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Pelvic Fixator

Q&Bir

Q1: What is a pelvic fixator and what is its primary life-saving purpose?
A1: A pelvic fixator is an external stabilization device used to rapidly control life-threatening bleeding and stabilize unstable pelvic ring disruptions. Its primary purpose is to reduce pelvic volume and stabilize fracture fragments, which helps control venous bleeding and prevent clot disruption in hemodynamically unstable patients.

Q2: What are the key biomechanical principles behind pelvic fixation?
A2: The fixator works by:

Volume Reduction: Closing the pelvic ring to reduce internal volume

Stability Provision: Creating a stable frame that prevents fragment movement

Tamponade Effect: Allowing natural tamponade of bleeding vessels

Load Transfer: Redirecting forces from injured to stable pelvic segments

Q3: What are the absolute indications for emergency pelvic fixation?
A3: Absolute indications include:

Hemodynamically unstable pelvic ring injuries

Open book fractures (APC injuries) with symphysis diastasis

Vertical shear injuries with significant displacement

Damage control orthopedics in polytrauma patients

Q4: What are the most critical complications and their prevention strategies?
A4: Most critical complications include:

Pin tract infections (20-50% in prolonged use)

Pin loosening in osteoporotic bone

Neurovascular injury during pin placement

Loss of reduction with inadequate frame stability

Iliac crest fracture from pin placement errors

Q5: How does the anterior frame configuration provide stability?
A5: The anterior frame typically uses:

Two pins in each iliac crest

Connecting rods creating a rectangular or trapezoidal frame

Multiplanar stability through triangulation

Ability to apply compression or distraction as needed

Q6: What is the typical timeline from application to definitive treatment?
A6: Most temporary fixators remain for:

Emergency phase: 24-72 hours for resuscitation

Temporary stabilization: 5-10 days until patient stabilizes

Definitive treatment: Conversion to internal fixation when medically safe

Q7: How do surgeons determine optimal pin placement sites?
A7: Key considerations include:

Iliac crest between inner and outer tables

1-2 cm posterior to anterior superior iliac spine (ASIS)

Avoiding the abdominal musculature and neurovascular structures

Bi-cortical engagement for maximum pull-out strength

Q8: What are the specific contraindications for external pelvic fixation?
A8: Contraindications include:

Local infection at pin sites

Severe iliac crest comminution

Morbid obesity limiting safe pin placement

Some posterior ring injuries requiring direct stabilization