Sinding-Larsen-Johansson syndrome: A case report.

The Sinding-Larsen-Johansson syndrome has a pathogenesis similar to that of the Osgood-Schlatter disorder and is the result of excessive force exerted by the patellar tendon on the lower pole of the patella. Clinically it is characterized by pain, which increases when the patellar is loaded during flexion, subpatellar swelling and functional limitation. The authors present a case of a 13-year-old boy who was a competitive youth team football player. He presented with anterior, spontaneous knee pain and swelling at the inferior pole of the patella. Ultrasonography (US) confirmed clinical diagnosis showing lesions typical of the Sinding-Larsen-Johansson syndrome. The patient was told to refrain from sports activity; after five months recovery was complete and US follow-up revealed no anomaly. The authors consider the case worthy of reporting because it is paradigmatic and to emphasize the role of US in the evaluation of the Sinding-Larsen-Johansson syndrome.