The Prevalence of Rib Fractures Incidentally Identified by Chest Radiograph among Infants and Toddlers.

OBJECTIVES: To determine the prevalence of incidental rib fractures identified by chest radiograph (CXR) obtained for indications unrelated to accidental trauma or nonaccidental trauma (NAT), and describe the histories associated with cases of incidental rib fractures and their proposed etiologies. It is hypothesized that incidental rib fractures are rare and alternative explanations for rib fractures occasionally used in a medico-legal context such as minor accidental trauma, undiagnosed medical conditions, and transient metabolic bone disturbances are unlikely to be the etiology of incidental rib fractures. STUDY DESIGN: A retrospective chart review of sequential CXRs of children ages 0 to <2 years was conducted from January 1, 2011 to October 31, 2016. CXRs were obtained in the emergency department, general pediatric or intensive care units, or outpatient pediatric clinics. Data collected included demographics, CXR indication and findings, history of cardiopulmonary resuscitation, laboratory and additional imaging results, and incidental rib fracture descriptions and proposed etiologies. RESULTS: A total of 7530 patients underwent 9720 CXRs associated with unique clinical encounters. Five CXRs had incidental rib fractures identified, making the prevalence of CXRs with incidental rib fractures in this cohort <0.1%. Of 5 identified incidental cases, mean age was 3.6 months, 3 were concerning for NAT, 1 was confirmed NAT, and 1 had radiographic findings consistent with osteopenia of prematurity. CONCLUSIONS: Identification of incidental rib fracture on CXR is rare. When detected in the absence of corresponding trauma history and/or objective laboratory or radiographic metabolic abnormalities, work-up for NAT should be pursued.