Thoraco Lumbar Fracture

Xray Assessment

 

A:  Alignment

B:  Bony

C:  Canal

D:  Disc

S:  Soft tissues

 

Goals of surgery

 

1.  Correct deformity

2.  Restore stability

3.  Decompress neural elements if required

 

MRI

 

Advantage

- defines level of conus

- may need anterior rather than posterior surgery if lesion above conus

 

Denis's 3 column Classification 1982

 

> 3 columns injured with translation

- unstable

 

Posterior column 

- supraspinous / infraspinous ligament / ligamentum flavum

- neural arch (lamina / pedicle / facet joints / spinous process)

 

Middle column 

- PLL, posterior disc & annulus

- posterior half vertebral body

- most important

 

Anterior column 

- ALL, anterior disc & annulus

- anterior half vertebral body

 

Denis Classification

 

1.  Compression fracture

- anterior column only

 

L1 anterior compression fracture MRI

 

2.  Burst fracture

- anterior and middle column disrupted

- widening of pedicles on AP

- decreased posterior body height compared to anterior

- may have retropulsed fragment

- this occurs at top of vertebral body between pedicles

- obscured by pedicles on lateral xray

 

Burst Fracture CT

 

3.  Flexion-distraction

- distraction of posterior structures

- disruption of middle column

- splaying of spinous processes on AP and lateral

- bony or ligamentous

- chance injury (pure bony)

- anterior column intact / no translation

 

4.  Fracture-dislocation

- all three columns disrupted

- characterised by translation

 

Surgical Indications

 

1.  Neurology 

- decompress 

- complete v incomplete

 

2.  Deformity

- correct deformity

 

Gertzbein SRS 1992

- 1109 patients

- kyphosis >30° associated with increased back pain

 

3.  Stability

- prevent neurology

- prevent deformity / late pain

 

4.  Multi-trauma patient

 

TLISS (Thoracolumbar Injury Severity Score)

 

Spine Trauma Study Group 

- 3 issues

- calculate a score

- gives an indication if patient needs surgery

 

1.  Injury Mechanism

 

Compression 1

Burst 2

Rotation 3

Distraction 4

 

2.  Posterior Ligament Complex

 

Intact 0

Suspected 2

Definite 3

 

3.  Neurology

 

Nil 0

Nerve root 1

Complete cord 2

Incomplete cord 3

Cauda equina 3

 

10 is maximum score

- < 4 no treatment

- 5 or more - surgery

- 4 - either way

 

Burst fracture

- 2 points for burst

- 2 for indeterminate posterior injury

- usually no neurology

- 4 in total

 

Timing

 

Incomplete neurology

- emergency

- especially if neurology worsening

- have more time if neurology stable

- i.e. time to get MRI

 

Complete neurology

- not an emergency

- surgery still indicated

- gain 1 or 2 neurological levels (crucial in C spine)

- prevent syrinx

- prevent development of neuropathic pain

- aid nursing / rehabilitation

 

Bohlman 1985 JBJS

 

184 thoracic spine fractures with complete cord injury

- no recovery with or without OT

- posterior fusion only to speed recovery

 

17 incomplete cord injuries treated with laminectomy

- 7 became worse

- hence contra-indicated

 

8 incomplete cord injuries treated with anterior decompress+ fusion

- all improved  

- decreased rehabilication time by 50% in operative group

 

Approach

 

Posterior

 

Indications

- flexion distraction

- fracture dislocation

- compression fractures

- +/- burst

 

Requires integrity of posterior column

- Gaines score

 

Issue

- disruption of posterior column

- higher risk of dural tears

 

Anterior

 

Indication

- decompression required

- i.e. burst with retropulsed fragment

- perform corpectomy via anterior approach

 

Anterior & Posterior

 

Gaines / Load sharing Classification

 

Enables decision be made

- short segment posterior stabilisation v

- anterior decompression and stabilisation

 

Gaines Class >/=7 = failure with pedicle screw construct alone

 

A. Comminution vertebral body on lateral X-ray

1. <30%

2. 30-60%

3. >60%

 

B. Apposition of Fragments

1. Minimal displacement

2. 2mm or <50% of body

3. > 2mm or >50% body

 

C. Deformity Correction

1. Kyphosis 3o or less

2. 4-9o

3. >10o needed

 

Score of 3-9

 

1.  Compression Fractures

 

DDx

- burst

- pathological

 

CT scan

- xray only 25% accurate distinguishing compression from burst

- indicated if anterior body height < half posterior body height

- i.e. > 50% anterior wedging

- assess integrity of middle column / look for retropulsed fragments

 

Operative Indications

- kyphosis > 30o

 

Non Operative Management

- elderly - mobilise

- young - extension orthosis / TLSO

- check standing X-ray 2/52

- ensure kyphosis < 20 - 30o

 

Surgery

- posterior approach

- instrumentation

 

2.  Burst Fracture

 

