Introduction: Pelvic ring injuries (PRI) are complex and potentially life-threatening lesions requiring precise classification and timely management. The increasing reliance on computed tomography (CT) imaging has led some institutions to bypass standard pelvic x-rays, potentially missing crucial diagnostic information. This study aimed to evaluate whether standard anteroposterior (AP) pelvic x-rays, particularly when obtained with and without a pelvic binder (PB), alter injury classification and treatment plans in comparison to CT imaging alone.

Methods: A retrospective cohort study was conducted at a level 1 trauma center, including all adult patients (≥18 years) with surgically treated PRI between January 2012 and December 2023. Inclusion required a complete imaging set (CT, AP x-ray with PB and AP x-ray without PB). An international PRI expert group independently assessed each patient's imaging in sequential order (CT alone, then additional AP x-ray with PB, then additional AP x-ray without PB). After each step, they provided injury classifications (Young and Burgess, AO/OTA) and a treatment plan. Changes in classification and treatment at each step were recorded and compared to surgical reports. Interobserver reliability was assessed using Fleiss' kappa.

Results: Among 28 patients with complete imaging sets, classification or treatment changes occurred in 60.7% and 42.9% of cases, respectively. Agreement with the baseline classification improved by 35.7% with sequential imaging. A direct correlation with treatment changes was found in 58% of classification changes. Interobserver reliability was slight to fair (k = 0.192-0.300), with modest improvement in Young and Burgess agreement (k = 0.192 to 0.261) but limited change in AO/OTA agreement.

Conclusion: Sequential imaging that includes standard AP pelvic x-rays, both with and without a PB, provides additional diagnostic clarity and can influence PRI classification and treatment planning for PRI. These findings support the continued use of standard AP pelvic x-rays alongside CT in acute trauma evaluation.