High-energy pelvic ring injuries: Are standard anteroposterior x-rays still relevant in the CT era?

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. 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. 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. 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.