Cervical fx

Question 1

What is the epidemiolgy of atlas fx?

Answer 1

• 7% of all cervical fx
• risk of Neurologic injury= LOW
• commonly missed due to inadequate imaging of occiptocervical junction

Question 2

What is the pathophysiology of atlas Fx?

Answer 2

• Hyperextension
• lateral compression
• axial compression

Question 3

Name any associated conditions with atlas fx?

Answer 3

• Spine fractures
  
  • 50% associated spinal injury
  • 40% assoc AXIS fracture

Question 4

What is the prognosis of atlas fx?

Answer 4

• Stabilty dependent on degree of injury and healing potential of TRANSVERSE ligament

Question 5

Describe the anatomy of Atlas bone?

Answer 5

• C1 is a ring containing 2 articular lateral masses
• lacks vertebral body or spinous process
• forms form 3 ossification centres
• incomplete formation of post arch is relatively common anatomic variant- doesn’t represent traumatic injury
• occipital-cervical junction & atlantoaxial junction are coupled
• intrinsic ligaments provide most stability
  
  • transverse ligament
  • paired alar ligaments
  • apical ligament
  • tectorial membrane- connects posterior bocy of axis to anterior foramen magnum and is the cephalad continuation of PLL

Question 6

What is the classification of atlas fractures?

Answer 6

• Type 1
  
  • Isolated ANT or POST ARCH Fx
• Type 2
  
  • Jefferson Burst Fx
  • Bilateral ANT & POST Arch FX
  • Stability determined by transverse ligament
• ​Type 3
  
  • ​Unilateral Lateral Mass Fx
  • stability determined by integrity of transverse ligament

Question 7

What is the classification of transverse ligament injuries?

Answer 7

• Type 1 - Intrasubstance tear
• Type 2 - Bony avulsion

Question 8

What imaging aids dx of atlas fx?

Answer 8

• Lateral xray
  
  • Atlanto-dens interval
    
    • <3mm normal adult ( <5mm child)
    • 3-5mm= injury transverse ligament
    • >5mm = injury to transverse lig, alar and tectorium membrane
• Open mouth odontoid view
  
  • to identify atlas fracture
  • sum of lateral mass displacement
  • if >7mm = transverse lig rupture assured- unstable

CT

• delinate fracture pattern & assoc injuries

MRI

• More sensitive at detecting injury to transverse lig

Question 9

What are the tx for atlas fx?

Answer 9

Non operative

• Hard cervical orthosis vs halo immobilisation 6-12 wks
  
  • for Stable Type 1- intact TL
  • Stable Jefferson fx- intact TL
  • Stable type 3- intact TL

Operative

• Posterior C1-2 Fusion vs Occipitocervical Fusion
  
  • ​for Unstable Type 2
  • unstable Type 3
• posterior C1-2 fusion preserves motion cf occiptocervical fusion
• C1-2 transarticular screw placement or *C1 lateral mass to C2 pedicle screw- *see pic
• Occiptocervical fusion used when unable to get adequate puchase of C1

Question 10

What are the complications of atlas fx?

Answer 10

• Delayed c spine clearance
  
  • higher rates of complications in pts with delayed c spine clearance so important to clear expeditiously

Question 11

Define an odontoid fracture?

Answer 11

• a fracture of the dens of the AXIS C2

Question 12

What is the epidemiology of Odontoid fracture?

Answer 12

• Incidence
  
  • most common fracture of the axis
  • accounts for 10-15% of all cervical fx
  • occurs bimodal distribution
    
    • elderly
      
      • missed, caused by simple falls
      • assoc increased morbidity/mortality
    • Young pts
      
      • blunt trauma to head-> cervical hyperextension/flexion

Question 13

What is the pathophysiology of odontoid fractures?

Answer 13

• Displacement maybe Anterior ( hyperflexion) or Posterior (hyperext)
• Anterior displacement=
  
  • TL failure
  • Atlanto-axial instability
• Posterior displacement
  
  • direct impact from ant arch during hypextension
• *A fx thru the base of the odontoid process severly compromises the stability of the upper cervical spine*

Question 14

Name any associated conditions with odontoid fx?

