Ulnar styloid fractures may contribute to negative outcomes after distal radius fractures due to its association with distal radioulnar (DRUJ)instability and injuries of the triangular fibrocartilaginous (TFCC) complex. This study assesses clinical outcomes of untreated ulnar styloid fractures after internal fixation of distal radius fractures.

Patients undergoing operative fixation for distal radius fractures from January 2004 to June 2006 were divided into those with and without ulnar styloid fractures. The two groups were compared in terms of wrist range of motion, ulnar sided wrist pain, extensor carpi ulnaris (ECU) tendinitis, TFCC grind test, and DASH scores.

Thirty-one males and 23 females aged 50.9 years(18–88 yrs, SD 16.5) were assessed. At 24 months, the presence of ulnar styloid fractures had no impact on ulnar-sided wrist pain (p=0.331), TFCC grind test(p=0.917) and distal radioulnar joint instability (p=0.957). There was a tendency towards ECU tendinitis (23.8% vs 6.1%, p= 0.058) in patients with ulnar styloid fractures. There was no significant difference in the range of motion and overall DASH scores (8.0 vs 5.9, p=0.474).

No association was found between ulnar styloid fractures and DRUJ instability in this study. Ulnar styloid fractures behave like avulsion injuries. In the absence of DRUJ instability, conservative management of ulnar styloid fractures during operative treatment of distal radius fractures do not compromise clinical outcome.