Thoracolumbar Spine Fractures

Key Points:

  • Most common cause of thoracolumbar spine trauma in pediatric patients is motor vehicle accidents accounting for up to 58% of all injuries. 
  • Compared with adults, pediatric patients have greater ligamentous flexibility and elasticity, shallower and more horizontal facets, and relative paraspinal muscle immaturity.
  • AP and lateral plain radiographs are often favored for initial imaging, with the addition of MRI for children with neurologic deficits.
  • The common fracture patterns include compression, burst, flexion-distraction, fracture dislocation injuries, apophyseal fractures/herniations, and spinous process and transverse process fractures.
  • For stable injury patterns TLSO bracing for 6 – 8 weeks maybe sufficient, however when indicated instrumented stabilization with or without arthrodesis maybe necessary for unstable patterns. 

Description:

Thoracolumbar spine trauma in pediatric patients is a rare entity.  When it occurs, it can be potentially very devastating with a wide array of presentations.  Treatment should be based on a strong understanding of the pediatric spine anatomy, biomechanics, and a thorough understanding of fracture pattern stability.

Epidemiology:

Fractures of the thoracolumbar spine account for 1% to 2% of all pediatric fractures.  The most common cause of pediatric spine trauma is motor vehicle accidents (even when seat belts are used), which lead to 33% to 58% of all injuries. Other mechanisms include fall from a height, sport related injuries, and child abuse.  Football, rugby, and skiing are associated with thoracolumbar spine injuries.  Additionally, sledding and all-terrain vehicle (ATV) use are also cited as high-risk activities for thoracolumbar spine injury as well.

Clinical Findings:

Initial assessments should include a motor and sensory exam with reflex assessment if possible with the addition of a rectal and genital examination.  Palpation of the spine for crepitation, ecchymosis and bony step-offs should be performed on survey.  Thoracolumbar spine injuries may include associated internal organ injury in the thorax and abdomen.    The incidence of concomitant abdominal or thoracic trauma is reported to be up to 42%.  Keeping this in mind, the examiner should look for signs of pneumothorax in addition to a distended and painful abdomen if spine trauma is suspected.  ATLS protocols should be maintained during initial assessment using pediatric spine board to elevate the child’s torso preventing neck hyperflexion when necessary.  This is particularly important if children are less than 6 years.

Imaging Studies:

Initial imaging should include AP and Lateral plain radiographs of the entire spine.   If neurological deficits are noted MRI imaging would be the next imaging modality.  MRI is also useful to determine if the posterior ligamentous complex of the spine is intact, helping guide therapy.  CT scanning of the spine has widely been an accepted practice in adults, however risks associated with radiation exposure make it an unsafe screening tool in children.  Some studies have shown that excess use of CT scan predispose children to an increased risk of thyroid cancer as they transition into adulthood.  CT scan is a better modality at identifying osseous detail compared to MRI, however as stated previously the radiation exposure needs to be considered.

Etiology:

In general, compared with adults, pediatric patients have greater ligamentous flexibility and elasticity, shallower and more horizontal facets, and relative paraspinal muscle immaturity. 
 
The spinal column has been described to have three separate columns:
Anterior column (Anterior Longitudinal Ligament, Anterior 2/3 of vertebral body and annulus), Middle Column (Posterior Longitudinal ligament, Posterior 1/3 of vertebral body and annulus), and Posterior Column (Pedicles, Facets, Ligamentum Flavum, Spinous Process, Posterior Ligament Complex).
 
Transverse Process Fractures –  The transverse processes (two per vertebral body) are located on each side of the vertebral body.  They can be described as lateral projections at the point where the lamina joins the pedicle.  Fractures of these are usually minor and typically occur as a result of blunt trauma to the level involved. Pelvic trauma can be associated with lumbar transverse process fractures.  This is usually as a result of iliolumbar ligamentous avulsion from the transverse processes in the setting of the injury. The patient will usually complain of point tenderness at the site of injury on physical exam.  If they occur in isolation no neurologic compromise usually occurs. Conservative therapy is usually the mainstay of treatment.        
 
Spinous Process Fractures –  The spinous process is a posterior inferior projection off the spinal lamina of a vertebra.  Fractures to these structures are similar to TP fractures in that they may occur due to direct or blunt trauma at a given level.  The patient will usually complain of point tenderness at the site of injury on physical exam.  If they occur in isolation no neurologic compromise usually occurs.  Conservative therapy is usually the mainstay of treatment.            
 
Compression Fractures –  The vertebral body is the main bony structure in the anterior aspect of the spinal column.  Compression fractures of the vertebral body in the thoracolumbar spine usually occur as a result of axial loading mechanism.  A collapse and or buckling of the vertebral body due to the force of injury is the typical cause of this injury pattern.  These fractures typically occur at the thoracolumbar junction.  The patient should be assessed closely for other axial loading type injuries in the lower extremities, and pelvis as these may concomitantly occur.  The patient may be noted to have tenderness at the effected level on exam. No neurological compromise is usually present if the injury occurs in isolation.  These fractures are typically managed conservatively.   
 
