Clinical Impact of United Versus Nonunited Fractures of the Proximal Half of the Ulnar Styloid Following Volar Plate Fixation of the Distal Radius

PurposeDistal radius fractures are often associated with a fracture of the ulnar styloid at its base. This study tested the null hypothesis that there is no difference in outcome between patients with union and nonunion of a fracture of the proximal half of the ulnar styloid 6 months after volar plate fixation of a fracture of the distal radius.MethodsA total of 36 consecutive patients with fractures of both distal radius and the proximal half of the ulnar styloid enrolled in 1 of 2 clinical trials evaluating volar plate fixation of the distal radius had no treatment of the ulnar styloid fracture. Six months after surgery, wrist function was assessed using the Mayo wrist score and the Gartland and Werley score system, and arm-specific health status was measured using the Disabilities of the Arm, Shoulder, and Hand questionnaire. Pain was assessed on a 10-point ordinal scale. Nonunion of the fracture of the proximal half of the ulnar styloid was defined as no signs of consolidation on 6-month postoperative radiographs. At the 6-month follow-up, patients were assessed for overall wrist function but not specifically for ulnar-sided wrist problems or stability.ResultsSixteen ulnar styloid fractures had united, and 20 had not. There were no differences in demographic and injury characteristics. There were no significant differences in motion; strength; Gartland and Werley scores; Mayo scores; Disabilities of the Arm, Shoulder, and Hand scores; or pain scores 6 months after fracture.ConclusionsNonunion of a fracture of the proximal half of the ulnar styloid has no effect on wrist function, pain, and upper extremity–specific health status 6 months after volar plate fixation of a fracture of the distal radius.Type of study/level of evidenceTherapeutic III.