Infant who fell out of bed

CXR of posterior rib fractures which were initially missed in child abuse
CXR AP (above) from initial skeletal survey was unremarkable. Repeat CXR AP (below) from follow-up skeletal survey 2 weeks later shows interval development of periosteal reaction around the left 8th-9th ribs posteriorly.

The diagnosis was healing left 8th-9th posterior rib fractures in a child abuse patient.