Monteggia’s fracture

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A fracture of the proximal third of the ulna with dislocation of the proximal head of the radius.

Mechanisms of injury include:

Fall on an outstretched hand with the forearm in excessive pronation.

The Ulna fractures in the proximal one-third of the shaft due to extreme dislocation.

Depending on the impact and forces applied in each direction, degree of energy absorption determines pattern, involvement of the radial head and whether or not open soft tissue injury occurs.

Isolated ulnar shaft fractures are most commonly seen in defence against blunt trauma (e.g. nightstick injury).

There are four types of classifications based upon displacement of the radial head.

Bado Classification – Monteggia Fractures

I – Extension type (60%) – ulna shaft angulates anteriorly (extends) and radial head dislocates anteriorly.

II – Flexion type (15%) – ulna shaft angulates posteriorly (flexes) and radial head dislocates posteriorly.

III – Lateral type (20%) – ulna shaft angulates laterally (bent to outside) and radial head dislocates to the side.

IV – Combined type (5%) – ulna shaft and radial shaft are both fractured and radial head is dislocated, typically anteriorly.

Management

Monteggia fractures may be managed conservatively in children with closed reduction by resetting and casting, but due to high risk of displacement causing malunion, open reduction internal fixation is typically performed.

Osteosynthesis by open reduction and internal fixation of the ulnar shaft is considered the standard of care in adults.

Osteosynthesis promotes stability of the radial head dislocation and allows very early mobilisation to prevent stiffness.

In children, the results of early treatment are always good.

If diagnosis is delayed, reconstructive surgery is needed and complications are much more common and results are poor.

In adults, the healing is slower and results usually not as good.

Complications of surgery can include non-union, malunion, nerve palsy and damage, muscle damage, arthritis, tendonitis, infection, stiffness and loss of range of motion, compartment syndrome, audible popping or snapping, deformity, and chronic pain associated with surgical hardware such as pins, screws, and plates.