CERVICAL SPINE FRACTURES…

Cervical Anatomy

Biomechanically SpecializedSupport of “large” Cranial massLarge range of motion

○ Flexion/extension○ Axial rotation

Unique osteological characteristics

C1 - Atlas

No body 2 articular pillars

Flat articular surfaceVertebral artery

foramen 2 arches

AnteriorPosterior

○ Vertebral artery groove

C2 Anatomy

Dens Embriological C1 body Base poorly vascularized Osteoporotic

Flat C1-2 joints Vertebral artery

foramena Inferomedial to

superolateral

Anatomy – The Ligaments Allow for the wide ROM of upper C-spine while

maintaining stability Classified according to location with respect to

vertebral canal Internal:

○ Tectorial membrane○ Cruciate ligament – including transverse ligament○ Alar and apical ligaments

External○ Anterior and posterior atlanto-occipital membranes○ Anterior and posterior atlanto-axial membranes○ Articular capsules and ligamentum nuchae

AtlantoAxial Anatomy

Tectorial Membrane

AtlantoAxial Anatomy

occiput

C1

C2

Tranverse Ligament

C1-C2 joint

Alar Ligament

AtlantoAxial Anatomy

TransverseLigamentFacet for

OccipitalCondyle

AtlantoAxial Anatomy

Vertebral Artery

APPROACH TO C-SPINE INJURIES

Following trauma or complaint of neck pain Obtain lateral AP, and odontoid views

The lateral view is only adequate if T1 can be visualized

If there is any doubt of fracture or prevertebral swelling , obtain oblique views and consider CT

All patients with sign/symptoms of cord injury require MRI

Cervical Views

AP

Odontoid

Obliques

Swimmer’s View

LATERAL VIEW

1. Anterior vertebral line (anterior margin of vertebral bodies)

2. Posterior vertebral line (posterior margin of vertebral bodies)

3.Articular pillar (where superior and inferior articular processes of cervical vertebrae have fused on either or both sides)

4. Spinolaminar line (posterior margin of spinal canal)

5. Posterior spinous line (tips of the spinous processes)

C1-C2 Predental space (distance between posterior

aspect of anterior arch of C1

and anterior aspect of

odontoid process )

should be< 3mm In adult

and less <5mm in children

Or less ring sign of C2

C3-C7

Anterior spinal, posterior spinal and

spinolaminar lines: should be

smooth lines Disc Spaces should be approximately same

anterior narrowing = flexion injury.

Widening = extension injury Facet joints should be parallel Interspinous distance should

decrease from C3 to C7 Transverse process of C7 points downward and

T1 UPWARDS

INTERVERTEBRAL DISC

SPACES

FACET JOINT

Prevertebral Soft Tissue

Nasopharyngeal space (C1) - 10 mm (adult)

Retropharyngeal spaceC 2-C4 ( between posterior pharyngeal wall and anterior border of vertebrae).

Retro tracheal space C5-7 (space between posterior tracheal wall and anterior inferior body C6 )

c3-4 5mm from vertebral body is normalC4-7 20mm from vertebral body is normal

5mm

22mm

10mm

AP View The height of the cervical

vertebral bodies should be approximately equal

The height of each joint space should be roughly equal at all levels.

Spinous process should be in midline and in good alignment.

Odontoid View An adequate film should include the

entire odontoid and the lateral borders of C1-C2.

Occipital condyles should line up with the lateral masses and superior articular facet of C1.

The distance from the dens to the lateral masses of C1 should be equal bilaterally.

The tips of lateral mass of C1 should line up with the lateral margins of the superior articular facet of C2.

The odontoid should have uninterrupted cortical margins blending with the body of C2.

Classification of Fractures of c-spine

HYPERFLEXION INJURIES Flexion teardrop fracture Hyper flexion Strain Wedge Compression fracture Bilateral facet Lock Unilateral facet dislocation Clay-shoveler’s fracture

Hyper extention injuries Hangman fracture Extention teardrop fracture laminar fracture Pillar fracture Posterior arch of c1 fracture

FRACTURE DUE TO AXIAL LOADING Jefferson fracture Burst fracture

OTHER INJURIES Odontoid fracture Rotational Injuries

Hyperflexion

Distraction creates tensile forces in posterior column

Can result in compression of body (anterior column)

Most commonly results from MVC and falls

Compression

Result from axial loading

Commonly from diving, football, MVA

Injury pattern depends on initial head position

May create burst, wedge or compression fx’s

Hyperextension

Impaction of posterior arches and facet compression causing many types of fx’s○ lamina○ spinous processes○ pedicles

With distraction get disruption of ALL

Evaluate carefully for stability

LOOK FOR CENTRAL CORD SYNDROME

Types of Injuries

Flexion Teardrop Fracture C5-6

fracture is the result of a combinationof flexion and compression ,most commonly at C5-6 The teardrop fragment comes from the anteroinferior aspect of the vertebral body. The larger posterior part of the vertebral body is displaced backward into the spinal canal.

Best seen on lateral view It is an completely unstable fracture associated with complete disruption of ligaments and anterior cord syndrome and quadriplegia 70% of patients have neurologic deficit. common in MOTOR VECHICLE ACCIDENT

Signs: Prevertebral swelling associated with anterior longitudinal ligament tear.

Teardrop fragment from anterior vertebral body avulsion fracture.

Posterior vertebral body subluxation into the spinal canal.

Spinal cord compression from vertebral body displacement.

Fracture of the spinous process.

Fracture of the body of c5 with a small fragment

anteriorly

Fracture of the spinous process of C4

Acute angulation at the level of C5C6 with displacement of C5 in posterior direction

Wedge fracture

Compression fracture resulting from flexion.

