Monteggia fracture-dislocation

Background

• common in kids (different tx for kids)
• FOOSH
• Easy to overlook the radial head dislocation (will result in worse outcome)
• Pediatric
  • radial head dislocation + proximal ulna fracture or plastic deformation of the ulna without obvious fracture
• Adult
  • proximal 1/3 Ulna fx + radial head dislocation (due to ulna shortening)
  • radial head can dislocate anterior, posterior, or laterally

Clinical Features

• Pain/swelling at elbow
• Radial head may be palpable in an anterolateral or posterolateral location
• spontaneous relocation possible: must palpate directly over
• May be associated with radial nerve injury (wrist drop, inability to extend the fingers et cetera)

Complex Associated Injuries

• open fracture
• olecranon fracture-dislocation
• radial head fx
• coronoid fx
• LCL injury
• terrible triad of elbow

Adult Imaging

• xray: AP, lat of elbow, forearm, wrist
• CT scan: fxs involving coronoid, olecranon, and radial head

Pediatric Imaging

• xray: AP, lat of elbow, forearm, wrist
  • assess radiocapitellar line on every lateral radiograph of the elbow: a line down the radial shaft should pass through the center of the capitellar ossification center

Management

• Consult ortho in the ED
• Adults: likely requires ORIF
• Peds: possible long arm cast vs ORIF

Complications

• consider open fracture (look for puncture wounds)
• compartment syndrome
• Posterior Interosseous Neuropathy (PIN) - radial nerve branch; affects ~10% of Monteggia Fxs
  • purely a motor syndrome resulting in finger drop, and radial wrist deviation on extension.
• malunion with radial head dislocation

See Also

• Forearm Fracture
• compartment syndrome

Source

• de laGarza JF. Monteggia fracture-dislocation in children. In: Beaty JH, Kasser JR, eds. Rockwood and Wilkins' Fractures in Children, 6th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2006:491-527.