 5mg/kg intramuscular injection of 5% solution of snail mucin twice weekly for four weeks. Blood was obtained from the cephalic vein before surgical arthrotomy, after surgical arthrotomy, immediately after radiographic confirmation of OA (Week 0) and at two weeks interval up to 4 weeks of treatment. Efficacy of the drugs was assessed by changes in plasma IL-6 and MMP-3, while safety was determined using the changes in packed cell volume (PCV), total white blood cell counts (WBC) and observable adverse reactions associated with the administration of the drugs. In this study, the PCV and WBC did not differ significantly (P> 0.05) from the control group. Plasma IL-6 and MMP-3 were significantly (P< 0.05) lower both in glucosamine-treated and snail mucin-treated dogs up to week 4 of treatment when compared with the control group. However, there were no significant (P > 0.05) differences in IL-6 and MMP-3 between the two treatment groups. In addition, painful swelling at the site of injection was observed in dogs treated with snail mucin, while no adverse reaction was observed in dogs treated with oral glucosamine. It was therefore concluded that both oral glucosamine and IM injection of snail mucin comparably modified the progression of OA. However, owing to the adverse reaction noted with IM injection of snail mucin, further study is required to determine the most appropriate route of administration. [ABSTRACT FROM AUTHOR]

Osteoarthritis is the more frequent cause of disability in adult people and it is associated to cartilage degeneration of affected joints. This cartilage has a limited ability to repair. Several treatments have been tested including the use of Mesenchymal Stem Cells. These cells are an attractive source for cartilage repair because of their availability to chodrogenic differentiation by progressing sequentially through the expression of cartilage specific extracelullar matrix molecules, as in the embryologic human development. The aim is to obtain, culture and differentiate rabbit Bone Marrow derived Mesenchymal Stem Cells in vitro to chondral lineage. By differential centrifugation the mononuclear cell level was obtained from rabbit bone marrow samples. This level was cultured until 70% confluence. Chondrogenic differentiation was performed in an aggregate culture system with TGF-b1. Sample quantity, culture efficiency, confluence time of cultures and differentiation quality were all evaluated. An average sample of 14.5 ml per side was obtained, culture efficiency was 80%, and average confluence time (70%) was 18 days. Differentiation culture had an 80% efficiency and optimal differentiation quality. Rabbit Bone Marrow derived Mesenchymal Stem Cells culture is a reproducible technique and by the use of an adequate methodology chondrogenic cells can be obtained in vitro. This model permits the study of chondral differentiation process and could have direct clinical application. This is the first successful Latin-American report in Mesenchymal Stem Cells culture and chondrogenic differentiation. [ABSTRACT FROM AUTHOR]