Radiology 2B Week 3

What are the most common locations for spinal injury

C1-C2

C5-C7

T12-L1

What are the most common causes of spinal column injury?

auto accidents and sports

What % of spinal fractures are associated with other fractures?

20%

What % of spinal fracture/dislocations have associated spinal cord injury?

10-14%

(40% cervical)

(10% thoracic)

(4% lumbar)

What % of spinal cord injuries occur without a fracture?

10%

What movement is most associated with spine injury?

Flexion

What is the term for a burst fracture of C1?

Jefferson fracture

What is the way Jefferson fractures occur?

Compression injury via forceful blow to skull vertex

What is the most common MOI of Jefferson fracture?

Auto accidents or diving injury

What is the most common C1 fracture?

Posterior arch fracture

T or F: Death or neurological deficit is common with Jefferson fracture

False (uncommon)

What % of Jefferson fracture occurs along other fractures of the cervical spine?

50%

What view is best for seeing Jefferson fracture?

APOM

What are the key findings of Jefferson fracture on x-ray?

Spreading of lateral masses

>8mm combined periodontoid space signifies transverse ligament rupture

What length of lateral mass overhang of the atlas indicates osseous break?

>7mm (both sides combined)

What is the term for a variation in children where the atlas grows faster than axis?

Pseudospread of lateral masses

What age does pseudospread of lateral masses occur prior to?

10 yo

What length of offset of lateral masses is considered abnormal in trauma?

3 mm

What is indicated if the periodontoid space is greater than 8mm?

Transverse ligament rupture

What is the most common fracture of C1?

Posterior arch fracture (50%)

What % of posterior arch fractures have additional cervical fractures?

80%

What type of atlas fracture results form avulsion from hyperextension of longus coli?

Anterior arch fracture

What must be differentiated from C1 anterior arch fracture?

C1 anterior arch accessory ossicle

What imaging modality is best for Jefferson fractures?

CT

What imaging modality is used to diagnose lateral mass fracture?

CT

What conditions is transverse ligament rupture commonly seen with?

Jefferson fracture

Inflammatory arthritis (RA, AS, PA, Reactive)

What is the radiographic finding of transverse ligament rupture?

Wide ADI on lateral radiographs

What % of Down syndrome patients transverse ligament laxity or agenesis?

20%

What is Steele's rule of thirds?

System of dividing atlas ring into thirds (1/3 cord, 1/3 space, 1/3 odontoid)

What is the name of translation of dens and transection of the spinal cord in the event of transverse ligament rupture?

Guillotine effect

What is the term for traumatic spondylolisthesis of C2?

Hangman's fracture

What part of C2 is broken in a hangman's fracture?

Pedicles bilaterally

What is the MOI of hangman's fracture?

forceful hyperextension (MVA / diving)

What is a type I spondylolisthesis?

Congenital/Dysplasitc (pedicle or pars agenesis)

What is a type IIa spondylolisthesis?

Isthmic (pars defect)

What is a type IIb spondylolisthesis?

Healed isthmic (elongated pars)

What is a type IIc spondylolisthesis?

Acute pars fracture

Which pars fracture has the smallest amount of slippage?

Type IIb

What is a type III spondylolisthesis?

Degenerative

What is a type IV spondylolisthesis?

Traumatic (spondylolytic spondylolisthesis)

What is the most common level of a type IV spondylolisthesis?

C2 (hangman's fracture)

What is a type V spondylolisthesis?

Pathological (e.g. metastatic growth)

What is a type VI spondylolisthesis?

Iatrogenic (due to surgical intervention)

What are the two types of teardrop fracture?

Flexion and extension

What is the term for avulsion of a triangular shaped fragment from the anterioinferior corner of a vertebral body?

Extension teardrop

What is the most commonly involved level of extension teardrop?

C2

What is the MOI of extension teardrop?

Acute hyperextension

What syndrome is extension teardrop associated with?

Central cord syndrome

T or F: Extension teardrop is stable

False

What is the most severe fracture of the cervical spine?

Flexion teardrop

What syndromes are caused by flexion teardrop?

