Ulnar Styloid Fracture with Distal Radioulnar Joint Subluxation/Dislocation

In 55 patients with ulnar styloid fractures, the site and displacement of the fracture was examined in relation to distal radioulnar joint subluxation/dislocation by computed tomography (CT). Distal radioulnar joint subluxation/dislocation confirmed with CT in 18 of 55 patients, irrespective of the site of the ulnar styloid fracture. In 21 patients with nondisplaced styloid fractures, only 3 fractures were associated with distal radioulnar joint subluxation/dislocation. In 34 patients where the styloid fracture was displaced for 3 mm or more, 15 fractures were associated with a distal radioulnar joint subluxation/dislocation. Therefore, ulnar styloid displacement of 3 mm or more suggests the need for further examination of the distal radioulnar joint.