pediatric spine trauma antwerp spine 2015final ......30/03/2015 1 lund university / faculty of...

30/03/2015

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Lund University / Faculty of Medicine / Department of Clinical Sciences / Radiology / Spine Antwerp/ 2015

Pediatric Spine Trauma- relevant and non-relevant imaging

findings and its mimicks -

Prof. Pia C Sundgren MD, PhD

Department of Diagnostic Radiology, Clinical Sciences, Lund University, Sweden


Lay-out

background

normal variants and mimics

traumatic spine injuries

stress injuries


injury to the spinal column and spinal cord is the major cause of disability, affecting predominatelyyoung healthy individuals

spinal cord injuries are rare in infants and children (1-2% of all pediatric trauma victims)

the type of injuries is slightly different in the pediatric population compared to adults

Introduction to traumatic spine and spinal cord injury


Cause < 3 years2 1-20 years1 overall

Motor vehicle 66% 44% 47.7%

Fall 15% 14% 20.8%

Pedestrian 11%

Bicycle 6%

Violence 14.6%

Sports 16% 14.2%

Spinal trauma and spinal cord injury

1Kokoska E et al. Characteristics of pediatric… J. Ped. Surg. 2001:36;100-105 (408 cases (+))2Polk-Williams A et al. Cervical spine injury…. J. Ped. Surg. 2008:43;1718-1721 (1523 cases (+))



< 8 years of age 50% in C1-C2 (-C3) region

incidence of dislocations

incidence of cord injuries

> 8 years of age shift towards C5 and below

- C-spine fractures

mortality rates 17% (overall), higher in small children



2Polk-Williams A et al. Cervical spine injury…. J. Ped. Surg. 2008:43;1718-1721 (1523 cases (+))

Children < 3 years of age

• injury to upper cervical spine C1-C4

47% cord injuries and 53.4% spine fractures

• injury to lower cervical spine C5-C7

53% cord injuries and 46.6% fractures

• most common sites:C2 (26.5%), followed by C7 (18.5%)

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increased flexibility of the cervical spine due to:

incomplete ossifications of the vertebral bodies

ligament laxity

incomplete development of the spinous process

increased head-to-torso ratio

week cervical musculature

cervical spine injuries at higher levels



Misdiagnosis of acute cervical spine injuries

< 8 years of age 24%> 9 years of age 15%

most common site of diagnostic error is the occiput to C2 region

predisposing factors for misdiagnosis:• unfamiliarity with pediatric cervical spine anatomy• not recognizing normal variants• suboptimal technique

Avellino AM et al The misdiagnosis of acute cervical spine injuries.. Childs Nerv system2005;21;122-127. (37 cases)


wedged vertebral bodies ossification congenital non-union

Pediatric spine - normal variants/findings

non calcified apophysis

Distance between atlasand dens:child < 4.5 mmadult 3 mm


Normal spine in infants and children

wedge-shaped vertebralbodies C2-C7


• normal developmental anatomy that may mimic trauma:

• ossification tip of dens (completes 3-6y)

incomplete ossification of tip of dens mimics increased distance C2-occiput


Courtesy Prof T Huisman


• normal developmental anatomy that may mimic trauma:

– secondary ossification centers

• unfused ring apophyses (normal physis are smooth with subchondral sclerotic lines)

Lustrin ES, et al. Radiographics 2003; 23: 539-560



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Synchondroses (symmetrical, expected location)



3 year old girl in high speed MVASynchondros or fracture?

Lund University / Faculty of Medicine / Department of Clinical Sciences / Radiology / Spine Antwerp/ 2015 Lund University / Faculty of Medicine / Department of Clinical Sciences / Radiology / Spine Antwerp/ 2015

6 month FU the fracture has healed


Typical spine injuries in children

the classsic ones: odontoid fracture, subluxation

cranio-cervical dislocation or disassociation

Chance fracture (“seatbelt injury”, especially in thoracic spine)

SWICORA

always look for ligamentous injury

NOTE: always look for more (common with multiple injuries)


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T1-w T2-w PD

Axial T2-wLund University / Faculty of Medicine / Department of Clinical Sciences / Radiology / Spine Antwerp/ 2015

C 5

C 5

C 6


C4

C5

C6Lund University / Faculty of Medicine / Department of Clinical Sciences / Radiology / Spine Antwerp/ 2015

Complex of occipital-atlanto-axial dislocation

occipital condyle is small, almost horizontal and lacks inherent stability

severe hyperextension w/wo distraction- rupture transverse lig. of the dens -

• anterior translation (hypereflextion)• posterior translation (hyperextension)• longitudinal

incomplete – subluxationcomplete – dislocation/disassociation

atlanto-occipital condyle distance > 5mm


Odontoid fracture + C0/C1 dislocation

always multiplanar reconstructions


Asymmetrical dislocation

CT underestimates the degree of soft tissue injury

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Vertebral bodies change shape on follow up !!Developing skeleton

