Osgood-Schlatter disease can cause a painful lump below the kneecap 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 Osgood-Schlatter disease is more common in boys, the gender gap is narrowing as more girls become involved with sports.
Age ranges differ by sex because girls experience puberty earlier than do boys. Osgood-Schlatter disease typically occurs in boys ages 13 to 14 and girls ages 11 to 12. The condition usually resolves on its own, once the child’s bones stop growing.
During activities that involve a lot of 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 shinbone.
This repeated stress can cause the tendon to pull away from the shinbone a bit, resulting in the pain and swelling associated with Osgood-Schlatter disease. In some cases, your child’s body may try to close that gap with new bone growth, which can result in a bony lump at that spot.
The pain associated with Osgood-Schlatter disease varies from person to person. Some have only mild pain while performing certain activities, especially running and jumping. For others, the pain is nearly constant and debilitating.
Osgood-Schlatter disease usually occurs in just one knee, but sometimes it develops in both knees. The discomfort can last from weeks to months and may recur until your child has stopped growing.
When to see a doctor
Call your child’s doctor if knee pain interferes with your child’s ability to perform routine daily activities. Seek medical attention if the knee is also swollen and red, or if the knee pain is associated with fever, locking or instability of the knee joint.