Answer 14

• Os odontoideum
  
  • Appears like a type 2 odontoid fx on xray
  • previously thought to be due to failure of fusion at the base of the odontoid
  • may represent the residules of old traumatic process
  • tx is obervation

Question 15

Describe the anatomy of axis?

Answer 15

• axis has odontoid process
  
  • develops from 5 ossification centres
  • subdental synchondrosis is an intial cartilaginous junction between dens & vertebral body that does not fuse until 6 years of age
  • secondary ossification centres appear 3ys fuses to dens at 12
• Axis Kinematics
  
  • C1-C2 atlantoaxial articulation
    
    • Diathrodal joint which provides
    • 50 degrees of cervical rotation
    • 10 degrees of flexion/extension
    • 0 lateral bend
  • C2-3 joint
    
    • 50 degrees of rotation
    • 50 degrees of flex/ext
    • 60 degrees lat bend
• Ligamentous stability
  
  • transverse ligament
  • Apical ligament
  • alar ligament
• Blood supply
  
  • Wateshed exists between apex and base of odontoid
  • apex supplied branches internal carotid A
  • base supplied branches vertebral A
  • limited blood supply affect healing type 2 odontoid fx

Question 16

Describe the classification of axix fractures?

Answer 16

• Anderson and D’Alonzo
• Type 1 = Oblique Avulsion fx, tip odontoid
  
  • avulsion by alar ligament
• Type 2= Fx thru WAIST
  
  • ​high non union rate- watershed blood supply
• ​Type 3 = fx extends into cancellous body C2
  
  • involves variable portion of C2/3 joint

Question 17

What are the symptoms and sign of axis fracture?

Answer 17

Symptoms

• Neck pain worse with motion
• dysphagia maybe present when assoc large retropharyngeal haematoma

Signs

• Myelopathy
• v rare as large x ssection of c spine here

Question 18

What imaging is important in axis fx?

Answer 18

Xrays

• Ap, Lateral. open mouth odontoid peg view
• flexion-extension: c spine instability in type 1
  
  • ADI ( atlantodens- interval) >10mm
  • <13mm Space Available for the cord

CT

• delinate fractures and assess stability

MRI

• If neurology present

Ct angio

• To determine locality of vertebral artery prior to post instrumentation

Question 19

What is the tx of axis fx?

Answer 19

• OS Odontoideum = Observe
• Type 1 avulsion = Hard Cervical Orthosis
• Type 2 Young pt
  
  • Halo vest immobilisation 6-12 wks if no risk factors for non union
  • Surgery if risk of Non union
• Type 2 Elderly
  
  • Hard Cervical orthosis 6-12wks- if not surgical fit
  • Surgery if surgically fit
• Type 3
  
  • Hard Cervical Orthosis 6-12 wks
  • no evidence to support halo over orthosis!!
  • elderly pt poorly tolerate halo-> aspiration, penumonia, death

Question 20

Describe the techniques of surgery to Axis fx?

Answer 20

• Posterior C1-2 fusion
  
  • for Type 2 fx w risk fx of nonunion
  • type 2/3 fx non unions
  • posterior c1-2 transarticular screw - see pic- avoid in pt w aberrant vertebral artery
  • or post C1 lateral mass and c2 pedicle
  • loss of 50% neck motion
• Anterior Odontoid osteosynthesis
  
  • iin type 2 fx with risk nu &
  • acceptable alignment/minimal displacement
  • obliq fx pattern perpendicular to screw trajection
  • pt body habitus allows screw trajection
  • assoc higher failure rates than post fusion
• transoral odontoidectomy
  
  • in severe post displacment & cord compression/neurological deficits

Question 21

Decribe the technique for anterior odontoid screw osteosynthesis?

Answer 21

• anterior apporach cervical spine
• single screw adequate
• assoc with higher failure rate cf post fusion
• preserves atlanto axial motion

Question 22

What are the complcaitions of axis fx?

