L. Heidelberg1, R. Uhlich1, P. Bosarge1, J. Kerby1, P. Hu1 1University Of Alabama at Birmingham,Acute Care Surgery,Birmingham, Alabama, USA
Introduction:
Despite little evidence to support an association of sternal fractures with blunt cardiac injury (BCI), displaced sternal fractures are viewed as more severe and more likely to result in BCI. Common recommendations include inpatient evaluation for observation and additional diagnostic screening. Little information exists regarding the depth and severity of sternal fracture displacement and it remains unclear if there is increased risk of BCI with increasing sternal fracture depth. The purpose of this study was to quantify fracture severity by the degree of displacement and evaluate the association of fracture severity with BCI.
Methods:
A retrospective review was performed at an American College of Surgeons verified level 1 trauma center from 2011-2014. All adult patients admitted to the trauma surgery service were eligible for inclusion, with patients excluded for pregnancy, age <18 years old, or lack of imaging. Patients with sternal fracture were identified from the trauma registry using ICD-10 codes. Sternal fracture displacement was measured by posterior displacement in the axial plane of computerized tomography of the chest. Fracture displacement was defined as mild (>0 mm, <5 mm), moderate (≥5 mm, <10 mm), or severe (≥10 mm). BCI was diagnosed using electrocardiogram or echocardiograph and graded according to standard AAST grading. Analysis was performed using χ2 and Student's t-test or one-way ANOVA for categorical and continuous variables respectively. Multivariate regression analysis was subsequently performed to assess the association of sternal fracture displacement with BCI. The primary outcome of interest was the association of BCI with severity of sternal fracture displacement.
Results:
235 patients with sternal fractures were identified and eligible for inclusion during the study period. 45% of patients suffered a displaced fracture, with the majority of these being mild (65.1%) or moderate (24.5%) in severity. Only 10.4% of patients had severely displaced fractures. Overall, 42.6% of patients were diagnosed with BCI. Of patients with BCI, there was no difference in mean fracture displacement when compared to patients without BCI (2.4 vs 1.6 mm, p=0.07)[Office1] . There was no significant increase in BCI with sternal fracture displacement when compared to patients with non-displaced fractures (44.3% vs 41.1%, p=0.62)[Office2] . While among patients with displaced fractures, the incidence of BCI increased with increasing severity (39.1% vs 50.0% vs 63.6%, p=0.25), this was not significant. Further, neither fracture displacement (OR 1.10, CI 95% 0.65-1.88) nor severe displacement (OR 2.34, CI 95% 0.64-8.54) were associated with significantly increased risk of BCI on multivariate analysis.
Conclusion:
There is no significant association between the depth of sternal fracture displacement and BCI. Further evaluation and management for BCI should be reserved in the absence of additional symptoms or findings.