Spine Trauma Classifications

Spine Trauma Classifications

1-General Principles

-The primary objective of spinal trauma classification systems is to provide a standardized framework that characterizes the severity, morphology, and stability of the injury, thereby guiding therapeutic decision-making and prognostication.

-Spine trauma classification: Earlier systems (Denis, Allen–Ferguson) emphasized

morphology alone, whereas modern frameworks (AO Spine-TLICS) integrate

morphology, neurological status, and modifiers.

-Contemporary classification systems incorporate neurologic status and mechanical

stability, enhancing communication, prognostication, research, and treatment planning.

2-Cervical Spine

-Upper Cervical Injuries :

Composed of occiput, atlas (C1), and axis (C2), collectively called the craniocervical junction (CCJ).

Occiput–C1: Provides 50% of cervical flexion–extension.

C1–C2: Provides 50% of cervical rotation.

Injury prevalence is bimodal, in children and adults >60 years.

Pediatric: Predominantly motor vehicle accidents or pedestrian–vehicle collisions.

Elderly: Most often due to falls.

a)Occipital Condyle Fractures

· The most widely used classification is the Anderson & Montesano system. 

Type I: Axial load; often comminuted; ligaments intact; unilateral stable, bilateral may be unstable (A).

Type II: Extension of basioccipital fracture from direct blow; ligaments intact; usually stable (B).

Type III: Alar ligament avulsion with medial fragment displacement into the foramen magnum; from forced rotation + lateral bending; potentially unstable (C).

b) Occiput-Atlas dislocations

· The most commonly employed classification system was described by Traynelis.

Type I – Anterior displacement of the occiput on atlas.

Type II – Longitudinal distraction; traction may worsen neurologic deficit.

Type III – Posterior subluxation/dislocation.

c) Atlas (C1) Fractures

· Described by Jefferson (1921); it involves anterior & posterior arches (weakest C1

points).

· 2–13% of cervical fractures; 25% of atlantoaxial injuries; mean age 30.

· The most common motor vehicle accidents are caused by axial load drops.

· Up to 50% with other cervical fractures—commonly dens, hangman’s, C2 teardrop, burst, or lateral mass fractures 

d) Atlantoaxial Subluxation and Dislocation

· Fielding and Hawkins presented the most commonly used classification scheme. 

Type I – Pure rotation.

Type II – Rotation + anterior displacement <3–5 mm → partial transverse ligament deficiency.

Type III – Rotation + anterior displacement >5 mm → complete transverse ligament deficiency.

Type IV – Rotation + posterior displacement.

e) Transverse Ligament Injuries 

· Primary stabilizer of the atlantoaxial joint.

· Disruption is irreparable; original strength and function cannot be restored.

· Dickman Classification (Dickman CA, Greene KA, Sonntag VK. Injuries involving the transverse atlantal ligament: classiication and treatment guidelines based upon experience with 39 injuries. Neurosurgery. 1996;38:44-50.)

Type I – Intrasubstance rupture.

- IA: Midportion tear.

- IB: Tear at periosteal insertion on atlas.

Type II – Bony avulsion from C1 lateral mass.

- IIA: Lateral mass comminuted.

- IIB: Lateral mass intact.

f) Fractures of the Odontoid

· Mechanism: flexion → anterior displacement; extension → posterior displacement.

· Anderson–D’Alonzo Classification

Type I –Tip avulsion at alar ligament insertion; may accompany severe occipitocervical injury.

Type II – Base/neck fracture at dens–C2 junction; poor healing from limited blood supply.

Type III – Extends into C2 body; larger cancellous surface allows better healing than Type II.

g) Hangman’s Fracture (Traumatic Spondylolisthesis of C2)

Type I

· Caused by hyperextension + axial load.

· Bilateral pars fractures with <3 mm translation, no angulation.

· Disc and anterior longitudinal ligament remain intact.

· May be associated with C1 posterior arch or dens fractures.

Type II & Variant

· Type II: >3 mm translation + angulation; axial load + hyperextension → flexion; disc disruption ± C3 or C2 body fracture.

· IIA: Marked angulation, ≤3 mm translation; flexion–distraction; disc & PLL disruption; traction widens disc space.

Type III

· Unstable; severe displacement/angulation with C2–C3 facet dislocation.

Disc & PLL disruption, frequent neurologic injury.

Mechanism: flexion–distraction → hyperextension.