Answer 22

• Non union
  
  • increased in type 2
  • risk factors include
    
    • >5mm posterior displacement
    • >1mm fracture displacement
    • fx comminution
    • angulation >10o
    • age >50 years
    • delay in tx > 4 days
    • posterior redisplacement >2mm

Question 23

What is a hangman’s fx?

Answer 23

• Traumatic anterior spondylolitheis if AXIS due to BILATERAL fx of PARS INTERARTICULARIS

Question 24

What is the mechanism of a hangman’s fx?

Answer 24

• Hyperextension
  
  • leads to fx of pars interarticularis
• Secondary Flexion
  
  • Tears PLL and disc
  • leads to Subluxation
• 30% have concomitant c spine fx

Question 25

What are the symptoms and signs of trumatic spondylothiesis of axis

Answer 25

Symptoms

• Neck Pain

Signs

• Pts are Neurologically Intact

Question 26

What imaging is helpful in dx of traumatic cervical spondylolithesis of axis?

Answer 26

• xrays
  
  • flexion/extension shows subluxation
• CT
  
  • delinate Fracture pattern
• MRI
  
  • suspicious of vascular injru to vertebral artery

Question 27

What is the classification system for traumatic cervical spondylolithesis of axis?

Answer 27

• Levine and Edwards

Question 28

Can you describe and the tx for type I traumatic cervical spondylolithesis of axis?

Answer 28

• • no angulation
• C2/3 remains intact
• stable fx pattern

tx

• Rigid cervical collar 4-6 wks

Question 29

Can you describe and the tx for type 2 traumatic cervical spondylolithesis of axis?

Answer 29

• >3mm horizontal displacement
• Significant angulation
• vertical fracture line
• C/3 disc& PLL interupted
• Unstable fx pattern

Tx

• If <5mm displacment then reduce with traction then HALO immobilisation for 6-12 wks
• if >5mm displacement ?surgery/ prolonged traction
• normally autofuse depsite displacement

Question 30

Can you describe and the tx for type 2a traumatic cervical spondylolithesis of axis?

Answer 30

• No horizontal displacment
• horizontal fracture line
• sig angulation

TX

• Avoid TRACTION
• Reduction with hyperextension then halo immobilisaiton 6-12 weeks

Question 31

Can you describe and the tx for type 3 traumatic cervical spondylolithesis of axis?

Answer 31

• Type 1 with assoc bilateral C2/3 facet disslocation
• rare injury

tx

• Surgical reduction of facet dislocation
• then Stabilisation
  
  • anterior C2-3 interbody fusion
  • posterior c1-3 fusion
  • Bilateral C2 pars screw osteosynthesis

Question 32

What is a cervical disc dislocation/fx?

Answer 32

• Spectrum of osteoligamentous pathology includes
• Unilateral facet dislocation
  
  • most freq missed c spine injury
  • ->25% subluxation on xray
  • assoc w monoradiculopathy- improves w traction
• Bilateral Facet dislocation
  
  • ->50% subluxation on xray
  • assoc sig spinal cord injury
• Facet fractures
  
  • more freq involves superior facet
  • maybe unilateral/ bilateral

Question 33

What is the epidemiology of cervical facet dislocations/fx?

Answer 33

• 75% of all facet dislocations occur within the subaxial spine C3-C7
• 17% of all injuries are fx of C7 or dislocations of C7-T1 junction

Question 34

What is the mechanism of cervical facet dislocations?

Answer 34

• Flexion & distraction +/- element of rotation
• so in a facet dislocation the posterior structures (interspinous ligament, facet capsule, liagmentum flavum, posterior annulus) are likely disrupted,

Question 35

What is the signs of cervical facet dislocation?

Answer 35

Signs

• Monoradiculopathy
  
  • pt w unilateral dislocation
  • C5/6 unilater
    
    • C6 radiculopathy
    • Weakness wrist extension
    • numbness in thumb
  • C6/7 unilat
    
    • C7 radiculopathy
    • weakness in triceps/wrist flexion
    • numbness to index/middle finger
• Spinal cord injury
  
  • Seen in bilateral facet dislocations
  • symptoms worsen with increasing subluxation

Question 36

What imaging is useful in dx of cervical facet dislocation/fx?

