Thoracolumbar Trauma319

25/10/59Ryan Janicki

Alexander R. VaccaroBrian K. Kwon

Thoracolumbar Trauma• The thoracolumbar spine is the transition point between the more

rigid thoracic spine and the more flexible lumbar spine• Neurological injury• Long-term pain and disability• High-velocity deceleration mechanisms

Outline• Anatomy• Initial Assessment and Management• Classification• Management Considerations• Complications

Anatomy

Posterior ligamentous complex(PLC)

Sprain during flexion

Watershed zone4-9 thoracic level

Initial Assessment and Management

• Clinical Evaluation• Imaging

Clinical Evaluation : primary survey

Clinical Evaluationsecondary survey• Complete neurological examination• ASIA work sheet• Risk factor for thoracolumbar injury• A high-energy mechanism of injury• Neurological signs or symptoms• Pain or tenderness on clinical examination• The presence of significant distracting injuries that might make both the patient and physician overlook a spinal injury (particularly in the absence of neurological deficits)

Imaging• Plain radiograph• identifying the level of injury• characterizing bony injuries • the relationship of one vertebral body to another• evaluating the overall alignment of the spine

Imaging• Widening of the interpedicular distance relative to other levels suggests

failure of the posterior vertebral body (middle column)• burst fractures

• Interspinous distances can sometimes also be appreciated, and widening is suggestive of a flexion-distraction injury• Radiographic signs that may indicate major ligamentous (including PLC)

disruption and instability• displacement of bone• widening of the interlaminar space, apophyseal joints• widening of the vertebral canal• disruption of the posterior vertebral body

Cobb method

Imaging• CT• Excellent bone• Visualization in any plane• Benefit of visceral imaging• Once a spine injury is identified CT scan or further radiographs of the entire

spine to rule out other noncontiguous fractures(4-28 %)

Imaging• MRI• T2-weighted fat suppression• Diskoligamentous soft tissues• Neurological structures(spinal cord, conus medullaris, cauda equina, and

nerve roots)• Disruption of PLC

• The sensitivity and specificity of MRI in predicting a torn PLC are 90% and 100%, respectively

• Discontinuity of the “black stripe” on T2-weighted MRI, which represents the posterior longitudinal ligament, or SSL, is often used

• Tears of the facet capsule and the ISL result in accumulation of fluid and is represented by high-intensity signal on T2-weighted imaging

Classification• Minor injury• Major injury

Denis and McAfee three column concept

Minor injuries• Involve only a part of a column and do not lead to acute instability• not accompanied by major injures

• 1. fracture of transverse process :usually neurologically intact except in two areas:a) L4–5 →lum bosacral plexus injuries (there m ay be associated renal injuries, check U/A for blood)b) T1–2 →brachial plexus injuries

• 2. fracture of articular process or pars interarticularis• 3. isolated fractures of the spinous process: in the TL spine: these are usually

due to direct trauma. Often diffcult to detect on plain x-ray• 4. isolated laminar fracture: rare,stable

Major injuries

Wedge compression

Type AFracture of both end plates

and separation of the anterior body.

Type CFracture of the inferior end plate

Type DFracture of the anterior vertebral body without involvement of the end plates

Type BFracture of the superior end plate

Note the absence of middle column involvement in all types, act as fulcrumMost common T6-T8, T12-L3

Burst FracturesType AFracture of both end plates-axial load

Type CFracture of the inferior end plate-rare

Type DBurst rotation-axial load with rotation

Type BFracture of the superior end plate(note the retropulsed bony fragment [shaded] at the level of the pedicles)-most common-axial load with flextion

Type EBurst lateral flexion-axial load with lateral flexion

Note1.the increased interpediculate distance seen on the anteroposterior views (types D and E)

Seat belt–TypeType AOne-level seat belt–type injury through bone -Chance fracture

Type CTwo-level injuriesthe injury to the middle column involves bone

Type DTwo-level injuriesto the middle columninvolves ligamentous

Type BOne-level seat belt–type injury through the ligaments-that only the anterior anulus and anterior longitudinal ligament are preserved

Note1.Flucrun anterior to anterior column(seat-belt)

Fracture-dislocation

Type AFlexion-rotation–type injuries through bone (slice fracture)

