Pediatric patients with isolated costal margin tenderness (CMT) on exam are very unlikely to have underlying intra-abdominal injury and also unlikely to benefit from CT. But make sure there are no other signs of abdominal injury.
Why does this matter?
Children have pliable chest walls. It is possible to have underlying injury with no rib fracture, given the chest wall elasticity. Also, in adults CMT is associated with intra-abdominal injury. But in prior studies in children, it did not seem to correlate. So does tenderness along the costal margin portend a bad prognosis for underlying abdominal injury in children? Should we CT these children?
CMT - Country Music Television or Costal Margin Tenderness?
This was a PECARN group subset of 1267 children with costal margin tenderness (CMT). Of these, 177 had isolated CMT and no other pre-defined signs of intra-abdominal injury: "abdominal or thoracic wall trauma, abdominal tenderness or pain, decreased breath sounds, or vomiting." No children with isolated CMT had intra-abdominal injury. Only 20% of kids had CT, but follow-up in the original study was extremely meticulous to catch any injuries or bad outcomes that may have been missed on CT. CT would likely be very low yield in such patients.
Costal Margin Tenderness and the Risk for Intra-abdominal Injuries in Children with Blunt Abdominal Trauma. Acad Emerg Med. 2018 Apr 13. doi: 10.1111/acem.13426. [Epub ahead of print]
Peer reviewed by Thomas Davis