Emerg Radiol DOI 10.1007/s10140-015-1330-9
CASE REPORT
Core curriculum illustration: pediatric traumatic spondylolisthesis of the axis Nupur Verma 1 & Steven H. Mitchell 2 & Ken F. Linnau 1
Received: 2 June 2015 / Accepted: 9 June 2015 # American Society of Emergency Radiology 2015
Abstract This is the 16th installment of a series that will highlight one case per publication issue from the bank of cases available online as part of the American Society of Emergency Radiology (ASER) educational resources. Our goal is to generate more interest in and use of our online materials. To view more cases online, please visit the ASER Core Curriculum and Recommendations for Study online at http://www. aseronline.org/curriculum/toc.htm Keywords Traumatic spondylolisthesis . Axis . C2 . Hangman’s fracture . Pediatric spine
History A 5-year-old boy was a restrained back seat passenger in a head-on collision with a tractor trailer. Front seat occupants, including his mother, expired at the scene. Patient was reported to have had two episodes of apnea en route for which he was intubated by emergency medical services (EMS).
dilated pupils. He is given mannitol 25 g intravenously for presumed elevated cerebral pressure, and subsequently his pupils are again reactive. He moves all extremities to noxious stimuli. Abrasions from the vehicle restraint device are present over his chest and abdomen. Computerized tomography (CT) of the cervical spine shows widening of the C2-3 disc space and bilateral facet joints consistent with distraction injury (Fig. 1). There is also 3 mm of anterolisthesis of C2 over C3 (Fig. 2). No fracture of the C2 pars articularis is present. Magnetic resonance (MR) of the cervical spine shows high signal on fluid sensitive sequence between the C2 and C3 level with transverse disruption of the posterior disk space and posterior ligamentous injury. There is also a hemorrhagic anterior cervical epidural fluid collection (Fig. 3). Additional posterior ligamentous injury is seen at the C4-C5
Findings At arrival to the hospital, his blood pressure is 109/69, heart rate is 109 beats per minute, and he has fixed and * Nupur Verma [email protected] 1
Department of Radiology, University of Washington, 325 Ninth Ave, Box 359728, Seattle, WA 98104, USA
2
Division of Emergency Medicine, Department of Medicine, University of Washington, Seattle, WA 98104, USA
Fig. 1 Coronal CT image of the cervical spine shows widening of bilateral facet joints at C1-2 consistent with distraction injury (arrows)
Emerg Radiol
Discussion
Fig. 2 Median sagittal CT reconstruction image shows anterolisthesis of C2 in relation to C3 and widening of the C2-3 disk space (arrow). The C2-3 interspinous distance is abnormally increased
level with a thin posterior fluid collection which extends inferiorly from C2 to the thoracic spine. CT angiogram of the neck vessels was performed and shows no vascular injuries. CT of the abdomen and pelvis showed high attenuation free fluid in the dependent pelvis, which on laparotomy was found to be the result of small bowel injury.
Fig. 3 T2 weighted sagittal MR image of the cervical spine shows high signal between the C2 and C3 level at the disk space and posterior longitudinal ligament disruption (arrow). There is pre-cervical hemorrhagic fluid (arrowhead). Additional posterior ligamentous injury is seen at the C4-C5 level with high signal in the posterior elements (asterisk)
Traumatic spondylolisthesis of the axis is an uncommon injury in children. It is often described as a Bhangman’s fracture^; however, this term is most commonly reserved for injuries which include fractures of the pars interarticularis of C2 [1]. The most common cause of traumatic spondylolisthesis in pediatric patients is motor vehicle crashes and falls [2]. Before the age of 10 years, the pediatric spine has a more cranial pivot point, horizontal orientation of the facets, and ligamentous hyperflexibility that results in different patterns of injury in children than in adults [1, 2]. Younger children more often suffer injury to the upper cervical spine with greater neurologic injury and fewer fractures, requiring high index of suspicion on imaging [2]. Diagnosis of traumatic spondylolisthesis in the upper cervical spine is complicated by pseudosubluxation that may be seen due to the hyperflexibility of the pediatric spine [2]. Pseu dosubluxation re presents m ild physiologic anterolisthesis in the upper cervical spine with flexion which can be misdiagnosed as ligamentous injury. Pseudosubluxation should be considered if anterolisthesis is 2 mm or less and if it reduces fully on extension [2]. Clinical features in blunt trauma which have been shown to be predictive of cervical injury are unique in the pediatric population and include altered mental status, neurologic deficits, torticollis, neck pain, major concomitant traumatic injuries to the torso, predisposing conditions, and trauma as the result of high-risk motor vehicle crash and diving [3]. Predisposing conditions in pediatric patients that increase the risk of cervical injury include Ehlers-Danlos, Marfans, and Klippel-Feil syndromes, achondrodysplasia, mucopolysaccharidosis, osteogenesis imperfecta, rickets, and previous cervical spine injury or surgery [3]. Careful imaging in cases with high clinical suspicion or risk factors is necessary. In cases of negative radiographic and CT exams, the rare syndrome of spinal cord injury without radiographic abnormality (sometimes referred to as SCIWORA) of the vertebral column may be present [2, 3]. In the setting of high cervical spine trauma imaging of the cerebral vessels with CT angiogram should be performed to assess for vascular injury. Traumatic spondylolisthesis of the axis is most often a stable injury often presenting with mild or no neurological deficits [2]. It is most often treated with ambulatory immobilization or halo vest [4]. The presence of ligamentous injury, as in this case, increases the risk for instability and most often the treatment is C2-C3 anterior cervical diskectomy and fusion or posterior fixation [2, 4].