Type BFlexion-rotation–type injuries through the disk

Note All 3 columnthe difference in rotation between involved spinal segments, which is best appreciated on anteroposterior views

Moving Forward from Purely Morphologic Classifications

previous classification systems+

patient’s neurological status+

guideline for whether surgical management=

Thoracolumbar Injury Severity Score (TLISS)Modified to

Thoracolumbar Injury Classification and Severity Score (TLICS)

Management Considerations

• Decision Making for Nonsurgical versus Surgical Treatment• Treatment Based on Fracture Morphology

Decision Making for Nonsurgical versus Surgical Treatment

• TLICS• Goal of surgical management• decompress neural structures• correct deformity• stabilize the spine

• Approach• posterior• anterior• combined approach

• Clinical scenarios

Posterior approach• Familiar and most common used• Posterior pedicle screw instrumentation• Correction of sagittal- and coronal-plane deformity is most easily

achieved with posterior instrumentation• For flexion-distraction injuries : pure distraction and little to no

anterior column injury• For burst fractures : burst fragment retropulse to spinal canal, ventral

decompression

Posterior approach• Axial-loading injuries in which the PLC and posterior longitudinal

ligament are intact• Shoud be wary : Posterior distraction across pedicle screw tend to

induce kyphosis• bending the rods into a slight degree of lordosis• using fixed-angle or side-loading screws : which allow one to lever down on

the proximal aspect of the cephalad screws

Anterior approach• Burst fractures in which vertebrectomy and anterior reconstruction

are required either to • decompress retropulsed fragments of bone directly off the ventral dura or• provide immediate restoration of the anterior weight-bearing column for

reason of mechanical stability

• Severe neurological deficit as the result of a large retropulsed piece of bones of mechanical stability• Reconstructed with a cage implant (using autogenous bone graft

from the vertebrectomy) or structural allograft

Anterior approach• Stabilized with a variety of different anterior fixation screw-plate

devices or rod-screw constructs• If PLC are intact : fixation may suffice to provide stability to the injury.• If PLC are disruption : anterior construct with posterior pedicle screw-

rod fixation• Contraindication : Obesity, previous abdominal surgery, and severe

pulmonary, chest, and abdominal trauma

Combined approach(360-degree instrumentation)• Burst fractures with significant PLC disruption• Vertebrectomy and anterior reconstruction, followed by posterior

pedicle screw instrumentation• Anterior column reconstruction can also be performed

posterolaterally from a costotransversectomy approach• Lower lumbar spine

Clinical scenarios

Neurologial status Posterior ligamentous complex

• Intact• Disrupted

• Intact• Incomplete neurological

deficit or cauda equina injury• Complete neurological deficit

Neurologically Intact/PLC Intact

• If surgery is chosen to promote early rehabilitation• Anterior (41%) and posterior (59%) approaches• Surgery not superior to conservative management• Management : most case no surgical intervention

Neurologically Intact/PLC Disrupted

• Flexion-distraction and severe compression injuries• Management• stabilized from a posterior approach

• Combination approach is required if the anterior column is severely comminuted

Incomplete Neurological Deficit or Cauda Equina Injury/PLC Intact

• Burst fractures (with pure axial loading and no significant distraction through the posterior elements)• Rarely with extension-distraction injuries• Management• early surgical intervention to decompress the neural elements

• Stabilized posteriorly before anterior decompression• Direct anterior approach and decompression followed by arthrodesis with a strut graft/cage and anterior instrumentation

Incomplete Neurological Deficit Or Cauda Equina Injury/PLC Disrupted

• Burst fractures, flexion-distraction fractures, and translational injuries• Management• combined anterior and posterior approach

• Stabilized posteriorly before anterior decompression

Complete Neurological Deficit/PLC Intact

• Severe burst fractures and extension-distraction fractures• Management • posterior approach for stabilization• anterior decompression to avoid posttraumatic syringomyelia plus

reconstruction of the anterior column was the optimal approach

Complete Neurological deficit / PLC Disrupted

• Management• posterior approach for realignment and stabilization was required• anterior approach : decrease the risk for posttraumatic syringomyelia

