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Figure 1. Anteroposterior radiograph of the right elbow.
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Figure 2. Lateral view of injured elbow.
A 13-year-old girl presents to the emergency department with right elbow pain from a fall 2 hours earlier. She is a gymnast and fell awkwardly on the right arm from approximately 6 feet high. She has an obvious deformity to the elbow and is unable to move her arm. She is, however, able to make a rock, paper, and scissors sign with her right hand. Radiographs are taken (Figure 1 and 2).
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Traumatic elbow dislocations in children are relatively rare injuries. Posterior dislocations are the most common type of elbow dislocation and are caused by a fall on an outstretched hand with the forearm supinated and the elbow in 15 to 20 degrees of flexion.1,2 The ulnar nerve is the most common nerve injured during a posterior lateral dislocation as the nerve is often stretched as the elbow goes into a valgus position.1,2
Asking the patient to perform “rock, paper, scissors” grossly tests motor function. Making a fist tests the medial nerve, paper tests the radial nerve (finger extension), and scissors test the ulnar nerve (spreading fingers apart). Medial epicondyle fractures can commonly occur in pediatric elbow dislocations as the medial condyle is the last ossification center in the distal humerus to fuse, usually by age 15 to 20 years. The medial epicondyle is the attachment site of the flexor pronator mass and ulnar collateral ligament.1,2
Recognizing a displaced medial epicondyle fracture is critical as the bone can block the elbow reduction. Significant displacement often requires open reduction and internal fixation of the medial epicondyle fracture with screw fixation, after closed reduction of the elbow, to prevent long-term elbow instability.1,2
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 Orthopaedics for Physician Assistants.
References
1. Gottschalk HP, Eisner E, Hosalkar HS. Medial epicondyle fractures in the pediatric population. J Am Acad Orthop Surg. 2012;20(4):223-232. doi:10.5435/JAAOS-20-04-223
2. Varacallo M, Parikh D, Mody K, Herman MJ. Pediatric elbow dislocations: acute management. In: Abzug JM, Herman MUJ, Kozin S, eds. Pediatric Elbow Fractures. Springer. 2018:169-184.
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