Knee problems are very common, and they occur in people of all ages. This section contains general information about several knee problems, including symptoms, diagnosis, and treatment of specific types of knee injuries and conditions.

The knee is the joint where the bones of the upper leg meet the bones of the lower leg, allowing hinge-like movement while providing stability and strength to support the weight of the body. Flexibility, strength, and stability are needed for standing and for motions like walking, running, crouching, jumping, and turning.

Several kinds of supporting and moving parts, including bones, cartilage, muscles, ligaments, and tendons, help the knees do their job. Each of these structures is subject to disease and injury. When a knee problem affects your ability to do things, it can have a big impact on your life. Knee problems can interfere with many things, from participation in sports to simply getting up from a chair and walking.