Arnold Besselaar, Daniel Green, Andrew Howard
Epiphyseal fractures of the distal femur with complete separation of epiphysis (Salter-Harris I) are classified as 33-E/1.1.
True Salter-Harris I fractures are rare and there is often a small metaphyseal fragment.
Children struck from the lateral side, common in sports and pedestrian injuries, often have lateral displacement of the distal fragment and valgus angulation.
Hyperextension mechanisms produce anterior displacement of the distal fragment and apex posterior angulation.
If these fractures are seen in children below walking age child abuse should be suspected.
Lateral x-ray of the knee of a 6-year-old boy following a fall form a bicycle, with normal vascularity of the leg