Update in Subaxial Cervical Trauma:
What the Clinician Needs to Know
Roy Riascos, MD
Eliana Bonfante, MD
Claudia Cotes, MD
Clark Sitton, MD
Maria Gule-Monroe, MD
Harry Papasozomenos, MD
Neurorradiology
The University of Texas Health Science Center – Houston
Introduction
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
• Blunt trauma of the cervical spine is a common
presentation to emergency departments with
more than 1 million cases per year. 2-10 % of
these cases will demonstrate injury to the
cervical spine.
• Greater than 60% of all cervical spine fractures
and more than three-fourths of the dislocations
are sub axial.
•
The major cause of cervical spine injury in the
young population are motor vehicle accidents,
acts of violence, and sports injuries. Falls or
other low energy mechanisms are more
common in the geriatric population.
• Imaging of the trauma patient has evolved in
recent years, with multidetector CT being
ordered as part of the initial management of
these patients. MRI is a potential modality for
problem solving but its use remains
controversial.
Purpose
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
• Review the anatomy of the Subaxial cervical
spine.
• To provide a review of the subaxial injuries in
terms of anatomy and currently used .
• Identify the role of imaging in the prognosis and
treatment of subaxial injuries.
Anatomy
• The subaxial cervical spine extends from the
inferior border of C2 to the superior endplate of
T1.
• Ligaments:
• The anteior longitudial ligament connects the anterior
aspects of the vertebral bodies.
Intervertebral disc
Vertebral body
Facet joint
• The posterior logitudinal ligament connects the posterior
aspects of the vertberal bodies.
• The ligamentum flavum connects the adjacent laminae.
• The interspinous ligament connects the spinous
processes.
• Joints
Anterior longitudinal
ligament
• The intervertebral discs connect the vertbral bodies
Posterior longitudinal
ligament
• The apophyseal facets communicate throgh synovial
joints on both sides.
Interspinous ligament
.
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
Indications for Imaging – Plain Films
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
• Three views: anteroposterior
(AP), lateral, and odontoid
view.
• Low cost and fast.
• Should be used when the
suspicion of injury is low
since it may fail to
demonstrate lesions that are
normally visible in other
modalities.
• Dynamic
views,
which
include flexion and extension
views, demonstrate unstable
cervical
spine
lesions.
However, range of motion
may be limited in the acute
setting.
c
b
a
d
e
Lateral (a), AP (b), od0ntoid (c), flexion (d) and extension views(e) of the
cervical spine.
Indications for Imaging – CT
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
• Study of choice when injury
of the cervical spine is
suspected.
• Multiplanar,
reformatted
sagittal
and
coronal
reconstruction provide high
quality images that improve
interpretation.
• The recommended slice
thickness for sagittal and
coronal reconstructions is
1.25 mm.
• Although newer scanners
have decreased radiation
exposures, these are higher
compared to plain film. CT
should be limited to patients
at high risk of cervical spine
injury.
Axial, sagital and coronal CT images in
bone reconstruction.
Indications for Imaging – MR
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
• Suspected myelopathy.
• Treatment planning for the
mechanically unstable spine.
• Patients who can not be
clinically evaluated for more
than 48 hours, patients with
neurological deficits, or
suggested ligamentous injury.
• The main role of MR is
detection of the type and
extent of spinal cord injury
which impacts patient
management . MR is better
suited for exclusion of spinal
cord lesions than detection of
ligamentous or other soft
tissue injuries.
T2 Sagittal without and with fat
saturation are used in cervical
trauma for evaluation of the soft
tissues in trauma.
Axial T2 sequences can help
evaluate the spinal canal and the
spinal cord.
Indications for Imaging – Magnetic Resonance (MR)
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
• MR performs slightly better in
detection of clinically
significant lesions.
• No studies compare more
current MR technology with
cadaveric studies; but MR has
only a slightly advantage in
the detection of occult
instability injuries not
detected on CT.
• MR does not provide any
additional clinically relevant
information in patients who
are alert, neurologically intact,
and younger than 60 years of
age.*
*Pourtaheri et al
T2 Sagittal without and with fat
saturation are used in cervical
trauma for evaluation of the soft
tissues in trauma.
