The forearm AP x-ray shows fracture of upper third of ulna with an impacted radial neck fracture. The radio-capitellar line is intact on this view.

The lateral radiograph again shows fracture of the upper third of ulna. The radio-capitellar line is off indicating the presence of radial head dislocation.

This combination of injury with proximal ulna shaft fracture & dislocated radial head constitutes Monteggia fracture dislocation.

The radio-capitellar line should be intact in both AP & lateral views of elbow.

The patient underwent operative reduction in theatre.