Spinal Trauma Flashcards
Features of primary SCI
Thought to be irreversible
Caused by rapid and violent spinal cord compression and distortion from the displacement of normally protective structures due to fracture or dislocation.
Features of secondary SCI
A consequence of a cascade of injury mechanisms all initiated by the primary injury including
Hypoxic ischaemic injuries
Electrolyte derangements
Lipid peroxidation
Vascular mechanisms
Vascular mechanisms of 2o SCI
Changes in spinal cord blood flow with ischaemia persisting and worsening for 24h in animal models.
Vasopsams, endothelial oedema, hocal haemorrahges with throbmosis and excitatory amino acids are all thought to contribute
Histological findings in acute SCI
Severe haemorrahges, predominantly in the grey matter (likely 2o to damage to the anterior sulcal arteries)
Multiple lesions in the surrounding white matter including disrupted myelin and axonal oedema.
Intramedullary vein occlusion
SBP targets for transfer of SCI from the scene of injury
>100
What proportion of patients with SCI require intubation in the first 24h
1/3rd
SCI at what level shows paradoxical abdominal movements with respiration?
Injury above C5
Intubation in acute SCI
Vital capacity threshold
<1L
Trials on methylprednisolone in SCI
NASCIS
Based on subgroup analysis with non-standardised experimental design and statistical artefacts
Summarise evidence for steroids in traumatic SCI
there is no concrete evidence that methylprednisolone has a useful role in neurological protection in early spinal cord injury
the NASCIS studies are fatally flawed
adverse effects include increased sepsis and hyperglycemia
steroid use could be considered on a case-by-case basis, but situations where the risk-benefit balance favours administration would be rare
The sensitivity of CT for identifying fractures in spinal trauma
99.3%
Use of MRI in trauma
Useful in patients whose CT results do not explain the neurological status.
Benefits of closed cervical reduction
Can be used with a reported 80% success and 80% improved neurological function.
Though worsening neurologic status from disc herniation after cervical traction may also occur.
Definitive C-spine clearance
CT
MRI (to evaluate soft tissues)
Clinical
Mortality in SCI
15%
Cause of death at the scene of SCI
High level SCI
CV instability
Respiratory compromise
Highest mortality rates are immediately following and within the first hours after SCI
Factors increasing odds of early death after SCI
>20
Male
>1 comorbidity
Concomitant systemic injury (ISS >15)
Concomitant TBI
Use of admission ASIA in prognosis
Predicted neurological recovery at 1y post-injury
What proportion of patients will convert from AIS A to an incomplete injury
10-15%
What proportion of AISA A injuries will convert to AIS D
2%
What is the chance of AI C converting to AIS D or E at 1y?
70%
Chance of walking at 1y after complete paraplegia
5%
Chance of walking at 1y after complete quadriplegia
0%
GM1 ganglioside
Largest prospective RCT in SCI
Class III evidence of improvement of the clinical outcome via optimisation of SC perfusion, not reproduced in LT follow up, not used in clinical practice currently.
