Describe the etiology and clinical manifestations of osteoarthritis (OA)

Answer 1

OA is not a specific entity, but a disease process involving all the structures of the joint, including the articular cartilage, the subchondral bone, the synovial fluid and synovial membranes, the ligaments, and the nerves and muscles supporting the joint. However, the most striking changes seen in OA are those within the load bearing articular cartilage. Although osteoarthritis has been classified as a non-inflammatory form, increasing evidence has shown that inflammation occurs as cytokines and metalloproteinases are released into the joint. These agents are involved in the excessive matrix degradation that characterizes cartilage degeneration in osteoarthritis. The progressive loss of articular cartilage and the inflammation of the other tissues composing the joint result in joint pain, stiffness, limited joint movement, wasting of periarticular muscles, and in some instances, joint instability and deformity. No specific laboratory abnormalities are associated with osteoarthritis and it is typically diagnosed on the basis of clinical and radiographic evidence.