Torus (Buckle) Fracture

Fig: Forearm radiograph shows a fracture as bulged cortex at the distal end of the radius. This is a classic torus (buckle) fracture.

Facts

• Axial loading on extremity with/without other forces (i.e. varus, valgus, hyperextension or hyperflexion)
• Failure of cortex on the compression side, resulting in fracture
  
• Torus (buckle) fracture of distal radius and ulna is most common fracture in lower forearm of young children
• Two appearances: 1) classic buckle fracture -- cortex bulges outward, 2) angled buckle fracture -- cortex angles inward (the second type is more difficult to appreciate)

Reference:
Jadhav SP, Swischuk LE. Commonly missed subtle skeletal injuries in children: a pictorial review. Emerg Radiol 2008 (November)