Of pediatric patients who have anteroposterior (AP) pelvic xrays (XR), there is a 4.6% rate of pelvic fracture or dislocation, compared to 10% in adults.
This study is a sub analysis of a prospective observational cohort of children with blunt torso trauma conducted by PECARN. 7808 patients had pelvic imaging, with 65% of them having an AP XR. The XR sensitivity ranged from 64-82% (based on age groups) for detecting fractures. All but one patient with a pelvic fracture not detected on XR had a CT scan. The CT scan detected all but 2 fractures both of which were picked up later as healing fractures on repeat pelvic XR. Some of the patients who had a missed fracture on XR were hemodynamically unstable or wound up requiring operative intervention.
The authors support the following algorithm:
-With hemodynamically unstability children, obtain a pelvic XR
-For hemodynamically stable children when the physician is planning to get a CT, there is no indication for XR
Bottom line: Consider using AP pelvic radiographs in the hemodynamically stable patient with a high suspicion for fracture or dislocation who are not undergoing CT.
References
Kwok et al. Sensitivity of Plain Pelvis Radiography in Children with Blunt Torso Trauma. Annals of Emergency Medicine 2015; 65: 63-71.
