Osgood-Schlatter disease

What is it?

Osgood-Schlatter disease is a common, temporary condition that causes knee pain in older children and teenagers, especially those who play sports and apply excessive stress to the patellar tendon (which connects the lower end of the knee cap to the upper part of the lower leg).

During activities that include a lot of jumping and bending — hockey, basketball, volleyball, soccer, skating, gymnastics, or ballet — the quadriceps muscle (thigh muscle) pulls tightly against the kneecap and the kneecap's anchor, the patellar tendon. The fibers of the patellar tendon are attached to the shinbone (tibia). With repeated pulling against these fiber connections, the tendon can become inflamed at or near its bone attachment. The result is pain and swelling at the tibial tuberosity, which is a raised area at the top of the shinbone. The tibial tuberosity is where the patellar tendon attaches to the bone.

This connection between the tendon and tibia is particularly vulnerable to stress and injury during times when the bone is growing rapidly and the patellar tendon is relatively short. For this reason, symptoms of Osgood-Schlatter disease usually appear between the ages of 9 and 14, during or after the teenage growth spurt. Overall, about 10% of children ages 12 to 15 experience Osgood-Schlatter disease, but it may affect up to 20% of adolescent athletes. The problem is more common in boys, though it appears to be increasing in frequency among girls as their participation in sports increases. In most cases, symptoms of Osgood-Schlatter disease develop gradually as a result of repeated stress on the patellar tendon. Less often, the condition is caused by a single trauma to the knee.

Symptoms

Symptoms of Osgood-Schlatter disease include:

• pain, tenderness and swelling of the soft tissues at the top of the shin bone, just below the kneecap
• redness and warmth below the kneecap
• a bony bump at the top of the shinbone.

The pain from Osgood-Schlatter disease can be a mild pain that lasts only while playing sports, or it can be a constant pain that severely limits regular participation in athletic activities. Pain can occur during stair climbing, kneeling, squatting or kicking. Pain usually appears in only one knee, although in about 20% to 30% of cases, both knees are affected.

Diagnosis

Your doctor may suspect that you have Osgood-Schlatter disease because of your age, your knee symptoms and, in many cases, your sports history. To confirm the diagnosis, your doctor will examine your knee to look for pain, tenderness, swelling and redness, and to check the range of movement that you have in your joint. He or she also will check the range of motion of your hip.

If the diagnosis is not obvious, your doctor may order knee X-rays. These X-rays might show tiny bone fragments that have separated from the top of your shinbone or abnormal areas of calcium deposits in the patellar tendon. If your pain is constant, or your knee tenderness is not confined to one spot, your doctor also may use these X-rays to look for other problems, such as a fracture, tumor or infection.

In some cases, your doctor may order an ultrasound or a magnetic resonance imaging (MRI) scan to further evaluate the patellar tendon.

Expected duration

Pain from Osgood-Schlatter disease can be very temporary for some people, but most people have symptoms for months. It is typical for this condition to last six to 18 months.

Prevention

You may help to prevent tendon injury by doing warm-up exercises before playing sports, especially exercises that stretch your thigh (quadriceps), hamstring and calf muscles. Use of appropriate sports equipment, proper technique, modifications in training intensity and avoiding "specialization" in a single sport at a young age may be helpful.

Treatment

Osgood-Schlatter disease eventually goes away on its own. Treatment depends on the severity of symptoms.

Although it may be uncomfortable for you to participate in activities that cause knee pain, it is not dangerous for you to do so. Continuing your activity can help you to maintain strength in your quadriceps and hamstring muscles, which is an important part of your recovery. During activities, you can do the following to help to limit your symptoms:

• Wear shock-absorbent insoles in your sports shoes.
• Use a heating pad or warm, moist compress for 15 minutes before a sports activity.
• Apply ice packs for 20 minutes after sports activities and periodically during the day.
• Wear a protective pad to shield the top of your shinbone.
• Elevate your leg by putting a pillow under your knee when it hurts.
• Take over-the-counter medications, such as ibuprofen (Advil, Motrin and others), to fight pain and inflammation.
• Stretch your quadriceps (thigh) muscles and hamstrings two or three times a day.
• Do exercises to strengthen your quadriceps muscles. This will help the muscles to pull more uniformly against their tendons, spreading out their stresses on the tendons.

If your knee pain is constant, it may be necessary for you to stop playing sports for a while, or to wear a brace for six to eight weeks. Casts and other immobilizers are avoided whenever possible, because they may cause muscles to weaken and this can delay your eventual recovery. Consultation with a physical therapist may be recommended.

An injection of hyperosmolar dextrose may be recommended; these are usually performed by a sports medicine specialist or orthopedic surgeon.

Surgery may be helpful if conservative treatments are not effective.

When to call a professional

See your doctor if you have symptoms that are typical for this condition, so that your diagnosis can be confirmed. Your doctor may refer you to a physical therapist or an orthopedic doctor for continued care.

Prognosis

Major symptoms from Osgood-Schlatter disease typically go away before age 18, or when a teenager's growth spurt ends and the bones mature. The condition may leave a permanent painless bump below the knee. In the years after recovery, about 60% of adults who once experienced Osgood-Schlatter disease have some pain with kneeling.

Additional info

American Academy of Orthopaedic Surgeons (AAOS)
http://www.aaos.org/

American Academy of Family Physicians (AAFP)
http://www.familydoctor.org/

National Institute of Arthritis and Musculoskeletal and Skin Diseases
http://www.niams.nih.gov/

American Physical Therapy Association
http://www.apta.org/