Lower Cervical Injuries

1- Subaxial (C3–C7): ⅔ of all cervical injuries.

· Spinal cord injury in 0.8–1.2%; incidence is higher in >65 years, rare in children.

· Male: female ≈ 2:1.

· Mechanisms: Vehicle collisions (50%), falls (40%, especially elderly).

2- Throcal-Lomber injury

Most common site of thoracic/lumbar injury; predominantly young males, high-energy trauma.

Location: >50% between T11–L1;  30% between L2–L5.

Mechanism: 50% motor vehicle accidents;  25% falls >6 ft (1.8 m).

Neurologic injury:  20% complete,  15% incomplete.

Associated injuries (>50% cases): fractures, head trauma, pulmonary, and intra-abdominal injuries.

Noncontiguous spinal injuries:  5%, remote from the primary site.

Classifications:

a) Nicoll (1949): Anterior wedge, lateral wedge, fracture–dislocation, isolated neural arch fractures.

b) Holdsworth: Mechanism-based (flexion, flexion–rotation, extension, compression); introduced the two-column theory:

i. Anterior column resists compression

ii. PLC resists tension

iii.  Stable: wedge compression, compression burst (PLC intact)

iv.  Unstable: dislocations, extension/dislocations, rotational fracture–dislocations

c) Denis Three-Column Model

Introduced by Denis (1983) to classify spinal trauma and stability.

Divides the spine into three anatomical columns:

 Anterior column → anterior longitudinal ligament + anterior two-thirds of vertebral body.

 Middle column → posterior one-third of vertebral body + posterior longitudinal ligament.

 Posterior column → facet joints + posterior ligamentous complex.

Primary paradigm: based on the morphological extent of injury to bony and ligamentous structures.

Widely adopted as a guide for trauma management; introduced the concept of instability.

Mechanical instability: failure of ≥ 2 columns.

Neurologic instability: deficit present (often mechanically unstable).

Provided the foundation for subsequent classification systems.

Three-column model validated in biomechanical cadaver studies; forms basis for modern classifications and treatment algorithms.

d) Magerl Classification of Thoracolumbar Trauma (1994)

Introduced by Magerl et al. (1994); focused on morphological assessment of osseous and ligamentous injury.

Type A – Compression injuries

· A1: Wedge compression (A1.1, A1.2, A1.3)

· A2: Split fractures (A2.1, A2.2, A2.3)

· A3: Burst fractures (A3.1, A3.2, A3.3)

Type B – Distraction injuries

· B1: Posterior tension band disruption, ligamentous (B1.1–B1.3)

· B2: Posterior tension band + osseous disruption (B2.1–B2.3)

· B3: Anterior tension band failure, hyperextension injuries (B3.1–B3.3)

Type C – Rotational / Translational injuries

· C1: Rotation with Type A pattern (C1.1–C1.3)

· C2: Rotation with Type B pattern (C2.1–C2.3)

· C3: Pure translational displacement (C3.1–C3.3)

Each type is further divided into 3 groups, each group into 3 subtypes → >50 distinct injury patterns.

Provided detailed morphological categorization but was criticized for excluding the neurological status of the patient.

e) Thoracolumbar Injury Classification and Severity Score (TLICS, 2005)

Developed by the Spine Trauma Study Group (2005) to standardize decision-making in thoracolumbar trauma.

Designed as an algorithmic tool for surgical decision-making.

Incorporates three major parameters:

a. Injury morphology (compression, burst, translation/rotation, distraction)

b. Integrity of the posterior ligamentous complex (PLC)

c. Neurological status (intact, nerve root injury, incomplete SCI, complete SCI, cauda equina)

Each parameter is assigned a weighted score → total score determines treatment pathway.

· ≤3 points: Nonoperative management recommended

· 4 points: Indeterminate (surgeon’s judgment)

· ≥5 points: Surgical stabilization recommended

Addressed limitations of purely morphological systems by integrating neurologic assessment.

Demonstrated good interobserver reliability across both Orthopedic and Neurosurgery disciplines.

f) Modified AO Spine Thoracolumbar Injury Classification (AO TLS)

Developed to address limitations of TLICS, particularly indeterminate cases (scores 3–5), e.g., neurologically intact burst fractures with suspected PLC injury.

Combines elements from Magerl (morphology) and TLICS (neurologic status, modifiers).

