UMEM Educational Pearls

Title: What's the Diagnosis? Images submitted by Dr. Joy Kay

Category: Visual Diagnosis

Posted: 8/7/2011 by Haney Mallemat, MD (Updated: 8/8/2011)
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13 year-old right-hand dominant male following assault with blunt object. Diagnosis?

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.

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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