Unilateral sacral fragility fractures are frequently managed with unilateral percutaneous iliosacral screw fixation, which may increase stress on the contralateral sacrum and lead to secondary fractures. This study compared complication rates between unilateral and bilateral screw osteosynthesis and evaluated risk factors for contralateral fracture following unilateral treatment.

This retrospective study included patients with unilateral sacral fragility fractures treated between 2018 and 2024. Patients were categorized into two groups: Group 1 (unilateral fixation) and Group 2 (bilateral fixation). Demographics, fracture morphology, and outcomes at 3 and 12 months postoperatively were assessed. Potential risk factors included comminution, sacral zone involvement, and concomitant anterior pelvic ring fractures.

A total of 119 patients were analyzed (44 unilateral, 75 bilateral). The complication rate was significantly higher in the unilateral group (26% vs. 7.1%; p = 0.03). Contralateral fractures occurred more frequently in the unilateral group, particularly in the presence of anterior pelvic ring fractures, although this association was not statistically significant (p = 0.2).

Bilateral screw osteosynthesis significantly reduces complication rates compared to unilateral fixation in the treatment of unilateral sacral fragility fractures. These findings support the routine consideration of bilateral fixation, particularly in patients with concomitant anterior pelvic ring injuries, to minimize the risk of contralateral sacral failure.