Axial T2 sequences can help
evaluate the spinal canal and the
spinal cord.
Classifications
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
Controversy concerning the affect
classification systems have on clinical
outcome, most imagers have resorted
to using descriptive terminology to
describe patterns of injury.
Recent efforts to further classify
subaxial lesions have been made giving
rise to the subaxial ligamentous injury
(SLIC) and the cervical spinal severity
score (CSISS) classifications. This exhibit
will review the two classifications and
discuss the clinical implications of them.
•Allen and Fergusson
•Cervical Spine Injury Severity
Score (CSISS)
•Sub-axial Injury Classification
(SLIC)
Allen and Fergusson Classification
Many classifications
• Based on mechanisms of injury the
cervical fractures are divided in the
following groups:
more than 60% of all cervical spine fractures .
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
Most widely utilized system for
description of fractures in the past.
This system does not quantify the
severity of a lesion or guide treatment
which is considered a limitation.
Harris et al (1) expanded this
classification in the mid 1980s.
Today this expansion is used rarely in
clinical practice.
• Compressive flexion
• Vertical compression
• Distractive flexion
• Compressive extension
• Lateral flexion
• Limited clinical use
• Rarely currently utilized
• Still of great value in the
comprehensive analysis of spectrum
of injuries during diagnostic
interpretation of images.
Cervical Spine Injury Severity Score (CSISS)
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
• Moore et al in 2006
• Assess cervical stability and translate
that into the likelihood of considering
surgery as a treatment option
• Imaging only
• System considers the bony and the
ligamentous components
• Spine is divided into four columns:
anterior, posterior right pillar and left
pillar
Diagram of a cervical spine (A) The spine is divided into
four columns: anterior, posterior right pillar and left pillar
. CSISS Classification (B).
Adapted from Anderson et al
Cervical Spine Injury Severity Score (CSISS)
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
The anterior column includes the
vertebral body, intervertebral disc, the
anterior and posterior longitudinal
ligaments.
The posterior column includes the
spinous process, the interspinous
ligament, the lamina and ligament
flava.
The lateral pillars include the pedicle
the pars articularis, the joint facet with
the capsules and the transverse
process.
Diagram of a cervical spine (A) The spine is divided into
four columns: anterior, posterior right pillar and left pillar
. CSISS Classification (B).
Adapted from Anderson et al
Cervical Spine Injury Severity Score (CSISS)
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
For each column, a score of 0 to 5 is
given, 0 representing no injury and 5
representing the most severe fracture or
dislocation possible for that column see
image. The numerical value is summed
of all four columns resulting in a final
score of 0 to 20 for each level.
This classification has yet to be
compared with prognosis. The authors
found that most patients with scores
greater than 7 likely received surgical
intervention, while only 3 of 20 patients
with score lower that 7 required surgical
reduction
Diagram of a cervical spine (A) The spine is divided into
four columns: anterior, posterior right pillar and left pillar
. CSISS Classification (B).
Adapted from Anderson et al
Sub-axial Injury Classification (SLIC)
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
• Proposed by Vaccaro et al in 2007
• Beyond mechanism of injury
• Components
• Injury morphology
• Disco-ligamentous complex (DLC)
integrity
• Neurological status of the patient
• Guide towards management strategies
• Better inter-rater reliability than the
Allen and Fergusson
Simple Compression
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
Diagrams demonstrating simple
compression morphology. The lesions
show a loss of anterior column height.
They can affect the anterior column, be
accompanied by DLC disruption or
laminar fractures. Non displaced lateral
mass or facet fractures are also
considered simple compression injuries.
Anterior Column
DLC disruption
Laminar fractures
Adapted from, Vaccaro et al, Spine. 32(21):2365-2374,
October 1, 2007.
Non-displaced lateral
mass fracture
Simple Compression
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
• Anterior column compression
with Epidural Hematoma:
• Anterior compression
fracture of C3 (white arrow
head), Increased signal in the
interspinous ligament (black
arrow head) and spinal canal
stenosis due to a posterior
epidural hematoma (arrows).
