Pathophysiology of Degenerative Joint Disease

Degenerative joint disease, or osteoarthritis, is a noninflammatory form of arthritis that is often the result of excessive wear and tear on a joint, sometimes due to sports or occupation. The weight-bearing joints are usually affected.

Function

• The condition is usually triggered by cartilage damage and erosion resulting from excessive mechanical stress.

Effects

• As the cartilage breaks down, the surface becomes rough and worn and interferes with normal joint movement. There are no systemic effects associated with osteoarthritis.

Autoimmune Response

• As a result of the tissue damage, the immune system triggers the release of enzymes that accelerate the degeneration of cartilage. Eventually, bone may become exposed and damaged, resulting in the development of cysts and osteophytes (bone spurs) around the margin of the bone.

Potential

• As the condition advances, pieces of cartilage can break off into the synovial cavity, causing further irritation. The joint space becomes narrower and secondary inflammation may occur in the surrounding tissues in response to stress on the joint.

Symptoms

• Common symptoms include limited movement and enlargement of the joint. If the knee is affected, walking may become difficult and muscle atrophy may occur. If the jaw is affected, chewing, talking and yawning become difficult and severe pain may occur.