Treatment of Capitellum Fracture with Chronic Radial Head Dislocation.

We encountered a case of capitellum fracture with radial head dislocation in which it was challenging to diagnose whether the dislocation was coincident with the fracture or this was chronic dislocation that presented before the fracture. Chronic radial head dislocation may be congenital or could occur in patients with untreated post-traumatic dislocation, although diagnosis is particularly challenging if the radial head dislocation is unilateral. Classical capitellum fracture involves anterosuperior bone fragment dislocation. However, in the present case, the bone fragment was present beneath the radial head, which suggests chronic radial head dislocation. When the bone fragment appears in a different position than usual, every effort should be made to understand the pathophysiology by reviewing the mechanism of onset, disease history, and imaging.