Thoracolumbar Thoracolumbar FracturesFractures

Mahmood Hassan, MD, PhDMahmood Hassan, MD, PhDConsultant NeurosurgeonConsultant Neurosurgeon

Fractured L2 & L4Fractured L2 & L407/2011

11/201107/2011

11/2011

CT scans CT scans

Dynamic StudiesDynamic Studies

07/201111/2011

11/2011

D2 & D3 FracturesD2 & D3 Fractures

BiomechanicsBiomechanicsThree biomechanical regions:Three biomechanical regions:The upper thoracic region (T1-T8) is The upper thoracic region (T1-T8) is rigid due to the ribcage which rigid due to the ribcage which provides stability.provides stability.

The transition zone T9-L2 is the The transition zone T9-L2 is the transition between the rigid & transition between the rigid & kyphotic upper thoracic part & the kyphotic upper thoracic part & the flexible lordotic lumbar spine. This flexible lordotic lumbar spine. This is where most injuries occur. is where most injuries occur.

Finally we have the L3-Sacrum zone Finally we have the L3-Sacrum zone which is flexible & this is the region which is flexible & this is the region where axial loading injuries occur.where axial loading injuries occur.

Ligamentous IntegrityLigamentous Integrity

BiomechanicsBiomechanics

In the upper thoracic spine the In the upper thoracic spine the center of gravity is anterior to center of gravity is anterior to the spine.the spine.

Axial loading will result in Axial loading will result in compressive forces anteriorly & compressive forces anteriorly & tensile forces posteriorly.tensile forces posteriorly.

This will result in flexion-type of This will result in flexion-type of injuries.injuries.

BiomechanicsBiomechanicsIn the lumbar spine due to the In the lumbar spine due to the lordosis, the center of gravity is lordosis, the center of gravity is posteriorly.posteriorly.Flexion & extension here is the Flexion & extension here is the product of a combination of rotation product of a combination of rotation & translation in the sagittal plane & translation in the sagittal plane between each vertebra.between each vertebra.Flexion type of injuries will straighten Flexion type of injuries will straighten the spine & result in axial loading.the spine & result in axial loading.In this lumber area we will see In this lumber area we will see many burst fractures.many burst fractures.

Ranges of segmental movementsRanges of segmental movements

L1-L2 L2-L3 L3-L4 L4-L5 L5-S1

Flexion/Extension 12 14 15 16 17

Lateralflexion 6 6 8 6 3

Axialrotation 2 2 2 2 1

(White and Panjabi, 1990) are (in degrees)

StabilityStability

Stable or NotStable or NotA simple anterior A simple anterior wedge # or just sprain wedge # or just sprain of the posterior of the posterior ligaments is stable.ligaments is stable.

A wedge # with rupture of A wedge # with rupture of the interspinous ligaments the interspinous ligaments is unstable, because is unstable, because the anterior & posterior the anterior & posterior columns are disrupted.. columns are disrupted..

Patterns of InjuryPatterns of InjuryFlexion InjuriesFlexion Injuries• Anterior Compression• 2 Column Burst• 3 Column Burst• Flexion Distraction• Chance• Translation

Extension InjuriesExtension Injuries• Mechanism is rare• Fused spine: less energy– Ankylosing spondylitis– Surgery• Translation common

Rotational InjuriesRotational Injuries• Rare• Subset of flexion• Facet jump

The The Holdsworth fracture Holdsworth fracture is an unstable is an unstable fracture dislocation of the fracture dislocation of the thoraco lumbarthoraco lumbar junctionjunction of the spine. of the spine. The injury comprises a fracture through a The injury comprises a fracture through a vertebral body, rupture of the posterior vertebral body, rupture of the posterior spinal ligaments and fractures of the spinal ligaments and fractures of the facet joints.facet joints.

Flexion/Compression Flexion/Compression FractureFracture

Occurs at the T1 & L1 levels usually. Occurs at the T1 & L1 levels usually. The amount of anterior column failure The amount of anterior column failure depends on the amount of compressive depends on the amount of compressive force. Usually there is some loss of force. Usually there is some loss of vertebral height with this injury, vertebral height with this injury, but as long as the middle and posterior but as long as the middle and posterior columns are intact, this fracture is considered stable.columns are intact, this fracture is considered stable.