ASIA A
Complete
No sensory or motor function is preserved in the sacral segments S4-5
No sensory or motor function is preserved in the sacral segments S4-5
ASIA grade
ASIA A
ASIA B
Sensory incomplete
Sensory but not motor function is preserved below the neurological level and includes the sacral segments S4-5 (light touch or pinprick or deep anal pressure
AND
No motor function is preserved more than three levels below the motor level on either side of the body
Sensory but not motor function is preserved below the neurological level and includes the sacral segments S4-5 (light touch or pinprick or deep anal pressure
AND
No motor function is preserved more than three levels below the motor level on either side of the body
ASIA grade
ASIA B
ASIA C
Motor incomplete
Motor function is preserved at the most caudal segments for voluntary anal contraction or the patient meets the criteria for sensory incomplete status and has some sparing of motor function more than three levels below the ipsilateral motor level either side of the muscles
Less than half of the key muscles below the single NLI have a muscle grade >3
Motor incomplete
Motor function is preserved at the most caudal segments for voluntary anal contraction or the patient meets the criteria for sensory incomplete status and has some sparing of motor function more than three levels below the ipsilateral motor level either side of the muscles
Less than half of the key muscles below the single NLI have a muscle grade >3
ASIA C
The threshold for motor function differentiating between ASIA C and D
C- less than half of key muscles below the single NLI have a muscle grade >=3
D- at least half of key muscles below the single NLI have muscle grade >=3
ASIA D
Motor incomplete status as defined in C with at least half or more of key muscle functions below the single NLI having a muscle grade >=3
Motor incomplete status as defined in C with at least half or more of key muscle functions below the single NLI having a muscle grade >=3
ASIA grade
D
ASIA E
Normal motor and sensory function in all segments
Normal motor and sensory function in all segments
ASIA grade
E
TRH for SCI
Demonstrated improvements in the NASCIS and Sunnybrook scales for incomplete SCI patients but criticised for T1 error (attrition with analysis of only 20 patients)
Ganacyclidine in SCI
Benefit in the treatment group that did not persist at 1y (insufficient statistical power).
Nimodipine in SCI
Compared nimodipine and MPSS to placebo (NASCI II) showed no beneift
Dynormin in SCI
Endogenous opioid, administered in NASCIS II
No benefit
Categories of current trials in SCI
Neuroprotective agents to limit secondary injury
Neuroregenerative agents aimed at promoting and supporting repair/regeneration.
Neuroprotective measures for SCI
CSF drainage via intrathecal line (there is some evidence of similar strategies reducing paraplegia during thoracic AAA surgery)
Electrica feild along the spinal axis.
Hypothermia showed some benefit in animal moels.
STATSCIS trial
RCT looking at early (<24h) vs late (>24h) decompression in traumatic SCI
Decompression prior to 24 hours after SCI can be performed safely and is associated with improved neurologic outcome, defined as at least a 2 grade AIS improvement at 6 months follow-up
Decompression in central cord syndrome
Poor outcome after early decompression has been published and hence there has been a move to avoiding early decompression though controversy has arisen in subsequent studies
Timing of surgical decompression of thoracic spinal injury
Limited, retrospective study found some benefit to early surgery in respect to ventilator-dependence, length of ICU stay, length of hospital stay, mortality, pulmonary failure.
Goal of spinal surgeon in managing cervical spine fractures
Prevent secondary neurological injury
Deformity
Pain
Re-establish stability
Epidemiology of cervical spine fracture
Biphasic, 15-45 then 65-80y
M>F
What proportion of cervical spine fractures are associated with neurological injury?
10%
Mechanism of c-spine fractures in young group
High velocity injuires
Mechanism of c-spine fracture in elderly group
Low energy, simple fall, commonly fracturing the odontoid process
Incidence of cervical spine truama in head injury patients
Up to 14%
3 view XR
lateral
Open-mouth odnotoid
AP XR
NEXUS criteria
No neurology
No midline neck tenderness
No intoxication
No altered GCS
No distracting injury
Can clinically clear low risk patients if all absent
Cervical spine clearance in the unconscious head injury
Remove collar if fine-cut CT scan demonstrates no bony misalignment or bony injury.
Immobilisation of AS patients
Should be in thier pre-injury fixed position, not forced into supine.
General adjuncts to the management of SCI patients
Careful immobilisation
Catheter
NGT
LMWH
PPI
Allen’s Classification
Mechanistic classification of C-spine injury
Compressive flexion, vertical compression, distractive flexion, compression extension, distractive extension and lateral flexion.
Each further category then subdivided based on the radiological severity of the injury.,
SLIC
Subaxial injury classification
Used to categorise fractures below the level of the C2
Based on morphology, disruption of ligamentous complex and neurology.
What radiological features suggest disruption of the ligamentous complex?
Facetal malalignment
Abnormal widening of anterior disc space
Kyphosis over a motion segment
High signal on STIR MRI sequence
Cervical fracture morphology
SLICs score:
No abnormality
0
Cervical fracture morphology
SLICs score:
Compression
1
Compression fracture
Cervical fracture morphology
SLICs score:
Burst
2
Burst fracture
Cervical fracture morphology
SLICs score:
Distraction fracture
3
Distraction fracture
Cervical fracture morphology
SLICs score:
Translation rotation
4
Translation rotation
Discoligamentous complex
SLICs Score:
Intact
0
Discoligamentous complex
SLICs Score:
Indeterminate
1
Discoligamentous complex
SLICs Score:
Disrupted
2
Neurological status
SLICs score:
Intact
0
Neurological status
SLICs score:
Root injury
1
Neurological status
SLICs score:
Complete cord injury
2
Neurological status
SLICs score:
Incomplete cord injury
3
Neurological status
SLICs score:
Cord compression
4
+1 in context of neurolgoical deficit
Cervical spine injury severity score
Proposed by Anderson
Used to grade the instability of fractures.
Proposes four columns of the cervical spine (Anterior, posterior, right and left lateral)
Uses a scoring system where 0-5 points are awarded based on the severity of the injury to bone and ligamentous structures in the four columns.
The sum of these scores gives the final CSISS.
Jefferson’s fracture
Burst fracture affecting C1 ring.
Initially used to describe a four-point fracture of the C1 bone with fractures affecting the anterior arch and posterior arch.
Jefferson fracture
What proportion of C1 fractures are associated with a C2 fracture?
30%
Why are isolated C1 fractures only rarely associated with neurological deficits?
As the bony elements tend to move outwards, away from the neural elements
Typical mechanism for Jefferson fracture?
Axial loading
What must be assessed in the presence of a C1 fracture?
The integrity of the transverse ligament
Measure the ADI
<3mm in adults and <5mm in children
What happens to the lateral masses of C1 when the transverse ligament is disrupted?
The lateral masses move outwards
What is Spence’s rule of 7
On a PEG view or coronal CT, the distance between the lateral edge of C1 and C2 can be measured.
If the sum of the two sides is >7mm then the transverse ligament is disrupted
Odontoid PEG view XR of the cervical spine showing likely disruption of the transverse ligament due to significant lateral mass overhang (Spence’s rule)
Management of C1 fractures
Very rarely surgically
If the transverse ligament is damaged- HALO
If the transverse ligament is intact- collar
C1 fracture with disrupted transverse ligament
HALO
C1 fracture with intact transverse ligament
Collar
Hangman’s fracture
Traumatic spondylolisthesis of axis.
Hangman’s fracture
Classification of Hangman’s fractures
Levine and Edwards classification
MOI Hangman’s fracture
RTA most common
Levine and Edwards classification
Type 1
Minimal translation (<3mm) without C2-3 angulation, stable
Levine and Edwards classification
Type 2
Significant C2-3 angulation and translation >3mm
Disc disruption
Unstable
Levine and Edwards classification
Type 2a
More angulation than type 2 without translation, unstable due to flexion-distraction injury
Levine and Edwards classification
Type 3
Severe C-3 angulation and translation; sometimes uni/bilateral facet dislocation
Unstable
Which Levine Edwards type fractures should be managed surgically?
Type 2a and 3
Approach to surgical fixation of Hangman’s fracture
Anterior approach with C2/3 discectomy and fusion
Epidemiology of Odontoid peg fractures
Common in elderly patients after a fall or young patients following cervical hyperflexion or hyperextension injury
Accounts for 10-15% of C-spine fractures
Classification of odontoid peg fractures?
Anderson D’Alonzo
Anderson D’Alonzo
Type 1
Fracture of the tip of the odontoid peg above the transverse ligament
Caused by avulsion of the alar ligament
Anderson D’Alonzo
Type 2
Fracture across the base of the peg, beneath the transverse ligament
Anderson D’Alonzo
Type 3
Fracture in the C3 vertebral body such that the peg is disconnected from the rest of the vertebral body.
