Mini Fragment and Small Fragment Screws are Comparable in Acute Syndesmotic Injury

Abstract

Ankle fractures are often accompanied by syndesmotic injuries, contributing to instability and potential long term complications. Syndesmotic injuries are traditionally fixed with either small fragment (3.5-mm diameter) or large fragment (4.5-mm diameter) syndesmotic screws. With regards to the recent emergence of less prominent implants for ankle fracture, this study was set out to compare the outcomes of mini fragment screws (2.7-mm or 2.8-mm diameter) and small fragment screws in syndesmotic fixation. Eighty-seven patients with traumatic syndesmotic injuries were retrospectively included for this study. Forty-four patients underwent mini fragment fixation and 43 patients underwent standard small fragment fixation. After-treatment was similar in both groups. Primary outcome consisted of the incidence of malreduction and secondary dislocation within three months. Secondary objectives were the incidence of the overall complication rate and implant removal rate. In total, malreduction was observed in three patients (3.4 %) and secondary dislocation in two patients (2.3 %), with no significant differences between the mini fragment and small fragment groups. Mini fragment fixation demonstrated a significantly lower overall complication rate (2.3 %) compared to the small fragment group (16.3 %)(p = .030). Implant removal rates were similar between the groups (27.3 % for mini fragment and 27.9 % for small fragment screws). This study suggests that both screw types are effective for fixation of acute syndesmotic injuries, with comparable malreduction and secondary dislocation rates. Prospective studies with longer follow-up, including functional outcome, are needed for comprehensive insights into optimal syndesmotic screw selection.

Keywords: Ankle; fixation; fracture; malreduction; syndesmosis; tibiofibular joint.