Hyperflexion InjuryHyperflexion Injury

Sagittal reconstructions of the CT

Chance fractureChance fracture• A flexion injury of the spine, first described by GQ A flexion injury of the spine, first described by GQ

Chance in 1948.Chance in 1948. It consists of a compression injury It consists of a compression injury to the anterior portion of the vertebral body & a to the anterior portion of the vertebral body & a transverse fracture through the posterior elements transverse fracture through the posterior elements of the vertebra the vertebral body. It is caused by of the vertebra the vertebral body. It is caused by violent forward flexion, causing distraction injury to violent forward flexion, causing distraction injury to the posterior elements.the posterior elements.

• The most common site at which Chance fractures The most common site at which Chance fractures occur is the thoracolumbar junction (T12-L2) and occur is the thoracolumbar junction (T12-L2) and midlumbar region in pediatric population.midlumbar region in pediatric population.

Seat Belt injurySeat Belt injury• • Lap belt injuryLap belt injury – – childrenchildren• • Fulcrum is beltFulcrum is belt• • Pure distractionPure distraction• • Associated injuries-Associated injuries-

Up to 50% of Chance fractures have associated Up to 50% of Chance fractures have associated intraabdominal injuries. Injuries associated with intraabdominal injuries. Injuries associated with Chance fractures include fractures of the pancreas; contusions or Chance fractures include fractures of the pancreas; contusions or lacerations of the duodenum; & mesenteric contusions or lacerations.lacerations of the duodenum; & mesenteric contusions or lacerations.

Lover’s FracturesLover’s Fractures

Usually seen in people jumping out of a window to escape Usually seen in people jumping out of a window to escape from the police or a jealous husbandfrom the police or a jealous husband

Burst fractureBurst fracture

Anterior and the middle column are disrupted,edema in the posterior soft tissues indicating involvement of the posterior column.

Burst FractureBurst FractureBurst fractures usually occur Burst fractures usually occur through a high-energy axial or through a high-energy axial or violent compressive load violent compressive load resulting in failure of both the resulting in failure of both the anterior and middle columns anterior and middle columns of the vertebrae e.g, after car of the vertebrae e.g, after car accident or fall from great accident or fall from great height with all or pieces of height with all or pieces of vertebra shattering into vertebra shattering into surrounding tissues & spinal surrounding tissues & spinal canal.canal.

Burst Fracture TypesBurst Fracture TypesType Patterns Force Applied

A Fracture of both end plates Pure axial loading

B Fracture of superior end plate Axial loading with flexion

C Fracture of inferior end plate Axial loading with flexion

D Burst Rotation Axial loading with rotation

E Burst lateral flexion Axial loading with flexion

Denis F. Clin Orthop 1984

Burst FractureBurst FractureA burst fracture is always A burst fracture is always unstable because at least unstable because at least the anterior & middle the anterior & middle column are disruptedcolumn are disrupted

Coronal reconstruction & Coronal reconstruction & an axial image an axial image

at the level of the fracture.at the level of the fracture.

Two-Column BurstTwo-Column Burst

• • TechnicallyTechnically unstable unstable––Non-operative treatmentNon-operative treatment• • Retropulsion (<50%)Retropulsion (<50%)• • Anterior height loss (<50%)Anterior height loss (<50%)• • Neurologically intactNeurologically intact

Three Column BurstThree Column Burst• Compression of all three columns• Neurological compromise common

Flexion Distraction InjuryFlexion Distraction Injury

• Highly unstable• Three column injuries• Operative repair may differ from burst–Assessment of distraction is critical

Fl-Disraction Vs Translation

Translation InjuryTranslation Injury

• • TranslationTranslation– – 50% anterolisthesis50% anterolisthesis– – Lateral subluxationLateral subluxation• • Fracture/DislocationFracture/Dislocation• • Disruption of Disruption of ligamentous stabilityligamentous stability

Predicting Predicting SoftSoft Tissue Injury Tissue Injury

Criteria to predict soft-tissue injury from bony injury are:

•Angulation greater than 20 degrees.

•Translation of 3.5 mm or more.

