Overview

What Is Osteoarthritis?

Osteoarthritis, the most common form of arthritis, is a chronic degenerative joint disease that affects mostly middle-aged and older adults. Osteoarthritis is characterized by the breakdown of joint cartilage. Although it can occur in any joint, usually it affects the hands, knees, hips or spine. The disease is also known as degenerative arthritis or degenerative joint disease.

Osteoarthritis can be classified as primary or secondary. Primary osteoarthritis has an unknown cause, while secondary osteoarthritis is caused by another disease, infection, injury or deformity. Osteoarthritis is characterized by the breakdown of cartilage in the joint. As the cartilage wears down, the bone ends may thicken, forming bony growths or spurs that interfere with joint movement. In addition, bits of bone and cartilage may break free and float in the joint space, and fluid-filled cysts may form in the bone, limiting joint movement.