Osteoarthritis is the most common arthritis found in the knee. It is a degenerative, “wear and tear” type of arthritis that occurs mostly in people 50 years of age and older, but may occur in young people too. In Osteoarthritis, the Cartilage in the knee joint gradually wears away. Therefore, the Cartilage becomes frayed and rough, causing the protective space between the bones to decrease. This can result in bone rubbing against bone, and produce painful bone spurs.