Paeds Trauma iSAWE 3

Question

A 7 year old boy has a fracture of the proximal ulna after a fall. Four weeks later he still cannot fully rotate his forearm.

Paeds Trauma iSAWE 3, ap and lateral radiographs of the forearm and elbow
AP and lateral radiographs of the forearm and elbow. Image by Hellerhoff, Wikimedia Commons, CC BY-SA 3.0.
  1. What injury has been missed and how is it classified?
  2. How would you have recognised it?
  3. How would you manage it acutely and when it presents late?

Answer

Missed injury

  • Monteggia fracture dislocation, proximal ulna fracture with radial head dislocation
  • Bado classification types I anterior, II posterior, III lateral and IV with a radial shaft fracture
  • Plastic deformation of the ulna is a subtle Monteggia equivalent in children

Recognition

  • A line through the radial neck should pass through the capitellum in every view (radiocapitellar line)
  • Always image the elbow and wrist with any forearm fracture
  • Check the posterior interosseous nerve

Acute management

  • Restore ulnar length and alignment, which reduces the radial head
  • Closed reduction and cast in supination for type I in young children
  • Intramedullary wire or plate fixation of the ulna for unstable patterns

Late presentation

  • Chronic Monteggia lesions are treated in children with ulnar osteotomy (lengthening and angulation), open reduction of the radial head and annular ligament reconstruction
  • Better results when performed within about 1 to 3 years
  • Untreated cases develop pain, valgus, limited rotation and radial head deformity

Related pages

Author Contributions

Orthofracs team

Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.