Late Distal Radio-Ulnar Joint Instability after Childhood Distal Forearm Fracture

Abstract

Introduction: Paediatric distal radius fractures are considered benign, and associated ulnar styloid injury is mostly ignored. Although a significant portion evolves to non-union, only a minority present associated complications such as ulnar pain, ulnocarpal abutment, or distal radio-ulnar instability. Distal radio-ulnar dislocations are rare and point to failure of the stabilizing mechanisms of this joint, warranting urgent reduction. Case Report: 18-years old male presents to the emergency department with a volar distal radio-ulnar joint dislocation after a twisting motion of the left wrist. Patient was submitted to urgent closed reduction under general anesthesia and cast immobilization, and surgical repair of ulnar styloid non-union and triangular fibrocartilage complex tear was performed 1 week later. At 6 months follow up the patient as achieved pain free full mobility without instability. Conclusion: The triangular fibrocartilage complex and distal radio-ulnar joint may be affected by seemingly benign injuries, later presenting with acute complications. Fracture and subsequent non-union of the ulnar styloid in the setting of a distal radius fracture is common and underdiagnosed, but clinical significance of and optimal treatment of this injury are still undefined.