Monteggia fracture dislocation

Last reviewed 12/2022

The M onteggia fracture dislocation is:

  • a fracture of the upper ulna, with
  • dislocation of the radial head

The history is one of a fall, usually with twisting and pronation of the forearm.

Either component may be missed. A dislocated radial head may be obscured by swelling. A high ulna fracture may be mistaken for a fractured olecranon.

A good lateral x-ray is required to fully show the fracture dislocation. The radial head is dislocated forwards and no longer seen pointing directly to the capitulum. The ulna is bowed forwards.

Closed reduction by manipulation may suffice in children but the fracture is so unstable that internal fixation by plating is usually necessary in adults. The arm should be immobilised in plaster for 6 weeks with the elbow held in flexion to prevent redislocation of the radial head.

Occasionally, a 'backward Monteggia' may occur. The radial head is dislocated posteriorly and the ulnar bowed backwards.