slic system
TRANSCRIPT
Dr. Ahmed Mirza Al-Shammasi, MB ChB2031040009
KFHU – Saudi Arabia
OutlinesOutlines
ObjectIntroductionThe SLIC system and Severity Score
◦Components◦Interpretation
Illustrative cases.Discussion ( Old vs. New )
ObjectObject
The authors review a novel Subaxial Cervical trauma classification system and demonstrate its application through a series of cervical trauma cases.
IntroductionIntroductionThe development of cervical
instrumentation and proliferation of cervical fusion technique have led to changes in the management of cervical trauma cases.
Cervical trauma cases are being treated outside tertiary or specialty centers.
Significant variability in the management.
IntroductionIntroductionAn ideal scoring system will standardize
treatment strategies.
Ideal system should include variables that influence clinical outcome ( # level, spinal alignment, neurological deficit etc. )
Old systems: Allen, Harris, White and Punjabi.
The SLIC system and Severity The SLIC system and Severity ScoreScore
Put together by the Spine Trauma Study Group
The score is based on Thoraco-lumbar Injury Classification and Severity Score system.
3 Major injury characteristics:◦ Injury morphology◦ Discoligamentous Complex (DLC)◦ Neurological status
Additional Minor descriptors◦ Injury level◦ Anatomical Osseous injury◦ Injury confounders
Injury MorphologyInjury MorphologyStructural relationship of
Vertebral Bodies to each other.Determined by RadiographyComponents:
◦No injury.◦Compression.◦Distraction.◦Rotation/Translation.
Loss of height of VB or
Disruption of vertebral endplate
Anatomical dissociation of
the spine through the vertical axis
Horizontal displacement of
one VB with respect to another
DLCDLCIntegrity of the Intervertebral disc, anterior
and posterior longitudinal ligaments, interspinous ligaments, facet capsules and ligamentum flavum.
Components:◦ Intact◦ Intermediate◦Disrupted
This descriptor is unique to SLIC system.
Abnormal facet alignment
Widening of anterior disc space
Translation/rotation of VB
Kyphotic alignment
Radiographic disruption is not
obviousHyper-intense signal
through disc or posterior ligament
region
Neurological statusNeurological statusOften the most influential factor
of medical decision making.Critical indicator of degree of
Spinal Cord Injury.Components:
◦Intact◦Root Injury◦Complete Cord Injury◦Incomplete Cord Injury
Continued Cord Compression
Minor ComponentsMinor Components
Spinal level of injuryOsseous injury description:
◦# or dislocation of transverse processes, pedicles, endplates, superior and inferior articular processes, lateral masses, facet joint, laminae and spinous processes.
Confounders◦Preexisting cervical disease◦Ankylosing spondylitis, DISH,
osteoporosis, previous surgery and degenerative diseases.
Application of SLIC systemApplication of SLIC systemInjuries are named according to
the following 6 descriptors:◦Spinal Level.◦Injury Morphology. (Major
component)◦Osseous Injury description.◦Status of the DLC. (Major
component)◦Neurological examination.◦Confounders. (Major component)
Application of SLIC systemApplication of SLIC systemNumerical values of appropriate components
are summed together.
Multiple injuries: Each level is treated as a separate injury. SLIC score is calculated independently.
Single level with multiple injury pattern: Only most severe injury is considered for scoring.
ScoreInterpretation
<4Non-operative
Treatment
4Operative vs. Non-
operative
≥5Operative Treatment
Illustrative Case No. 1Illustrative Case No. 1
17 y/o female patientPresented after 30-foot-fall with
severe neck pain.Neurological examination was
normal.
CT: Burst fracture of C-7 vertebra
MRI: Normal signal intensity of disc and both the anterior and posterior ligamentous
structures
Total SLIC score = 2
Non-surgical treatment
Illustrative Case No. 2Illustrative Case No. 253 y/o presented with neck and left
sided arm pain after motorcycle accidentNeurological examination:
◦Left biceps weakness◦Decreased light-touch and pin-prick
sensation in the index fingerImaging showed
◦Anterior translation of C-5 on C-6◦C-5 inferior articular facet and C-6 superior
articular facet fractures◦ Increased signal intensity in the posterior
ligamentous structures
Total SLIC score = 6
Surgical treatment
Discussion (Old vs. New)Discussion (Old vs. New)AdvantagesAdvantages
SLIC system and Severity score:◦Focuses on a framework that is clinically
relevant◦Easy to apply, reliable◦Free of geographic or language biases
Allen and Ferguson, Harris◦Based on presumed mechanism of injury◦Classify injuries into a variety of
anatomical fracture patterns with arbitrary descriptors.
◦Lack practicality and clinical relevance.◦Associated with terminology has been
ineffective in describing traumatic conditions of subaxial spine
Discussion (Old vs. New)Discussion (Old vs. New)AdvantagesAdvantages
SLIC system is the first system to address both neurological exam. and DLC status in clinical judgment.
Inter-rater agreement on the management of subaxial trauma:
SLIC: 74% Old systems: 57-64%
Inter-rater reliability:SLIC: 94% Old systems: 68-71%
DrawbacksDrawbacks
Neurological examination◦Potential source of bias (subjective
information).◦ In state of spinal shock, it is difficult to
differentiate between complete and incomplete SCI.
MRI:◦There is no evidence, up to date,
defining the specificity and sensitivity of MRI in the diagnosis of DLC disruption.
◦ Individual interpretation may result in variation (Inter-rater reliability).
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