Osgood-Schlatter disease(OSD)is a chronic fatigue injury due to repeated microtrauma at the patellar ligament inseion onto the tibial tuberosity, usually affecting boys between ages 10-15 years. Osgood-Schlatter disease is seen in active adolescents, especially those who jump and kick, which is why it is seen more frequently in boys. Clinically, patients present with pain and swelling over the tibial tuberosity exacerbated with exercise. Illustration of Osgood-Schlatter disease.