Thoracolumbar AOSpine Injury Classification System

In 2016 the AOSpine published an algorithm for determining the need for surgical intervention on injuries to the thoracolumbar spine injuries (37).

Type of Injury Subtype Injury # Points Assigned
Type A – Compression Fx
A0 – Minimal Injury

(e.g. transverse process fx)

0
A1 – Compression Fx 1
A2 – Pincer Compression Fx 2
A3 – Incomplete Burst Fx

(only involves one end-plate)

3
A4 – Complete Burst Fx 5
Type B – Tension Band Injury
B1 – Osseous Disruption Tension Band 5
B2 – Posterior Tension Band Injury

(including ligamentous injury)

6
B3 – Anterior Tension Band Injury 7
Type C – Translational Injury 8
Neurological Injury
N1 – None, neurologically intact 0
N2 – Resolved, transient symptoms 1
N3 – Persisting radicular symptoms 2
N4 – Incomplete spinal cord injury 4
N5 – Complete spinal cord injury 4
N6 – Neurological exam unattainable 3
Patient Specific Modifiers
M1 1
M2 0
  • Nonsurgical management: Recommended when the sum of all categories is 0–3.
  • Surgical management: Recommended when the sum of all categories is ≥5.
  • Consideration of either intervention: Necessary when the total equals 4.