Young boy with knee pain

A 15-year-old boy presented to the clinic complaining of right knee pain. He had the pain after a basketball game. The pain was mainly over the tibial tuberosity and did not radiate to other location. He did not have any past injury to his leg and there was no fever. He was well and had no significant past medical history.

On examination, there was tenderness over the right tibial tuberosity and there seemed to be a lump. There was some slight inflammation over the area. Otherwise, he was normal.

What is your diagnosis?

Answer: Osgood-Schlatter's Disease.

This common condition occurs when there is a traction injury of the apophysis into which part of the patellar tendon is inserted. The typical presentation is pain after activity in a young adoloscent with no history of injury. X-ray may show fragmentation of the apophysis, but diagnosis is more often made clinically.