The Effect of Ulnar Styloid Fractures on Patient-Rated Outcomes After Volar Locking Plating of Distal Radius Fractures

Purpose: Ulnar styloid fractures commonly occur with distal radius fractures (DRFs). Ulnar styloid fractures that involve the insertion of the radioulnar ligaments can cause distal radioulnar joint (DRUJ) instability, and the literature suggests that these fractures should be treated with open reduction internal fixation (ORIF). However, in the absence of DRUJ instability, the effects of ulnar styloid fractures are unknown. The purpose of this study is to evaluate the outcome of ulnar styloid fractures without DRUJ instability on patient-rated outcomes after DRF ORIF. Methods: Between 2003 and 2008, a cohort of DRF patients treated with volar plating was enrolled. Patients with DRUJ instability treated at the time of distal radius ORIF were excluded. Radiographs were evaluated to identify and characterize ulnar styloid fractures. Patient-rated outcomes were measured at 6 weeks, 3 months, 6 months, and 12 months postoperatively using the Michigan Hand Outcomes Questionnaire (MHQ). Regression analysis was performed to determine whether the presence of an ulnar styloid fracture, the size or displacement of the fracture, or the healing status of the fracture was predictive of MHQ scores. Results: One-hundred and forty-four patients were enrolled; 88 patients had ulnar styloid fractures. During the collection period, DRUJ instability was found intraoperatively in 3 patients; these patients had ulnar styloid ORIF and were not enrolled. The 144 patients with a stable DRUJ after DRF ORIF maintained DRUJ stability after surgery. In these patients, the presence of an ulnar styloid fracture did not affect MHQ scores. Furthermore, the size of the ulnar styloid fracture, the degree of displacement, and the healing status of the ulnar styloid did not affect MHQ scores. Conclusions: In patients with a stable DRUJ after DRF ORIF ulnar styloid fractures did not affect subjective outcomes as measured by the MHQ. Type of study/level of evidence: Prognostic III.