Flexion compression injury Best seen on lateral view Stable Common in Elderly patients with osteoporosis or 

osteogenesis imperfecta

Wedge shape vertebra

Antersuperior body fracture

Hangman’s Fracture C-2

Fx through the pars interarticularis of C2 secondary to hyperextension

Best seen on lateral view

Hyperextention injury Stable fracture ?

 The most common scenario would be frontal motor

vehicle(hitting dash board)

Hanging falls, diving injuries contact sports.

Neurological involvement is rare

Classification of Hangman' s fractures 

Type I (65%) hair-line fracture C2-3 disc normal

Type II (28%) displaced C2 disrupted C2-3 disc ligamentous rupture with

instability C3 anterosuperior compression

fracture Type III (7%)

displaced C2 C2-3 Bilateral interfacet dislocation Severe instability

TYPE 1 HANGMAN FRACTURE There is a hair-line fracture and there is no displacement.C23 NORMAL  

HANGMAN FRACTURE TYPE 3

Anterior dislocation of the C2 vertebral body

BILATRAL C2 pars interarticularis fractures.

Prevertebral soft tissue swelling

The CT-images confirm the fracture-lines of the hangman's fracture.They run through the pars interarticularis resulting in a traumatic spondylolysis.In this case there was no neurologic deficit, because the spinal canal is widened at the level of the fracture.

Extention tear drop fracture

AVULSION FRACTURE of anterio inferior content

of the axis resulting from hyperextention This injury is stable in flexion but highly unstable in extension.

common in diving accidents It also may be associated with the central cord

syndrome .

The CT confirms the displaced anteroinferior bony fragment. This fragment is a true avulsion, in contrast to the flexion teardrop fracture in which the fragment is produced by compression of the anterior vertebral aspect due to hyperflexion.

Jefferson Fracture C-1

• Best seen on odontoid view• Unstable fracture • Fracture due to AXIAL LOADING • frequently associated with

• diving into shallow water(axial blow to the vertex of the head )

•  impact against the roof of a vehicle• fall from playground equipments

Fracture is caused by a compressive downward force that is transmitted evenly through the occipital condyles to the superior articular surfaces of the lateral masses of C1. This process displaces the masses laterally and causes fractures of the anterior and posterior arches, along with possible disruption of the transverse ligament.

SIGNS ON XRAY: Displacement of the lateral masses of vertebrae C1 beyond the margins of the body of vertebra C2.

<2mm bilateral is always abnormal<1-2 mm or unilateral displacement can be due to head rotation

CT is required to 1. define the extent of fracture 2. detecting fragment in spinal cord

BURST FRACTURE C3-7 Same mechanism as jefferson fracture i.e axial compression

but Located at c3-7 Stable fracture The intervertebral disc is driven into the vertebral body below. Posterior fragments dislocation common Require ct for fracture evaluation and bone fragment in spinal

cord

Odontoid Fracture C2 Fracture of the odontoid (dens) of C2

3 categories, I-III

Best seen on open-mouth odontoid view or lateral radiograph result from blunt trauma to head leading to cervical hyperflexion or

hyperextension Unstable fracture Occur in both elderly and young patients 75% cases are children

Classification 

Type I: Avulsion of the tip of the dens where it is attached to C1.This is a rare fracture. It is potentially stable.?

Type II: Through the base of the dens. Most common fracture. Always unstable and poor healing.

Type III: Fracture through the body of the axis and sometimes facets.Can be unstable, but has a better prognosis than type II due to better healing of the fracture which runs through the metaphyseal body of C-2

Type 1 odontoid fracture

Type II

Type III

CT IMAGE

Dens

DENS

The image through the lateral part of C2 nicely shows, that the fracture runs through the body of C2, i.e. a type III odontoid fracture.The posterior dura is in a normal position, but the anterior dura is displaced (arrow).

Showing Central location of spinal cord injury

Clay Shoveler’s Fracture Oblique avulsion fracture of a spinous process C6-T1 C7>C6>T1

Best seen on lateral view Powerful Hyperflexion injury(shoveling) Stable fracture Common in motor vehicle accidents sudden muscle contraction direct blows to the spine

Ap view show ghost sign with 2 spinous processes ???

Case 1 5 yo girl Hit by car while

riding bike VSA at scene Vitals recovered

by EMS

Rose et al, Am J Surg 2003;185(4)

Atlanto-Occipital Dislocation 2.5 x more common in

children than adults Due to small occipital

condyles and horizontal atlanto-occipital joints

Suspect if distance between occipital condyles and C1 is > 5mm at any point

Usually have ++ soft tissue swelling

OccipitoAtlantal Dissociation (OAD)

Commonly FatalPresent 6-20% of post mortem studies– Alker et al, 1978– Bucholz & Burkhead,1979– Adams et al, 1992

50% missed injury rate1/3 Neurological Worsening– Davis et al, 1993

OccipitoAtlantal Dissociation (OAD)

Symptoms/Findings– Wallenberg Syndrome

Lower Cranial nerve deficitsHorner’s syndromeCerebellar ataxiaCruciate paralysisContralateral loss of pain and

temperature

Radiographic Lines

BC/OA >1 considered abnormal

Limited Usefulness Positive only in Anterior

Translational injuries False Negative with pure

distraction

Powers et al, Neurosurg, 1979

Powers’ Ratio

QUESTIONS

REFERRENCES

Text Book of Radiology and imaging

(DAVID SUTTON) Primer of Diagnostic Imaging Radiology Review Manual(Dahnert)

Thank You!