J Pediatr Orthop B. 2008 May;17(3):120-4. Maus U, Andereya S, Ihme N, Gravius S, Niedhart C, Ohnsorge JA, Niethard FU. Onset of Perthes’ disease is reported frequently from the age of 2 years. Latest publications showed cases with onset of this disease in infancy at ages of 17 and 18 months. We report the case of a 13-month-old boy, who presented with left-sided limping. Radiological examination showed reduced height and fragmentation of the femoral head. Magnetic resonance imaging showed the typical signs of an avascular necrosis. Follow-up was done after 3, 7 and 15 months. Plain radiography showed the femoral head in a state of reparation. This is the youngest documented case of Legg-Calvé-Perthes’ disease and is discussed under consideration of the current literature.