SLIC — Subaxial Cervical Spine Injury Classification¶

Overview¶

The Subaxial Cervical Spine Injury Classification and Severity Scale (SLIC) is a scoring system analogous to TLICS but designed specifically for injuries of the subaxial cervical spine (C3–C7). Developed by the Spine Trauma Study Group, SLIC evaluates three parameters — fracture morphology, disco-ligamentous complex (DLC) integrity, and neurological status — and produces a composite score that guides management.

Scoring Components¶

1. Fracture Morphology¶

Pattern	Points
No abnormality	0
Compression fracture	1
Burst fracture	2
Distraction (facet perch, hyperextension)	3
Translation/rotation (facet dislocation, teardrop with translation)	4

2. Disco-Ligamentous Complex (DLC) Integrity¶

Status	Points
Intact	0
Indeterminate	1
Disrupted	2

The DLC includes the intervertebral disc, anterior and posterior longitudinal ligaments, interspinous ligaments, ligamentum flavum, and facet capsules.

3. Neurological Status¶

Status	Points
Intact	0
Root injury	1
Complete cord injury	2
Incomplete cord injury	3
Continuous cord compression with neurodeficit (modifier)	+1

Clinical Pearl

As with TLICS, incomplete spinal cord injury scores higher than complete cord injury in SLIC. The +1 modifier for ongoing spinal cord compression in the setting of a neurological deficit reflects the urgency for decompression in patients with potentially recoverable function.

Score Interpretation¶

Total SLIC Score	Recommended Management
≤3	Conservative (non-operative)
4	Surgeon's judgment
≥5	Operative

Key Differences from TLICS¶

Feature	SLIC (Cervical)	TLICS (Thoracolumbar)
Ligamentous parameter	Disco-ligamentous complex (DLC)	Posterior ligamentous complex (PLC)
DLC/PLC indeterminate	1 point	2 points
DLC/PLC disrupted	2 points	3 points
Continuous cord compression modifier	+1 point	Not included

Imaging Assessment¶

CT evaluates morphology — compression, burst, facet subluxation/dislocation, and translation. Sagittal and coronal reformats are essential.

MRI assesses DLC integrity (high T2/STIR signal in disc and ligaments), spinal cord signal (edema, hemorrhage, compression), and epidural hematoma.

Key MRI findings suggesting DLC disruption include disc space widening or high signal, disruption of the anterior or posterior longitudinal ligaments, and facet capsule edema or disruption.

Limitations¶

Moderate interobserver reliability for DLC assessment
Does not account for specific fracture patterns at C0–C2 (upper cervical spine)
Does not incorporate patient comorbidities or bone quality
Some degree of overlap with the AO Spine Subaxial Cervical Classification

Key Points¶

SLIC is the cervical spine counterpart of TLICS, using morphology, DLC integrity, and neurological status
Scores ≤3 favor conservative treatment; scores ≥5 favor surgery
Incomplete cord injury with ongoing compression is the highest-scoring neurological category
MRI is critical for evaluating DLC integrity and spinal cord injury
SLIC applies to C3–C7 injuries; the upper cervical spine (C0–C2) has its own classification systems

References¶

Vaccaro AR, Hulbert RJ, Patel AA, et al. The subaxial cervical spine injury classification system: a novel approach to recognize the importance of morphology, neurology, and integrity of the disco-ligamentous complex. Spine (Phila Pa 1976). 2007;32(21):2365-2374. PubMed: 17906580
Spitnale MJ, Grabowski G. Classification in Brief: Subaxial Cervical Spine Injury Classification and Severity Score System. Clin Orthop Relat Res. 2020;478(10):2390-2398. PMC7491911
Joaquim AF, Patel AA, Vaccaro AR. Cervical injuries scored according to the Subaxial Injury Classification system: An analysis of the literature. J Craniovertebr Junction Spine. 2014;5(2):65-70. PMC4158633
Subaxial cervical spine injury classification. Radiopaedia. radiopaedia.org/articles/subaxial-cervical-spine-injury-classification
Subaxial Injury Classification and Severity Scale (SLICS) Calculator. MDCalc. mdcalc.com/calc/10085