Key Sensory PointsKey Sensory Points

ASIA Classification SystemASIA Classification SystemGrade Motor Examination

0 Total paralysis

1 Visible or palpable contraction

2 Active movement, full range of motion; gravity (-)

3 Active movement, full range of motion vs gravity

4 Active movement, full range of motion vs moderate resistance

5 Active movement, full range of motion vs full resistance

Grading of Clinical Instability Grading of Clinical Instability White & Panjabi Check List: White & Panjabi Check List:

Element Point Value

Cauda Equina damage 3

> 8% Relative flexion sagittal plane translation 2

> 9% extension sagittal plane translation 2

< - 9 degrees Relative flexion sagittal plane rotation 2

Destroyed anterior element 2

Destroyed posterior element 2

Antcipated dangerous loading 1

Count of five or more points to Clinical Instability

New Injury Severity ScoringNew Injury Severity ScoringA New Classification of Thoracolumbar InjuriesA New Classification of Thoracolumbar InjuriesThe Importance of Injury Morphology, the Integrity of the PosteriorLigamentous Complex, and Neurologic StatusAlexander R. VaccaroAlexander R. Vaccaro, MD,* Ronald A. Lehman, Jr., MD,† R. John Hurlbert, MD, PhD,‡SPINE Volume 30, Number 20, pp 2325–2333 ©2005, Lippincott Williams & Wilkins, Inc.

Because neurologic status plays such an important role in patient assessment and surgical decision making, it comprises one of the three main injury characteristics in this classification algorithm.

Classification algorithmClassification algorithm

Key PointsKey Points Thoracolumbar Injury Classification & Severity Score is designed to depict the features important in predicting-

• spinal stability, • future deformity & • progressive neurologic compromise.

Facilitating appropriate treatment recommendations.

Key PointsKey PointsThe composite injury severity score derived from this classification system assigns between 1 and 4 points to three critical components of an injury.

•Fractures with 3 points or less are considered nonoperative candidate.•Fractures with scores of 4 points can be considered for nonoperative or operative intervention. •Fractures with 5 or greater points are considered surgical cases.

Key PointsKey Points

In operative candidates, features of this classification system, such as -

•posterior ligamentous integrity & the•neurologic status of the patient

Directs the optimal surgical approach.

ISS Also assists Decision MakingISS Also assists Decision Making

ISScore was-?

The MR images show bone marrow edema in the involved The MR images show bone marrow edema in the involved vertebral body, but no additional soft tissue injury.vertebral body, but no additional soft tissue injury.

Conservative treatment thoracolumbar injuries Conservative treatment thoracolumbar injuries

Meticulous readingMeticulous reading

Not to miss any pointNot to miss any point

Management in the Emergency DepartmentManagement in the Emergency Department

Much attention has been given to injuries of the Much attention has been given to injuries of the cervical spine, but injuries to the thoracolumbar cervical spine, but injuries to the thoracolumbar region are actually more common. Because of the region are actually more common. Because of the anatomy involved, these injuries are often anatomy involved, these injuries are often accompanied by multiple serious injuries to other accompanied by multiple serious injuries to other areas of the body and may be overlooked during areas of the body and may be overlooked during resuscitation and stabilization. resuscitation and stabilization. - Sandra M. Schneider, MD, FACEP, Editor Executive Summary

Roque, Pedro MD; Feiz-Erfan, Iman MD; LoVecchio, Frank DO, MPH; Wu, Teresa S. MD, FACEP; Falcone, Robert E. MD, FACSEmergency Medicine Reports. 32(13):157-166, June 6, 2011.

Approach to Acute Thoracolumbar Approach to Acute Thoracolumbar Spine FractureSpine Fracture

CT scan is the imaging study of choice for CT scan is the imaging study of choice for thoracolumbar injuries. thoracolumbar injuries.

To differentiate a burst fracture from a compression To differentiate a burst fracture from a compression fracture, sagittal reconstructions and axial views fracture, sagittal reconstructions and axial views are necessary. are necessary.

A thorough perineal examination is indicated in A thorough perineal examination is indicated in patients with a possible thoracolumbar injury. This patients with a possible thoracolumbar injury. This includes assessment of bladder function, rectal includes assessment of bladder function, rectal tone, bulbocavernosus reflex, and anal wink. tone, bulbocavernosus reflex, and anal wink.

Surgical Intervention warrantedSurgical Intervention warranted

The posterior column is essential for spinal stability.

Radiographic findings suggestive of posterior column

disruption include - Kyphosis > 20 degrees, Loss of 50% of anterior vertebral height, Facet dislocation, Multiple adjacent compression fractures, and Compromise of > 30% of the spinal canal. 

Alternative to standard surgical approaches less invasive Alternative to standard surgical approaches less invasive procedures are becoming popular in the management of procedures are becoming popular in the management of

traumatic & degenerative spine diseases.traumatic & degenerative spine diseases.

STANDARD OPEN MICRODISCECTOMY VERSUS MINIMAL ACCESS TROCAR MICRODISCECTOMY:RESULTS OF A PROSPECTIVE RANDOMIZED STUDY: Neurosurgery 61:174–182, 2007