Cervical anterior cervical cord syndrome

Quadriplegia

What is the most common level of flexion teardrop?

C5-C6

What is the MOI of flexion teardrop?

Diving head-first, MVA deceleration

What is MRI used to assess in flexion teardrop?

Ligamentous structures

Spinal cord

What are the symptoms of anterior cord syndrome?

Complete motor paralysis

Loss of pain and temperature sensation

Position and vibration sense preserved

What injury is anterior cord syndrome associated with?

Severe flexion injury

What % of all C2 fractures are odontoid?

50%

What portion of odontoid fractures have associated cervical spine fractures?

1/3

What is the term for an avulsion of dens tip?

Type 1 odontoid fracture

What ligament is involved in avulsing the tip of the odontoid?

Alar ligament

What is the term for fracture at the dens-body junction?

Type 2 odontoid fracture

What is the most common odontoid fracture?

Type 2

What is the term for a fracture deep into the C2 body below the dens-body junction?

Type 3 odontoid fracture

What is the only unstable odontoid fracture?

Type 2

What are the three spinal columns recognized in the post-fracture spinal stability?

Anterior (ALL to mid-vertebral body)

Middle (Mid-vertebral body to PLL)

Posterior (PLL to supraspinous ligament)

Involvement of how many columns are required for a dens fracture to be considered unstable?

>1

What % of all C2 fractures are odontoid?

50%

What portion of odontoid fractures have associated cervical spine fractures?

1/3

What is the term for an avulsion of dens tip?

Type 1 odontoid fracture

What ligament is involved in avulsing the tip of the odontoid?

Alar ligament

What is the term for fracture at the dens-body junction?

Type 2 odontoid fracture

What is the most common odontoid fracture?

Type 2

What are the three spinal columns recognized in the post-fracture spinal stability?

Anterior (ALL to mid-vertebral body)

Middle (Mid-vertebral body to PLL)

Posterior (PLL to supraspinous ligament)

Involvement of how many columns are required for a dens fracture to be considered unstable?

>1

What is the term for a developmentally un-united tip of the odontoid process?

Os terminal persistens (Bergmann ossicle)

T or F: Avulsion of the occipital condyle is caused by the same ligament as Type 1 odontoid fracture, but is more likely

True

What are the three divisions of the spinal column?

Anterior

Middle

Posterior

Where does the anterior column run from?

ALL to mid-vertebral body

Which column of the spine is most commonly fractured?

Anterior

Where does the middle column run from?

Mid-vertebral body to PLL

Where does the posterior column run from?

PLL to supraspinous ligament

Fractures involving how many columns is at risk for neurological insult?

>1

T or F: fractures of the middle column of the spine exclusively are very common

False (they almost never happen)

T or F: fracture of the middle column will always be unstable

True

What are the AKAs for vertebral body compression fracture?

Wedge fracture

anterior compression fracture

What is the MOI of vertebral body compression fracture?

Forceful hyperflexion

T or F: Vertebral body compression fracture is stable

True (due to IVD, ALL, and PLL intact)

What levels are vertebral body compression most common at?

C5-C7

What is the finding of vertebral body compression on the lateral view?

Anterior VB wedging

What is the soft tissue finding of vertebral body compression fracture on x-ray?

Retropharyngeal soft tissue swelling (>20 mm)

What is the diagnostic loss of VB height from the anterior to the posterior?

>3 mm

What is the term for vertical compression of the vertebral body propelling nucleus pulpous through the endplate into vertebral body?

Burst fracture

What type of vertebral fracture is comminuted?

Burst fracture

What is the term for movement of bone from a VB fracture into the spinal column?

Retropulsion

What imaging modality is best for seeing retropulsion of bone into the canal in a burst fracture?

CT

What is the finding of burst fracture on the lateral view?

Comminuted vertebral body

What is the finding of burst fracture on the AP view?

Increased inter-pediculate distance (best seen in lumbar spine)

What other fracture often occurs with burst fracture?

Neural arch fracture

What part of the spine is most commonly affected by burst fracture?

Lumbar

What is the definitive imaging modality for articular pillar fracture?

CT