Should ulnar styloid be fixed following fixation of a distal radius fracture?

Fracture of the base of the ulnar styloid has shown to have higher incidence of TFCC tears and DRUJ instability leading to nonunion and impaired function. Poorer functional outcomes of the distal radius fracture have been attributed to the untreated associated ulnar styloid fractures while some studies have shown no difference. Thus, the treatment remains controversial. However, it has been shown that fractures at the base of the ulnar styloid have a higher incidence of tears in the triangular fibrocartilage complex (TFCC) and instability in the distal radioulnar joint (DRUJ), which can lead to nonunion and impaired function. Despite this, there are currently no studies comparing the outcomes of surgically and conservatively treated patients.

A retrospective study was conducted to analyze the outcomes of intra-articular distal radius fractures associated with base of ulnar fracture treated with distal radius LCP fixation. The study included 14 patients who were treated surgically and 49 patients who were treated conservatively, with a minimum follow-up of 2 years. Radiological parameters such as union and amount of displacement, VAS score for ulnar-sided wrist pain, functional assessment using the modified Mayo score and the quick DASH questionnaire and complications were analyzed.

At the final follow-up, the mean scores for pain (VAS), functional outcomes (modified Mayo score), disability (QuickDASH score), range of motion, and non-union rate were found to be statistically insignificant (p > 0.05) between the surgically treated and conservatively treated groups. However, patients with non-union had statistically significant higher scores for pain (VAS), greater post-operative displacement of the styloid, poorer functional outcomes, and higher disability (p < 0.05).

While there was no significant difference in ulnar-sided wrist pain and functional outcomes between the surgically treated and conservatively treated groups, the conservatively treated cases had a higher risk of non-union, which can negatively impact functional outcomes. The amount of pre-operative displacement was found to be a key factor in predicting non-union and can be used as a guide for determining the management of this type of fracture.