Osteoarthritis of the Knee (Degenerative Arthritis of the Knee)
While age is a major risk factor for osteoarthritis of the knee, young people can get it too. For some individuals, it may be hereditary. For others, osteoarthritis of the knee can result from injury or infection or even from being overweight. Here are answers to your questions about knee osteoarthritis, including how it's treated and what you can do at home to ease the pain.
What Is Osteoarthritis?
Osteoarthritis, commonly known as wear and tear arthritis, is a condition in which the natural cushioning between joints -- cartilage -- wears away. When this happens, the bones of the joints rub more closely against one another with less of the shock-absorbing benefits of cartilage. The rubbing results in pain, swelling, stiffness, decreased ability to move and, sometimes, the formation of bone spurs.
Who Gets Osteoarthritis of the Knee?
Osteoarthritis is the most common type of arthritis. While it can occur even in young people, the chance of developing osteoarthritis goes up after age 45. According to the Arthritis Foundation, more than 27 million people in the U.S. have osteoarthritis, with the knee being one of the most commonly affected areas. Women are more likely to have osteoarthritis than men.
What Causes Knee Osteoarthritis?
The most common cause of osteoarthritis of the knee is age. Almost everyone will eventually develop some degree of osteoarthritis. However, several factors increase the risk of developing significant arthritis at an earlier age.
- Age. The ability of cartilage to heal decreases as a person gets older.
- Weight. Weight increases pressure on all the joints, especially the knees. Every pound of weight you gain adds 3 to 4 pounds of extra weight on your knees.
- Heredity. This includes genetic mutations that might make a person more likely to develop osteoarthritis of the knee. It may also be due to inherited abnormalities in the shape of the bones that surround the knee joint.
- Gender. Women who are 55 and older are more likely than men to develop osteoarthritis of the knee.
- Repetitive stress injuries. These are usually a result of the type of job a person has. People with certain occupations that include a lot of activity that can stress the joint, such as kneeling, squatting, or lifting heavy weights (55 pounds or more), are more likely to develop osteoarthritis of the knee because of the constant pressure on the joint.
- Athletics. Athletes involved in soccer, tennis, or long-distance running may be at higher risk for developing osteoarthritis of the knee. That means athletes should take precautions to avoid injury. However, it's important to note that regular moderate exercise strengthens joints and can decrease the risk of osteoarthritis. In fact, weak muscles around the knee can lead to osteoarthritis.
- Other illnesses. People with rheumatoid arthritis, the second most common type of arthritis, are also more likely to develop osteoarthritis. People with certain metabolic disorders, such as iron overload or excess growth hormone, also run a higher risk of osteoarthritis.