Knee pain is a common complaint that affects people of all ages. Knee pain may be the result of an injury, such as a ruptured ligament or torn cartilage. Medical conditions — including arthritis, gout and infections — also can cause knee pain.
Sometimes called degenerative arthritis, osteoarthritis is the most common type of arthritis. It's a wear-and-tear condition that occurs when the cartilage in your knee deteriorates with use and age.
OA usually appears after the age 50, because it involves overuse.
Bursitis is a painful condition that affects the small, fluid-filled sacs — called bursae — that cushion the bones, tendons and muscles near your joints. Bursitis occurs when bursae become inflamed.
The most common causes of bursitis are repetitive motions or positions that put pressure on the bursae around a joint. Examples include: