Pelvis Injuries

1. The 2-Minute Kinematics

• High-Energy Trauma: The pelvic ring is highly stable and requires immense force to disrupt; consequently, pelvic fractures most commonly result from high-speed motor vehicle collisions, motorcycle accidents, automobile versus pedestrian incidents, falls from significant heights, or massive crush injuries.
• Low-Energy Trauma: In the elderly population, isolated pubic rami fractures can occur from low-energy mechanisms (such as falling from a chair) secondary to underlying fragility and osteopenia.
• Biomechanical Failure: When the structural integrity of the pelvic ring is breached, the primary life-threat is rapid, exsanguinating internal hemorrhage from disrupted venous plexuses and arterial supplies. Pelvic ring fractures act as an independent risk factor for death, carrying a 30% mortality rate in patients who present in shock.

2. The Bedside Action Plan

• Immediate Stabilization: The single most critical ED intervention for a hemodynamically unstable pelvic fracture is reducing pelvic volume to tamponade bleeding. Immediately apply a pelvic binder, wrap, or sling.
• Advanced Resuscitation: Initiate massive transfusion protocols. For refractory shock, interventions include preperitoneal packing or Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA).
• Open Fractures: Open pelvic fractures can result in rapidly exsanguinating hemorrhage; these require immediate packing and urgent surgical consultation.
• Log-Rolling: Avoid log-rolling patients with obvious pelvic fractures, as this disrupts forming clots and worsens bleeding.

3. The Diagnostic Grid

• Targeted Physical Exam: Inspect the pubis, iliac bones, hips, and sacrum for swelling, bruising, and crepitus. You must meticulously inspect the perineum for lacerations or hematomas, evaluate the urethral meatus for blood, and perform a rectal examination to assess sphincter tone and check for gross blood (which indicates an open fracture pattern).
• Mandatory Neurovascular Checks: Assess distal peripheral pulses and verify motor/sensory function in bilateral lower extremities to rule out associated vascular disruption or lumbosacral plexus injuries.
• Indications for Angiography (The FAST Algorithm): In the hemodynamically unstable patient, an eFAST exam is mandatory. If the eFAST shows intraperitoneal free fluid, the patient goes emergently to the operating room for laparotomy. If the eFAST is negative (no other identifiable source of hypotension), the patient must be routed immediately for pelvic angiography and embolization in Interventional Radiology (IR).

4. The Visual Board

• Explicit X-Ray Interpretation: In cases of isolated trauma, an anteroposterior (AP) pelvic radiograph is indicated. If major multitrauma is suspected, request a trauma pan-CT scan instead.
• Key Radiographic Patterns: Look for specific disruptions to the pelvic ring, categorized into patterns of Anterior Posterior Compression (APC), Lateral Compression (LC), and Vertical Shear (VS) injuries.
• Occult Signs: Carefully evaluate the symphysis pubis and sacroiliac (SI) joints for diastasis or widening, which implies significant ligamentous disruption and pelvic instability even if obvious bony fractures are minimal.

5. The Classification Matrix

• Young-Burgess Classification: Used to describe the mechanistic pattern of the fracture: Anterior Posterior Compression (APC) Types I-III, Lateral Compression (LC) Types I-III, and Vertical Shear (VS).
• WSES Grade (World Society of Emergency Surgery): This classification system prioritizes the hemodynamic presentation of the patient over anatomic stability, guiding the algorithmic approach to resuscitation (binder vs. preperitoneal packing vs. angioembolization).

6. The Danger Zone

• Cognitive Trap (Springing the Pelvis): Do not try to "spring the pelvis" to assess stability. This classic physical exam maneuver is unreliable, completely unnecessary, and can cause catastrophic additional hemorrhage or tissue damage by dislodging life-saving clots.
• Premature Fixation on Orthopedics: Complex pelvic fractures that cause exsanguination are a major exception to the rule that orthopedic injuries are addressed only after stabilization; in these patients, treating the pelvis is the resuscitation.
• Missed Open Fractures: Failing to perform a rectal or perineal exam can lead to missing an occult open pelvic fracture (e.g., vaginal or rectal laceration communicating with the fracture), which carries a massive risk for devastating pelvic sepsis.

7. Mcq Masterclass

• High-Yield "Buzzwords": "Hemodynamically unstable with negative FAST" = proceed to pelvic angiography and embolization. "Positive FAST with pelvic fracture" = proceed to the OR for emergent laparotomy.
• Common Exam Distractors: A board question will frequently offer "springing the pelvis" or "rocking the iliac crests" as a next physical exam step to confirm instability—this is a fatal trap and always the wrong answer.
• Transfer Criteria: "Unstable pelvic ring fracture," "pelvic fractures with ongoing bleeding," and "displaced acetabular fractures" are automatic trauma transfer criteria to a higher level of care.

8. The Boardroom Script

"I am consulting you for an [Age]-year-old patient who sustained a high-energy trauma via [MVC/fall] resulting in a hemodynamically [stable/unstable] pelvic ring fracture. The initial plain film/CT demonstrates a [Young-Burgess pattern: e.g., Anterior Posterior Compression Type III] with significant diastasis. I have placed a pelvic binder and initiated our massive transfusion protocol. The eFAST is [negative/positive], and [Interventional Radiology/General Surgery] has been consulted for [angioembolization/laparotomy]. On my secondary survey, the perineal and rectal exams show [no gross blood/evidence of open fracture], and distal lower extremity neurovascular function is [intact/compromised]. The patient requires your urgent evaluation for definitive bony stabilization."