Comparison of united and nonunited fractures of the ulnar styloid following volar-plate fixation of distal radius fractures

Introduction: The purpose of this study was to determine whether associated nonunion of ulnar styloid fracture following plate-and-screw fixation of a distal radius fracture (DRF) has any effect on wrist functional outcomes, ulnar-sided wrist pain or distal radioulnar joint (DRUJ) instability. Materials and methods: A total of 91 consecutive patients with a DRF and an accompanying ulnar styloid fracture treated by open reduction and volar locking plate fixation were included in this study. In the first part of the analysis, the 91 study subjects were subdivided according to the presence or not of ulnar styloid union (20 and 71, respectively) by radiography at final follow-up (average 23 months). These two cohorts were compared with respect to wrist functions at 3 months postoperatively and the final follow-up visit, and ulnar-sided wrist pain and DRUJ instability at the final follow-up visit and ulnar styloid length as determined radiographically at final follow-up. In the second part of the analysis, 49 of the 91 study subjects with an ulnar styloid base fracture were subdivided according to the presence or not of ulnar styloid base fracture union (12 and 37, respectively) at final follow-up by radiography. These two groups were also compared with respect to the above-mentioned parameters. Results: Ulnar styloid fractures united in 20 (22%) of the 91 patients at final follow-up visit (average 23 months). No significant differences were found at any time during follow-up between patients who achieved or did not achieve ulnar styloid fracture union or ulnar styloid base fracture union. Conclusion: Ulnar styloid nonunion does not appear to affect wrist functional outcomes, ulnar-sided wrist pain or DRUJ stability, at least when a DRF is treated by open reduction and volar plate fixation. (C) 2010 Elsevier Ltd. All rights reserved.