Trauma X-ray - Upper limb
Radius and ulna

Typical fracture patterns arise in the forearm bones depending on mechanism of injury and the age of the patient.

In the elderly, osteoporotic fractures of the distal radius are common. In children, bone compliance allows for buckle or 'greenstick' type injuries.

Many fractures of the forearm have eponymous titles. Use of these terms often leads to confusion, and so should be used with caution.

Forearm fracture/dislocation

The radius and ulna form an anatomical unit, joined throughout their length by an interosseous ligament and stabilised at the elbow and wrist, thus forming a ring. If there is a fracture of the shaft of one of these bones with visible shortening, there will likely be dislocation at the wrist or elbow of the other.

If the ulnar shaft fractures with shortening, then the radius will dislocate at its point of weakness at the elbow (Monteggia fracture-dislocation). If the radius fractures with shortening, then the ulna will dislocate at its point of weakness at the distal radioulnar joint (Galeazzi fracture-dislocation).

Forearm fractures of childhood

Children's bones are more compliant and therefore often buckle rather than completely break as in adults. If there is a visible fracture in the cortex on one side with buckling on the other this is termed a 'greenstick' fracture. Buckling without a visible fracture line is termed a 'torus' injury.