Examqo › Examqo library › Neurosurgery › Spine
Subaxial cervical injuries and facet dislocations
In the lower neck (C3 to C7) the decision to operate is made by the SLIC score — injury morphology, integrity of the disco-ligamentous complex and neurological status — and a bilateral facet dislocation, with translation of 50% or more, is an unstable injury with a high risk of spinal cord damage.
Why it matters in the exam
The exam asks about mechanism and the radiograph. A unilateral facet dislocation is caused by flexion with rotation and shows anterior translation of about 25% of the vertebral body, usually with a root injury only; a bilateral dislocation is caused by flexion-distraction and shows translation of 50% or more, usually with severe cord injury. "Perched facets" are an intermediate state in which the tip of the upper facet rests on the tip of the lower. In an awake, cooperative patient closed reduction with traction in Gardner-Wells tongs and repeated neurological checks is possible; in a patient who cannot be assessed, or before open reduction, MRI is done to exclude a disc herniation that could be pushed into the canal.
The SLIC score: morphology — compression 1, burst 2, distraction 3, rotation or translation 4; disco-ligamentous complex — intact 0, indeterminate 1, disrupted 2; neurology — intact 0, root 1, complete cord injury 2, incomplete cord injury 3, plus one point for continuous cord compression with a deficit. A score of 5 or more — surgery; 3 or less — non-operative; 4 — either. In the injured cord a mean arterial pressure of 85 to 90 mmHg is kept for 7 days, and decompression is done early, preferably within 24 hours. Neurogenic shock — hypotension and bradycardia in an injury above T6 — differs from spinal shock, which is a temporary loss of reflexes below the injury; return of the bulbocavernosus reflex marks the end of spinal shock. Methylprednisolone is not routine; by AO Spine 2017 it is only an option within 8 hours.
Key points
- SLIC: morphology, ligamentous complex, neurology; 5 or more — surgery.
- Unilateral — about 25%; bilateral — 50% or more.
- Closed reduction in an awake patient; MRI in a patient who cannot be assessed.
- Mean arterial pressure 85 to 90 for 7 days.
- Neurogenic shock — bradycardia and hypotension above T6.
Summary table
| Injury | Mechanism | Translation and presentation | Treatment |
|---|---|---|---|
| Unilateral facet dislocation | Flexion and rotation | About 25%, usually root injury | Reduction and fixation |
| Bilateral facet dislocation | Flexion-distraction | 50% or more, cord injury common | Early reduction and fixation |
| Flexion teardrop fracture | Flexion and axial loading | Anteroinferior fragment with retropulsion of the body | Surgical fixation |
| Central cord syndrome | Hyperextension in an older person with stenosis | Arms weaker than legs | Non-operative or surgery depending on compression |
| Clay-shoveler's fracture | Flexion or muscle pull | Spinous process of C7 or T1 | Non-operative |
A free exam question
לגבי נעילת פצטים דו״צ ( bilateral locked facets )בעמ״ש צווארי , מה משקף נכון את המנגנון ,ההסתמנות או הטיפול בפגיעה זו ? (the question as examined, in Hebrew)
- א. בד״כ המנגנון שגרם לפגיעה הוא היפרארסטנציה קשה( severe hyperextension )
- ב. הגובה הנפוץ ביותר לפגיעה זו הינו C3-4
- ג. הסיכוי להסתמנות עם פגיעה מוטורית בהגעה לבית החולים פחות מ- 10%
- ד. יש התווה נגד לניסיון לרדוקציה סגורה( closed reduction ) אם יש פריצת דיסק טראומתית ב- MRI
In the full version for subscribers
- A simple algorithm
- Memory aid
- Exam traps
- 5 review cards
- Enough for IMLE
The full version is open to subscribers of: Neurosurgery, Orthopedic surgery, Emergency medicine.
Subscriber? Read the full topic Plans and prices 25 free questions
Sources
- AANS/CNS Guidelines for the Management of Acute Cervical Spine and Spinal Cord Injuries, 2013 — Closed reduction of cervical fracture-dislocation; blood pressure management
- AO Spine guideline for the management of acute spinal cord injury, 2017 — Timing of decompression and methylprednisolone
- Subaxial Cervical Spine Injury Classification (SLIC), 2007 — Scoring and treatment thresholds
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.