Elbow Dislocation on MRI & X-ray: Imaging Findings

Simple elbow dislocations involve purely capsuloligamentous injury without associated fractures. The lateral ulnar collateral ligament is the primary restraint disrupted, followed sequentially by the anterior capsule and the medial ulnar collateral ligament in the Horii circle of disruption described by O'Driscoll. Complex elbow dislocations involve associated fractures of the radial head, coronoid, or both, constituting the terrible triad injury. Coronoid fractures are classified by the Regan–Morrey system (Type I: tip avulsion, Type II: up to 50% of coronoid, Type III: greater than 50%) or the O'Driscoll classification, with larger fragments representing greater instability.

Closed reduction should be performed as soon as possible, ideally in the emergency department with adequate analgesia and procedural sedation. For a posterior dislocation, the most common direction, traction is applied to the forearm along its long axis while the elbow is gently flexed, and the olecranon is simultaneously lifted anteriorly. Neurovascular examination before and after reduction is mandatory. Vascular compromise—absent radial pulse, hand pallor, or expanding hematoma—is an indication for emergency reduction, and if the pulse does not return after reduction, vascular surgery consultation for arterial exploration is required, as the brachial artery is at risk in severely displaced posterolateral dislocations.

After successful closed reduction of a simple elbow dislocation, the joint is splinted in 90 degrees of flexion for 7 to 10 days to allow initial soft tissue healing, followed by progressive range-of-motion exercises. Most patients regain functional motion within 6 to 8 weeks, though some residual extension loss of 10 to 15 degrees is common. Return to sport occurs at 3 to 6 months. Complex dislocation with fractures typically requires surgical fixation of the radial head and coronoid, ligament repair or reconstruction, and a longer rehabilitation course of 6 to 12 months. Stiffness is the most common long-term complication, and heterotopic ossification can develop in high-energy injuries.