[A young soccer player with a painful patella].

A 12-year-old boy presented with pain at the knee. At physical examination there was no knee effusion, a maximum knee function, but with local tenderness during palpation of the lower patellar bone. Radiographs showed osseous fusion abnormalities at the lower third of the patella at the lateral and axial knee radiographs. The diagnosis was a Sinding-Larsen-Johansson syndrome. Treatment was centered at providing equilibrium between exercise and rest.