Background: An anteroposterior pelvic radiograph (PXR) continues to be recommended by Advanced Trauma Life Support protocol as an early diagnostic adjunct in the resuscitation of blunt trauma patients. At the same time, computed tomographic (CT) scanning has become a practice standard for diagnosis of most abdominal and pelvic injury. The objective of this study was to determine the necessity of obtaining an early PXR in stable trauma patients who will undergo CT scanning during the initial resuscitation.
Methods: A retrospective review of all blunt trauma patients undergoing immediate abdomen and pelvic CT scanning was performed from July 2000 until June 2001 at an urban Level I trauma center. These patients were divided into two groups depending on whether they also received a PXR (group I) or not (group II). At the time of the study, there was no formal protocol to determine which patients underwent pelvic radiography. Radiology reports of all PXRs and CT scans were reviewed. Patient demographics and Injury Severity Scores (ISSs) were abstracted from our trauma registry. The data were analyzed using Student's test.
Results: A total of 686 patients with blunt trauma underwent CT scanning of the abdomen and pelvis. Group I consisted of 311 (45%) patients with an average ISS of 12.3 +/- 0.7. In group I, 56 (10%) patients were found to have at least one pelvic fracture on CT scan, 38 of which were also identified on the PXR. Defining CT scanning as the definitive test, the sensitivity and specificity of the PXR in group I was 68% and 98%, respectively. The false-negative rate for pelvic radiography was 32%. In all patients with a positive PXR, the majority (55%) had either additional fractures or an increase in the Young and Burgess grade of fracture diagnosed on CT scan. Group II consisted of 375 patients, with 16 fractures noted in 13 (3%) patients, none of which required treatment. The mean ISS of group II was 8.0 +/- 0.5.
Conclusion: The PXR has limited sensitivity for detecting pelvic fractures compared with CT scanning. Selected hemodynamically stable patients who undergo CT scanning during their immediate resuscitation do not need a routine PXR. The PXR may continue to be beneficial in unstable patients, those with positive physical findings, or those who cannot undergo CT scanning because of other clinical priorities.