Core Components:

a. Fracture morphology

b. Neurologic status

c. Modifiers (injury-specific/patient-specific)

a) Fracture Morphology

Type A – Compression injuries

A0: Minor injury (transverse/spinous process fracture)

A1: Wedge compression

A2: Pincer fracture (endplates, no posterior wall)

A3: Incomplete burst (without posterior wall involvement)

A4: Complete burst (with posterior wall involvement)

Type B – Tension-band injuries (no translation)

B1: Osseous posterior tension band injury (e.g., Chance fracture)

B2: Ligamentous posterior tension band injury

B3: Anterior tension band failure (e.g., ankylosing spondylitis)

Type C – Translational injuries

Translation/distraction with complete disruption of spinal column

Includes complete soft tissue hinge disruption even without visible listhesis

b) Neurologic Status

N0: Intact neurologic exam

N1:Transient deficit, full recovery

N2: Nerve root injury (weakness, radiculopathy)

N3: Cauda equina / incomplete SCI

N4:Complete SCI

NX:Neurologic exam not assessable (e.g., intubated, sedated)

c) Modifiers

Modifiers were incorporated to account for variables that may influence

surgical decision-making. These are categorized into injury-specific and

patient-specific factors.

M1 (Injury-specific): Indeterminate tension band injury (suspected on imaging)

M2 (Patient-specific): Conditions complicating management (ankylosing spondylitis, DISH, osteoporosis, severe burns, etc.)

If multiple patterns exist, classify by the highest injury type present. 

References

1. Anderson PA, Montesano PX. Morphology and treatment of occipital condyle fractures. Spine (Phila Pa 1976). 1998;13:731–736.

2. Traynelis VC. Classification system of occiput–atlas dislocations. In: Rothman RH, Simeone FA, eds. The Spine. 7th ed. Philadelphia: Elsevier; 2018:1295.

3. Levine AM, Edwards CC. Fractures of the atlas. J Bone Joint Surg Am. 1991;73:680–691.

4. Fielding JW, Hawkins RJ. Atlanto-axial rotatory fixation (fixed rotatory subluxation of the atlanto-axial joint). J Bone Joint Surg Am. 1977;59:37–44.

5. Zadnik PL, Sciubba DM. Anatomy, Cervical Spine. In: Papadakos PJ, Gestring ML (eds). Encyclopedia of Trauma Care. Berlin, Heidelberg: Springer; 2015. doi:10.1007/978-3-642-29613-0_577.

6. Dickman CA, Greene KA, Sonntag VK. Injuries involving the transverse atlantal ligament: classification and treatment guidelines based upon experience with 39 injuries. Neurosurgery.1996;38:44–50.

7. Anderson LD, D’Alonzo RT. Fractures of the odontoid process of the axis. J Bone Joint Surg Am.1974;56:1663–1674.

8. Fehlings MG, Vaccaro A, Wilson JR, et al. Early versus delayed decompression for traumatic cervical spinal cord injury: results of the Surgical Timing in Acute Spinal Cord Injury Study (STASCIS). PLoS One. 2012;7(2):e32037.

9. Caron T, Bransford R, Nguyen Q, et al. Spine fractures in patients with ankylosing spinal disorders. Spine. 2010;35(11):E458–E464.

10. Hasler RM, Exadaktylos AK, Bouamra O, et al. Epidemiology and predictors of cervical spine injury in adult major trauma patients: a multicenter cohort study. J Trauma Acute Care Surg.2012;72(4):975–981.

11. Nicoll EA. Fractures of the dorso-lumbar spine. J Bone Joint Surg Br. 1949;31:376–394.

12. Holdsworth F. Fractures, dislocations, and fracture-dislocations of the spine. J Bone Joint Surg Am. 1963;45:6–20.

13. Denis F. The three-column spine and its significance in the classification of acute thoracolumbar spinal injuries. Spine (Phila Pa 1976). 1983;8(8):817–831.

14. Magerl F, Aebi M, Gertzbein SD, Harms J, Nazarian S. A comprehensive classification of thoracic and lumbar injuries. Eur Spine J.1994;3(4):184–201.

15. Patel AA, Whang PG, Brodke DS, et al. Evaluation of two novel thoracolumbar trauma classification systems. Indian J Orthop.2007;41(4):322–326.

16. AO Spine Knowledge Forum Trauma. AO Spine Textbook: Comprehensive Overview on Surgical Management of the Spine. AO Foundation; 2020.

17. Rothman RH, Simeone FA. The Spine. 7th ed. Philadelphia: Elsevier; 2018.