Congenital Posterior Dislocation of the Radial Head

June 4, 2018

Adeet Amin, BS; Matthew Fisher, BS; and Lynnette Mazur, MD, MPH
University of Texas Health Science Center at Houston McGovern Medical School

Amin A, Fisher M, Mazur L. Congenital posterior dislocation of the radial head [published online June 4, 2018]. Consultant for Pediatricians.


A 14-year-old boy presented to the clinic with a sore throat, which was diagnosed as streptococcal pharyngitis and treated appropriately. However, he was also concerned about a bump on his left elbow that had been enlarging over the past year and had caused limited rotation of his forearm (Figure 1). There was no history of trauma. He denied pain, tingling, numbness, and difficulty moving his fingers. His birth history and past medical history were unremarkable, and the family history was negative for similar problems.


Figure 1. Initial presentation of the elbow.


Physical examination. On examination, he had full range of motion of his shoulders and hands and was able to fully flex both elbows, but he could not fully extend his left elbow, and he was only able to rotate the left forearm to a neutral position. A nontender bony protuberance was palpable on the posterior aspect of the elbow, and there was a prominence of the ulna at the left wrist. Strength and sensation were normal, and there were no other associated defects.

Possible etiologies included congenital, traumatic, and pathologic (Table).

Table. Differential Diagnosis of Painless Posterior Elbow Masses

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