Slic System

1. Dr. Ahmed Mirza Al-Shammasi, MB ChB
2031040009
KFHU – Saudi Arabia

2. OutlinesOutlines
Object
Introduction
The SLIC system and Severity Score
◦Components
◦Interpretation
Illustrative cases.
Discussion ( Old vs. New )

3. ObjectObject
The authors review a novel Subaxial Cervical
trauma classification system and demonstrate
its application through a series of cervical
trauma cases.

4. IntroductionIntroduction
The 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.

5. IntroductionIntroduction
An 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.

6. 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

8. Injury MorphologyInjury Morphology
Structural relationship of Vertebral
Bodies to each other.
Determined by Radiography
Components:
◦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

9. DLCDLC
Integrity 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 obvious
Hyper-intense signal
through disc or posterior
ligament region

11. Neurological statusNeurological status
Often 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

12. Minor ComponentsMinor Components
Spinal level of injury
Osseous 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.

14. Application of SLIC systemApplication of SLIC system
Injuries 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)

15. Application of SLIC systemApplication of SLIC system
Numerical 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.
Score Interpretation
4 > Non-operative Treatment
4
Operative vs. Non-
operative
≤5 Operative Treatment

16. Illustrative Case No. 1Illustrative Case No. 1
17 y/o female patient
Presented after 30-foot-fall with severe
neck pain.
Neurological examination was normal.

17. CT: Burst fracture of C-7
vertebra
MRI: Normal signal
intensity of disc and both
the anterior and posterior
ligamentous structures

18. Total SLIC score
= 2
Non-surgical
treatment

19. Illustrative Case No. 2Illustrative Case No. 2
53 y/o presented with neck and left sided arm
pain after motorcycle accident
Neurological examination:
◦Left biceps weakness
◦Decreased light-touch and pin-prick sensation in the
index finger
Imaging 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

21. Total SLIC score
= 6
Surgical
treatment

22. 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

23. 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%

24. 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).

25. Thank you for ListeningThank you for Listening