The Shattered Pelvis: Slideshow

Pelvic fractures are a common diagnosis in clinics and emergency departments. All pelvic fractures are not created equally, and if not properly diagnosed, significant morbidity and mortality can result. Clinical and radiographic cases are presented here to test the discerning clinician's ability to appropriately detect pelvic fractures. The x-ray shown demonstrates widening of the pubic symphysis (white arrow) and right sacroiliac joint (yellow arrow) due to an anteroposterior compression injury.

An 80-year-old woman presents to the emergency department (ED) with acute-onset right hip pain after awkwardly walking down a flight of stairs. An anterior posterior (AP) x-ray of her pelvis is ordered and reveals what etiology for this woman's pain?

In this 80-year-old woman with sudden onset of right hip pain there is an acetabular roof fracture (yellow arrow) and disruption of the right pubis ischium (white arrow). The disruption of the right pubic ischium is difficult to visualize because of the lack of contrast differentiation in this older woman with osteoporosis. Patients with severe osteoporosis are at risk for fracture, even with minimal trauma. CT would be the next appropriate diagnostic test to aid in therapeutic planning.

A patient is brought to the ED after a large multivehicle roll-over accident. An AP x-ray of the pelvis is ordered. How many injuries can be identified? Is this likely to be a stable injury?

There are 3 identifiable injuries in this AP x-ray. There is a displaced fracture of the medial right acetabular roof (white arrow). The right sacral iliac (SI) joint is wider than normal (yellow arrow) and in comparison to the left. There is a right pubic fracture (red arrow) which is only partially seen due an artifact (curved black arrow) resulting from a buckle. This was demonstrated to be an unstable injury because there are fractures involved the right pelvis at 3 levels. The trauma backboard can be seen overlying the field of view (blue arrow).

A multitrauma patient is brought into the trauma bay in the ED. An AP x-ray is ordered to assess for pelvic fracture. Because the pelvis has a complex 3-dimensional structure, complex pelvic injury is often difficult to fully assess using conventional x-rays. How many pelvic fracture patterns can be identified?

There are 4 fractures identified on this AP pelvic x-ray. The right SI joint is widened by a diastasis (separation) fracture (black arrow). The left femoral head has been driven superiorly into the left acetabulum (dotted red arrow) with associated fractures of the proximal left pubic bone and distal left iliac bone (blue arrows). The pubic symphysis has been fractured (double-headed yellow arrow) with displacement and rotation of the left anterior pelvis superiorly away from the right side of the pubic symphysis (double headed red arrow). The image is made more complex by the presence of artifacts which are on or under the patient, such as the trauma board and metal clips (white arrows).

Widening or disruption of the pubic symphysis (double-headed black arrow) is concerning for pelvic instability. Multiple classification schemes are available to describe the stability of hip fractures. The Tile system classifies injuries on the integrity of the posterior SI complex. The Young classification system is based on the mechanism of injury: lateral compression, anteroposterior compression, or vertical sheer. This x-ray is an example of an anteroposterior compression fracture. The displacement of 2.5 cm represents damage at the SI joint (black arrow) and is usually an indication for operative stabilization. These injuries imply rupture of the anterior sacroiliac, sacrospinous, and sacrotuberous ligaments rendering the pelvis rotationally unstable.

A patient presents with multiple-system trauma from an automobile accident. The scout view from the CT of the pelvis reveals how many different fractures?

The scout image reveals fractures of both the superior and inferior pubic rami (white arrows) and bilateral posterior diastatic fractures of the SI joints (broken blue arrows), termed a Malgaigne fracture. These vertically oriented fractures with both anterior and posterior effects on the pelvis are often associated with superior displacement of the lateral portion of the pelvis. Rupture of the pelvic floor may occur with injury to the posterior SI joint complex with tearing of the sacrospinous and sacrotuberous ligaments.

CT images of a Malgaigne fracture are shown. Fractures (black arrows) are noted involving the left SI joint, sacrum, and iliac bone (top left), the anterior left pubic bone (top right) and the left inferior pubic ischium (bottom). Malgaigne fractures are associated with heavy bleeding. If the pelvis is unstable with vertical migration or posterior displacement, then traction is used to pull the pelvis back down into a reduced position (equal leg lengths). One half of patients treated nonoperatively (traction) may expect long-term low back pain and/or leg discomfort, and one third will have a pelvic obliquity with limp.

