Backache in a 16 Year Old
Radiology Cases in Pediatric Emergency Medicine
Volume 6, Case 13
Abu N.G.A. Khan, MD
Maimonides Medical Center
Peter S. Dayan, MD
Columbia Presbyterian and Babies Hospital
Columbia College of Physicians and Surgeons
     A 16 year old athletic female walked into the 
pediatric emergency department with a history of falling 
down 14 stairs, landing on her back.  She complained 
solely of pain in the lower back.  She denied any head 
trauma, loss of consciousness, vomiting,  abdominal 
pain, or difficulty on urination.  She had no past history 
of trauma to the back and had never been hospitalized.
     Exam:  She is alert and active but uncomfortable 
secondary to back pain.  She is able to ambulate 
without any support.  No neurologic deficit is noted on 
neurological examination.  
     Back examination:  No focal tenderness over the 
lumbo-sacral spine noted.  Mild to moderate tenderness 
over the right paraspinal region.  No CVA tenderness, 
no abdominal tenderness.  No bruises or echymoses.
     She is felt to have a soft tissue injury of her back.  
Although there is a low suspicion for fracture,  
lumbo-sacral radiographs are ordered.

View radiographs.

     Interpretation:  The L2 vertebra shows some loss of 
height of the anterior vertebral body.  The posterior 
vertebral line is intact.  A compression deformity of  
L2 is suspected.  A CT scan is ordered to examine the 
extent of injury.

View CT scan.

     CT Scan:  Multiple 5-mm continuous axial sections 
of the lumbo-sacral spine were obtained from the upper 
border of L1 to the level of S3 without intravenous 
contrast.  Serial cuts of L2 are shown here (cuts 7, 8 
and 9 shown left, right and bottom, respectively) There 
is a wedge compression deformity of L2 vertebral body 
with preservation of the disc spaces above and below 
this level.  There is minimal retropulsion of the L2 body 
not causing any significant compression of the thecal 
sac.  The superior end plate and part of the body 
appear fragmented as seen on image cuts 7, 8 and 9. 
There is minimal prevertebral soft tissue prominence.  
The bony spinal canal is normal in size and 
configuration.  No significant posterior bulging or 
herniation of the disc is present.

     Hospital Course:  She was hospitalized under the 
neurosurgery service for observation and discharged 
home in two days with a brace.

     Thoraco-lumbar fractures are a major cause of 
disability (1).   Ninety percent of all spinal fractures  are 
in the thoraco-lumbar region.  Fractures at the 
thoraco-lumbar junction have a significant incidence of 
neurologic deficit of up to 40% in one series (2).  
Several factors contribute to thoraco-lumbar 
     a.  In the lumbar spine , there are no ribs to provide 
additional stability as in the thoracic region (3).
     b.  The alignment of the spine changes from a 
kyphotic curvature in the thorax to a lordotic alignment 
in the lumbar spine (4).
     c.  Lumbar spinal segments are more mobile than 
thoracic segments.  The mobility is due in part to the 
changing orientation of the facet joints.  The coronal 
orientation of the facets in thoracic region is more 
stable then the oblique orientation of the lumbar region.

The Three Column Concept
     The management and outcome of lumbosacral spine 
injuries largely depend upon the stability of the spinal 
column.  There are different models to describe the 
stability following an injury.  The three-column concept 
described by Denis (5,6) in 1983 is the most accepted. 

View three-column diagram:  Fig1

Fig.1:  Lateral View of Lumbo-sacral Vertebrae
     1.  The anterior column consists of the anterior 
longitudinal ligament and the anterior part of the 
vertebral body.
     2.  The middle column extends from the middle 
portion of the vertebral body to the posterior aspect of 
the vertebral body and includes the posterior 
longitudinal ligament.
     3.  The posterior column includes all bony and 
ligamentous structures posterior to the posterior 
longitudinal ligament and includes the pedicles, facets, 
spinous processes and all associated ligaments.

     Fractures involving only the anterior columns are 
considered stable, while fractures that involve the 
middle or all three columns are considered unstable.

Types of Thoraco-lumbar Fractures
     Thoraco-lumbar fractures and dislocations have 
been classified by different investigators (1,4).  
However, no one classification system is inclusive of all 
injury patterns.  Currently the classification described by 
McAfee, et al. (7), is the most widely recognized.  Their 
TLS injury scheme consists of five distinctive injury 
patterns:  wedge compression fractures, burst 
fractures, Chance fractures, flexion-distraction injuries 
and translational injuries (see Fig 2). In recent years, 
the increased use of magnetic resonance imaging 
(MRI) and helical CT scanning has led to improvements 
in classifying TLS injuries.