Asymmetrical dislocation


Consider the complex when

- distance odontoid process and the basion > 12 mm

- occipital condyles and atlas > 5mm

- Wackenheim line does not touch the tip of the odontoid process

- joint widening on CT and joint fluid on MRI

Complex of occipital-atlanto-axial dislocation


Occipital-atlanto-axial dislocation


Craniocervical distraction injury

CT sag CT sag CT cor

CT upon admission


MRI upon admission

T1 sag T2 corT2 sag




MRI 6 days later

T1 sag T2 corT2 sag

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T2 stir

MRI 6 days later


Spinal cord injury without radiographic abnormality

- SCIWORA -

specific to children and extremely rare in adults

incidence: 19-34% of all spinal cord injuries in children

more common in younger children < 8 years of age

can have delayed onset of clinical symptoms and signs up to 4 days after initial injury

recurrent SCIWORA several days to weeks afterinitial event (17%)


• immature and elastic pediatric spine• vulnerable to external forces• allows for significant inter-segmental movement• transient disc protrusion

compression and stretching of the spinal cord

cord injury

Spinal cord injury without radiographic abnormality

- SCIWORA -


The elasticity of neonatal bony spine is eight times that of the cord

Biomechanics in children

5cm

6/7 mm

Leventhal H. J. Pediatr 56:447 1969 Courtesy Dr M Gallucci, Italy


SCIWORA

Courtesy Dr M Gallucci, Italy


SCIWORA

Courtesy Dr M Gallucci, Italy

4 month later

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2 year old boy in high Speed MVA

Courtsey Dr M Castillo, Chapel Hill, USA

SCIWORA


3 year old in MVA

SCIWORA


T2-wSTIRT1-w


horizontal splitting of the neural arch and vertebral body

- flexion-distraction of the spine - high energy motor vehicle accidents

- often in thoracolumbar junction

- transition from rigid to mobile area

- change of intervertebral facet orientation (cor > sag)

- going from kyphotic to lordotic spine curve

Chance fracture


Chance fracture

- failure of the interspinous ligaments at flexion- anterior axial loading- burst fracture of the vertebral body- widening of spinous processes

in adolescent spine:- fracture line through the physeal plate

(never through disc)in adult spine:

- fracture line through the intervertebral disc/ vertebral body

Courtesy Dr J Schneider, BaselLund University / Faculty of Medicine / Department of Clinical Sciences / Radiology / Spine Antwerp/ 2015

Alar and transverse ligaments

Ligamentous injury

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Tectorial membrane injury

hematoma


tectorial membrane

Ligamentous injury and retroclival hematoma

always use soft tissue algorithm (CT)


Plexus injury

methemoglobin

Day 4

Day 14

pseudomeningocele


Spondylolysis / spondylolisthesis

• decfects in pars interarticularis due to stress fracture stress reaction to isthmus (the weakest part )

• anterior or posterior displacement (slip) of a vertebra or vertebral column in relation to the vertebrae below

• most common L5 in relation to S1

• due to congenital defect (?), micro-trauma (sports),degenerative changes (elderly)


Natural history and symptoms• majority (66%) of asymptomatic pars interarticularis defects occur before 12 years of age

• only 13% become symptomatic (Fredrickson study - followed 500 kids for 20 years)

• spondylolysis and -olisthesis are seen with equal frequencyin asymptomatic as in symptomatic patients

• the degree of forward slip is not correlated with the degreeof pain or disability

symptoms: low back pain worsened with activity, reduced range of motion, numbness, weakness ofleg due to nerve compression

Fredrickson BE The natural history of spondylolysis.. J Bone Joint Surg 1984Beck RW et al Radiographic anomalies … j Manipulative Physiol Ther. 2004Libson E et al Symptomatic and asymptomatic … Int Orthop. 1982


Widening of the spinal canalChange in contour due to -olisthes

Courtesy of M Annertz, Lund, Sweden

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15 year old boy with back pain, no known trauma, decreased football practice!

Rt Lt

Courtesy of M Annertz, Lund, Sweden


Rt


Rt Lt

Pseudoarthros


Summary

• important to have good knowledge about- pediatric spine anatomy- variants

• good quality images

• restrictive with CT in small children (radiation)

• liberal with MRI

• high incidence of dislocations and cord injury (<10 yrs)

• important to have good knowledge about- pediatric spine anatomy- variants

• good quality images

• restrictive with CT in small children (radiation)

• liberal with MRI

• high incidence of dislocations and cord injury (<10 yrs)


Thank you

pediatric spine trauma antwerp spine 2015final ......30/03/2015 1 lund university / faculty of...

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