Purpose or Case Report: We sought to quantify the sensitivity of plain film interpretation for rib fractures in patients < 3 years of age. Acute rib fractures can be challenging to detect on plain film imaging and can have serious implications if they are attributed to child abuse. We retrospectively reviewed plain films with known rib fractures to quantify “missed” and “occult” fractures.
Methods & Materials: We performed a retrospective review of all chest/rib films done at our facility from 1990 – 2020 in patients < 3 years that were reported to contain rib fractures. Patients were identified by the term “rib fracture” in the radiology report and/or by the ICD-10 code for “rib fracture.” Our research team retrospectively reviewed these films and recorded the location and number of fractures initially noted by the original reading radiologist, those that were seen on the initial radiograph in retrospect by our reviewers (“missed”), and how many were seen only with subsequent healing (“occult”). Occult and missed rib fractures were categorized by etiology, including abuse, CPR, metabolic bone disease, osteopenia of prematurity, rickets, and trauma.
Results: The results of our study showed that of the total 234 fractures identified in 56 unique patients, a total of 58 fractures (25%) were initially missed and 43 fractures (18%) were occult. The most common location for rib fractures were the 6th and 7th ribs in the lateral and posterior locations. There was no consistent location for missed or occult fractures in our dataset. Thirty patients (53.6%) had fractures related to abuse, 1/56 (1.8%) due to CPR, 4/56 (7.1%) due to metabolic bone disease, 11/56 (19.6%) patients had fractures in the NICU, 1/56 (1.8%) had known rickets, 7/56 (12.5%) were related to known accidental trauma, and 2/56 (3.6%) were from unknown etiology.
Conclusions: Rib fractures are difficult to detect on radiographs. Our study showed that a substantial proportion of rib fractures are missed or occult on initial radiographs.