Pelvic fractures in younger, healthier patients are frequently due to high-impact injuries. As a result, it is important to be aware of the potential for multiple other associated injuries. Three CT images are shown from a multitrauma patient. The top left image reveals a widely displaced left iliac fracture (white arrow) with an expanding left pelvic hematoma (double-headed yellow arrows). The bottom image reveals a posterior right liver laceration. The top right image reveals a large right pneumothorax. Any one of these injuries could prove to be potentially life threatening if not adequately addressed.

A postmenopausal, middle-aged woman presents to clinic with long-standing pelvic pain that has increased in severity over the last several weeks. She denies any history of recent or remote trauma. An x-ray of the pelvis is ordered which reveals what abnormalities?

The AP x-ray of the pelvis reveals multiple insufficiency fractures. Fractures are noted involving the right anterior pubic bone (double-headed black arrow) resulting in inferior displacement of the left anterior pelvis (double-headed white arrow). Both SI joints are irregular with widening (black arrows). Insufficiency fractures are stress fractures that develop after normal stress is applied to weakened bone -- in this case, osteoporosis. Bone scintigraphy and MRI are the imaging modalities of choice for the detection of occult insufficiency fractures which may not be readily apparent on plain x-rays or CT.

An axial CT image at the level of the SI joints in the same patient reveals a bilateral pattern of lytic changes in the iliac bones (white arrows) lateral to the SI joints.

What imaging procedure would be appropriate as the next step?

3D reformats of the CT scan provide excellent anatomic evaluation of the pelvis. In this patient with chronic renal disease and pelvic pain, there are bilateral irregular insufficiency fractures of the iliac wings (curved black arrows). The pubic symphysis is widened (double-headed white arrow) with elevation of the left pubis. The use of 3D imaging is invaluable in the assessment of large complex structures such as the bony pelvis.

CT provides additional information that is often not readily apparent on x-rays. This axial CT scan was performed on a patient who complained of limited range of motion in the left hip and was subsequently diagnosed with anterior and posterior pelvic fractures noted on a pelvic x-ray. The image shown demonstrates a bone fragment trapped in the left acetabulum (broken white arrow), a large posterior acetabular defect (white arrow) and a displaced fragment of the acetabular injury displaced to the anterior aspect of the left femoral head (broken yellow arrow). These are important details that will aid in surgical planning.

What is an alternative imaging study in occult hip pain?

MRI is an excellent alternative means of imaging the patient with occult hip pain.

A patient with a history of minor trauma presents with occult left hip pain after a negative x-ray and CT scan of the pelvis. An MRI was performed of the pelvis. Coronal (left) and axial (right) T1-weighted images demonstrate a fracture fragment (white arrow) of the superior left femoral head marked by an occult fracture line (black arrow).

What additional information might be learned by MRI of the hip in pelvic trauma?

MRI is the best modality for the evaluation of soft tissue structures. An axial T2-weighted MRI image is shown of a young patient who experienced left hip pain out of proportion to an otherwise routine left acetabular fracture first diagnosed on a pelvic x-ray. The MRI demonstrates hemorrhage along the medial left pelvic wall (black arrow) and edema in the gluteus muscles posterior to the left hip (white arrows).

Images courtesy of Lennard A. Nadalo, MD

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For more information, see the following resources:

• eMedicine, Emergency Medicine: Pelvic Fracture in Emergency Medicine
• eMedicine, Radiology: Pelvic Insufficiency Fracture Imaging
• eMedicine, Radiology: Pelvic Ring Fracture Imaging
• eMedicine, Orthopedic Surgery: Pelvic Fractures

Contributor Information

Author
Lennard A. Nadalo, MD
Clinical Professor, Department of Radiology
University of Texas Southwestern Medical School
Consulting Staff
Envision Imaging of Allen and Radiological Consultants Association
Dallas, Texas

Disclosure: Lennard A. Nadalo, MD, has disclosed no relevant financial relationships.

Editor
Lars Grimm, MD, MHS
House Staff
Department of Internal Medicine
Duke University Medical Center
Durham, North Carolina

Disclosure: Lars Grimm, MD, MHS, has disclosed no relevant financial relationships.

Reviewer
Jose Varghese, MD
Associate Professor of Radiology
Boston University School of Medicine
Boston, Massachusetts

Disclosure: Jose Varghese, MD, has disclosed no relevant financial relationships.