Why is femur fracture fixation prioritized first in polytrauma patients?

Femur Fracture Fixation in Polytrauma: Timing and Approach

In polytrauma patients, femur fracture fixation should be prioritized using a damage control orthopedics (DCO) approach with initial temporary stabilization followed by delayed definitive fixation to reduce mortality and morbidity. 1

Assessment of Patient Status

The approach to femur fracture fixation in polytrauma patients should be based on:

1. Hemodynamic stability assessment:

   • Presence of circulatory shock
   • Blood pressure stability
   • Ongoing bleeding
   • Coagulopathy status

2. Respiratory function:

   • Presence of respiratory failure
   • Risk of fat embolism syndrome
   • Pulmonary contusion

3. Associated injuries:

   • Severe visceral injuries (brain, thorax, abdomen)
   • Pelvic ring injuries
   • Spinal cord injuries

Treatment Algorithm

For Hemodynamically Stable Patients (without severe associated injuries):

• Early definitive osteosynthesis within first 24 hours is recommended
• This reduces local and systemic complications
• Particularly important for femoral shaft fractures which carry high risk of respiratory complications 1

For Hemodynamically Unstable Patients or Those with Severe Associated Injuries:

• Initial phase: Temporary stabilization with external fixator or skeletal traction
• Definitive phase: Delayed definitive osteosynthesis after patient stabilization (typically after day 4-7) 1

Rationale for Damage Control Approach

Early definitive fixation in unstable polytrauma patients can trigger a "second hit" phenomenon that leads to:

1. Massive operative blood loss
2. Lactic acidosis and hypothermia
3. Systemic inflammatory response syndrome (SIRS)
4. Multiple organ failure (MOF)
5. Acute respiratory distress syndrome (ARDS) 1, 2

Studies have shown that immediate intramedullary nailing within 24 hours is associated with 6.69 times greater odds of developing acute lung injury compared to initial external fixation with later conversion in borderline polytrauma patients 2.

Optimal Timing for Definitive Fixation

The ideal timing for conversion from temporary to definitive fixation is:

• After day 4 post-injury for physiologically deranged polytrauma patients 1
• Approximately 1 week after injury when:
  • Intracranial pressure has normalized
  • Respiratory function has improved
  • Patient is hemodynamically stable
  • Inflammatory markers have decreased 2

Special Considerations

Head Injuries

• Pelvic fracture-associated bleeding and coagulopathy can worsen head injuries through secondary bleeding
• Acute hemorrhage control and coagulopathy reversal are essential
• Careful monitoring of brain injuries with early re-scanning is recommended 1, 2

Complications of Different Fixation Methods

• External fixation: Higher complication rates (21.9%) when used as definitive treatment
• Intramedullary nailing: Lower complication rates (5.4%) but higher risk when done early in unstable patients 2

Outcomes

The damage control approach has demonstrated:

• Reduction in mortality rates compared to predicted mortality
• Lower incidence of ARDS and MOF
• Decreased systemic complications 3

By following this approach, femur fracture fixation in polytrauma patients can be managed effectively while minimizing the risk of secondary systemic complications that could increase morbidity and mortality.