Trauma! Pelvic Fractures I

aka Trauma Tribulation 027

A 27 year old female was BIBA following a horse riding accident. She arrives in the ED in spinal precautions. She had transient hypotension en route that resolved with a 500 mL bolus of normal saline. The paramedics report tenderness on palpation of her iliac crests. Her vital signs are T 36.2C, P 90/min, R 22/min, BP 115/ 70 mmHg, SpO2 98%OA and GCS 15.

As leader of the trauma team you’d better know your stuff when it comes to pelvic trauma…

Questions

Q1. Why are pelvic fractures important in major trauma?

Pelvic fractures are important because they are associated with:

  • High energy mechanisms, such as:
    — motor vehicle crashes
    — collisions with pedestrians
    — falls from height
  • Major haemorrhage, which can be difficult to control
  • Other major injuries
    — Intra-abdominal organs (28%), including aortic injury
    — Hollow viscus injury (13%)
    — Rectal injury (up to 5%)
  • High morbidity and mortality (overall mortality is 10-30%; up to 50% if shocked)

Note that stable pelvic fractures (Tile Class A) that do not involve the pelvic ring (e.g. pubic ramus fractures and avulsion fractures) are associated with much less morbidity.

You proceed to examine the patient.

Q2. How do you examine the pelvis?

With extreme care!

Inspect for

  • echymoses, deformity, asymmetry, wounds

Palpate the skeletal  structures

  • pubic symphysis, iliac crests, the posterior sacroiliac joints, ischial tuberosities as well as the the spine extending inferiorly to the sacrum and coccyx

Assess for mobility

  • Gently compress the iliac crests to fell for instability
  • If there is no pain or movement felt on compression, gently distract the iliac crests (some experts, such as Scott Weingart, advise against distraction)
  • A gentle technique and cautious approach is important to avoid aggravating haemorrhage if the pelvis is fractured.

This maneuver should only be performed once, ideally by the most senior trauma doctor present. Do not ‘rock’ the pelvis! Be gentle!

Patients with suspected pelvis fractures also need careful examination of:

  • Rectum — digital rectal exam to palpate for rectal injury (e.g. blood, wounds), bony fragments, sphincter function and a boggy or high-riding prostate.
  • Perineum and genitalia — check for coexistent genital trauma, blood at the meatus, and scrotal or other perineal hematomas. Perform a vaginal exam in women for vaginal tears.
  • Lower limb length discrepancy and malrotation, and neurology
  • The abdomen, e.g. tenderness, distention, external signs of trauma

Normal examination in an alert adult patient effectively rules out significant pelvic injury (93-100% sensitivity) unless there are distracting injuries. Any injuries missed tend to be be clinically insignificant or managed conservatively anyway.

Learn more:

Q3. Why is it important to detect rectal injury in patients with pelvic trauma?

For these reasons:

  • Rectal injury is common (up to 5%)
  • signifies an open fracture — which are more likely to be hemodynamically unstable
  • may require fecal diversion, pre-sacral drainage and perineal debridement
  • Risk of death from secondary sepsis

As the assessment continues you consider what investigations to order.

Q4. What investigations may be useful in assessing patients with suspected pelvic fractures?

As always investigations are selected based on history and examination to determine diagnosis, management and/or prognosis. Depending on the clinical situation additional investigations may be be needed.

Bedside tests

  • Venous blood gas (VBG)
    — monitor hemoglobin (Hb), lactate and acidemia in major haemorrhage
  • FAST scan
    — assess for intraperitoneal fluid in a hemodynamically unstable patient with suspected pelvic fracture
    — Positive scan suggests haemorrhage from intra-abdominal injury and the need for laparotomy
    — False positives may result from associated bladder rupture
  • Diagnostic peritoneal aspirate (DPA)
    — can be used to rule out a false negative FAST scan in a haemodynamically unstable patient
    — DPA is performed above the umbilicus in patients with suspected pelvic fractures to avoid aspirating a pelvic hematoma
    — A positive result is the aspiration of 10 mL of frank blood or GI contents
    — this is an open procedure performed by a surgeon skilled in the technique, and may take 20 minutes

Laboratory tests

  • Group and save, or cross match (4-8 units) if severely injured
  • full blood count and coagulation profile
    — baseline Hb to allow monitoring for a drop over time as a result of hemorrhage
    — platelets and clotting factors may be depleted in major haemorrhage
  • BhCG in women of child bearing age

Imaging

  • AP pelvis x-ray
    — a normal x-ray does not exclude pelvic fractures completely, but does rule out pelvic fracture as a cause of haemodynamic instability
  • CT abdomen and pelvis with IV contrast
    — performed in the haemodynamically stable patient to rule out intra-abdominal and retroperitoneal injury, and to characterize the type and severity of pelvic injury and may identify those suited to inetrventional radiology
  • Angiography
    — used to identify arterial injury and to guide embolisation

Learn more:

Q5. Which major trauma patients should get a pelvic x-ray?

Indications for pelvis x-ray include:

  • Hemodynamically unstable
  • Altered mental state
  • Distracting injuries
  • Children (physical exam is less reliable)
  • Abdominopelvic CT not being done for another reason

Do not perform pelvis x-ray if:

  • Normal examination and the patient is alert and able to ambulate
  • Abdominopelvic CT will be performed anyway for another reason

Note that the miss rate for pelvic fractures using plain films varies from about 4 to 23% in different studies, and other studies comparing radiographs to CT scans indicates that the sensitivity of pelvic radiographs is only 64-78%. Even when an injury is detected by plain radiography, CT is generally necessary to further delineate the nature of injury and rule out other injuries.

A CT scan is the imaging modality of choice for assessing pelvic ring injury.

