Mini-Anchor Fixation vs Conservative Treatment for Hauck Type II Ulnar Styloid Fractures Associated With Distal Radius Fractures: A Retrospective Cohort Study.

Abstract

BACKGROUND Hauck type II ulnar styloid fractures (USFs) occur at the base of the ulnar styloid process, where the triangular fibrocartilage complex attaches. Nonunion or disruption at this level may compromise distal radioulnar joint (DRUJ) stability, although the clinical significance of associated USFs in distal radius fractures (DRFs) remains debated. This retrospective cohort study compared outcomes after mini-anchor fixation vs no ulnar styloid fixation in patients with DRFs and concomitant Hauck type II USFs. MATERIAL AND METHODS Forty-five patients treated between 2021 and 2023 were included. Twenty-three patients underwent mini-anchor fixation of the ulnar styloid (group A), and 22 did not (group C). Primary outcomes were USF union and ulnar-sided or DRUJ stability-related complications. Secondary outcomes included wrist range of motion, grip strength, the Modified Mayo Wrist Score, and the Quick Disabilities of the Arm, Shoulder, and Hand score. RESULTS All DRFs healed in both groups. USF union occurred in all patients in group A, whereas 2 nonunions occurred in group C (P=0.233). Ulnar-sided pain was less frequent in group A than in group C (P=0.346), and DRUJ subluxation occurred only in group C (P=0.489). Range of motion, grip strength, and functional outcome scores were comparable between groups. CONCLUSIONS Mini-anchor fixation was associated with higher union rates and fewer ulnar-sided or DRUJ-related complications, although differences were not statistically significant, and overall wrist function was similar between groups. Given the modest sample size, these findings should be considered preliminary and require confirmation in larger prospective studies.