Chapter 18 – Pelvic Trauma




Abstract




Pelvic fractures are serious injuries, accounting for 20% of deaths due to trauma.1 Most high energy pelvic fractures are due to motor vehicle accidents, including motorcycles, and falls from a significant height. Since these injuries can have major effects on hemodynamics, especially in the setting of multi-trauma, time is of the essence, with focus on early diagnosis and management.





Chapter 18 Pelvic Trauma



Michael K. Abraham



Pelvic Fractures


Pelvic fractures are serious injuries, accounting for 20% of deaths due to trauma.1 Most high energy pelvic fractures are due to motor vehicle accidents, including motorcycles, and falls from a significant height. Since these injuries can have major effects on hemodynamics, especially in the setting of multi-trauma, time is of the essence, with focus on early diagnosis and management.



Anatomy




  • The pelvis is a complex structure that has a bony and ligamentous framework.



  • Disruption of either ligaments, bones, or a combination of both can lead to pelvic instability and, subsequently, due to the rich vascular supply of the pelvis, hemodynamic instability.



  • Hemorrhage may occur from surfaces of fractured bones, arterial injury, venous plexus injury, and extra pelvic sources (Figure 18.1). Pelvic hemorrhage is difficult to treat due to the myriad of potential sources of bleeding. The most common source of bleeding is the venous plexus (90%), which causes many treatment issues. The pelvis provides access to the retroperitoneal space, abdomen, and thighs, depending on the fracture. This access may result in significant blood loss before enough pressure forms to tamponade the vessels.2



  • The hip joint is comprised of the acetabulum and the proximal femur (Figure 18.2). The dense bone, designed for weight bearing, takes a great deal of force to injure in younger people. In older patients, however, osteopenia contributes to greater risk of fracture.



  • Acetabular fractures require a good deal of force and are usually associated with falls or motor vehicle injuries. A “dashboard injury” occurs when a flexed knee hits the dashboard of a car. This transmits forces into the posterior column of the acetabulum and often causes a posterior hip dislocation.



  • Significant pelvic trauma and fractures are associated with multisystem injuries.





Figure 18.1 (1) Sacrum; (2) Ilium; (3) Ischium; (4) Pubis: (4a) Body of pubic bone, (4b) Superior pubic ramus, (4c) Inferior pubic ramus, (4d) Pubic tubercle; (5) Pubic symphysis; (6) Acetabulum; (7) Obturator foramen; (8) Coccyx, Red dotted line = Linea terminalis





Diagnosis




  • Due to the mechanism of injury and the forces needed to cause injury, pelvic and hip trauma are often apparent. The initial examination depends on the mechanism and patient age. An elderly female with a fall from standing may have the sole complaint of pain with bearing weight and a fracture. However, a young male is unlikely to sustain a fracture with the same mechanism. High energy mechanisms are associated with fractures in younger patients.



  • Patients with pelvic injuries often have associated multi-system traumatic injuries. Isolated subtle pelvis and hip fractures may be more difficult to diagnose due to the lack of forceful mechanism, such as fall from a standing height.



  • Examination includes inspection, palpation, mobility, and neurovascular assessment.



  • Initial examination may be notable for differences in height or rotation of the iliac crests. Leg length discrepancy may be present if the acetabulum is involved. Pelvic stability should be assessed, with care to not excessively push down and out on the iliac crests. This mechanism may exacerbate unstable fractures and lead to greater hemodynamic instability. Rather, the iliac crests should be gently compressed to evaluate instability. If instability is found, pelvic binding is recommended. Repeat examinations for instability are not recommended.



  • Fracture communication with the vaginal or rectal areas should be evaluated, as these types of open fractures carry a much higher risk of complications.



  • Patients with no debilitating injuries should be ambulated.