View TLS injury types:  Fig2

Fig. 2:  Types of thoraco-lumbar fractures

     1.  Wedge compression fractures are the most 
common type of lumbar fracture (4).  They occur during 
hyperflexion and axial loading (as was likely in our 
case).  The vertebral body fails under a compressive 
load and its anterior portion becomes compressed while 
the middle column remains intact.  This fracture is 
rarely associated with neural injury unless multiple 
adjacent vertebral bodies are compressed.  
Radiographically, the wedge deformity is best 
appreciated on the lateral view.  A CT scan is used to 
confirm that the posterior vertebral body, pedicles and 
lamina are intact.
     2.  A burst fracture of the spine was first described 
by Holdsworth (8) in 1963 and redefined by Denis (6) in 
1983 as being a fracture of the anterior and middle 
columns of the spine with or without an associated 
posterior column fracture.  Both a compression fracture 
and burst fracture occur during hyperflexion and axial 
loading of a vertebra.  With a burst fracture, however, 
there is compression of the vertebra and intervertebral 
disk in such a fashion that the compressed disk 
adjacent to the affected vertebra herniates into the 
vertebral body.  As a result, the vertebra fractures 
outward with retropulsion of bone fragment into the 
spinal canal and an increase in interpeduncular 
distance (distance between the pedicles).  Because all 
burst fractures have the potential for severe neurologic 
sequelae, they should be considered unstable during 
the initial emergency department evaluation.  Unstable 
burst fractures are treated with surgical stabilization to 
improve long-term alignment.  For stable fractures, the 
neurologic outcome may be similar for surgically and 
non-surgically treated patients (1,4).
     3. A Chance fracture is commonly associated with 
lap seat belt use in high-speed motor vehicle crashes 
(9).  A Chance fracture is a horizontal vertebral injury 
that results from flexion about an axis that is anterior to 
the anterior spinal longitudinal ligament.  This vector of 
force results in the horizontal disruption of the spinous 
process, lamina, transverse processes, pedicles and 
the vertebral body.  A lateral radiograph best illustrates 
the split in the posterior arch and vertebral body.  More 
subtle signs include an increase in adjacent spinous 
process distancec above and below the injury and an 
increase in the height of the posterior vertebral body.  
An anterior-posterior radiograph may demonstrate the 
split in the transverse processes.  Since the fracture 
runs in an axial plane, a routine axial CT scan may miss 
a Chance fracture.  It is important to perform the 
reconstruction in the sagital plane to detect the fracture 
and any malalignment due to ligamentous injury.
     4.  A flexion distraction injury is one in which the axis 
of flexion is posterior to the anterior spinal longitudinal 
ligament.  There is compressive failure of the anterior 
column and destructive forces placed on the middle and 
posterior columns lead to a tear of the posterior 
longitudinal ligament.  Typically, these injuries involve 
both ligamentous and bony structures and can extend 
over more than one vertebral level.  These injuries are 
considered unstable because the middle column and 
often the posterior column are disrupted.  Radiographic 
findings include anterior impaction with compression 
fracture of the vertebral body and posterior distraction 
with fanning of the spinous processes.
     5.  Translational injuries are associated with 
shearing forces that disrupt all three columns.  The 
shearing forces are most often directed posteriorly to 
anteriorly but may also be directed anteriorly to 
posteriorly.  Since the ligament of the spinal canal is 
affected, these injuries are always unstable and are 
associated with a very high incidence of neurologic 
deficit (6).  Lateral radiographs demonstrate anterior 
translation of the upper vertebrae with respect to the 
lower vertebrae.  On the AP radiograph, the 
interspinous distance at the affected level is widened 
and there may or may not be a rotational malalingment 
of the vertebra.  CT scan may show "naked facets" or a 
double vertebra, if the dislocation is severe.

     Thoraco-lumbar spine injuries are common and 
often result in serous morbidity.  Forty-seven percent of 
patients with spine trauma and 64% with spinal cord 
injuries have concomitant injuries elsewhere (10).  In 
the setting of multiple trauma, in which most TLS 
injuries occur, strict spinal cord injury precautions must 
be observed until injury has been ruled out.  A working 
knowledge of spinal column anatomy is crucial to 
evaluate and manage these injuries.  Application of 
Denis' three-column model to assess spinal stability 
and McAfee's classification of fracture/dislocation 
facilitate management decisions. 

     1.  Kraemer WJ, Schemitsch EH, Lever J, McBroom 
RJ, McKee MD and Waddell JP.  Functional outcome of 
thoraco-lumbar burst fracture without neurological 
deficit.  Journal of  Orthopedic Trauma 
     2.  Frankel HL, Rozycki GS, Ochsner MG, et al.  
Indications for obtaining survillance thoracic and lumbar 
spine radiographs.  J Trauma 1994;37:673-676.
     3.  Kaye JJ, Nance EP.  Thoracic and lumbar spine 
trauma.  Radiol Clin North Am 1990;28:361-377.
     4.  Brandser EA, Ei-Khoury GY.  Thoracic and 
lumbar spine trauma.  Radiol Clin North Am 
     5.  Denis F.  Spinal instability as defined by the three 
column spine concept in acute trauma.  Clin Orthop 
     6.  Denis F.  The three column spine and its 
significance in the classification of acute thoracolumbar 
spinal injuries.  Spine 1983;8:817-831.
     7.  McAfee PC, Yuan HA, Fredrickson BE, et al.  
Value of computed tomography in thoraco-lumbar 
fracture:  An analysis of one hundred consecutive 
cases and a new classification.  J Bone Joint Surg 
     8.  Holdsworth FW.  Fractures, dislocations and 
fracture/dislocation of the spine.  J Bone Joint Surg 
     9.  Savitsky E, Votey S.  Emergency department 
approach to acute thoracolumbar spine injury.  J  
Emerg Med 1997;15(1):49-60.
     10.  Saboe LA, Reid DC, Davis LA, et al.  Spine 
trauma and associated injuries.  J Trauma 

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Web Page Author:
Loren Yamamoto, MD, MPH
Professor of Pediatrics
University of Hawaii John A. Burns School of Medicine