Monteggia Fracture Dislocation

Fracture of the proximal third of the ulna with dislocation of the radial head.

Fracture is more common in children, rare in adults.

Treatment depends on the age of the patient.

There are four types of this fracture /dislocation.

The normal position of the radial head and the shaft should line up with the capitellum in any position, dislocation of the radial head may be missed.

1- Type I:
– A fracture of the middle or proximal third of the ulna with anterior dislocation of the radial head and characteristic apex anterior angulation of the ulna.
– Most common of all types, about 60%.
– In children, immobilize in flexion and supination.
– Flex the elbow more than 90 degrees to relax the biceps.

2- Type II:
– 15% .
– Fracture of the middle or proximal third of the ulna with posterior dislocation of the radial head and characteristic apex posterior angulation of the ulna.
– Immobilize in extension.

3- Type III:
– 20%.
– Fracture to the ulna just distal to the coronoid process with lateral dislocation of the radial head.

4- Type IV:
– 5%.
– Fracture of the proximal or middle third of the ulna with anterior dislocation of the radial head, and a fracture of the proximal third of the radius below the bicipital tuberosity.
– Surgery even in children.
– Neurovascular examination is important.
– Nerve injury, especially involving the posterior interosseous nerve, is not uncommon (observe).
– Watch the patient for compartment syndrome.

Treatment:

1- Treatment in adults: ORIF of the ulna: when the ulna is properly aligned and fixed, the radial head will reduce by itself.
– Radial head instability may usually be caused by nonanatomic reduction of the ulna or by interposition of the ulnar ligament.
– Fracture of the ulna may need bone graft for healing.

2- Treatment in children:
– The radial head ossifies around 4 years of age.
– Type I-III fractures: do closed reduction of the ulna to restore the length of the ulna and reduce the radial head, immobilize in flexion and supination.
– Type IV fracture: Surgery, or in cases where unable to reduce the radial head or length of the ulna, use an IM rod or a plate.
– Do osteotomy of the ulna.
– Open reduction of the radial head followed by plating of the ulna.

Courtesy: Prof Nabil Ebraheim, University of Toledo, Ohio, USA