  • The mainstay of diagnosis includes plain radiography, although the sensitivity is reported to be as low as 80% in some studies.3, 4 Several studies state that plain radiographs are unnecessary if the patient has a normal physical examination and is hemodynamically stable.4 Depending on patient hemodynamic status, CT may be the highest yield. Alternatively, if the patient has significant hemodynamic instability, a prompt plain film can demonstrate significant pelvic fractures leading to hemorrhage (open book fracture) and indicate the necessity for operative repair without further diagnostic imaging.



  • Pelvic x-ray is indicated for patients with hemodynamic instability, altered mental status, distracting injury, pediatrics, and if the CT abdomen/pelvis cannot be completed for another reason. Pelvic X-ray is not required if the patient is alert, able to ambulate, and has a normal examination.




    • Normal findings on AP pelvis radiograph (Figure 18.3): Symphysis pubis = 0.5 cm; sacroiliac joint = 2 mm; small offset of pubic rami.5



  • CT scan is the diagnostic test of choice due to increased sensitivity and specificity and the additional diagnostic information gained with the imaging of the abdominal and pelvic organs, as well as vasculature.



  • Bedside ultrasonography is essential, with FAST. Bleeding from pelvic injury is typically confined to the retroperitoneal space and may be difficult to evaluate using US. FAST may be negative in this setting.6, 7



  • MRI for subtle hip and pelvic fracture is warranted if injury is strongly suspected with negative imaging and the patient is unable to bear weight.



  • Pelvic fracture classifications include Tile and Young – Burgess (Tables 18.1 and 18.2). The classification of fractures is important to determine the need for operative management.810



  • Laboratory assessment includes CBC, coagulation profile/thromboelastography, metabolic panel, and beta hCG in reproductive aged women.



  • VBG for lactate and base deficit/excess can be helpful for evaluation of hemodynamic compromise.


Figure 18.3



(A) Illustration of the different patterns of pelvic fractures.





(B) Pelvic x-ray showing bilateral pubic and ischial rami fractures resulting in a “butterfly” fragment. This injury is often associated with significant bleeding.





(C) Pelvic x-ray showing unstable Malgaigne fracture with widening of symphysis pubis, right acetabular fracture, left rami fracture, and left sacroiliac joint disruption. This type of fracture is always associated with severe bleeding.





(D) Pelvic x-ray shows severe pubic symphysis diastasis. This is partially unstable and may be associated with significant bleeding. Arrows show bilateral inferior rami fractures.





(E) CT scan shows fracture of the sacral bone with severe displacement. It is usually associated with severe bleeding from the presacral venous plexus or the iliac vessels


(reproduced with permission from Color Atlas of Emergency Trauma, Second Edition, illustration at (A) by Robert Amaral)



Table 18.1 Tile8 classification of pelvic fractures
























Type Description Stability
A All avulsion fractures, individual iliac wing fractures, isolated pubic rami fractures, minimally displaced ring fractures, and transverse fractures of the sacrum or coccyx Yes
B Posterior arch-incomplete disruption; AP (open book) and LC injuries; unilateral or bilateral Partial
C Posterior arch – complete disruption; includes iliac, sacroiliac, and vertical sacral injuries from vertical shearing forces; unilateral or bilateral. No



Table 18.2 Young–Burgess classification of fractures9














































Stability
Anteroposterior Compression
I. Symphysis diastasis <2.5 cm Yes
II. Symphysis diastasis >2.5 cm, sacrospinous and anterior SI ligament disruption, Partial
III. Symphysis diastasis >2.5 cm, with complete disruption of the anterior and posterior SI ligament No
Lateral Compression
I. Sacral crush injury on ipsilateral side Yes
II. Sacral crush injury with disruption of posterior SI ligaments; iliac wing fracture may be present (crescent fracture); rotationally unstable No
III. Severe internal rotation of ipsilateral hemipelvis with external rotation of contralateral side No
Vertical Shear
Vertical displacement of symphysis and sacroiliac No
Combined Mechanisms
Any combination of the above mechanisms No


Treatment




  • Initial stabilization of the patient is paramount, as many patients with pelvic injuries will suffer from multiple injuries and can be hemodynamically unstable.



