UMEM Educational Pearls

Question

13 year-old right-hand dominant male following assault with blunt object. Diagnosis?


Answer

Answer: Monteggia fracture

 

Monteggia Fracture

  • Ulnar fracture with dislocation of proximal radioulnar joint (often subtle); do not confuse with Galeazzi fracture (radial-shaft fracture with distal radioulnar dislocation)
  • Due to fall on outstretched hand with arm in hyper-pronation or with direct trauma to forearm as in defensive wounds (e.g., nightstick injury).
  • Ulnar fracture typically the proximal third (although any portion can be involved).
  • Relatively uncommon; 1-2% forearm fractures
  • Interosseous membrane (between radius and ulna) transmits forces to radioulnar joints and causes associated dislocations.
  • Suspected forearm fractures should always include Xray of the wrist, forearm, and elbow  
  • Bado classification system (Type I-IV) used; based on displacement of radial head.
  • Children may be treated with closed reduction and immobilization; adults usually require open reduction and internal fixation.
  • Radial head dislocations should be reduced within 6-8 hours as can lead to articular damage and/or nerve injury.
  • Radial, ulnar and/or median nerve neuropraxias (motor or sensory deficits) may complicate injury with resolution over several weeks.

References

Bruce H.E., Harvey J.P., Wilson J.C. Monteggia Fractures. J Bone Joint Surg Am. 1974;56:1563.

Reckling F.W. Unstable fracture-dislocation of the forearm (Monteggia and Galeazzi lesions). J Bone Joint Surg Am. 1982;64:857.

http://emedicine.medscape.com/article/1231438-overview
 

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