28. Denis Classification:
The three column
spine
• The anterior column is formed by
the anterior longitudinal ligament,
the anterior annulus fibrosus, and
the anterior part of the vertebral
body.
• The middle column is formed by
the posterior longitudinal
ligament, posterior annulus
fibrosus, and the posterior wall of
the vertebral body.
• The posterior column is formed by
the posterior bony complex
(posterior arch) alternating with
the posterior ligamentous
complex: supraspinous ligament,
interspinous ligament, capsule,
and ligamentum flavum.
29. Stable and Unstable Fractures
• Stable fractures don't cause spinal deformity or
neurologic (nerve) problems. With a stable fracture, the
spine can still carry and distribute your weight pretty well.
• Unstable fractures make it difficult for the spine to carry
and distribute weight. Unstable fractures have a chance
of progressing and causing further damage. They may
also cause spinal deformity.
• If one column is disrupted, other columns may provide
sufficient stability to prevent spinal cord injury.
31. pathophysiology
• Cervical spine injuries are best classified according to
several mechanisms of injury. These include:
flexion
flexion-rotation
extension
extension-rotation
vertical compression
lateral flexion
imprecisely understood mechanisms that may result in
odontoid fractures and atlanto-occipital dislocation.
32. Fx classified
according to
pathophysiolog
y
Flexion
Simple wedge
Fx
Flexion tear
drop
Anterior
subluxation
Bilateral facet
dislocation
Clay shoveler
fracture
Anterior
atlantoaxial
dislocation
Flexion-rotation
Extension
Extension-
rotation
Vertical
compression
Lateral flexion
Multi-
mechanism
38. Flexion Injury
• Common injuries associated with a flexion mechanism
include the following:
• Simple wedge compression fracture without posterior
disruption
• Flexion teardrop fracture
• Anterior subluxation
• Bilateral facet dislocation
• Clay shoveler fracture
• Anterior atlantoaxial dislocation
39. Simple wedge fracture
• The anterior vertebral body bears most of the force,
sustaining simple wedge compression anteriorly without
any posterior disruption.
• Radiographically the anterior border of the vertebral
body has diminished height and increased concavity
along with increased density due to bony impaction. The
prevertebral soft tissues are swollen.
• The posterior column remains intact, making this a
stable fracture that requires only use of a cervical
orthosis for treatment.
40.
41. Flexion teardrop fracture
• A flexion teardrop fracture occurs when flexion of the
spine, along with vertical axial compression, causes a
fracture of the anteroinferior aspect of the vertebral body.
This fragment is displaced anteriorly and resembles a
teardrop
• This injury involves disruption of all 3 columns, making
this an extremely unstable fracture that frequently is
associated with spinal cord injury. Initial management is
application of traction with cervical tongs.
42.
43. Anterior subluxation
• Anterior subluxation in the cervical spine occurs when
posterior ligamentous complexes rupture. The anterior
longitudinal ligament remains intact. No associated bony
injury is seen.
• Radiographically, the lateral view shows widening of
interspinous processes, and anterior and posterior
contour lines are disrupted in flexion views (see the
image below). Since the anterior columns remain intact,
this fracture is considered mechanically stable by
definition
• Anterior subluxation is rarely associated with neurologic
sequelae. Nevertheless, most authorities approach this
injury as if it were potentially unstable
44.
45. Bilateral facet dislocation
• This injury involves the annulus fibrosus, anterior
longitudinal ligament and posterior ligamentous complex.
• Radiographically, this is seen as a displacement of more
than half of the anteroposterior diameter of the vertebral
body in the lateral view.
• This is an extremely unstable condition and is associated
with a high prevalence of spinal cord injuries.
• Initial management is closed reduction and traction with
cervical tongs.
46. Clay shoveler fracture
• Abrupt flexion of the neck, combined with a heavy upper
body and lower neck muscular contraction, results in an
oblique fracture of the base of the spinous process,
• Injury commonly occurs in lower cervical vertebrae;
• Injury also may be seen in the anteroposterior view as a
vertically split appearance of the spinous process in the
lower vertebrae
• This fracture is considered stable.
• Management involves only cervical immobilization with
an orthotic device for comfort.
47.
48. Flexion-rotation Injury
• Common injuries associated with a flexion-rotation
mechanism include:
• unilateral facet dislocation and
• rotary atlantoaxial dislocation.
49. Unilateral facet dislocation
• Pathophysiology
• Although the posterior ligament is disrupted, vertebrae
are locked in place, making this injury stable.
• The lateral view, The anteroposterior view and The
oblique view is useful.
• The injury seldom is associated with neurologic deficits.
The orthopedic consultant performs initial management,
applying cervical traction to attempt closed reduction.
50.
51. Rotary atlantoaxial dislocation
• This injury is a specific type of unilateral facet
dislocation.
• Radiographically, the odontoid view shows asymmetry of
the lateral masses of C1 with respect to the dens along
with unilateral magnification of a lateral mass of C1 (wink
sign).
• This injury is considered unstable because of its location.
52.
53. Extension Injury
• Common injuries associated with an extension
mechanism include:
• hangman fracture
• extension teardrop fracture
• fracture of the posterior arch of C1 (posterior neural
arch fracture of C1)
• posterior atlantoaxial dislocation.
