Ballistic Pelvic Fractures with Bowel-First Trajectory are Associated with Increased Rates of Bony Infection: a Multicenter Assessment.

Abstract

To compare deep infection rates from ballistic ilium fractures in which the trajectory traversed the bowel before entering bone versus those that enter the bone before bowel, and to identify factors associated with deep infection of the bony pelvis. Design: Retrospective cohort study. Eight Level I trauma centers. Patients 18 years or older with ballistic ilium fractures (OTA/AO 61) and minimum 6-months of radiographic and clinical follow-up from January 2019 to December 2024. The primary study outcome was the rate of secondary deep pelvic bony infection requiring subsequent surgical irrigation and debridement. Associations between ballistic trajectory (traversing bowel before entering bone [Bowel] versus bone before entering the abdomen [Bone]) were determined from computed tomography images; concomitant associated injuries, patient characteristics, and other interventions with the primary outcome were assessed using multivariable logistic regression. A total of 201 patients with ballistic ilium fractures were included; 88.6% were male, and the average age was 32.9 ± 12.3 years. Of these, 83 (41%) sustained ballistic injuries that traversed the bowel before entering bone (Bowel), 69 (34%) entered the bone before the bowel (Bone), and 49 (24%) had an indeterminate trajectory. The Bowel cohort had a higher average injury severity score (20.2 versus 12.5, p<0.001), lower prevalence of other drug use (39.8% versus 56.5%, p=0.025), and greater incidence of exploratory laparotomy (90.4% versus 36.2%, <0.001). Bowel patients experienced higher rates of deep infection requiring surgical debridement (10.8% versus 1.4%, p=0.017). On multivariate analysis, deep infection requiring surgical bony debridement was significantly associated with bullet trajectory traversing the bowel before entering the bone (odds ratio 14.6, 95% confidence interval 1.3-160.8, p=0.021). Ballistic ilium fractures that traverse the bowel before entering bone were associated with higher rates of deep infection requiring bony debridement. The role of acute bony irrigation and debridement in these patients warrants further investigation. Prognostic Level III.