Monteggia & Galeazzi injuries

The radius and ulna form a ring with two joints. If one bone is broken and shortened, the other must dislocate at one end. Monteggia: ulnar fracture with dislocation of the radial head. Galeazzi: radial shaft fracture (distal third) with dislocation of the distal radioulnar joint (DRUJ).

Mechanism

Falls on the outstretched hand with forced pronation; direct blows ("nightstick" mechanism).

Clinical findings

• Any isolated ulnar fracture: check the radial head. Any radial shaft fracture: check the DRUJ (prominent ulnar head, painful rotation).
• Monteggia: posterior interosseous nerve palsy (finger drop).

Imaging

• AP and lateral of the whole forearm, including elbow and wrist: always image the joint above and below a forearm fracture.
• Radiocapitellar line on every elbow view (Monteggia); distal radioulnar joint on the wrist lateral (Galeazzi).

• Always X-ray the whole forearm including elbow and wrist. The radiocapitellar line must point at the capitellum in every view.

Classification

Bado I–IV

Monteggia by the direction of the radial head dislocation: I anterior (most common), II posterior, III lateral, IV with radial shaft fracture.

Galeazzi

Radial shaft fracture with DRUJ injury; fractures within 7.5 cm of the wrist are more often unstable.

Types shown in 3D

Bado I

Ulnar shaft fracture angulated anteriorly with anterior dislocation of the radial head (most common, especially in children).

Bado II

Posterior angulation and posterior dislocation of the radial head (adults, often with a radial head fracture).

Bado III

Ulnar metaphyseal fracture with lateral dislocation of the radial head (children).

Bado IV

Fracture of both bones at the same level with anterior dislocation of the radial head.

Galeazzi

Radial shaft fracture in the distal third with dislocation of the distal radioulnar joint: the radius shortens and the ulnar head becomes prominent. Plate the radius, then test the DRUJ.

Treatment

Adults

Open reduction and plate fixation of the broken bone restores length and usually reduces the dislocated joint. Then test the joint: an unstable DRUJ is pinned or held in supination; a radial head that stays dislocated suggests malreduction of the ulna or interposed tissue.

Children

Monteggia: closed reduction of the ulna (plastic deformation counts!) and above-elbow cast; unstable patterns get an intramedullary wire or plate.

Aftercare

Early motion after plating.

Complications

• Missed dislocation (chronic Monteggia is difficult to treat)
• Loss of forearm rotation
• Nerve palsy