My surgical practice: Implications of occult first rib fractures and how to approach their management

Our institution recently adopted new protocols increasing the indications for obtaining a CT angiography (CTA), now including all patients with blunt trauma. Thus, patients immediately get a chest XR in the trauma bay and are sent for a CTA chest thereafter. To take advantage of the contrast bolus already in use, the protocol has extended the CTA to include the neck as well. First rib fractures (FRF) require substantial force and stretch, and their anatomical proximity to the vertebral and subclavian arteries make them particularly concerning. However, when there is no displacement of a FRF, the incidence of associated vascular injury has been found to be as low as 3%. This low incidence has prompted many studies to suggest that a CTA for a non-displaced FRF may not be warranted in the absence of clinical signs. ^, Unfortunately, the literature has not specifically analyzed the significance of occult FRF (oFRF) and how to approach the work-up. oFRF are usually non-displaced fractures that are not apparent on initial plain film (CXR) but are evident on subsequent CT scans (Fig. 1). With the ever-increasing use of pan-CT scans, the incidence of diagnosed FRF has increased at least 5-fold over the past several years. However, mortality and other complications from rib fractures have decreased, suggesting that occult findings may not carry the same prognostic weight as clearly identifiable FRF (cFRF) (Fig. 2). Because of this uncertainty, we set out to investigate whether oFRF carry the same implications as cFRF when assessing for associated vascular and brachial plexus injuries. The available literature has found the incidence of FRF associated vascular injury to range from 1.4% to 8.2%, but it does not differentiate between types of FRF. Thus, we reasoned cFRF would have an incidence of vascular injury along the higher end, and oFRF would have an incidence closer to 1.4%. These assumptions dictated we would need at least 88 patients per group to achieve enough power to detect significant differences.