Osteoarthritis (OA) is a complex process affecting many different joint areas in the body. The joints most commonly affected are the knees, hips, and hands. From a patho-physiological point of view, some features are crucial for the diagnosis, such as cartilage fibrillation and thinning, subchondral sclerosis and the presence of osteophytes. The currently most widely used definitions of OA include pathogenetic features (mechanical and biological events), morphologic features (changes in articular cartilage and subchondral bone) as well as clinical features (joint pain, stiffness, tenderness, limitation of movement, crepitus and occasionally inflammation/effusion).<br />The features that until now have been used for diagnosis and classification are based on radiographic and/or clinical descriptions. From a clinical perspective, OA is the most prevalent rheumatic joint disorder, causing pain and stiffness of the joints and for the individual impaired function and health status. For epidemiological descriptions of prevalence and incidence of OA, radiographic criteria are the most reliable and commonly used. Definitions of radiographic OA include descriptions of cartilage thinning (such as joint space narrowing), subchondral bone involvement (sclerosis) and/or the presence and grading of osteophytes. Although there are geographical variations in the occurrence of OA of different joint areas, OA is seen in all populations studied. The prevalence and incidence estimates show a vide variation, however. Still the epidemiological studies of OA are hampered by a number of factors including different definitions of the disorder, different subsets of disease, and low degree of correlation between different definitions (radiographic vs clinical). Several highly suggested risk factors have been identified for knee OA. Several of these may be important targets for intervention or prevention, such as physical activity, body mass index, nutritional constituents and quadriceps strength. There is a need for prospective studies evaluating risk factors in hip and hand OA. Although there are problems in studying OA epidemiologically, the available data have shown that OA is an extremely common and disabling disorder. Through a further development of both epidemiological and other methods of OA research, this area can continue to be exciting and rapidly developing.
Phospholipase A2 inhibitor–loaded micellar nanoparticles attenuate inflammation and mitigate osteoarthritis progression
