The musculoskeletal system is formed by bones, joints, muscles, tendons and ligaments and contributes to the support, protection, stability and movement of the human body. Musculoskeletal injuries can be caused by accident, overuse (due to sports or work environment), degeneration (due to human aging) and by other diseases.
Articular cartilage is a highly specialized type of connective tissue. It is a thin, smooth, soft and elastic film, which covers the articular surfaces of the bones (part of the bones that involved in the formation of a joint). Articular cartilage consists of water, collagen, proteoglycans, proteins and chondrocytes. The unique composition, ensures particular mechanical properties: it can be compressed, absorbing high loads and severe vibration at the joint moves, and then returns to its original thickness
In this way, the articulation motions are smooth, easy and painless. The special characteristic of the articular cartilage is that has no vessels (arteries, veins). For this reason, articular cartilage has little or no regenerative capacity. This means that a cartilaginous lesion hardly restored by itself.
Defects of articular cartilage observed in the following cases:
Features of synovial fluid
Synovial fluid functions
Osteoarthritis (OA), also known as degenerative arthritis or degenerative joint disease is a group of mechanical abnormalities involving degradation of the joint, including the articular cartilage and subchondral bone. The symptoms can include joint pain, tenderness, stiffness, locking, and sometimes a fluid diffusion in the hinge region. A variety of causes-hereditary, developmental, metabolic and mechanical means can initiate processes leading to loss of cartilage. When bone surfaces are less well protected by cartilage, bone may be exposed and destroyed. As a result of reduced movement due to pain, regional muscles may atrophy, and ligaments may become more lax.
The sarcopenia is the loss of mass, strength and muscle function associated with age. Today is one of the key areas of aging research. The pathophysiology of sarcopenia associated with oxidative stress, the increase of the circulating pro-inflammatory kittokinon and also with the physical inactivation and malnutrition.
It has been shown that sarcopenia has been associated with a functional decrease, impotence, falls, bony fractures, immunosuppression, and disturbance of thermoregulation. The most common definition of sarcopenia is the following: the gradual loss of the mass and quality of the skeletal musculature that occurs in elders. The etiology of sarcopenia is multifactorial and can be described as a set of changes related to the age of the muscle-skeletal cells, their formation and tissue function. There are factors intrinsic and extrinsic. In respect to the endogenous factors we can mention: the reduction of anabolic hormones (testosterone, growth hormone, IGF-1 estrogens),the increase of the apoptotic activity of the muscle fibers, the increase of the proinflammatory cytokines (TMF-a, IL-6), oxidative stress as a result of the accumulation of free radicals, and changes in mitochondrial function in muscle cells. Among the external factors we can mention: the lack of energy and protein intake, acute and chronic diseases, insulin resistance, vascular diseases, chronic morbidity results in the reduction of physical activity and in the increase of the production of proinflammatory cytokines that play a dominant role in the activation proteolysis.