Answer 36

• Xrays
  
  • lateral
  • unilateral facet dislocation- 25% subluxation(pic)
  • bilateral facet dislocation- 50% subluxation
  • loss of disc height ? retropulsed disc in canal
• CT
  
  • essential for more detailed bony anatomy
• MRI
  
  • when acute facet dislocation in pt w altered mental state
  • failed closed reduction before open reduction to look for disc herniation
    
    • if find ant disc herniation need to open anterior first
  • any neurological deterioration

Question 37

what is the tx for cervical facet dislocation/fx?

Answer 37

Non operative

• Cervical Orthosis/ external immobilisation 6-12 wks
• for facet fractures wout sig subluxation/dislocation/kyphosis

Surgery

1. Immediate closed reduction , then MRI then surgical stabilisation

• for bilat facet disclocation w deficits in awake & cop pt
• unilat facet dislocation w deficits in awke & coop pt
• never closed reducition on pt w altered mental state
• Always do MRI b4 surgery so check no disc
  
  • PSF/ ACDF in absence of disc
  • ACDF if disc herniation
• 26% pts will fail closed reduction & require open

2.MRI then open reduction + surgical stabilisation

• for facet dislocations when pt changed mental state
• or failed closed reductions
• if anterior disc need to go in anteriorly

Question 38

Can you how you do a closed reduction of cervical facet dislocation?

Answer 38

• Adequate aneathesia
• sedation
• supervision of respiratory function
• serial cross table laterals- do in theatre
• gradually increase axial traction with addition of weight ( can give >50lbs)
• a compotnet of cervical flexion can aid reduction
• perform serial neuro exams and xray after each weight
• abort if neurological exam worsens & obtain urgent MRI

Question 39

Describe the type of cervical vertebral body fractures?

Answer 39

By fracture Pattern

• Compression
• Burst fracture
• flexion teardrop fx
• extension teardrop fx

Allen and ferguson classification

of subaxial spinal injuries by mechanism used only for research

Question 40

What compression cervical fractures characterised by?

Answer 40

• Compressive failure of Anterior vertebral body without disruption of posterior body cortex and without retropulsion into canal
• often assoc with posterior ligamentous injury

Question 41

What Burst cervical fx characterised by?

What are they associated with?

Answer 41

• fracture extension thru posterior cortex with retropulsion into spinal canal
• often assoc with posterior ligamentous injury
• often assoc with complete/incomplete spinal injury
• frequently unstable
• usually requires Surgery

Question 42

What flexion teardrop cervical fractures characterised by?

Answer 42

• fx of anterior inferior portion of vertebra
• post portion of vertebra RETROPULSED POST
• often assoc w post ligament injury
• assoc with SPINAL cord injury
• normally unstable
• Requires Surgery

Question 43

What extension teradrop avulsion cervical fractures characterised by?

Answer 43

• small fleck of bone avulsed of anterior endplate
• usually at c2
• must differentiate from true tear drop fx
• mechanism= extension
• stable injury pattern
• Not assoc with Spinal cord injury
• TX= cervical collar 6-12 wks

Question 44

What are the tx options for cervical spine fractures?

Answer 44

Non operative

• collar immobilisation 6-12 wks
• stable mild compression fx
• ant teardrop avulsion fx
• ext halo immobilisation
• only if stable fx pattern

Surgery

• Anterior decompression, corpectomy, strut graft and fusion with instrumentation
  
  • burst fx w cord compression
  • unstable tear drop
  • compression fx with angulation 11^{0 or}25% loss in height
• Posterior decompression, fusion w instrumentation
  
  • sig injury to post elements
  • ant decomp not required

Question 45

Describe the 2 types of occiptiocervical dislocation?

