XR

Question 1

Basic Views of C-Spine

Answer 1

AP, AP Open Mouth, Lateral (need to include T1 and see prevertebral tissues), B/L Oblique, Flex/Ext

Question 2

Cervical Spine Open Mouth

Answer 2

see dens, lateral masses should be symmetrical, C1/C2 alignment

Question 3

`Cervical AP View

Answer 3

uncovertebral joints, TPs, SPs (want to see alignment of SPs)

Question 4

Cervical Lateral

Answer 4

*Need to see all 7 vertebrae and T1, ant + post columns (bodies), Intervertebral disc space, SPs, facet joints, prevertebral soft tissue (more for trauma pt’s want to see ant to vertebral bodies)

Question 5

Normal Variants in Lateral C-Spine XR

Answer 5

pseudosubluxation of C2 and C3, normal in children
Predental Space (from dens to C1 arch), normally 3mm in adults, 5mm in children

Question 6

C Spine Oblique

Answer 6

see neural foramina, facet joints, and pedicles

Question 7

C Spine Flex/Ext

Answer 7

helps detect ligamentous injury (instability) that not apparent in neutral view

Question 8

C SPine Flex/Ext Sx of instability

Answer 8

in flex view: 3.5mm translation displacement (shouldnt be more than 1mm), 1.7mm+ disc space widening, angulation of >11degrees in contiguous vertabrae

Question 9

atlanto-dens interval (ADI) for instability

Answer 9

• in children <3mm
• interlaminar and interspinous distances should remain symmetric while facet jts and intervertebral disc spaces shouldnt widen

Question 10

Dens Fx

Answer 10

Type I: <5%, Fx through tip of dens at insertion of alar ligament, usually stable
Type 2: Most common; fracture throught dens, UNSTABLE
Type 3: Subdentate (through body of C2); stable

Question 11

Flexion Injuries: 1. ant dislocation, 2. wedge, 3. unstable wedge; 4. u/l interfacet dislocation; 5. b’l interfacet dislocation; 6. flexion teardrop

Answer 11

1. hyperflexion sprain, ant dislocation with interspinous lig tear; 2. ant vert body fx; 3. ant wedge with ligament damage; 4. u/l facet jump; 5. jumped facets with anterolisthesis; 6. large fx of ant body with post ligamentous damage

Question 12

atlanto-occipital disassociation

Answer 12

decapitation, usually fatal

Question 13

jumped facets

Answer 13

dislocation of vertebral facet joint in which inf articular facet of sup vertebra lies ant to the superior articular facet of inf vertebra

• can be u/l (50%)
• imaging: anteriorlisthesis, widening of interspinous distance and facet joint

Question 14

Extension injuries: 1. hangman’s Fx; 2. ext teardrop; 3. hyperext w/pre-exist spondylosis

Answer 14

1. Fx @ pedicles, vertebral arch separates from body; 2. anterior teardrop with tear of ALL; 3. looks like a tear of the IV disc

Question 15

Hangman Fx

Answer 15

Fx involving both pars articularis of C2, 2/2 to hyperext and distraction; imaging shows fx’s of b/l lamina and pedicles and usually anterolisthesis at C2-C3

Question 16

Jefferson Fx

Answer 16

Burst Fx of C1- usually ant and post arches; 2/2 to axial loading (ie diving on head)
imaging: open mouth lateral offset of C1 on C2, lateral view shows widening of atlantodens interval if traversing lig damaged

Question 17

unstable cervical Fxs

Answer 17

Flex: B/l interfacetal dislocation; flexion teardrop Fx, wedge Fx w/post lig rupture
Ext: odontoid Fx type II; hangman’s Fx, ext teardrop fx
Vert Compression: burst

Question 18

Lumbar Lateral Spine XR

Answer 18

IV disc spaces, SPs, pedicles, alignment, vertebral body height

Question 19

Scotty Dog Sign

Answer 19

post elements of lumbar spine form figure of Scotty Dog in lumbar oblique view (nose- TP, eye- pedicle, front leg- inf articular facet, ear- sup art facet, neck- pars interarticularis), Fx of neck= pars defect

Question 20

spondylolisthesis

Answer 20

one vertebra slips forward (anterolisthesis) or backward (retrolisthesis), compared to the next vertebra below

Question 21

5 types of spondylolisthesis

Answer 21

1. dysplastic: defect in formation in part of vertebra (can be congenital)
2. Isthmic: caused by defect in pars interarticularis
3. degenerative: caused by djd
4. traumatic: caused by direct trauma; usually fx of pedicle, lamina, or facet joints
5. pathologic: caused by abnormal bone (ie tumor)

Question 22

Grades of Spondylolisthesis

Answer 22

1= 0-25%
2= 25-50%
3= 51-75%
4= 76-100%
5= >100% or spondyloptosis

Question 23

spondylolysis

Answer 23

pars defect; defect of lumbar vertebra at the pars interarticularis which is ant to lamia and post to pedicle; typically 2/2 to stress fx from repetitive injury

Question 24

spondylosis

Answer 24

degenerative change

Question 25

Flexion Fxs of Thoracic/ Lumbar

Answer 25

1. compression fx: ant vertebral body breaks/ loses height while posterior is intact. Usually stable.
2. axial burst fx: