1. Classification of Thoracolumbar spine injuries
Abdulaziz Alomar, MD, MSc FRCSC
Assistant Professor and consultant Orthopaedic surgeon. KKUH, KSU

2. Historical Classification Systems
Summary
Comments
Nicoll
Differentiates stable from unstable fractures
Serves as a foundation for subsequent classification systems
Holdsworth
Modifies previous classification systems to include the mechanisms of injury and two-column theory
Fails to appreciate some burst fracture instabilities
Kelly & Whitesides
Refines the two-column model
Classification guides treatment of neurologic deficit
Denis
Development of the three-column model
The middle column is the primary determinant of mechanical stability.
Gertzbein et al.
Suggests a posterior component, anterior component and body component
Involves the vertebral body as it
relates to kyphosis.

3. Denis
Goal:
To emphasize pathologic anatomy of different types of spinal injuries, each of which was based on a different mechanism of injury.
did not consider methods of treatment or the results.

4. Denis: Three-column model
Anterior column- formed by the ALL, the anterior annulus, and the anterior portion of the vertebral body
Middle osteoligamentous- the critical feature. Very important to spinal stability; consists of PLL, the posterior portion of the annulus, and the posterior aspect of the vertebral body
Posterior column- includes the neural arch, facet joints and capsules, ligamentum flavum, and remaining ligamentious complex
Denis F. Clin Orthop Relat Res. 1984

5. Denis: Middle-column concept
Developed to define burst fracture
middle column is the primary determinant of mechanical stability of the thoracolumbar region of the spine.

6. Denis- Minor injuries Isolated fractures of Transverse process.
Articular process.
pars interarticularis, or
Spinous process.

7. Denis- Major injuries
Compression type

8. Denis- Major injuries
Burst Type E

9. Denis- Major injuries
Seat belt type

10. Denis- Major injuries Fracture dislocation type Shear type
Flexion rotation
Flexion distraction

11. Load Sharing Classification
Created system in response to poor patient outcomes when the vertebral body sustained a disproportionately severe injury
Classification system grades:
Amount of damaged vertebral body
Spread of the fragments in the fracture sight
Amount of corrected kyphosis
McCormack et al. Spine, 1994

12. Load Sharing Classification
Load-Sharing Classification: a straight-forward way to describe the amount of bony comminution in a spinal fracture
Can help the surgeon select short-segment pedicle-screw-based fixation using the posterior approach for less comminuted injuries and the anterior approach for those more comminuted injuries .

13. Load sharing classification

15. AO Classification
Based on the review of 1445 consecutive thoracolumbar injuries
Primarily based on pathomorphological criteria
Categories based on:
Main mechanism of injury
Pathomorphological uniformity
Prognostic aspects regarding healing potential
Magerl et al. Eur Spine J

16. AO Classification
Classification reflects progressive scale of morphological damage by which the degree of instability is determined
Consists of a grid for sub-grouping injuries into three types:
A, B and C
Every type has three groups, each of which contains three subgroups with specifications
Magerl et al. Eur Spine J

17. AO Classification
Types have a fundamental injury pattern which is determined by the three most important mechanisms acting on the spine
Compression
Distraction
Axial torque
Magerl et al. Eur Spine J

18. AO Classification Type A(compression)

19. AO Classification Type B (Distraction)

20. AO Classification Type C (Torsion)

21. Examples of AO Classification

22. AO Classification-

23. AO Classification

24. AO Classification

25. Summary
Currently no classification system that has achieved global clinical utility and acceptance.