Osgood Schlatter Disease (OSD), also known as “apophysitis of the tibial tubercle,” is a common overuse injury in growing adolescents, particularly in those who are active in athletics that involve running or jumping, such as soccer or basketball.
OSD develops when continuous physical stress and repetitive movements lead to inflammation of the growth plate where the tendon that begins at the kneecap, called the patellar tendon, meets the shinbone, or tibia. A growth plate is an area of cartilage near the end of a bone that hardens into bone by the time a child reaches adulthood. Some growth plates connect tendons to bone.
The growth plate affected in OSD is covered by a bony point (tibial tubercle) that is attached by the patellar tendon to the muscles in the front of the thigh (quadriceps). With activity, the quadriceps muscles engage the patellar tendon, which in turn exerts tension over the growth plate. When this happens repeatedly, inflammation of the growth plate can occur. Over time, the tibial tubercle can develop a visible bump from the repeated tension.
OSD is most common during adolescent growth spurts in puberty, when bones, muscles, tendons and other structures are changing rapidly and can be most vulnerable to stress and injury. This condition typically affects boys more than girls; however, with more girls participating in sports, the frequency of OSD in females is on the rise. OSD can affect one or both knees and symptoms can last until the end of puberty. For boys, OSD generally develops around the age of 13 or 14. It is usually seen in girls between 11 and 12 years of age.
Symptoms of OSD include pain, redness, tenderness, and swelling at the site of the tibial tubercle, which lies at the top of the shinbone. There may be muscle tightness surrounding the knee. Pain typically increases with activities such as running, kneeling and jumping, and decreases with rest.
OSD usually resolves on its own when the bones stop growing. Until then, symptoms can be relieved with ice, rest and over the counter anti-inflammatory medication. Exercises to stretch and strengthen the quadriceps can reduce the tension on the patella tendon and can help stabilize the knee joint. A patellar tendon strap that fits around the leg just below the kneecap can be worn during activity to support the patellar tendon and distribute some of the stress away from the shinbone. Children in general, but especially children with overuse injuries, benefit from cross training and engaging in sports and activities such as swimming or cycling, that involve different movements, muscles and joints in the body. Surgery is extremely rare and only an absolute last resort. If the pain is debilitating or if the pain does not subside after the child has reached full height, surgery to remove the bony protrusion may be considered.
If an adolescent you know complains of knee pain or limps while walking, have him or her evaluated by a sports medicine physician who is fellowship-trained in conditions of the knee to get a diagnosis. Other knee injuries may require immediate treatment.