Mechanisms of joint destruction, pain and disability in osteoarthritis.
Osteoarthritis is characterised by progressive erosion of articular cartilage, and bony overgrowth at the joint margins. Cartilage integrity requires a balance between synthesis and degradation of matrix components, and the latter is augmented in osteoarthritis through the action of chondrocyte-derived metalloproteinases. Synthesis rates also increase but fail to keep pace with the losses. Synovial inflammation, a mild and inconstant feature of osteoarthritis, is more likely to be a consequence of cartilage breakdown than a cause, and its contribution to pain is uncertain. The origins of pain and disability are complex; pathological changes in the joint capsule and periarticular ligaments are a likely source, but nocturnal pain may be related to raised pressure in subchondral bone. In addition to structural damage in the joint, psychosocial factors, muscle weakness, and comorbidities may contribute.
UMDNJ-Robert Wood Johnson Medical School, New Brunswick, USA.
R S
RS
Pinals
D006801:Humans; D010003:Osteoarthritis / Q000150:complications / Q000473:pathology / Q000503:physiopathology; D010146:Pain / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control