“Occult” rib fractures diagnosed on computed tomography scan only are still a risk factor for solid organ injury

INTRODUCTION: Prior to the widespread use of computed tomography (CT) scan imaging, lower rib fractures diagnosed on chest X-rays (CXRs) were considered a risk factor for abdominal solid organ injury (ASOI). However, CXRs miss about 50% of the rib fractures that are detected on CT scans. We hypothesized that these “occult” rib fractures would not be predictive for ASOI. MATERIALS AND METHODS: Retrospective review of a level I trauma center's database identified all adult blunt trauma patients (n = 11,170) over a 5-year period. Data were abstracted for demographics, injury severity score, presence of ASOI, extremity, pelvic and spine fractures as well as presence and location of rib fractures. RESULTS: Rib fractures correlated with the presence of ASOI, regardless of whether they were diagnosed by CXR or CT scan alone (P < 0.01). Middle (3-7) and lower (8-12) rib fractures, especially, correlated with the presence of ipsilateral ASOI (P < 0.0001). DISCUSSION: Although CT scan detects more rib fractures than CXR, rib fractures remain a marker for increased likelihood of ASOI regardless of the modality by which they are diagnosed. Patients with rib fractures also have a greater incidence of spine and pelvic fractures. As the trauma community debates moving away from routine whole-body CT imaging towards a more selective approach, these results suggest that any clinical suspicion of rib fractures, despite a negative CXR, may warrant further investigation.