Spine



Spine


Vidyadhar Upasani

Burt Yaszay

Peter Newton



INTRODUCTION

Pediatric spine fractures are rare with only 5% of all spinal cord and vertebral column injuries occurring in children age 16 and under. Although uncommon, spine fractures in children can lead to deformity, instability, and potentially neurologic sequelae. An extra measure of vigilance is called for in evaluating spine injuries because both the clinical and initial radiographic findings can be subtle. Successful treatment is based on knowledge of the radiographic, anatomic, and developmental differences between the pediatric and adult spine.


Etiology

The location, pattern, and etiology of a child’s spine fracture is primarily dependent on the patient’s age at the time of injury (Table 18-1) with birth trauma and child abuse being the most common reason for spinal injury in children under age 2 years. In patients between the ages of 2 and 8 years, the most frequent mechanisms of injury are
falls, motor vehicle accidents and child abuse. Children older than 8 years of age are more commonly injured in motor vehicle accidents, sports, and even gunshot wounds.

“What people want is not knowledge but certainty”

Bertrand Russell








Table 18-1 Spine Fractures in Children (United States)


















Age


Most Common Causes


0-2 years


Birth trauma


3-8 years


Falls, MVA, child abuse


8 years and older


MVA, sports (swimming, diving, surfing), gunshot wounds



MVA, Motor vehicle accident.



Level of Injury

The majority of spinal column fractures in childhood occur in the thoraco-lumbar spine. Cervical spine fractures in patients age 8 years or younger commonly involve the upper cervical spine (above C4), most often involving the occiput—C1-C2 complex and are potentially fatal. Patients older than 8 more typically sustain injures below C4 with a much lower fatality rate.


Applied Anatomy

The patterns and types of spine injuries seen in children reflect unique age-related features of the developing spine.

In children less than 8 years of age, anatomic factors place the upper cervical spine at greater risk for injury. These include the relatively large head size compared to the body, increased ligamentous laxity, relative strap muscle weakness, and horizontal, shallow facet joints. In addition, there is increased spinal column elasticity as compared to older children and adults. Injuring forces are dissipated over several adjacent motion segments at times exceeding the elasticity of the spinal cord itself. Spinal cord injury without radiographic abnormality (known by the acronym SCIWORA) can occur resulting in both subtle and severe neurologic abnormalities. An urgent magnetic resonance imaging (MRI) study is required to identify pathology.

Equally perplexing to the uninitiated are several normal developmental features that can be misinterpreted as evidence of injury to the spine. Lateral C-spine views in children under age 2 years may be hard to interpret because the anterior ring of the C1 vertebra has not yet ossified. Thus, the dens-C1 interval cannot be measured. The den-to-central synchondrosis of C2, appearing as a lucent line below the level of the body-dens interface, does not usually fuse until about age 6 years and may be over-interpreted as an odontoid fracture.

Absence of the characteristic normal cervical lordosis with the presence of frank kyphosis is seen in up to 14% of patients less than age
8 years. This can be misinterpreted as representing injury with related muscle spasm. Os odontoideum, thought to represent either a failure of fusion of the top of the dens to the body of C2 or non-union of an occult fracture, can be difficult to distinguish from an acute fracture. Further evaluation of these patients with advanced imaging should be undertaken if this condition is identified on screening trauma radiographs, as fixation or upper cervical fusion may be required if true pathology is present.

In infancy, notching of the anterior and posterior vertebral bodies by vascular channels is common and is sometimes confused with a vertebral body fracture. The anterior channel generally disappears by age 1, whereas the posterior notch persists throughout life. Many issues make reading infant neck films problematic (Figs. 18-1, 18-2). In adolescents, the presence of the vertebral body ring apophysis also presents a challenge in diagnosing spinal column fractures because the injuring force can traverse this cartilaginous growth plate, producing deformity that is unrecognizable on plain films. Normal, somewhat wedge-shaped vertebrae can be common up to age 8 years and are distinguished from a compression fracture by noting a similar appearance in the neighboring vertebrae and the absence of associated soft tissue findings.






Figure 18-1 Lateral C-spine view in an infant. The odontoid or dens (green arrow) is identified, but there is no bone noted anterior to it (black arrow). This is because the anterior ring of C1 has not yet ossified.






Figure 18-2 Moderate head tilt and rotation seen in an AP view of the C-spine in an infant with torticollis.

After age 8 the spine begins to mature. The ligaments and facet capsules strengthen, the facets become more vertically oriented and the vertebral bodies become more rectangular. By late childhood, the patterns of spinal injury and healing become similar to the adult.

“By late childhood, the patterns of spinal injury and healing become similar to the adult”







Figure 18-3 Klippel-Feil syndrome includes congenital fusion of 2 or more cervical vertebrae. The AP view is less diagnostic in this case but does show spina bifida occulta at the C7 level.


Further complicating matters include congenital and syndromic conditions that have associated cervical spine manifestations. Klippel-Feil syndrome is characterized by congenital fusion of two or more cervical vertebrae (Fig. 18-3). Given the relative lack of motion segments and resultant longer lever arm within the cervical spine, these patients are thought to be at greater risk for fracture, and a higher level of scrutiny should be given following trauma. This is also true for Down syndrome (trisomy 21) patients whose ligamentous laxity may result in upper cervical instability, potentially causing cervical myelopathy. A careful instability assessment with lateral flexion-extension radiographs should be performed when evaluating injury in these patients.


Initial Evaluation

Evaluating a child with a suspected spinal fracture, ligamentous injury, or spinal cord injury (SCI) depends largely on the setting in which the child is seen. Because the vast majority of pediatric spinal fractures and spinal cord injuries are due to motor vehicle accidents, sports-related injuries and falls. The first orthopaedic evaluation will occur in the emergency department.

Given the increased participation of children in organized sports, a physician may, on occasion, be required to perform an evaluation on the athletic field and to coordinate the safe handling and transport of the potentially spine injured child to a medical facility. On the field, or at the scene of an accident, any children complaining of neck or back pain, or transient/prolonged neurologic symptoms, must be treated as though they have a spinal injury.

Early immobilization will help to prevent further instability or propagation of an SCI. Because the child’s head is relatively large in relation to the body, a spine board with an occipital recess is ideal for transport as this avoids inadvertent neck flexion (Table 18-2). If this is unavailable, any rigid platform with blankets placed beneath the shoulders and trunk will suffice. A pediatric cervical orthosis and sandbags or towels placed on each side of the head will limit further motion. Until the cervical spine is cleared, movement of the patient should only be performed with in-line traction and a logroll technique.

Once the airway, breathing and circulation have been secured, a brief secondary survey can be performed. A brief history in the awake, alert, and cooperative child is important. Any history of numbness, tingling, brief paralysis, or complaint of neck or back pain should alert the physician to the possibility of a spine injury. Physical examination begins with inspection of the body for signs of possible trauma to the spine including obvious or subtle deformity, abrasions, edema, or bruising.

Inspection for abdominal wall ecchymosis suggestive of a lap belt injury is important when evaluating a child involved in a motor vehicle
accident. Pain or step-off along the spinous processes should raise suspicion. Range of motion of the spine should only be attempted in the awake and cooperative child in whom there is no suspicion of an unstable injury.








Table 18-2 Emergency Transport of an Infant with Possible Spine Injury (Herzenberg et al.)














Incorrect


Correct


image


image


image


Straight board


Neck flexed


Hole in board to accommodate head


Neck now straight


Trunk elevated on pad or blanket


Neck now straight



Nov 17, 2018 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Spine
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