Burst Fractures – These fractures are typically the result of an axial loading injury.  These injuries, just as compression fractures, also usually occur at the thoracolumbar junction.  Burst Fractures usually occur involving the anterior and middle columns of the spine with varying degrees of retropulsion into the spinal column.  However, it must be noted that posterior elements can be involved as well.  Theses fractures can have varying presentation depending on degree of spinal canal involvement.  If on cross-sectional imaging and clinical exam there is no concern, then conservative therapy can be utilized.  However, if there is neurological compromise and significant retropulsion into the canal (described as > 50%) then operative management may be warranted.     
 
Chance Fractures – These fracture types are a result of flexion distraction injuries of the spinal column.  This injury pattern is typically seen as a result of seat belt injury.  Flexion distraction injuries of the spine can vary from purely osseous to purely ligamentous, or a combination of both.  Both the posterior and the anterior columns are affected in this injury type.  There is a distractive force which causes the posterior column to fail in tension, and the anterior column fails in distraction or compressive flexion.  Patients should be assessed for visceral/abdominal and head injuries.  Once again, if on cross-sectional imaging (MRI) and clinical exam there is no concern and the injury is through the bony elements, then conservative therapy can be utilized.  However, if there is neurological compromise and/or there is compromise of the ligamentous structures rendering the level unstable, then operative management may be necessary.
 
Apophyseal Fractures – Children at risk of these injures are those with open physes in the spinal column usually between the ages of 10 through 14.  Separation occurs of the apophysis with resultant herniation into the spinal canal.  The patient may present with radicular signs and symptoms due to root compression.  Depending on severity of presentation either conservative or operative management will be needed. 
 
Thoracolumbar Fracture Dislocations – These catastrophic injuries usually occur in the setting of major high energy blunt trauma.  These injuries are associated with nerve root and/or spinal cord injury.  The patient will be noted to have deformity on exam such as bony step off.  Additionally, significant neurological findings are present with deficits varying based on injury.  These injuries must be reduced and stabilized surgically.

Treatment:

For stable fracture patterns a thoracolumbosacral orthosis (TLSO) can be fashioned for the patient to allow for early mobilization.  This must be maintained for 6 – 8 weeks with follow up imaging.  Burst Fracture types with significant retropulsion (> 50%) into the canal and neurological compromise may necessitate decompression of the canal with anterior or posterior instrumentation arthrodesis.  In Flexion-Distraction type injuries (Chance type) in which alignment cannot be maintained nonoperatively, surgical stabilization with posterior instrumentation fusion is treatment of choice.  If there is a purely ligamentous injury with loss of integrity of the posterior ligamentous complex in older children, then these injuries are also treated as above.  If apophyseal herniations result in significant neurological compression of the spinal cord or nerve roots, then surgical decompression may be required. Thoracolumbar fracture dislocations need to be stabilized with rigid instrumented constructs combined with arthrodesis with or without surgical decompression.

Complications:

All operative interventions have risks for wound complications and infections and iatrogenic neurological injury.  Families need to be made aware of this risk prior to undergoing surgical interventions.  Pediatric patients with thoracolumbar neurologic injury have a risk of progressive skeletal deformity.  There may be a role of prophylactic bracing even in curves < 10 degrees in this population.  Curves > 20 degrees will likely progress despite bracing.   Surgical deformity correction is an option for patients with large progressive curves or sitting imbalances.  If progressive neurologic decline is noted, then MRI should be obtained to look for underlying spinal dysraphisms.

References:

  1. Daniels AH, Sobel AD. Pediatric Thoracolumbar Spine Trauma. Journal of the American Academy of Orthopaedic Surgery. 2013; 21(12); 707-16.
  2. Mahan ST, Mooney DP, Karlin LI, Hresko MT. Multiple Level Injuries in Pediatric Spinal Trauma. The Journal of Trauma: Injury, Infection, and Critical Care. 2009;67(3):537–542.
  3. Muchow RD, Egan KR, Peppler WW. Theoretical increase of thyroid cancer induction from cervical spine multidetector computed tomography in pediatric trauma patients. Journal of Trauma Acute Care Surg. 2012; 72(2): 403-9.
  4. Parent S, Dimar J, Dekutoski M. Unique Features of Pediatric Spinal Cord Injury. Spine. 2010;35(215):202–208.
  5. Sawyer J. Age-related Patterns of Spine Injury in Children Involved in All-Terrain Vehicle Accidents. Journal of Pediatric Orthopaedics. 2012;32(5):435–439.
  6. Vaccaro AR, Lehman RA Jr, Hurlbert RJ, et al: A new classification of thoracolumbar injuries: The importance of injury morphology, the integrity of the posterior ligamentous complex, and neurologic status. Spine (Phila Pa 1976) 2005;30(20):2325-2333.
  7. Vander Have KL, Caird MS, Gross S, et al. Burst fractures of the thoracic and lumbar spine in children and adolescents. J Pediatr Orthop. 2009;29(7):713–719.

Top Contributors:

Norman Otsuka, MD