Radial head dislocation due to gigantic solitary osteochondroma of the proximal ulna: case report and literature review.

Developmental anterior dislocation of the radial head resulting from a congenital solitary osteochondroma of the proximal ulna is an extremely rare condition. We present a case of a 4-year-old girl with this condition affecting her right elbow, which was treated by a trapezoidal shortening osteotomy at the radial neck following an oblique ulnar osteotomy with angulation and elongation after a complete resection of the tumor mass. The child remained asymptomatic with symmetric carrying angles during 2.5 years of follow-up post-surgery. We discuss the nature of this condition and review the literature.