Pelvic Fractures

Overview

Definition

A pelvic fracture is a disruption in the cortex of 1 of the pelvic bones. These fractures include iliac wing fractures, acetabular fractures, and the pelvic ring (the sacrum and the 2 innominate bones).

Anatomy

Several bones create a bony ring, meeting at the pubic symphysis in the front and the sacrum in the back. 

• The pelvis with its attaching ligaments and muscles supports the weight of the upper body.
• Rests on the hip joints
• Protects abdominal organs including the intestines, bladder, major nerves, and blood vessels
• Pelvic fractures may occur at any location on the bones depending on the nature of the accident and the areas of impact. The acetabulum refers to the part of the pelvis that meets the upper end of the femur at the hip joint.

Classification

The Young-Burgess classification has 3 categories of pelvic fractures designated by mechanism.

• Anterior to posterior compression (APC) injuries:
  • External rotation of the hemipelvis with separation of the symphysis pubis and tearing of the posterior ligamentous complex
  • Increased pelvic volume → life-threatening hemorrhage
• Lateral compression (LC) injuries:
  • Force directed laterally into the pelvis
  • Fracture is more common than in APC injuries.
  • The most frequent cause of death in patients with LC injuries is closed head injury.
• Vertical shear (VS) injuries:
  • Vertical displacement of the hemipelvis (common in falls from great heights or motorcycle collisions)
  • The iliac wing is driven up relative to the sacrum, with disruption of the ligaments, pelvic floor, and the strong posterior sacroiliac complex.

Acetabular fractures are classified in detail by several systems (Letournel, Brandser and March, and Judet). In general, they are categorized into simple (single) or complex (multiple) fractures, named for their location(s):

• Anterior wall fracture
• Anterior column fracture
• Transverse 
• Posterior column
• Posterior wall
• Any combination of the above

Epidemiology

• Incidence of traumatic fractures: 37/100,000 people per year
• Incidence of pelvic insufficiency fractures due to osteoporosis: 92/100,000 per year
• Pelvic fractures make up 3% of all skeletal injuries regardless of age:
  • < 35 years of age: Men predominate.
  • > 35 years of age: Women predominate.
• Mortality: 5%–30%

Etiology

• Low-energy mechanisms or repetitive stresses in the elderly with osteoporosis:
  • Also called “insufficiency fractures” or “fragility fractures” of the pelvis
  • Most commonly involve the pubic rami and can occur in isolation
  • Only ⅓ result from a fall; ⅔ occur without trauma.
  • Risk factors:
    • Advanced age
    • Prior pelvic fracture
    • Hormone deficiency (menopause in women and hypogonadism in men)
    • Use of steroids (glucocorticoid therapy)
    • Low body weight
    • Smoking
    • Excess alcohol intake
    • History of pelvic radiation
• High-energy trauma in healthy adults: 
  • Motor vehicle accidents as passenger or pedestrian
  • Fall from a significant height
  • Victims of violence
• Acetabular fractures:
  • Occur when the head of the femur is driven into the pelvis due to a blow to either the side or front of the knee
  • Often occurs as a dashboard injury accompanied by a fracture of the femur

Clinical Presentation

The examination of a pelvic fracture is done within the larger context of the trauma patient in the ED, following the advanced trauma life support (ATLS) method for assessment and simultaneous treatment of injuries. The pelvis is a prominent source of bleeding and must be examined carefully, especially in hypotensive patients.

History

• Patients or first responders will report a recent high-energy blunt or penetrating trauma: 
  • Motor vehicle accident
  • Fall from a great height
  • Attack with a blunt or sharp object
• The clinician must determine from the patient or companions:
  • The mechanism of trauma
  • Site of injury
  • Further details if possible
• Types of injuries that cause pelvic fractures:
  • Vehicle accidents:
    • Types of restraints
    • Airbags
    • Patient position in the vehicle
    • Status of other passengers
  • Falling trauma:
    • Freefall or downstairs
    • Height (distance)
    • Type of landing (e.g., feet first)
  • Attack with a weapon:
    • Time of injury
    • Type of weapon (e.g., baseball bat, knife, handgun, rifle, or shotgun)
    • Distance from the assailant
    • Amount of bleeding noted at the scene

Physical examination

It is essential to examine a patient with a suspected pelvic fracture for possible comorbidities.

• Hemodynamic status, may have hypotension:
  • If hemodynamically unstable, need to wait on further diagnostic tests
  • Patient needs to go to interventional radiology or OR.
• Inspection/palpation:
  • Lower abdominal quadrants: pain exacerbated on palpation of the bony pelvis
  • Buttocks/rectal examination:
    • Anal tone
    • High-riding prostate
  • Genital area:
    • Vaginal examination with blood or bone shards
    • Scrotal hematoma
  • Perineum:
    • Perineal ecchymosis
    • Ruptured urethra may show blood in the urinary meatus.
    • Presence of urine, stool, or other environmental contaminants indicates severe injury (hollow viscus perforation).
• Discrepancy in limb length/rotational deformity with no apparent lower limb fracture
• Mechanical instability:
  • Open- and closed-book maneuvers 
  • Cephalad migration of fractured hemipelvis
• Lower extremity neurovascular abnormalities

Diagnosis

Diagnosis of a pelvic fracture is initially made clinically and confirmed with visualization on diagnostic imaging. Patients with a pelvic fracture involving the pelvic ring may also have urethral or bladder injuries; urgent urologic consultation is necessary.