Emerg Radiol
In summary, it is important for emergency radiologists to recognize the unique clinical risk factors of cervical spine injury in the pediatric patient and the higher incidence of purely ligamentous trauma. Prompt imaging workup and diagnosis, including CTA of the neck vessels and MR of the cervical spine, allow for expeditious surgical consultation and minimization of neurological deficits.
Conflict of interest The authors declare that they have no competing interests.
References 1.
McGrory BJ, Klasse RA, Cha EY et al (1993) Acute fractures and dislocations of the cervical spine in children and adolescents. J Bone Joint Surg Am 75(7):988–995 2. Klimo P, Ware ML, Gupta N et al (2007) Cervical spine trauma in the pediatric patient. Neurosurg Clin N Am 18(4):599–620 3. Leonard JC, Kuppermann N, Olsen C et al (2011) Pediatric Emergency Care Applied Research Network. Factors associated with cervical spine injury in children after blunt trauma. Ann Emerg Med 58(2):145–155 4. Bransford RJ, Alton TB, Patel AR et al (2014) Upper cervical spine trauma. J Am Acad Orthop Sur 22(11):718–729
CASE REPORT
Core curriculum illustration: pediatric traumatic spondylolisthesis of the axis Nupur Verma 1 & Steven H. Mitchell 2 & Ken F. Linnau 1
Received: 2 June 2015 / Accepted: 9 June 2015 # American Society of Emergency Radiology 2015
Abstract This is the 16th installment of a series that will highlight one case per publication issue from the bank of cases available online as part of the American Society of Emergency Radiology (ASER) educational resources. Our goal is to generate more interest in and use of our online materials. To view more cases online, please visit the ASER Core Curriculum and Recommendations for Study online at http://www. aseronline.org/curriculum/toc.htm Keywords Traumatic spondylolisthesis . Axis . C2 . Hangman’s fracture . Pediatric spine
History A 5-year-old boy was a restrained back seat passenger in a head-on collision with a tractor trailer. Front seat occupants, including his mother, expired at the scene. Patient was reported to have had two episodes of apnea en route for which he was intubated by emergency medical services (EMS).
dilated pupils. He is given mannitol 25 g intravenously for presumed elevated cerebral pressure, and subsequently his pupils are again reactive. He moves all extremities to noxious stimuli. Abrasions from the vehicle restraint device are present over his chest and abdomen. Computerized tomography (CT) of the cervical spine shows widening of the C2-3 disc space and bilateral facet joints consistent with distraction injury (Fig. 1). There is also 3 mm of anterolisthesis of C2 over C3 (Fig. 2). No fracture of the C2 pars articularis is present. Magnetic resonance (MR) of the cervical spine shows high signal on fluid sensitive sequence between the C2 and C3 level with transverse disruption of the posterior disk space and posterior ligamentous injury. There is also a hemorrhagic anterior cervical epidural fluid collection (Fig. 3). Additional posterior ligamentous injury is seen at the C4-C5
Findings At arrival to the hospital, his blood pressure is 109/69, heart rate is 109 beats per minute, and he has fixed and * Nupur Verma [email protected] 1
Department of Radiology, University of Washington, 325 Ninth Ave, Box 359728, Seattle, WA 98104, USA
2
Division of Emergency Medicine, Department of Medicine, University of Washington, Seattle, WA 98104, USA
Fig. 1 Coronal CT image of the cervical spine shows widening of bilateral facet joints at C1-2 consistent with distraction injury (arrows)
Emerg Radiol
Discussion
Fig. 2 Median sagittal CT reconstruction image shows anterolisthesis of C2 in relation to C3 and widening of the C2-3 disk space (arrow). The C2-3 interspinous distance is abnormally increased
level with a thin posterior fluid collection which extends inferiorly from C2 to the thoracic spine. CT angiogram of the neck vessels was performed and shows no vascular injuries. CT of the abdomen and pelvis showed high attenuation free fluid in the dependent pelvis, which on laparotomy was found to be the result of small bowel injury.
