Irreducible Traumatic Radial Head Dislocation Due to Annular Ligament Interposition in a Child with Ulnar Plastic Deformation: A Case Report

Irreducible Isolated Radial Head Dislocation in a Child Due to Annular Ligament Interposition: A Case Report

The annular ligament of the elbow is essential for its stability, playing a key role in both the proximal radioulnar and humeroradial joints, as well as supporting surrounding muscles and ligaments. Radial head dislocation is rare in children, and when isolated they can be challenging to reduce and may require surgical intervention. An 11-year-old boy presented with an anteromedial dislocation of the radial head after a fall. Initial, closed reduction was attempted and failed, requiring surgical intervention, where we found a rupture of the annular ligament and interposition, which was repaired after reduction. At one year of follow-up, the patient achieved full range of motion and stability of the elbow. Radial head dislocation is rare in children and even more rare without associated ulna fractures. Evaluating radiographs for plastic deformities of the ulna is crucial, as these injuries are often overlooked. Failed closed reductions may rise suspicion of interposed structures. Isolated post-traumatic radial head dislocation is a rare occurrence requiring prompt recognition and management. While most cases are treated with closed reduction, those that are not reducible or suspected soft tissue interposition may require open reduction. Thorough clinical evaluation, both vascular and neurologic and preoperative imaging are essential. Early intervention and meticulous surgical techniques can lead to favorable functional outcomes.

Traumatic Irreducible Pediatric Radial Head Dislocations: A Unique Case and Review of the Literature

Background

Irreducible radial head dislocations are uncommon injuries and blocks to reduction typically result from interposed soft tissue. We report the case of a pediatric patient who sustained an irreducible radial head dislocation with a concomitant posterior elbow dislocation and coronoid process fracture. To the author's knowledge, irreducible radial head dislocations presenting as part of a terrible triad like constellation of injuries have not been previously reported. A case-based review of the literature was also performed.

Case Description

A 7-year-old male presents to our pediatric hospital as a transfer from an outside hospital after sustaining a posterolateral radial head and posterior elbow dislocation secondary to a fall. CT imaging and 3D reconstruction revealed a Type 1 coronoid process fracture. At our institution, closed attempts at reduction in the operating room under fluoroscopy with general anesthesia were also unsuccessful. Open reduction of the radial head and repair of the soft tissue structures was ultimately required to stabilize the patient's elbow injury.

Conclusion

Irreducible pediatric radial head dislocations are rare and inherently unstable injuries. To the authors' knowledge, there are no prior reports of irreducible radial head dislocations that present in a terrible triad like fashion with a coronoid process fracture and posterior elbow dislocation. In the present report, successful treatment of this injury required open reduction and soft tissue repair. Level of Evidence: IV.