• eFAST (extended Focused Assessment with Sonography for Trauma) ultrasound:
  • Ideal for initial evaluation of intraperitoneal bleeding
  • Hypoechogenicity around the bladder → suggests pelvic bleeding
  • Cannot detect retroperitoneal (extraperitoneal) blood associated with pelvic fractures
• X-ray: An anteroposterior (AP) X-ray of the pelvis is the best screening test for pelvic fractures.
• CT scan:
  • Best visualization of pelvic anatomy to assess for bleeding:
    • Pelvic
    • Intraperitoneal
    • Retroperitoneal (extraperitoneal)
  • Uncovers hip dislocation/acetabular fracture
  • Unstable patients should not be taken to the CT scanner.
• MRI remains the gold standard for evaluating minor pelvic fractures in older adults. 
• Interventional radiology (IR):
  • Wrap the pelvis in a pelvic binder first.
  • Pelvic angiography may demonstrate extravasation from damaged arteries.
  • An interventional radiologist may perform an embolization to stop the bleeding.

Management

For pelvic fractures that involve loss of integrity of the pelvic ring (the sacrum and the 2 innominate bones), definitive fracture management and bleeding control are carried out by the trauma and/or orthopedic surgeon. For pelvic fragility fractures in the elderly that do not require surgery, pain control and early mobilization are important.

Treatment goals

• Return the patient to their pre-injury functional level to the greatest extent possible.
• Proper alignment of the bones (correcting the displacement) during healing is vital.
• If the joint does not heal correctly → cartilage loss and osteoarthritis → loss of motion, decreased function, and pain.

Initial management

• Rapid hemorrhage control and fluid resuscitation
• Temporary external fixation to stabilize the pelvis: 
  • Centered over the greater trochanters to prevent further pelvic bleeding:
    • Sheet
    • Pelvic binder
    • Other noninvasive pelvic circumferential compression device
  • Temporary measure until the patient can be taken to the OR or transferred to a trauma center.
  • Should be avoided in LC-type fractures with an internal rotation component

Nonsurgical treatment

• Pain control
• Early mobilization with physical therapy
• Gait assistance with walker or crutches
• Stable nondisplaced pelvic fractures without dislocation:
  • May require closed reduction under anesthesia 
  • May need external fixation
• Surgery may not be indicated for:
  • Simple acetabular fractures of the anterior wall
  • Elderly patients with severe osteoporosis
  • Patients with multiple comorbidities or infections

Surgery

• Surgical management of pelvic fractures depends on:
  • Joint stability
  • Fragment size and comminution
  • Patient’s age and comorbidities 
• Acetabular fractures are difficult to treat due to the proximity of:
  • Major blood vessels to the legs
  • Sciatic nerve 
  • Intestines
  • Ureter and bladder
• May need to wait for 5–10 days following an injury that causes an acetabular fracture due to the significant bleeding: 
  • Open reduction and internal fixation of acetabular fractures are based on the location of the fracture(s):
    • Anterior or ilioinguinal approach for the anterior column, both columns, anterior column plus posterior hemitransverse, or T-shaped fractures
    • Posterior surgical approach for posterior wall, posterior column, transverse plus posterior wall, or posterior column plus posterior wall fractures
    • Transverse approach depends on whether the predominant direction of displacement is anterior or posterior.
  • Extensive comminution or displacement of both anterior and posterior fragments may require sequential surgeries (anterior and posterior) or, less commonly, an extended iliofemoral approach.
  • Worst prognosis is seen with the associated transverse and posterior wall fractures:
    • High incidence of sciatic nerve palsy 
    • Potential osteonecrosis of the femoral head

Complications

• Hemorrhage (most important reversible factor)
• Hypovolemic shock 
• Bowel or urinary incontinence (S2–S5 sacral nerve root injury)
• Sexual dysfunction (S2–S5 sacral nerve root injury):
  • Dyspareunia
  • Erectile dysfunction
• Urethral trauma

Prognosis

• Simple acetabular fractures: 80%–85% of patients can expect a good to excellent recovery following surgery, provided that the hip can be properly aligned and fixed.
• Pelvic fractures and the often-associated concomitant injuries are potentially life-threatening and can lead to a significantly lower quality of life.
• Mortality:
  • 10%–42% in closed pelvic fractures and hypotension
  • 50% in open pelvic fractures