Thoracolumbar Spinal Injury

A thoracolumbar spinal injury is a common form of spinal injury as a thoracolumbar region is the most prone site of injury among spinal trauma.

15-20% of fracture occurs in the thoracolumbar region and neurological injury is seen in approximately 20% of cases.

The thoracolumbar region is prone to injury as it is much stiffer than the lumbar spine in flexion-extension and lateral bending due to the restraining effect of the rib cage as well as thinner intervertebral disc

Whereas lumbar facet orientation will limits rotation in the lumbar spine( approx. 10° only)

Conus medullaris ends at the L1-L2 level

Spinal canal diameter/spinal cord dimension is smallest at the T2-T10 region so it is prone to neurological injury after trauma.

Neurological deficits are more commonly secondary to skeletal injury most commonly seen at T1-T4 ( complete deficit related to spinal cord injury with varying degrees of nerve root injury)

But caudal to L1 there is exclusively root injury as conus medullaris ends here.

Similarly T2-T10 there is a circulatory watershed area that drives its proximal blood supply from antegrade vessels in upper thoracic vessels called Artery of adamkiewicz (T9-L2)

Sacral sparing:

Triad

Classification of thoracolumbar spinal injury

3 Column classification system of thoracolumbar injury

One column injury: Stable

2/3 column injury: Unstable

Denis classification of thoracolumbar spinal injury (1984)

Major Spinal Injuries

1. Compression fractures (48%)
2. Burst fractures (14%)
3. Fracture dislocation (16%)
4. Seat-belt type ( flexion-distraction) injury (5%)

Minor Spinal Injuries

1. Articular process fractures (1%)
2. Transverse process fractures (14%)
3. Spinous process fractures (2%)
4. Pars interarticularis fractures (1%)

McAfee et al classification of thoracolumbar spinal injury

It neither gives prognostic/ nor treatment guidelines

1. Wedge Compression fracture (ant. Column only)
2. Stable Burst Fracture (ant + middle)
3. Unstable Burst Fracture (ant +middle +post)
4. Chance Fracture (from post-anterior)
5. Flexion-distraction injury (ant. Column compression+ middle/post tensile column)
6. Translation Injury (shear form)

Thoracolumbar Injury Severity Score (T.L.I.S.S ) classification

3 dimentional classification

1. Morphology
   • Compression =1
   • Burst =2
   • Translation= 3
   • Distraction =4
2. Posterior ligamentous injury
   • Intact =0
   • Suspected=2
   • Disruption=3
3. Neurology
   • Intact =0
   • Root cord injury=2
   • Complete=2
   • Incomplete=3
   • Cauda equine=3

If above point is

<3: non surgical

4 : surgeon choice

>4 it is indicative of surgery

However, this classification doesn’t give an approach/type of surgery so another classification system is developed

Which is given by load sharing classification:

Load Sharing classification of thoracolumbar spinal injury

McCormack Gains et al (1994)

Point value assigned as per

1. Vertebral Body communition (on saggital plane)
   • Little: 30% =1
   • More: 30-60%=2
   • Gross: >60%=3
2. Fracture fragment apposition
   • Minimal=1
   • Spread (2 mm displacement of <50% crosssection of body)=2
   • Wide (2mm displacement of  >50% crosssection of body)=3
3. Kyphosis
   • Little: ≤ 3°=1
   • Moderate: 4-9°=2
   • Most: ≥ 9°=3

If the score is ≥ 6 it is better treated with anterior column reconstruction to posterior stabilization

AO classification of thoracolumbar spinal injury

It gives treatment protocol but doesn’t consider neurology

1. Type A: Compression —>PLC intact (d/t axial load=rarely fix)
2. Type B: Distraction—>PLC injured (sometimes Fix)
3. Type C: Translation —>PLC injured + translation (always fix)

How Urgent to OPERATE in Thoracolumbar Spinal Injury??

Urgent Surgery for thoracolumbar injuries are done is following conditions:

1. Fracture/dislocation
2. Progressive neurological deficit
3. DCO (Damage control orthopedics)

Early means, within 6 hours Decompression needs to be done

In polytrauma—> posterior stabilization is an emergency and anterior surgery is done later as an elective procedure

Indication of conservative treatment for Thoracolumbar Spinal Injury??

Conservative treatments are done for the following categories of fractures.

Stable fracture with/without neurological involvement as

– clinical outcome: same as conservative/ operative

– the radiological outcome may be better

How to Operate in Thoracolumbar Spinal Injury??

Different surgical approaches are discussed regarding stabilization

• Anterior
• Posterior
• Combined

Principle of surgery for Thoracolumbar Spinal Injury

1. Adequate and immediate stability with rehabilitation
2. Bone on bone
3. Save/ Preserve level
4. Decompression with canal clearance

Anterior Surgery is mandatory in

1. Severe osteoporosis
2. If needed keep a larger diameter cage in the lumbar spine ( 2 end plate damage)

Posterior approach

The mainstay of treatment:

• Approach technically easier with low morbidity
• Short segment pedicle fixation: reduction of deformity with canal compromise
• Transpedicular grafting: vertebral body reconstruction
• When emergency surgery is required
• Imp in case of dislocation

Anterior stabilization helps in :

• Direct and complete canal clearance
• Better kyphotic correction

Short Vs Long Segment fixation in Thoracolumbar Spinal Injury??

Regarding fixation, there is always doubt whether a surgeon goes for a long-segment fixation or a short-segment fixation. Following are certain indications:

1. PLC ligamentous injuries: (flexion-distraction injuries)
   1. LONG ( 2 levels above /below)
2. PLC bony injury: Chance fracture
   1. SHORT: one level above/ below
3. Burst fracture: Stable fractures
   1. SHORT
4. More than 30° Kyphosis

SHORT + Anterior Reconstruction in a Single-stage

LONG if staged anterior later

Complete vs Incomplete Neurological Injury

1. Absence of peri-anal sensation
2. Absence of peri-anal voluntary motor function
3. Absence of peripheral reflexes
4. With/without priapism or bulbocavernosus reflexes