54. Hangman fracture (traumatic
spondylolisthesis of C2)
• Terminology
• Radiographically, a fracture line should be evident
extending through the pedicles of C2 along with obvious
disruption of the spinolaminar contour line.
• Although considered an unstable fracture, it seldom is
associated with spinal injury.
• When associated with unilateral or bilateral facet
dislocation at the level of C2, this particular type of
hangman fracture is unstable.
• All other types of hangman fracture can be managed
initially with a cervical orthotic device.
55.
56. Extension teardrop fracture
• As with flexion teardrop fracture, extension teardrop
fracture also manifests with a displaced anteroinferior
bony fragment.
• The fragment is a true avulsion (in contrast to the flexion
teardrop fracture)
• The fracture is common after diving accidents and tends
to occur at lower cervical levels. It also may be
associated with the central cord syndrome due to
buckling of the ligamenta flava into spinal canal during
the hyperextension phase of injury.
• This injury is stable in flexion but highly unstable in
extension. Initial management is avoidance of iatrogenic
extension and cervical traction with tongs.
57.
58. Fracture of the posterior arch of C1
(posterior neural arch fracture)
• This fracture occurs when the head is hyperextended
• Radiographically, the lateral projection shows a fracture
line through the posterior neural arch. The odontoid view
fails to show any displacement of the lateral masses of
C1 with respect to the articular pillars of C2, a finding
that distinguishes this fracture from a Jefferson fracture.
• This fracture is stable.
• Initial management involves the differentiation of this
benign fracture from a Jefferson fracture. Once this is
accomplished, only use of a cervical orthosis is required.
59.
60. Vertical (axial) Compression Injury
• Common injuries associated with a vertical compression
mechanism include:
• Jefferson fracture (burst fracture of the ring of C1)
• burst fracture (dispersion, axial loading)
• atlas fracture
• isolated fracture of the lateral mass of C1 (pillar
fracture).
61. Jefferson fracture (burst fracture of the
ring of C1)
• This fracture is caused by a compressive downward
force. Quadruple fracture of all 4 aspects of the C1 ring
occurs.
• Radiographically the fracture is characterized by bilateral
lateral displacement of the articular masses of C1. This
finding differentiates it from a simple fracture of the
posterior neural arch of C1.
• The lateral projection usually reveals a striking amount of
prevertebral soft tissue edema.
• When displacement of the lateral masses is more than
6.9 mm complete disruption of the transverse ligament
has occurred and immediate referral for cervical traction
is warranted.
62.
63. Burst fracture of the vertebral body
• This fracture involves disruption of the anterior and
middle columns, with a variable degree of posterior
protrusion of the latter.
• Radiographically, this fracture is evidenced by a vertical
fracture line in the frontal projection and by comminution
and protrusion of the vertebral body anteriorly and
posteriorly.
• Posterior protrusion of the middle column may extend
into the spinal canal and can be associated with anterior
cord syndrome.
• Initial management of burst fractures with a loss in height
of more than 25%, retropulsion, or neurologic deficit is
accomplished by applying traction with cervical tongs.
When none of those problems exist, the fracture is
considered stable.
64.
65. Multiple or Complex Injuries
• Common injuries associated with multiple or complex
mechanisms include:
• odontoid fracture
• fracture of the transverse process of C2 (lateral
flexion)
• atlanto-occipital dislocation (flexion or extension with
a shearing component)
• occipital condyle fracture (vertical compression with
lateral bending)
66. Odontoid process fractures
• The 3 types of odontoid process fractures are classified
based on the anatomic level at which the fracture occurs
• With types II and III fractures, the fractured segment may
be displaced anteriorly, laterally, or posteriorly. Since
posterior displacement of segment is more common, the
prevalence of spinal cord injury is as high as 10% with
these fractures.
• Initial management of a type I dens fracture is use of a
cervical orthosis. Manage types II and III fractures by
applying traction with cervical tongs.
67.
68.
69. Atlanto-occipital dislocation
• When severe flexion or extension exists at the upper
cervical level, atlanto-occipital dislocation may occur.
• Atlanto-occipital dislocation involves complete disruption
of all ligamentous relationships between the occiput and
the atlas.
• Death usually occurs immediately
• Radiographically, disassociation between the base of the
occiput and the arch of C1 is seen.
• Cervical traction is absolutely contraindicated, since
further stretching of the brainstem can occur.
70.
71. Mechanical Instability
1. Trafton has ranked specific cervical injuries based on
their degree of mechanical instability.[1] The list below
ranks cervical spine injuries in order of instability (most
to least unstable):
2. Rupture of the transverse ligament of the atlas
3. Fracture of the dens (odontoid fracture)
4. Burst fracture with posterior ligamentous disruption
(flexion teardrop fracture)
5. Bilateral facet dislocation
6. Burst fracture without posterior ligamentous disruption
72. 7. Hyperextension fracture dislocation
8. Hangman fracture
9. Extension teardrop (stable in flexion)
10.Jefferson fracture (burst fracture of the ring of C1)
11.Unilateral facet dislocation
12.Anterior subluxation
13.Simple wedge compression fracture without posterior
disruption
14.Pillar fracture
15.Fracture of the posterior arch of C1
16.Spinous process fracture (clay shoveler fracture)
