Osgood-Schlatter disease can cause a painful, bony bump on the shinbone just below the knee. It usually occurs in children and adolescents experiencing growth spurts during puberty.

Osgood-Schlatter disease occurs most often in children who participate in sports that involve running, jumping and swift changes of direction — such as soccer, basketball, figure skating and ballet.

While the condition was once more common in boys, the gender gap has narrowed as more girls have become involved with sports.

Osgood-Schlatter disease typically occurs in boys ages 12 to 14 and girls ages 10 to 13. The difference is because girls enter puberty earlier than do boys. The condition usually resolves on its own, once the child's bones stop growing.

Knee pain and swelling just below the kneecap are the main indicators of Osgood-Schlatter disease. Pain usually worsens during certain activities, such as running, kneeling and jumping, and eases with rest.

The condition usually occurs in just one knee, but it can affect both knees. The discomfort can last from weeks to months and can recur until your child stops growing.

When to see a doctor

Call your child's doctor if knee pain interferes with your child's ability to perform daily activities. Seek medical attention if the knee is swollen and red, or if the knee pain is associated with fever, locking or instability of the knee joint.

During activities that involve running, jumping and bending — such as soccer, basketball, volleyball and ballet — your child's thigh muscles (quadriceps) pull on the tendon that connects the kneecap to the growth plate at the top part of the shinbone.

This repeated stress can cause the tendon to pull on the growth plate where the tendon inserts into the shinbone, resulting in the pain and swelling associated with Osgood-Schlatter disease. Some children's bodies try to close that gap with new bone growth, which can result in a bony lump at that spot.

The main risk factors for Osgood-Schlatter disease are:

• Age. Osgood-Schlatter disease occurs during puberty's growth spurts. Age ranges differ by sex because girls enter puberty earlier than do boys. Osgood-Schlatter disease typically occurs in boys ages 12 to 14 and girls ages 10 to 13.
• Sex. Osgood-Schlatter disease is more common in boys, but the gender gap is narrowing as more girls become involved with sports.
• Sports. The condition happens most often with sports that involve running, jumping and swift changes in direction.
• Flexibility. Tightness in the quadriceps muscles can increase the pull of the kneecap's tendon on the growth plate at the top of the shinbone.

Complications of Osgood-Schlatter disease are uncommon. If they occur, they might include chronic pain or localized swelling.

Even after symptoms have resolved, a bony bump might remain on the shinbone just below the kneecap. This bump can persist to some degree throughout your child's life, but it doesn't usually interfere with knee function.

In rare cases, Osgood-Shlattter disease can cause the growth plate to be pulled away from the shinbone.

During the physical exam, your doctor will check your child's knee for tenderness, swelling, pain and redness. X-rays may be taken to look at the bones of the knee and leg and to more closely examine the area where the kneecap tendon attaches to the shinbone.

Osgood-Schlatter disease usually resolves without formal treatment. Symptoms typically disappear after your child's bones stop growing.

Medications

Over-the-counter pain relievers such as acetaminophen (Tylenol, others), ibuprofen (Advil, Motrin IB, Children's Motrin, others) or naproxen sodium (Aleve) might help.

Therapy

A physical therapist can teach your child exercises to stretch the thigh's quadriceps, which can help reduce the tension where the kneecap (patella) tendon attaches to the shinbone. A patellar tendon strap also can help relieve the tension. Strengthening exercises for the quadriceps and legs in general can help stabilize the knee joint.

Surgery

In very rare cases, if pain is debilitating and doesn't subside after the growth spurt, surgery to remove the bony overgrowth might be recommended.

It might help your child to:

• Rest the joint. Limit time spent doing activities that aggravate the condition, such as kneeling, jumping and running.
• Ice the affected area. This can help with pain and swelling.
• Stretch leg muscles. Stretching the muscles on the front of the thigh (quadriceps), is especially important.
• Protect the knee. When your child is participating in sports, have him or her wear a pad over the affected knee where the knee can become irritated.
• Try a strap. A patellar tendon strap fits around the leg just below the kneecap. It can help to "tack down" the kneecap's tendon during activities and distribute some of the force away from the shinbone.
• Cross-train. Suggest that your child switch to activities that don't involve jumping or running, such as cycling or swimming, until symptoms subside.

You'll likely first bring this problem to the attention of your family doctor or your child's pediatrician. He or she might refer you to a doctor who specializes in knee injuries or sports medicine.

What you can do

Bring to the appointment a written list that includes:

• Detailed descriptions of your child's symptoms
• Information about medical problems your child has had in the past
• Information about medical problems common in your family
• All the medications and dietary supplements your child takes
• Questions you want to ask

Below are some basic questions to ask a doctor who is examining your child for possible Osgood-Schlatter disease. If any additional questions occur to you during your visit, don't hesitate to ask.

• Do you expect my child will be able to continue in his or her current sport?
• Does my child need to change his or her activities, such as playing a different position or training with different exercises? If so, for how long?
• What signs or symptoms would signal a need for my child to take a complete break from athletics?
• What other self-care measures would help my child?

What to expect from your doctor

Your child's doctor is likely to ask a number of questions, such as:

• How severe is your pain?
• Does your pain occur before, during or after your workouts — or is it constant?
• Have you noticed swelling near your kneecap?
• Have you had problems with mobility or stability?
• What is your exercise or sports-training routine?
• Have you recently changed your training routine, such as training harder or longer or using new techniques?
• Are you able to tolerate the pain while playing your sport at your usual intensity?
• Are your symptoms affecting your ability to complete normal, daily tasks, such as walking up stairs?
• What at-home treatments have you tried? Has anything helped?
• Have you had a recent injury that may have caused knee damage?