Osgood-Schlatter disease, also known as osteochondritis of the tibial tuberosity. It is a common condition that commonly affects boys aged 11-15 years and can develop unilaterally or bilaterally. The main manifestation is limited pain in the front of the knee. The pain is obvious when the child goes up and down steps, runs or jumps. The pain is aggravated by direct pressure due to tension and pulling of the patellar ligament when kneeling down. The pain is relieved or disappears after rest. x-ray shows soft tissue swelling and hypertrophy at the patellar ligament attachment above the tibial tuberosity, sometimes with calcification or ossified “fragments”. This disease is a self-healing disease. The duration of the disease is about 2 to 3 years. Treatment should be limited to physical activity, prohibit running and jumping activities for 3 to 6 months, can make the symptoms alleviate. Topical Fotarine emulsion can also be used.