Characteristics

- axial load

- most common thoracolumbar junction

- retropulsed fragment here causes conus

 

Definition

- anterior & middle column disrupted

- posterior column injured but no displacement / translation

 

X-ray

- pedicle widening on AP

- posterior body height decreased on lateral < 50%

 

Thoracic Burst Xrays LateralThoracic Burst Xrays AP Widened Pedicles

 

CT

 

Look for canal compromise

- cord signal change

- kyphotic deformity

 

Burst Fracture CT No Canal CompromiseBurst Fracture Coronal

 

Retropulsed fragments

- always between pedicles

- typically one or two main fragments (saloon door)

- assess canal compromise

 

Thoracic Burst CT Canal Fragment SagittalThoracic Burst CT Canal Fragment Axial

 

Burst Fracture Axial CT

 

MRI

- HNP

- cord signal change

- assess posterior ligament integrity

- assess level of conus medullaris

 

Thoracic Burst MRI Sagittal Kyphosis and Cord SignalThoracic Burst MRI Canal Compromise

 

Clinically

 

1.  High association abdominal trauma

- duodenum, aorta, spleen

 

2.  Neurology

- complete v incomplete

- from retropulsed fragments

 

Non-Operative management

 

Indications

- no neurology 

- no deformity / < 30o kyphosis

- stable

 

TLSO

 

Surgical Indications

 

TLISS > 4

- usually means neurology

 

Kyphotic deformity

 

Failure non operative

 

Anterior corpectomy and strut graft

 

Indication

- decompression of retropulsed fragments in patient with neurology

 

Lumbar Burst Fracture0001Lumbar Burst Fracture0002Lumbar Burst Fracture0003Lumbar Burst Fracture0004

 

Technique

- approach as per level

- thoracoabdominal for T11 - L1

- thoracotomy for T2 - T10

- remove disc above and below and remove vertebral body

- remove fragments / need to know if 1 or 2

- screws in vertebral body above and below

- 2 screws in a lateral plane

- insert fibular strut allograft / titanium cage

- augment with cage

 

Posterior instrumentation 

 

Indication

- < 7 gaines criteria

- no neurology

 

Technique

- ligamentotaxis clears canal / PLL acts as bowstring

- pedicle screws lumbar, avoided in thoracic

- use transverse process and pedicle hooks in thoracic

- bone graft inserted via pedicles

- need to do before 5 days post injury

 

Burst Fracture Posterior stabilisation 3Burst Fracture Posterior stabilisation

 

Thoracic Burst Posterior Stabilisation APThoracic Burst Posterior Stabilisation Lateral

 

3.  Flexion Distraction

 

Definition

 

Seat belt injuries

- injury all 3 columns

- posterior fails in tension

- anterior and middle in distraction

- anterior undisplaced with no translation

 

Associated injuries

 

1.  Hollow viscus

 

Anderson et al J Orthop Trauma 1991

- 2/3 have injury to hollow viscus

- duodenum very common as second part fixed

- 1/4 have hemoperitoneum from mesenteric laceration

 

2.  Ileus

- very common

- manage NBM / NGT

 

Types

 

1.  Pure bony

- through vertebral body

- Chance fracture

 

2.  Ligamentous

- through disc space and facet joints

 

Thoracolumbar Chance Fracture CT CoronalThoracolumbar Chance Fracture CT Sagittal

 

3.  Combined

- rare injury

 

Management

 

Bony chance

- can heal in hyperextension orthosis

- assess reduction in brace / < 15o kyphosis

- otherwise can fix with pedicle screws and TP hooks of same vertebrae

 

Ligamentous

- treat surgically as unstable and ligament heals poorly

- respond well to short segment posterior instrumentation

- above and below disc space injured

- i.e. T12 and L1 instrumented

 

TL Chance Fracture Stabilisation LateralChance Fracture Stabilisation APTL Chance Fracture

 

Neurology / deformity

- reduction and posterior stabilisation

- add decompression if required

 

4.  Translational - Fracture / Dislocation

 

T12 L1 Soft Tissue Chance CT 2T12 L1 Soft Tissue Chance CTT12 L1 Soft Tissue Chance MRI

 

Background

 

3 Column injury

- high energy

- unstable by definition

- required operative stabilisation

- profound neurological deficit common

 

Types

1.  Shear

2.  Flexion-distraction with translation

3.  Flexion-rotation

- unilateral facet dislocation

- < 25% translated

 

Management

 

Incomplete or no neurology

- rare

- great care must be taken to not worsen patient

- MRI to exclude disc / determine level of conus

 

Options

- posterior approach / decompression / reduction / stabilisation

- consider anterior approach if HNP / above level conus

 

Levels

- 1 up and 1 down sufficient unless

- osteoporosis

- thoracolumbar junction

 

T12 L1 Soft Tissue Chance OTT12 L1 Soft Tissue Chance Posterior StabilisationT12 L1 Soft Tissue Chance Posterior Decompression