Pediatric bone is porous, while adult bone is more solid, or cancellous.  Unlike adult bone, its porosity gives it a plasticity that allows it to bend, buckle, or deform without complete fracture.  Torus fractures are incomplete fractures characterized by wrinkling or buckling of the cortex. In ancient Greek architecture, a torus is a bump on the base of a column and these fractures, which occur on the end of long bones, take on such an appearance. They are unique to pediatric patients.

     The most common location for a torus fracture is the distal radius, but these injuries can also be seen at the proximal radius, distal humerus, distal femur and proximal tibia.  They occur at the diaphyseal-metaphyseal junction, where the transition from relatively porous to more dense bone predisposes to local failure when exposed to an axial load.