Slideshow
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Figure 1. Anteroposterior radiograph of the left elbow.
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Figure 2. Lateral radiograph of the left elbow.
A 5-year-old child presents to the urgent care clinic with pain in her left elbow after she fell off of the monkey bars a few hours ago. She landed on the left hand with the arm in extension and has been unable to move the elbow since sustaining the injury. Anteroposterior and lateral radiographs of the left elbow are obtained (Figures 1 and 2).
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A Monteggia fracture is a fracture that occurs at the proximal third of the ulnar with a dislocation of the radial head or plastic deformation of the ulna without obvious fracture and radial head dislocation.1,2 These fractures are rare in children and can be missed at the initial presentation in up to 50% of pediatric patients.1
A missed diagnosis can cause disabling consequences since a persistent radial head dislocation can start to cause permanent loss of elbow motion and stability after just 2 weeks.1,2 When establishing a diagnosis, the patient’s range of motion should be carefully scrutinized for full elbow flexion and extension and full forearm supination and pronation.1-3
It is crucial for providers to be able to recognize an intact radiocapitellar joint on radiography. This often can be difficult to do because of the numerous ossification centers of the elbow. If there is any confusion on radiographic interpretation, imaging of the contralateral elbow should be obtained for a side-by-side comparison.2,3
The nonoperative treatment of choice is an acute closed reduction and long arm cast with the forearm placed in supination. The radial head will often reduce spontaneously when the ulna length is restored. Closed reduction should be performed as soon as possible; the reduction becomes more difficult as time from injury passes. Chronic Monteggia fractures, defined as a dislocation older than 4 weeks, usually require an open reduction. Open reduction and internal fixation is only performed in patients with closed growth plates.1-3
Dagan Cloutier, MPAS, PA-C, practices in a multispecialty orthopedic group in the southern New Hampshire region and is editor in chief of the Journal of Orthopedics for Physician Assistants.
References
1. Soni JF, Valenza WR, Matsunaga CU, Costa ACP, Faria FF. Chronic Monteggia fracture-dislocation in children surgical strategy and results. Acta Ortop Bras. 2019;27(5):244-247.
2. Allen D. Monteggia fracture—pediatric. OrthoBullets website. Updated March 7, 2020. Accessed October 19, 2020. https://www.orthobullets.com/pediatrics/4015/monteggia-fracture–pediatric.
3. Hubbard J, Chauhan A, Fitzgerald R, Abrams R, Mubarak S, Sangimino M. Missed pediatric Monteggia fractures. JBJS Rev. 2018;6(6):e2.
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