Management of Sternal Manubrium Fracture with Hematoma
Most sternal manubrium fractures with hematoma should be treated conservatively with analgesia and early mobilization, but the presence of retrosternal hematoma significantly increases the risk of concomitant injuries (5-fold increased odds) and mandates comprehensive cardiac and thoracic evaluation before discharge. 1, 2
Initial Assessment and Risk Stratification
All patients with manubrium fractures must undergo immediate ECG and cardiac troponin testing, as these fractures carry higher risk of cardiac injury compared to sternal body fractures. 1, 3 Patients with normal ECG and normal troponin levels can be safely discharged without prolonged observation. 1, 3
Critical Imaging Protocol
- CT chest without IV contrast is the imaging modality of choice for detecting sternal fractures using sagittal and 3D reconstructions. 1, 4
- The presence of retrosternal hematoma on CT is a red flag - it increases the odds of concomitant injury 5.35-fold and indicates need for thorough evaluation of associated injuries. 2
- Manubrium fractures themselves carry 6.85-fold increased odds of concomitant injury compared to sternal body fractures, making comprehensive imaging essential. 2
Cardiac Monitoring Requirements
- Monitor for arrhythmias if ECG shows abnormalities or troponin is elevated, as approximately 6% of sternal fracture patients develop cardiac complications. 1, 3
- Echocardiography is NOT routinely needed for isolated fractures with normal ECG and troponins, but should be performed if there are signs of heart failure, abnormal heart sounds, or hemodynamic instability. 1, 3
Classification and Treatment Algorithm
Manubrium fractures can be classified into three types that guide treatment decisions: 5
Type A: Transverse Fractures
- Mechanism: Direct blunt trauma or torso flexion in the 1st intercostal space
- Instability pattern: Sagittal instability
- Treatment: Conservative if minimally displaced; longitudinal plate osteosynthesis if unstable 5, 6
Type B: Oblique Fractures
- Mechanism: Seat belt injury (most common cause - 77% of manubrium fractures) 6
- Instability pattern: Rotatory instability affecting shoulder girdle
- Treatment: Transverse plate fixation for significant dislocation causing shoulder girdle instability 5, 6
Type C: Combined/Fragmentary Fractures
- Mechanism: Direct blunt trauma with simultaneous torso flexion
- Instability pattern: Multi-directional instability
- Treatment: T-form or H-form plate configurations 5
Conservative Management (First-Line for Stable Fractures)
Conservative treatment is appropriate for isolated, non-displaced manubrium fractures without significant instability. 1, 4, 7
Pain Management and Mobilization
- Provide appropriate analgesics tailored to patient comorbidities and begin early mobilization as soon as pain allows. 1
- Start range-of-motion exercises within the first few days, including shoulder, elbow, wrist, and hand motion. 1
- Restrict above-chest-level activities until fracture healing is evident. 1
Monitoring During Conservative Treatment
- Serial clinical assessment for development of complications including respiratory compromise from pain-limited breathing. 7
- Short-term pain relief is sufficient for truly isolated fractures, but remember that only 1.2% of sternal fractures are truly isolated. 7
Surgical Indications and Techniques
Surgical stabilization is indicated for profoundly dislocated fractures causing instability of the upper sternum and shoulder girdle. 5, 6
Surgical Approach
- Anterior plating through a medial approach using low-profile titanium plates (such as MatrixRib®) provides sufficient stabilization. 6
- Plate orientation depends on fracture type: longitudinal for Type A, transverse for Type B, T-form or H-form for Type C. 5
- Timing: Most surgical cases (59.5%) require operative intervention, with good outcomes reported. 7, 8
Surgical Outcomes
- No serious postoperative complications were found in systematic review of 76 surgically repaired cases. 8
- Follow-up shows sufficient consolidation without complications when appropriate fixation technique is used. 6
Critical Pitfalls and Associated Injuries
The most dangerous pitfall is assuming the manubrium fracture is isolated - 98.8% of sternal fractures have associated injuries. 7
High-Risk Associated Injuries to Exclude
- Extremity fractures, brain injury, lung contusion, and intraabdominal injuries are the most common concomitant injuries. 7
- Life-threatening cardiopulmonary injuries require resuscitation and active treatment - these are the actual causes of mortality, not the sternal fracture itself. 7
- Manubrium fractures specifically have higher rates of severe concomitant thoracic organ injuries compared to sternal body fractures. 5
Hematoma-Specific Concerns
- Retrosternal hematoma presence mandates systematic evaluation for concomitant injury - it is found in 70.5% of sternal fracture patients and strongly predicts associated injuries. 2
- Motor vehicle accidents with retrosternal hematoma carry particularly high risk for multiple injuries requiring comprehensive trauma evaluation. 2
Special Considerations for Elderly Patients
- Assess for underlying osteoporosis and consider calcium/vitamin D supplementation. 1
- Perform fall risk assessment and implement multidimensional fall prevention strategies. 1, 4
- Monitor for secondary complications including deep vein thrombosis in less mobile patients. 1
- Orthogeriatric comanagement may improve functional outcomes and reduce hospital length of stay. 4
- Systematic evaluation for risk of subsequent fractures should include DXA scanning in patients over 50 years. 4
Rehabilitation Protocol
- Early post-fracture introduction of physical training and muscle strengthening is essential for optimal recovery. 4
- Long-term continuation of balance training particularly in elderly patients to prevent future falls. 4
- Patient education about expected recovery timeline and warning signs of complications is mandatory before discharge. 4