Degenerative Joint Pathophysiology: Mechanisms of Osteoarthritis
Osteoarthritis (OA) is a progressive disease of the entire joint, characterized by the breakdown of articular cartilage and underlying bone. Once thought to be purely "wear and tear," OA is now understood as an active inflammatory process involving the synovial membrane and subchondral bone.
The Cascade of Joint Destruction
Cartilage Fibrillation: The smooth surface of the cartilage develops cracks and irregularities.
Osteophyte Formation: The bone attempts to heal itself by growing "spurs" at the joint margins, which causes pain and restricts movement.
Synovitis: Fragments of cartilage break off into the joint fluid, causing the lining (synovium) to become inflamed and produce excess fluid (effusion).
Therapeutic Pathways
Management focuses on biomechanical unloading (weight loss and physical therapy) and pharmacological intervention. In advanced stages, where the joint space is completely lost, arthroplasty (joint replacement) remains the most effective intervention to restore mobility.