Sinding-Larsen-Johansson disease

Definition

A rare osteochrondrosis characterized by chronic traction injury of the immature osteotendinous junction where the patellar tendon inserts into the inferior pole of the patella. It is typically seen in active adolescents. Patients present with point tenderness at the inferior pole of the patella associated with focal swelling and restriction of knee joint range of movement. Radiographic features include thickening of the proximal patellar tendon (potentially followed by dystrophic calcification and/or ossification) and fragmentation of the inferior pole of the patella.