Simple Compression
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
• Anterior column with DLC
Disruption:
• Fracture of the inferior
endplate of C5 that extends
to the interverterbal disc
(arrows). An anterior epidural
hematoma causes narrowing
of the spinal canal with
increased signal in the spinal
cord (arrow heads).
Simple Compression
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
• Laminar Fractures
• CT shows spinous fractures of
C7 and T1 (arrows), slight
compression fractures of the
C7 verterbal body are noted
(arrow head).
Simple Compression
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
• Non displaced lateral mass
fracture:
CT shows a non displaced
fracture of the right lateral
mass of C6 (white arrow). MR
STIR WI shows bone marrow
edema at the fracture site.
Burst
Burst fracture: severe compression
lesion that involves the whole vertebral
body and can be associated with
retropulsed fragments. Lateral (A) and
sagittal (B) diagrams of the cervical
spine.
.
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
Adapted from, Vaccaro et al, Spine. 32(21):2365-2374,
October 1, 2007.
Burst
• Burst Fracture
Burst compression fractures of
C5 and C6 with posterior
retropulsed fragments and a
disc extrusion which narrows
the spinal canal (arrow heads).
Hyperintensity is noted in the
spinal cord (arrows).
.
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
Distraction
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
• Distraction morphology. Diagrams
demonstrating distraction morphology .
Lesions are characterized by
dissociation of the vertical axis involving
the disc-ligamentous complex. Lesions
may be circumferential and associated
to facet dislocations.
Circumferential
Facet dislocation
• Anterior distraction in hyperextension
may be associated to spinous process
fractures. Distraction in hyperflexion
can be associated to posterior
ligamentous injury.
Adapted from, Vaccaro et al, Spine. 32(21):2365-2374,
October 1, 2007.
Anterior distraction with
extension
Anterior distraction with
flexion
Distraction
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
• Anterior distraction with
flexion
CT shows laminar fractures
with fractures of the spinous
processes (arrow). Disruption
of the ligamentum flavuminterspinous ligament is
present (arrow heads)
Distraction
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
• Anterior Distraction with
Extension:
Widening of the C5-6
intervertebral disc space with
DLC compromise and
interuption of the ALL (arrow).
Sagittal T1 and axial GRE WI
show an anterior epidural
hematoma (arrowhead).
Distraction
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
• Anteiror Disruption with
Extension:
Disruption of the anterior
longitudinal ligament at C5-6
(white arrow) with a
prevertebral hematoma and
fluid in the C5-6 intervertebral
disc consistent with disruption
of the DLC. The spinal cord is
compressed (arrow head).
Translation/Rotation
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
Translation/rotation morphology.
Diagrams demonstrating translation
and rotation injuries. These injuries are
characterized with complete DLC
disruption. Translation can happen in
the sagittal plane, associated to pedicle
fractures or joint facet fractures.
Rotational injuries can also be present
in addition to the axial translation.
Adapted from, Vaccaro et al, Spine. 32(21):2365-2374,
October 1, 2007.
Translation in
sagittal plane
Translation with
facet fracture
Translation with
pedicle fracture
Rotational injury
Translation/Rotation
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
• Translation in the saggital
plane.
• Slight translation in the
sagittal plane (black arrow
head) with incresaed signal in
the spinal cord ((white
arrow).
Translation/Rotation
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
• Translation with pedicle
fracture:
• Anterior displacement of C6
on C7 with complete overlap.
Fracture of the spinous
process of C6 (white arrow
head, and compression of the
spinal cord is noted (white
arrow). The interspinous soft
tissues show edema (black
arrow). Fracture of the
pedicle of C6 is noted (black
arrow head)
Translation/Rotation
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
• Translation with facet
fracture:
• CT before reduction and MR
after reduction show
widening of the C6-7
interverterbal space with
fluid occupying the space
(black arrowhead). The
interspinous space in
widened (white arrow);
fracture of the superior joint
facet in present (white arrow
head).
