The Jefferson Fracture
Radiology Cases in Pediatric Emergency Medicine
Volume 5, Case 4
Linton L. Yee, MD
Kapiolani Medical Center For Women And Children
University of Hawaii John A. Burns School of Medicine
A 7-year-old male was diving off a ledge when he
landed head first in shallow water. He was pulled
semiconscious from the water by lifeguards. While
maintaining his airway, the lifeguards placed the patient
in full C-spine immobilization. When the patient
became more alert, he complained of pain to his upper
neck region. Paramedics transported the patient to the
Upon arrival, the patient is awake, alert, cooperative,
and in C-spine immobilization. His vital signs are
normal, and the neurologic exam is nonfocal. He
continues to complain of upper neck pain.
A cross table lateral neck radiograph is obtained.
View lateral neck radiograph.
With the patient in in-line manual immobilization, the
cervical collar is released, and the cervical spine is
palpated. The exam is remarkable for tenderness in
the upper cervical spine region. The lateral neck
radiograph is suggestive of mild prevertebral soft tissue
AP and odotoid open mouth views are obtained.
The AP view is normal.
View the odontoid views.
This is a poorly taken radiograph. The ideal open
mouth odontoid view should have the odontoid centered
in the mouth with the lateral masses of C1 clearly
visible. However, emergency physicians are commonly
presented with such poorly positioned radiographs
because it is often very difficult to properly position a
patient, with neck pain. It is often impossible to obtain a
satisfactory open mouth view in very young children
who are not cooperative. In such patients, a CT scan
may be necessary. Avoid the pitfall of misinterpreting a
poorly positioned odontoid view. In this radiograph,
only the lower lateral corners of the lateral masses of
C1 are visible. However, this should be sufficient to
make the diagnosis of a Jefferson fracture.
View the alignment of the lateral masses.
The lateral margins of the lateral masses (inferior
articular facets of C1) should align with the lateral
margins of the structures below it (superior articular
facets of C2). The space between these two facets is
the atlanto-axial joint. In this radiograph, the lateral
masses of C1 are displaced outward, indicating a
"bursting" of the ring of C1 (the Jefferson Fracture).
A Jefferson fracture is a compression and/or
bursting fracture of C1. This unstable fracture is the
result of a direct blow to the vertex of the head (axial
compression load), either from a fall or from an object
striking the vertex of the head. Neurologic injury is rare
but can occur if there is involvement of C2.
The axial load to the head (skull and occipital
condyles) focuses the stress on the C1 lateral masses,
causing them to be compressed against the superior
articular facets of C2. In the most classic cases, the
damage to C1 usually occurs in four places, with
fractures in two sites anteriorly and two sites
posteriorly. The transverse diameter of the spinal canal
is increased as a result of the displacement of the
lateral masses. When C1 is fractured in less than four
places, transverse ligament tears are common and can
lead to more instability. If the transverse ligament
remains intact, there will be no neurologic deficits, and
the lateral cervical spine X-ray may appear normal. If
the transverse ligament is ruptured, C1 will move
forward on C2, and the spinal cord will be compressed.
Radiographic findings can show bilateral
displacement of the C1 lateral masses when compared
to the C2 articular pillars. There can be unilateral
lateral displacement of the C1 lateral mass if there is no
movement of the opposite lateral mass. Routine
radiographs sometimes may not show evidence of a
The open mouth odontoid view will best show the
lateral displacement of the C1 lateral masses. Neck
rotation can cause false positive radiographs. A
pseudo-Jefferson fracture has the radiographic
appearance of a true Jefferson, but is the result of
cartilage artifact and the increased growth of the atlas
in comparison to C2. CT of the upper cervical spine is
indicated if there is any suggestion of a Jefferson
Approximately one-third of Jefferson fractures are
associated with other cervical spine fractures, with C2
associated fractures being the most common.
A repeat open mouth odontoid view of our patient is
View repeat odontoid view.
The lateral (outward) displacement of the lateral
masses is clearly visible in this radiograph.
View anatomic outlines for above.
The lateral masses are clearly displaced.
View normal odontoid radiographs.
These two odontoid views show the normal
alignment of the lateral masses and the superior facets
of C2 below them.
View our patient's CT scan.
This CT image of our patient shows the unilateral
fracture of the "ring" of C1. The odontoid process is
visible. The spinal cord is faintly visible posterior to the
odointoid within the neural arch.
Cornelius R, Leah J. Imaging evaluation of cervical
spine trauma. Neuroimaging Clinics of North America
Fesmire F, Luten R. Pediatric cervical spine.
Journal of Emergency Medicine 1989;7:133-142.
Roberge R. Facilitating cervical spine radiography in
blunt trauma. Emergency Medicine Clinics of North
Daffner R. Evaluation of cervical vertebral injuries.
Seminars in Roentgenology 1992;27(4); 239-253.
Gerlock A, et al. The cervical spine in trauma. WB
Saunders Company, Philadelphia, 1978.
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Web Page Author:
Loren Yamamoto, MD, MPH
Associate Professor of Pediatrics
University of Hawaii John A. Burns School of Medicine