Early OA typically occurs due to which mechanism?

Early OA typically occurs due to which mechanism?

• A. Joint damage (malalignment, injury, mechanical) or inflammation
• B. Infection
• C. Autoimmune attack
• D. Vascular occlusion

Answer: (A)

Early osteoarthritis is driven primarily by mechanical damage to the joint. Abnormal loading from malalignment, prior injury, or repetitive stress creates focal cartilage injury. In response, chondrocytes release matrix-degrading enzymes, proteoglycans are lost, and the cartilage surface becomes softened and fissured. Once the articular cartilage deteriorates, subchondral bone changes and mild synovitis may emerge, but these are secondary to the initial mechanical damage. The other mechanisms listed—infection, autoimmune attack, or vascular occlusion—describe septic arthritis, autoimmune inflammatory arthritis, and avascular necrosis, respectively, which are not the typical initiating processes for early OA.

Early osteoarthritis is driven primarily by mechanical damage to the joint. Abnormal loading from malalignment, prior injury, or repetitive stress creates focal cartilage injury. In response, chondrocytes release matrix-degrading enzymes, proteoglycans are lost, and the cartilage surface becomes softened and fissured. Once the articular cartilage deteriorates, subchondral bone changes and mild synovitis may emerge, but these are secondary to the initial mechanical damage. The other mechanisms listed—infection, autoimmune attack, or vascular occlusion—describe septic arthritis, autoimmune inflammatory arthritis, and avascular necrosis, respectively, which are not the typical initiating processes for early OA.