Neurologial status Posterior ligamentous complex

Management

Intact Intact Conservative

Intact Disrupted Posterior +/- anterior

Incomplete neurological deficit or cauda equina injury

Intact Posterior + anterior

Incomplete neurological deficit or cauda equina injury

Disrupted Posterior + anterior

Complete neurological deficit Intact Posterior +/- anteriorAvoid post-traumatic syringomyelia

Complete neurological deficit Disrupted Posterior +/- anteriorAvoid post-traumatic syringomyelia

Treatment Based on Fracture Morphology

• Wedge Compression Fractures• Burst Fractures• Flexion-Distraction Injuries• Fracture-Dislocations

Wedge Compression Fractures

• Stable• Anterior aspect of the vertebral body, with the posterior aspect of the

vertebral body and the PLC being left intact• The greatest danger with this fracture morphology is misclassification• Short-segment pedicle screw stabilization or cement augmentation• Significant loss of vertebral height• Kyphosis• previous laminectomies• persistent pain

Wedge Compression Fractures• Unstable• 1. a single compression fracture with:

a) loss of > 50% of height with angulation (particularly if the anterior part of the wedge comes to a point)

b) excessive kyphotic angulation at one segment. : > 30°, > 40°)• 2. 3 or more contiguous compression fractures• 3. neurologic deficit (generally does not occur with pure compression

fracture)• 4. disrupted posterior column or more than minimal middle column failure• 5. progressive kyphosis: risk of progressive kyphosis is increased when loss of

height of anterior vertebral body is > 75%. Risk is higher for lumbar compression fractures than thoracic

Burst Fractures

• Unstable fracture, neurological deficit or both• Surgery• Decompression of neural structures with stable internal fixation over the

fewest segments

• Neurologically intact patients,intact PLC, stable fracture• Nonoperatively in the large majority of cases• Bed rest followed by mobilization in a cast or thoracolumbar orthosis for up to

16 weeks

Burst Fractures• Surgical indication• 1.anterior vertebral body height ≤ 50% of the posterior height• 2.residual canal diameter ≤ 50% of normal (note: retropulsed bone in the

canal is often resorbed with either bracing or surgery and is therefore controversial as an isolated indication for surgery)• 3.kyphotic angulation ≥ 20°• 4.when the increased interpediculate distance usually present on the initial

film widens further on AP x-ray when standing in brace/cast• 5.neurologic deficit (incomplete)• 6.progressive kyphosis

Burst FracturesAnterior approach• maintain sagittal alignment• posterior ligaments have been

disrupted : add posterior approach

Posterior approach• Familiarity• direct decompression of the

neural elements is more difficult• how far the instrumentation and

fusion construct need to extend above and below the fracture

Common surgical options for burst or severe compression fracture• If instrumentation alone is needed• a) 2 levels above and 2 levels below the fracture• b) if the index level can be included (i.e. if the pedicles are intact enough to

accept shorter screws), similar biomechanical stability can be achieved by placing screws at the index level (the fractured level) and then just 1 above and 1 below

• If decompression of the spinal canal and/or anterior support is needed, corpectomy and strut graft (e.g. with expandable cage) with percutaneous pedicle screws may be used. Approaches:• a) from posterior approach e.g. laminectomy with transpedicular approach

and impacting bone anteriorly out of canal with a mallet and reverse angled Scoville curette• b) lateral corpectomy and removal of bone from canal

Stable anterior or middle column

Seat belt–Type Injuries

• Disruption of the entire PLC,unstable• Flexion with the axis of rotation is within the body : distractive disruption

of the PLC but compressive failure of the vertebral body anteriorly• Failed posteriorly in tension + no anterior column failure

• posterior tension band with pedicle screws and single-level fusion

• Compromised the anterior column• additional fixation points to share the axial loading

• Entire injury has gone through the bone (i.e., a bony “Chance” fracture)• Simple restoration of the posterior tension band with a short-segment pedicle

screw

Fracture-Dislocations

• Always unstable, significant neurological compromise• Surgery• reduction and stabilization

• A posterior approach usually achieves spinal alignment. A staged anterior procedure may be required if there is persistent ventral compression

Complication

Complication• Complications associated with immobilization occur• Infection• S.aureus

• Implant failure