Pelvic Fracture

Description

• 3% of all bony fractures
• Pelvis is made up of sacrum and 2 innominate bones:
  • The innominate bones consist of the ilium, ischium, and pubis
• Boney structures are stabilized by a network of ligaments, musculature, and other soft tissues in the pelvic area
• Anterior stability and support are provided by the symphysis pubis and pubic rami
• Posterior stability and support are provided by the sacroiliac (SI) complex and pelvic floor
• Pelvis provides protection for lower urinary tract; GI tract; gynecologic, and vascular, and nervous structures contained in the region:
  • Pelvic fractures have a high associated morbidity and mortality rate and require urgent diagnosis and therapy
• Unstable pelvic fractures are high risk for associated injuries including:
  • Pelvic hemorrhage and hemorrhagic shock
  • Intra-abdominal and GI tract injuries
  • Genitourinary and urinary tract injuries
  • Uterine and vaginal injuries
  • Neurologic injuries
  • Arterial and venous plexus injuries

Etiology

• 65% of pelvic fractures are caused by vehicular trauma, including pedestrians struck by automobiles
• 10% caused by falls
• 10% caused by crush injuries
• The remainder caused by athletic, penetrating, or nontraumatic injuries
• Mortality rate from pelvic fractures is 6–19%:
  • Increases with open fractures or evidence of hemorrhagic shock
• Significant hemorrhage can occur in unstable, high-energy pelvic fractures (Tile type B and C fractures):
  • Bleeding most common with posterior injuries involving the vascular plexuses
  • Retroperitoneal hematoma may tamponade in the enclosed pelvic space

• Includes stable single bone and avulsion fractures as well as pelvic ring fractures
• Predicts need for operative repair
• Type A: Stable pelvic ring injuries:
  • A1: Avulsion fractures of the innominate bone (ischial tuberosity, iliac crest)
  • A2-1: Iliac wing fractures
  • A2-2: Isolated rami fractures; most common pelvic fracture
  • A2-3: 4-pillar anterior ring injuries
  • A3: Transverse fractures of sacrum or coccyx
• Type B: Partially stable pelvic ring injury (rotationally unstable, but vertically stable):
  • B1: Unilateral open-book fracture
  • B2: Lateral compression injury:
    • B2-1: Ipsilateral double rami fractures and posterior injury
    • B2-2: Contralateral double rami fractures and posterior injury (bucket-handle fracture)
  • B3: Bilateral type B injuries
• Type C: Unstable pelvic ring injury – rotationally and vertically unstable, Malgaigne fracture:
  • Anterior disruption of symphysis pubis or 2–4 pubic rami with posterior displacement and instability through sacrum, SI joint, or ileum:
    • C1: Unilateral vertical shear fracture
    • C2: Unilateral vertical shear combined with contralateral type B injury
    • C3: Bilateral vertical shear fracture
• Acetabular fractures (posterior lip, central/transverse, anterior column, or posterior column fractures)

• Based on mechanism of injury
• Only fractures that result in disruption of pelvic ring included; no single bone, avulsion, or acetabular fractures
• Predicts chance of associated injuries and mortality risk:
  • LC: Lateral compression
  • APC: Anteroposterior compression
  • VS: Vertical shear
  • CM: Combination of injury patterns

• Children can have greater hemorrhage
• Nonaccidental trauma is a concern