Osteoarthritis is a type of arthritis (degenerative arthritis) that is caused by the breakdown and eventual loss of the cartilage that is in between your joints. Cartilage is a protein substance that serves as a "cushion" in your joint. As the cartilage breaks down, the bones begin to rub against each other, resulting in damage to the surface of the joint. Pain and discomfort will occur, preventing you from being able to exercise and stay active. It can even result in significant disability.
Osteoarthritis is synonymous with aging, and it can be inherited. Scientists now believe that it is mainly caused by a combination of these factors as well as obesity and joint injuries that lead to the development of knee OA.
Among over 100 different types of arthritis conditions, osteoarthritis is the most common, affecting over 20 million people in the United States alone. Before age 45, osteoarthritis occurs more frequently in males. After age 55 years, it occurs more frequently in females. Osteoarthritis commonly affects the hands, feet, spine, and large weight-bearing joints, such as the hips and knees.