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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