Posterolateral elbow dislocation with sub flexor displacement of radial head fragment

Abstract

Elbow joints are the second most common joints to dislocate, second only to shoulder joints with most of the dislocations occurring in the posterolateral direction. The dislocations can be simple involving capsuloligamentous structures around the joint or complex involving associated bony injuries. The dislocations can be disabling for the patients with the sequelae involving decreased range of movement, valgus instability due to ruptured medial collateral ligament complex, ectopic calcification, degenerative changes and neurologic deficits. The terrible triad is a type of complex elbow dislocation involving fracture of radial head along with coronoid process fracture. This injury is highly unstable and most of the time requires surgical intervention. We present 2 cases of terrible triad injuries that needed surgical intervention. The radial head fractures in both the cases could be classified as Mason type 2 injuries and the coronoid fractures could be classified as type 1 fracture according to Regan and Morrey classification. The aim of this report is to highlight the medial and distal migration of the fractured fragment of the radial head to the anterior aspect of ulna underneath flexor digitorum profundus, at the junction of proximal third and distal two thirds of the shaft of ulna. On radiographs, this could be mistaken for fractured fragment of coronoid process of ulna, which could mislead the surgeon pre and intra operatively causing delay and confusion in the surgery.