Fig. 3 T2 weighted sagittal MR image of the cervical spine shows high signal between the C2 and C3 level at the disk space and posterior longitudinal ligament disruption (arrow). There is pre-cervical hemorrhagic fluid (arrowhead). Additional posterior ligamentous injury is seen at the C4-C5 level with high signal in the posterior elements (asterisk)
Traumatic spondylolisthesis of the axis is an uncommon injury in children. It is often described as a Bhangman’s fracture^; however, this term is most commonly reserved for injuries which include fractures of the pars interarticularis of C2 [1]. The most common cause of traumatic spondylolisthesis in pediatric patients is motor vehicle crashes and falls [2]. Before the age of 10 years, the pediatric spine has a more cranial pivot point, horizontal orientation of the facets, and ligamentous hyperflexibility that results in different patterns of injury in children than in adults [1, 2]. Younger children more often suffer injury to the upper cervical spine with greater neurologic injury and fewer fractures, requiring high index of suspicion on imaging [2]. Diagnosis of traumatic spondylolisthesis in the upper cervical spine is complicated by pseudosubluxation that may be seen due to the hyperflexibility of the pediatric spine [2]. Pseu dosubluxation re presents m ild physiologic anterolisthesis in the upper cervical spine with flexion which can be misdiagnosed as ligamentous injury. Pseudosubluxation should be considered if anterolisthesis is 2 mm or less and if it reduces fully on extension [2]. Clinical features in blunt trauma which have been shown to be predictive of cervical injury are unique in the pediatric population and include altered mental status, neurologic deficits, torticollis, neck pain, major concomitant traumatic injuries to the torso, predisposing conditions, and trauma as the result of high-risk motor vehicle crash and diving [3]. Predisposing conditions in pediatric patients that increase the risk of cervical injury include Ehlers-Danlos, Marfans, and Klippel-Feil syndromes, achondrodysplasia, mucopolysaccharidosis, osteogenesis imperfecta, rickets, and previous cervical spine injury or surgery [3]. Careful imaging in cases with high clinical suspicion or risk factors is necessary. In cases of negative radiographic and CT exams, the rare syndrome of spinal cord injury without radiographic abnormality (sometimes referred to as SCIWORA) of the vertebral column may be present [2, 3]. In the setting of high cervical spine trauma imaging of the cerebral vessels with CT angiogram should be performed to assess for vascular injury. Traumatic spondylolisthesis of the axis is most often a stable injury often presenting with mild or no neurological deficits [2]. It is most often treated with ambulatory immobilization or halo vest [4]. The presence of ligamentous injury, as in this case, increases the risk for instability and most often the treatment is C2-C3 anterior cervical diskectomy and fusion or posterior fixation [2, 4].
Emerg Radiol
In summary, it is important for emergency radiologists to recognize the unique clinical risk factors of cervical spine injury in the pediatric patient and the higher incidence of purely ligamentous trauma. Prompt imaging workup and diagnosis, including CTA of the neck vessels and MR of the cervical spine, allow for expeditious surgical consultation and minimization of neurological deficits.
Conflict of interest The authors declare that they have no competing interests.
References 1.
McGrory BJ, Klasse RA, Cha EY et al (1993) Acute fractures and dislocations of the cervical spine in children and adolescents. J Bone Joint Surg Am 75(7):988–995 2. Klimo P, Ware ML, Gupta N et al (2007) Cervical spine trauma in the pediatric patient. Neurosurg Clin N Am 18(4):599–620 3. Leonard JC, Kuppermann N, Olsen C et al (2011) Pediatric Emergency Care Applied Research Network. Factors associated with cervical spine injury in children after blunt trauma. Ann Emerg Med 58(2):145–155 4. Bransford RJ, Alton TB, Patel AR et al (2014) Upper cervical spine trauma. J Am Acad Orthop Sur 22(11):718–729
