Healthy articular cartilage is a remarkably durable tissue, capable of withstanding compressive forces several times your body weight. However, cartilage has virtually no blood supply, meaning it relies on joint fluid for nutrients and has extremely limited capacity for self-repair — losing roughly 0.1-0.2 mm of thickness per decade after age 40.
As cartilage thins, the underlying bone absorbs more mechanical stress with each step and movement. The body responds by forming osteophytes (bone spurs) and increasing synovial fluid production, which causes the swelling, warmth, and stiffness characteristic of arthritic joints.
Simultaneously, chronic low-grade inflammation releases enzymes called matrix metalloproteinases (MMPs) that accelerate cartilage breakdown. This creates a self-perpetuating cycle where damaged tissue triggers more inflammation, which causes further damage — progressively narrowing the joint space and increasing bone-on-bone contact.