Learn more:

As expected the AP pelvic x-ray confirms a fractured pelvis.

Q6. How are pelvic fractures classified?

There are various systems for classification, these are the 2 most often used:

  • Tile classification
    — based on pelvic stability and useful for guiding pelvic reconstruction
  • Young-Burgess classification
    — more useful in the ED as it is based on mechanism and also indicates stability (I to III subclassification)

The Tile classification

  • Tile A
    — Rotationally and vertically stable
    — pubic ramus fracture, iliac wing fracture, pubic stasis diastasis <2.5 cm
  • Tile B
    — Rotationally unstable, vertically stable
    B1: pubic symphysis diastasis >2.5 cm and widening of the sacroiliac joints (open book fracture due to external rotation forces on the hemipelvises)
    B2: pubic symphysis overriding (internal rotation force on hemipelvises)
  • Tile C
    — Rotationally and vertically unstable
    — disruption of SI joints due to vertical shear forces
    C1: unilateral
    C2: bilateral
    C3: involves acetabulum

The Young-Burgess classification

  • Anteroposterior compression (APC)
    — common feature is diastasis of the pubic symphysis or vertical fracture of the pubic rami
    APC I: Pubic symphyseal diastasis, <2.5 cm, no significant posterior ring injury (stable)
    APC II: Pubic symphyseal diastasis >2.5 cm, tearing of anterior sacral ligaments (rotationally unstable, vertically stable)
    APC III: Hemipelvis separation with complete disruption of pubic symphysis and posterior ligament complexes (completely unstable)
  • Lateral compression (LC)
    — common feature is a transverse fracture of the pubic rami
    LC I: Posterior compression of sacroiliac (SI) joint without ligament disruption (stable)
    LC II: Posterior SI ligament rupture, sacral crush injury or iliac wing fracture (rotationally unstable, vertically stable)
    LC III: LC II, with open book (APC) injury to contralateral pelvis (completely unstable)
  • Vertical shear injuries (VS)
    — common feature is a vertical fracture of the pubic rami
    — displaced fractures of the anterior rami and posterior columns, including SI dislocation (completely unstable)
  • Combined mechanism (CM) fractures
    — massive pelvic injuries that don’t fit the other categories (completely unstable)

APC fractures typically result from ‘head on’ collisions, LS fractures from ‘side on’ impacts and VS fractures from falls from height or ‘head on’ motor vehicle crashes. The Young-Burgess classification was originally thought to predict extent of haemorrhage but this has not been supported by subsequent research. The ‘lesser’ fractures can still result in arterial haemorrhage in some cases.

Q7. What other important specific injuries are associated with pelvic fractures?

Important specific injuries associated with pelvic fractures include:

  • Bladder and urethral injury (5-20%)
    — posterior urethra with pelvic fractures
    — anterior urethra with straddle injuries
  • Intra-abdominal injury
    — spleen and liver (12%)
    — bowel (4%)
  • About 5% of pelvic fractures are open and may involve rectal or vaginal tears

Other injuries (e.g. head, chest) may also be present, especially as the presence of pelvic fractures implies a high energy mechanism of injury.

Q8. What are the potential complications of pelvic fractures?

Acute

  • major haemorrhage and shock (leading mechanism of death)
  • visceral and soft tissue injury:
    — fractures may be compound into the perineum or vagina
    — lacerations into the rectum or bladder
    — urethral injuries common in males
  • sacral plexus injury
  • ileus
  • fat embolization
  • acute respiratory distress syndrome
  • venous thromboembolism
  • abdominal compartment syndrome

Late

  • infection (second most common mechanism of death)
  • fracture complications (e.g. osteoarthritis, malunion)
  • disability and immobility
  • incontinence
  • sexual dysfunction
  • dystocia following subsequent pregnancy

The video below shows an OSCE style systematic approach to a patient with a pelvic fracture:

The management of pelvic trauma and ensuing hemorrhage is discussed in Trauma Tribulation 028 — Trauma! Pelvic Fractures II.

References and Links

Lifeinthefastlane.com

Journal articles and textbooks

  • Cullinane DC, Schiller HJ, Zielinski MD, Bilaniuk JW, Collier BR, Como J, Holevar M, Sabater EA, Sems SA, Vassy WM, Wynne JL. Eastern Association for the Surgery of Trauma practice management guidelines for hemorrhage in pelvic fracture–update and systematic review. J Trauma. 2011 Dec;71(6):1850-68. Review. PubMed PMID: 22182895.
  • Fildes J, et al. Advanced Trauma Life Support Student Course Manual (8th edition), American College of Surgeons 2008.
  • Legome E, Shockley LW. Trauma: A Comprehensive Emergency Medicine Approach, Cambridge University Press, 2011.
  • Marx JA, Hockberger R, Walls RM. Rosen’s Emergency Medicine: Concepts and Clinical Practice (7th edition), Mosby 2009. [mdconsult.com]
  • Suzuki T, Smith WR, Moore EE. Pelvic packing or angiography: competitive or complementary? Injury. 2009 Apr;40(4):343-53. Epub 2009 Mar 17. Review. PubMed PMID: 19278678.
  • White CE, Hsu JR, Holcomb JB. Haemodynamically unstable pelvic fractures. Injury. 2009 Oct;40(10):1023-30. Epub 2009 Apr 16. Review. PubMed PMID: 19371871.

Social media and other web resources

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Comments

  1. says

    i came here from emcrit. thanks for the review.

    regarding your notes: in weingart’s hemodynamically unstable pelvic trauma podcast he notes DPA as a one minute needle aspiration that might not need a surgeon, it sounds like your description of DPA above is more like DPL.

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