
In osteoarthritis, the cartilage that protects and cushions the joints breaks down over time. As the cartilage wears down, the bone surfaces rub against each other. This damages the tissue and bone, which then causes pain. Osteoarthritis is common in the knee joints.
| By | Healthwise Staff |
| Primary Medical Reviewer | Anne C. Poinier, MD - Internal Medicine |
| Specialist Medical Reviewer | Stanford M. Shoor, MD - Rheumatology |
| Last Revised | April 8, 2011 |