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
• Diffuse Idiopathic Skeletal
Hyperostosis:
Patient with DISH shows
fracture of the anterior
bridging osteophytes with a
preverterbal hematoma and of
the transverse process of C7.
bone marrow contusion isn the
lower cervical bodies,
consistent with bone
contusions.
SLIC- How to use the classification What the Clinical needs to know
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
The three categories of the SLIC system are
identified and reported as seen in table 1.
The report should include the spinal level, the
injury level morphology, the bony injury
descriptor, the DLC status and descriptors,
the neurological status, and confounding
factors (presence of ankylosing spondylitis,
diffuse idiopathic skeletal hyperostosis,
osteoporosis, previous surgery, spondylosis,
etc).
A numeric value is assigned to each category
and the numerical sum is the SLIC score.
Higher scores indicate more significant injury
and an increased need for surgical
intervention. If multiple injuries occur at
different levels, each level is assigned a
separate score.
Challenges of the Classifications
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
• Although great improvement have been
made using these new classification
systems, challenges in the evaluation of
subaxial cervical injuries remain. Some
of these are:
• The signal changes in the cervical spinal
cord don’t always correlate with the
findings in the neurological exam. The
cord abnormalities are not included in
the scoring system, however they are
extremely relevant for patient care ,
especially in non responsive patients.
• Overlap exists in parameters of the new
classifications and we find it difficult to
isolate the lesions to single categories
of the proposed systems.
• The evaluation of other traumatic soft
injuries such as acute disc herniations
or epidural hematomas is not
considered in the scoring systems, yet
has a strong clinical impact.
• Image quality limitations are not taken
into account, which are usual in acute
traumatic injuries.
Summary
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
• The subaxial ligamentous injury (SLIC)
and the cervical spinal severity score
(CSISS) classifications are a new effort to
classify subaxial traumatic cervical
injuries. Neuroradiologists should be
aware of the clinical implications of
using these classifications, and how they
can provide improvement in patient
outcomes.
• The SLIC classification integrates
imaging and neurological findings, and
has shown a strong correlation with
treatment planning.
• Radiologists should actively be included
in evolving new classifications systems
for subaxial injuries.
• Although the Allen and Fergusson
Classification has limited clinical utility,
it is still of great value in the
comprehensive analysis of spectrum of
injuries during diagnostic
interpretation of images.
• Non ligamentous soft tissue injuries
such as the presence of epidural
hematomas and cord compression are
not included in these classifications.
• Radiologists must know which system
is used at their institutions to be able
to know what is the pertinent
information to include in their reports.
References
Introduction
Purpose
Anatomy
Indications for imaging
• Plain Films
• CT
• MRI
Classifications
Allen and Fergusson
CSISS
SLIC
• Morphology
•Simple
compression
•Burst
•Distraction
•Translation
•How to use
Summary
Vaccaro, A. R. et al. The subaxial cervical spine injury classification system: a novel approach to recognize
the importance of morphology, neurology, and integrity of the disco-ligamentous complex. Spine 32,
2365–2374 (2007).
78.
Allen, B. L., Jr, Ferguson, R. L., Lehmann, T. R. & O’Brien, R. P. A mechanistic classification of closed,
indirect fractures and dislocations of the lower cervical spine. Spine 7, 1–27 (1982).
79.
Marcon, R. M. et al. Fractures of the cervical spine. Clin. São Paulo Braz. 68, 1455–1461 (2013).
80.
Stone, A. T. et al. Reliability of classification systems for subaxial cervical injuries. Evid.-Based SpineCare J. 1, 19–26 (2010).
81.
Harris, J. H., Jr, Edeiken-Monroe, B. & Kopaniky, D. R. A practical classification of acute cervical spine
injuries. Orthop. Clin. North Am. 17, 15–30 (1986).
82.
Kwon, B. K., Vaccaro, A. R., Grauer, J. N., Fisher, C. G. & Dvorak, M. F. Subaxial cervical spine trauma.
J. Am. Acad. Orthop. Surg. 14, 78–89 (2006).
83.
Anderson, P. A. et al. Cervical spine injury severity score. Assessment of reliability. J. Bone Joint Surg.
Am. 89, 1057–1065 (2007).