Does an ulnar styloid fracture interfere with the results of a distal radius fracture?

The ulnar styloid is a supportive structure for the capsular ligament complex of the distal radioulnar joint. The relation between fractures of the ulna and distal radius is not clear, especially in regard to whether ulnar fractures predict worse outcomes for distal radius fractures. The objective of this study was to analyze the influence of ulnar styloid fractures in patients with reducible and unstable distal radius fractures.

A total of 100 patients with unstable and reducible distal radius fractures, with or without an ulnar styloid fracture, were randomly assigned to treatment with transarticular bridging external fixation or transulnar percutaneous pinning. Follow-up was obtained for 91 patients. For the secondary data analysis, three patient cohorts were created: a no ulnar styloid fracture group with the radius fracture treated by pinning or external fixation (n = 30); an ulnar styloid fracture with radius fracture group treated by external fixation (n = 31); and an ulnar styloid fracture with radius fracture treated by pinning (n = 30). Functional and radiological outcomes were measured at 6 and 24 months. Functional outcome measures included wrist pain (visual analogue scale) and the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire.

At 24 months, patients with both fractures had worse wrist pain and worse scores on the DASH questionnaire than the patients with an isolated distal radius fracture; and those treated by pinning had less wrist pain and showed better scores on the DASH questionnaire than the patients treated by fixation.

Ulnar styloid fracture may be a predictive factor of worse functional outcome for distal radius fracture. Pinning and above-the-elbow casting, used to treat ulnar styloid fractures, led to better function than fixation.