What Are the Pathological Mechanisms of Osteoarthritis?

Osteoarthritis is a common degenerative condition characterized by destructive changes in the linings of joints throughout the body. Certain pathological mechanisms (disease-related processes) typically occur as the disease progresses.

Initiating Factors

• The changes associated with osteoarthritis can stem from factors including age-related changes, chronic joint overuse, family history, bone injury and excess body weight, according to Medline Plus.

Cartilage Changes

• In the initial stage of osteoarthritis, the cartilage that normally provides smooth contact between bones begins to lose its elasticity, according to the Arthritis Foundation. This loss makes cartilage more susceptible to damage from everyday use or injury.

Bone Changes

• Eventually, changes in cartilage lead to abnormalities in the associated bone, reports the Arthritis Foundation. These abnormalities may include cyst formation, thickening of the bone and the formation of growths called bone spurs (osteophytes).

Inflammation

• Cartilage breakdown also may trigger inflammation of the joint lining called the synovium, notes the Arthritis Foundation. This, in turn, can cause further cartilage destruction.

Fragmentation

• The Arthritis Foundation notes that deterioration can release cartilage and bone fragments into the fluid of affected joints, leading to symptoms including pain and irritation.