Definition of osteoarthritis

Irreversible, substantial degenerative damage to the surface of the joint

A normal, healthy joint is made up of two or more bones joined together by ligaments and joint capsule. The surface of the joint has a smooth gliding surface, made of special cartilage.

Osteoarthritis is a condition, where that surface cartilage gets damaged over a large area. In the initial stages of osteoarthritis, there may be no symptoms of pain, stiffness or swelling. At some point, sometimes spontaneously, sometimes triggered by an injury, the symptoms begin.

Normal and arthritic knee