What is the recommended evaluation and management for a patient with a suspected sternal injury?

Sternal Injury: Evaluation and Management

For patients with suspected sternal injury from blunt chest trauma, obtain CT chest (preferably with IV contrast) along with ECG and cardiac troponin levels to guide management—patients with normal ECG and troponins can be safely discharged, while those with abnormalities require cardiac monitoring and echocardiography. 1

Initial Assessment Algorithm

Hemodynamic Status (First Priority)

• Unstable patients (systolic BP <90 mmHg or mean BP <65 mmHg despite fluids): Immediate FAST exam for pericardial effusion/tamponade, followed by urgent CT if feasible or direct to OR 1
• Stable patients: Proceed with systematic evaluation below

Mandatory Initial Workup for All Sternal Fractures

Three essential tests determine disposition:

1. ECG - Obtain immediately and repeat at 6 hours 1, 2

   • Acute changes indicate 6% risk of arrhythmias/myocardial contusion
   • Normal ECG essentially excludes significant cardiac injury

2. Cardiac troponin I - Draw at 4-8 hours post-injury 1, 2

   • Rising levels mandate echocardiography
   • Normal troponin with normal ECG = safe discharge

3. CT chest - Imaging modality of choice 1

   • Without contrast: Accurately detects sternal fractures on sagittal/3D reconstructions, identifies hemothorax/hemopericardium by attenuation values
   • With IV contrast: Superior for detecting bleeding sources, cardiac chamber rupture, pericardial tears, associated vascular injuries
   • Preferred over chest X-ray which misses 70% of sternal fractures 1

Critical Pitfall to Avoid

Sternal fractures are considered benign ONLY when isolated. 1 However, 98.8% of sternal fractures have associated injuries 3. The fracture itself rarely causes death—mortality stems from concomitant injuries (cardiac contusion, myocardial rupture, great vessel injury, pulmonary contusion) 3, 4.

Disposition Decision Tree

Safe for Discharge:

• Normal ECG at presentation AND 6 hours
• Normal cardiac troponins
• No displacement on CT
• No associated injuries
• Oral analgesics sufficient 1, 5

Requires Admission with Cardiac Monitoring:

• Abnormal ECG (even if troponins normal initially)
• Rising troponin levels
• Perform transthoracic echocardiography if either abnormal 1

Requires Surgical Consultation:

• Displaced/unstable fractures with manubriosternal dislocation 6
• Hemopericardium or cardiac tamponade (triad: high-attenuation pericardial effusion, peri-portal low attenuation, IVC/SVC distention) 1
• Flail chest with sternal involvement 7

Specific Imaging Findings That Change Management

On CT, immediately escalate care if you see:

• Hemothorax or hemopericardium → Obtain IV contrast study to identify bleeding source 1
• Empty pericardial sac, "collar sign," or cardiac malposition → Suggests pericardial rupture with cardiac herniation (high mortality) 1
• Pneumopericardium → Indicates pericardial tear 1

Evidence Strength Note

The ACR Appropriateness Criteria (2020) 1 provide the strongest guideline-level evidence. These emphasize that echocardiography is NOT recommended for isolated sternal fractures when ECG and troponins are normal 1—a key point since routine echocardiography wastes resources without improving outcomes 5.

The multicenter study 2 revealed concerning underutilization: only 72% received initial ECG, 33% had follow-up monitoring, and 30% had troponin assessment. This represents a quality gap, as 6% developed arrhythmias/contusion that would have been missed.

Conservative vs. Surgical Management

• Conservative (39.7% of cases): Isolated, non-displaced fractures with normal cardiac workup 3
• Surgical fixation (59.5% of cases): Displaced fractures, especially with polytrauma, flail chest, or persistent pain 3, 7, 6
• Modern titanium plating superior to wire fixation for biomechanical stability 6