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.