Knee pain can be caused by arthritis, excessive foot pronation or overuse of the muscles that protect this vulnerable joint and can affect people of any age.
Most chronic knee pain is avoidable. Research published in the New England Journal of Medicine suggests that exercise and physical therapy are just as effective as surgery for relief from chronic knee pain related to arthritis. Learning to strengthen and stretch key muscles that support the knees, and other ways to protect and take care of our knees, can ultimately prolong the health of this vital body part.
Cruciate Ligament Injuries
Cruciate ligament injuries are sometimes referred to as sprains. This injury does not necessarily cause pain, but can be disabling. You may hear a popping sound, and the leg may buckle when trying to stand on it.
If a person overuses a tendon during certain activities such as dancing, cycling, or running, the tendon stretches and becomes inflamed. People with tendinitis often have tenderness at the point where the patellar tendon (at the knee cap) meets the bone. In addition, they may feel pain during aggressive movement. A complete rupture of the quadriceps or patellar tendon is not only painful, but also makes it difficult for a person to bend, extend, or lift the leg against gravity.
This syndrome occurs when plicae (bands of synovial tissue) are irritated by overuse or injury. Synovial plicae are the remains of tissue pouches found in the early stages of fetal development. As the fetus develops, these pouches normally combine to form one large synovial cavity. If this process is incomplete, plicae remain as four folds or bands of synovial tissue within the knee. Injury, chronic overuse, or inflammatory conditions are associated with this syndrome. Symptoms of plica syndrome include pain and swelling, a clicking sensation, and locking and weakness of the knee.
Iliotibial Band Syndrome
An inflammatory condition caused when a band of tissue rubs over the outer bone (lateral condyle) of the knee. Although iliotibial band syndrome may be caused by direct injury to the knee, it is most often caused by the stress of long-term overuse, such as sometimes occurs in sports training and, particularly, in running. A person with this syndrome feels an ache or burning sensation at the side of the knee during activity. Pain may be localized at the side of the knee or radiate up the side of the thigh. A person may also feel a snap when the knee is bent and then straightened. Swelling is usually absent, and knee motion is normal.
The disease may also be associated with an injury in which the tendon is stretched so much that it tears away from the tibia and takes a fragment of bone with it. The disease most commonly affects active young people, particularly boys between the ages of 10 and 15, who play games or sports that include frequent running and jumping. Young people with this disease experience pain just below the knee joint that usually worsens with activity and is relieved by rest. A bony bump that is particularly painful when pressed may appear on the upper edge of the tibia (below the kneecap). Usually, the motion of the knee is not affected. Pain may last a few months and may recur until the child’s growth is completed.
Injuries to the Menisci
The menisci can be easily injured by the force of rotating the knee while bearing weight. A partial or total tear may occur when a person quickly twists or rotates the upper leg while the foot stays still (for example, when dribbling a basketball around an opponent or turning to hit a tennis ball). If the tear is tiny, the meniscus stays connected to the front and back of the knee. If the tear is large, the meniscus may be left hanging by a thread of cartilage. The seriousness of a tear depends on its location and extent. Those with this injury feel some pain, particularly when the knee is straightened. If the pain is mild, the person may continue moving. Severe pain may occur if a fragment of the meniscus catches between the femur and the tibia. Swelling may occur soon after injury if there is damage to blood vessels. After an injury, the knee may click, lock, feel weak, or give way. Although symptoms of meniscal injury may disappear on their own, they frequently persist or return and require treatment.
Medial and Lateral Collateral Ligament Injuries
The cause of collateral ligament injuries is most often a blow to the outer side of the knee that stretches and tears the ligament on the inner side of the knee. Such blows frequently occur in contact sports such as football or hockey. When suffering this injury, you may feel a pop and the knee may buckle sideways. Pain and swelling are common.
This disorder is caused by the softening and breakdown of the kneecap cartilage. It occurs most often in young adults and can be caused by injury, overuse, misalignment of the patella, or muscle weakness. Instead of gliding smoothly across the lower end of the thigh bone, the kneecap rubs against it, thereby roughening the cartilage underneath the kneecap. The most frequent symptom of is a dull pain around or under the kneecap that worsens when walking on an incline or when the knee bears weight as it straightens.
Osteochondritis dissecans results from a loss of the blood supply to an area of bone underneath a joint surface. It usually involves the knee. The affected bone and its covering of cartilage gradually loosen and cause pain. This problem usually arises spontaneously in an active adolescent or young adult. It may be caused by a slight blockage of a small artery or to an unrecognized injury or tiny fracture that damages the overlying cartilage. A person with this condition may eventually develop osteoarthritis. Lack of a blood supply can cause bone to break down. This disorder is thought to be inherited.
There are many forms of arthritis, rheumatic diseases, and related conditions and they all can affect the knees in some way. The symptoms are different for the different forms of arthritis. For example, people with rheumatoid arthritis, gout, or other inflammatory conditions may find the knee swollen, red, and even hot to the touch. Any form of arthritis can cause the knee to be painful and stiff.