Answer 45

• Traumatic occipitocervical dislocation
  
  • severe injury, pt rarely survives
  • most pt die of brainstem destruction
  • 19% of fatal cervical injuries
  • os those survive high neurological injury
  • mechanism- translation/distraction
• ​Acquired occipitocervical instability
  
  • ​in Down’s syndrome

Question 46

Can you describe the classification of occiptiocervical instability?

Answer 46

• type 1 - anterior
• type 2- longitudinal dislocation
• type 3 - posterior

Question 47

What do the radiographs show of occipitocervical instability?

Answer 47

• Low sensitivity in detecting injury
• Powers ratio
  
  • used to detect occipitocervical instability
  • Powers ratio = C-D/A-B
  • C-D = distance from basion to post arch
  • B-A= distance from ant arch to opisthion
  • ratio normal =1
  • if >1 = anterior dislocation
  • if <1
    
    • post ​atlanto-occipital dislocation
    • odontoid fx
    • ring of atlas fx

Question 48

What is th tx of occiptiocervical instability?

Answer 48

• Non op- don’t use traction= 10% risk of neurological deterioration
• Operative
  
  • Occipitocervical fusion
    
    • mot cases require stabilisation
    • modular occiptial plates
    • position 8mm unicortical screw 2cm lateral and 2cm inferior of external occiptal protruberance-5cm lateral is the thickest portion of occiput- see pic
    • don’t put screw just below external occiptal protuberance as major dural venous sinuses here and risk of penetration

Question 49

What is the epidemiology of occipital condyle fx?

Answer 49

• Involve the craniocervical junction
• approx 1-3% population
• often missed due to low sensitivity of plain xrays
• dx on CT

Question 50

What is the mechanism of occiptial condyle fx?

Name any assoc injuries?

Answer 50

• High energy- non pentrating to head/neck
• fx patterns dependent on directional forces

assoc injuries

• c spine fx
• polytrauma
• intrcranial bleeding
• brainstem and vascular lesion
• elevated ICP

Question 51

What is the prognosis of occiptial condyle fx?

Answer 51

• High mortality rate 11% - associated injuries

Question 52

Describe the anatomy of occipital condyles?

Answer 52

• Paired prominences of occipital bone
• form lateral aspects of foramen magnum
• forms the occiptioatlantoaxial complex
• 6 main synovial articulations
• ligamentus structure
  
  • Transverse L
  • apical ligament
  • paired alar ligaments
  • tectorial membrane
• Proximity to
  
  • Medulla oblongata
  • vertebral arteries
  • Lower cranial nerves CN IX-XII

Question 53

Describe the classification of occipital condyle fractures?

Answer 53

• Anderson and Montesano
• Type 1
  
  • impaction type due to compression between atlanto-odontoid joint
  • stable as minimal fragment displacment into foramen magnum
• Type 2
  
  • basilar skull fx extends into 1/2 occipit condyles
  • direct blow ot skull
  • stable as alar lig and tentorium membrane intact
• Type 3
  
  • avulsion fx of condyle in region of alar lig
  • due to forced rotation and lat bending
  • unstable due to craniocervical disruption

Question 54

What are the signs and symptom of occiptial condyle fracture?

Answer 54

Symptoms

• high cervical pain
• reduced head rom
• torticollis
• lower cranial n deficit
• motor paresis

signs

• CN IX, X, XI affected

Question 55

what imaging useful in occipital condyle fx?

Answer 55

• Xrays
  
  • Ap, lateral ope mouth ap view
• CT
  
  • method of choice
• MRI
  
  • soft tissue craniocervical trauma

Question 56

What is the tx of occiptial condyle fx?

Answer 56

Non op

• Analgesia, cervical orthosis( semi-rigid/rigid)
  
  • type 1 & 2
  • type 3 without instability

Operative

• Type 3 with overt instability
• neural compression from displaced fx
• assoc occipital- atlanto-axial injuries
• C0-C2/3 occipitocervical arthrodesis using semi rigid segmental fixation or post decompression and instrumented fusion
• may need bone graft/removal of bony fragments