Knee problems in teenagers may be caused by injury, disease or weak spots in the kneecap that can become inflamed. Knee pain in teenagers is common and may be a short-term problem. Any symptoms, such as a swollen knee, persistent pain, redness or warmth of the skin, or being unable to walk without pain, should be evaluated by a doctor.
Active teenagers who regularly participate in sports or lifting weights may feel knee pain due to Osgood-Schlatter disease. This disease is caused by inflammation of a tendon located below the knee that is attached to the shinbone. Osgood-Schlatter causes a tender bump to appear under the knee at the top of the shinbone. Activity may cause increased pain and require your teenager to rest until symptoms improve. Osgood-Schlatter disease typically disappears when growth of the knee bone is over.
This knee problem in teenagers typically affects girls. The knee sits in a groove, which allows the bone to slide when walking, running and bending. When the kneecap pops out of the groove, it's called patellar dislocation. A dislocated knee causes pain, swelling, tenderness on and around the knee, and the knee may also give way, which can cause the teenager to fall down. Immobilizing the knee using a leg brace is the usual treatment.
Collateral Ligament Injuries
Teenagers who play sports usually sustain this type of injury. Trauma to the knee can tear the ligaments on the inside or outside of the knee. The medial ligament is on the inside of the knee and the lateral ligament is on the outside. Symptoms of this knee problem in teenagers include pain, swelling and difficulty walking. Minor ligament tears are usually treated with rest, anti-inflammatory medication and immobilization of the leg. Surgery may be required when the tear is severe.
Parapatellar Knee Pain Syndrome
Active teenagers can develop this knee problem that is caused by cartilage under the knee being worn down or softened. Pain is typically felt in the front of the kneecap and aggravated by activity. Buckling of the knee or feeling a grinding sensation while moving are also symptoms of this knee problem. Resting the knee, anti-inflammatory medicine and physical therapy are the most common treatments. Cartilage that is severely damaged or is caught between the bones may need surgery.
Osteochondritis dissecans (OCD) occurs when there is a lack of blood flow to the kneecap. This causes bone tissue to die and bone and cartilage to separate. Pain is usually felt when a piece of bone comes loose and is floating in the knee. OCD may cause the knee to lock up, feel weak and make a clicking noise. There is a loss of full range of motion in the teenager's knee, so the leg can't be fully extended or bent. Swelling may be present and stiffness after resting for an extended period of time. Mild cases of OCD are treated with rest and avoiding high-impact physical activities. If symptoms continue, arthroscopic surgery may be needed.