  • If pelvic injury is suspected, obtaining a Type and Screen/Crossmatch is recommended, with the understanding that blood transfusions may be necessary either peri- or intraoperatively.



  • Hemorrhage is one of the most worrisome sequelae of fractures. Studies have shown a correlation between type of fracture and volume of blood transfusions with unstable fractures.11



  • Uncrossmatched blood should be available, as damage control resuscitation is paramount to initial resuscitation efforts.



  • The pelvis should be stabilized (Figure 18.4). For “open book” fractures this requires a pelvic girdle or sheet forcefully tied around the pelvis at the level of the greater trochanters. For other unstable fractures the goal is to limit mobility of the pelvis, and splinting may be sufficient.



  • The decision for surgical intervention is complex and not algorithmic. It will require discussion with consultant services and will vary depending on the resources available.



  • The best course of treatment for a stable patient will be transfer to a trauma center if possible.



  • Unstable patients with hemoperitoneum should go to the OR for laparotomy and possible packing of the pelvis – orthopedics can be consulted to perform external fixation of the pelvis at that time.



  • Interventional Radiology, if available, may be able to perform angiography of the pelvic vessels with the goal of hemostasis (Figure 18.5).



  • REBOA is a newer but promising treatment that may help temporize unstable patients with pelvic fractures and hemodynamic compromise.



  • Fractures of the femur shaft should be brought to length using traction while awaiting orthopedic repair.



  • Isolated acetabular fractures should be stabilized and prepared for orthopedic repair; reduction of any dislocations should be considered if operative repair is not imminent.


Figure 18.4



(A) Illustration of external pelvic binder device being placed (left). Patient with pelvic binder applied (right).





(B) Radiographs of a patient with pubic symphysis diastasis before (left) and after (right) reduction and pelvic binder application. This type of immobilization is ideal for pubic symphysis diastasis, but not other types of pelvic fractures.





(C) CT scan showing fracture of the right iliac wing (circle). Application of a pelvic binder in this type of fracture is contraindicated because it worsens the fracture displacement


(reproduced with permission from Color Atlas of Emergency Trauma, Second Edition, illustration at (A) by Robert Amaral)




Figure 18.5 Angiograms of patients with complex pelvic fracture showing severe active bleeding


(reproduced with permission from Color Atlas of Emergency Trauma, Second Edition)


Pitfalls




  • Delay in the stabilization of the pelvis can lead to exsanguination.



  • Delay in consulting surgical consultants: trauma, orthopedics, vascular.



  • Delay in obtaining blood for transfusion.



  • Missing other injuries in the chest and abdomen, since one can be focused on issues from the pelvic injuries.




Key Points




  • Pelvic fractures due to trauma are associated with significant morbidity and mortality.



  • Stabilize the pelvis to limit hemodynamic instability and splint the pelvis.



  • Select diagnostic imaging carefully, as patients may be too unstable for CT or MRI evaluations.



  • Mobilize consultants in a timely fashion, including trauma surgery, orthopedics, and interventional radiology.



  • Always complete a focused but complete secondary examination for other injuries, as pelvic trauma is usually present with multisystem injury.



Hip Fractures


The term “hip fracture” actually consists of proximal femur fractures. These injuries commonly affect the elderly, who experience greater rates of falls and bone disease. Hip fractures in younger patients are more commonly due to high-energy mechanisms. Unfortunately, 30 day all-cause mortality for isolated hip fracture approaches 22%, while mortality is 36% at one year.12, 13



Anatomy


Fractures can be broken into intracapsular fractures (femoral head or neck fracture) and extracapsular fractures (intertrochanteric and trochanteric femur fracture) (Figure 18.6).




  • Intracapsular fractures have limited blood supply and may undergo avascular necrosis (AVN). However, extracapsular fractures are at low risk of AVN, due to excellent blood flow.


Jan 10, 2021 | Posted by in EMERGENCY MEDICINE | Comments Off on Chapter 18 – Pelvic Trauma
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