My 12-year-old son played a lot of sports this summer. Now he complains a lot about the front of his left knee hurting, even though he never injured it.
We suspect your son has a condition called Osgood-Schlatter Disease, although what is occurring hardly qualifies as a "disease."
During early puberty, bones and muscles begin to grow rapidly. As a result, there occurs a relative loss of flexibility of muscle. This lack of flexibility, coupled with extensive use of muscles from a full sports schedule, results in an overuse injury of muscle in which tiny "micro tears" appear in muscle fibers at the point where they insert onto bone.
Treatment consists of avoiding sports that aggravate the pain, icing the tender area and using non-steroidal, anti-inflammation medications such as ibuprofen. Once the pain has decreased, a program of gently stretching and strengthening of the muscles of the front of the thigh will also help. Return to athletics should be avoided until your son can play pain free.
Dr. Wilson is director of general pediatrics at the Johns Hopkins Children's Center; Dr. Joffe is director of adolescent medicine.