[Osgood-Schlatter disease in adolescent athlete. Case report].

Knee pain is one of the most frequent musculoskeletal symptoms in young physically active males. Common entities of clinical diagnosis as osteochondritis/apophysitis and others that need complementary studies should be considered in the differential diagnosis. We present the case of a 12-year-old male athlete with continuous pain in his right knee that intensifies with physical activity and with direct pressure. Diagnosis of Osgood-Schlatter disease is made by exploratory data, pain-to-finger palpation on the anterior tibial tuberosity, and is confirmed by radiology. This entity is described as well as the main pathologies derived from overuse to make differential diagnosis and to stress preventive measures regarding a correct orientation in the sport activity.