Case Presentation by Dr. Jeanise Butterfield
An 18 year old girl was riding her horse when the horse stopped suddenly and put his head down. She slid off the front of her horse landing on the posterior aspect of her left should and neck, rolling onto her back (think somersault). She complains of severe back pain. There is tenderness of the thoracic and lumbar spine diffusely with no neurologic deficits. CT of the cervical spine was within normal limits. Radiographs of the thoracic and lumbar spine are shown below.
1) By mechanism of her injury, which type of spinal column injury do you suspect?
2) Is there deformity visible on radiograph?
c) More information required
3) Which of the following is a stable spinal fracture?
a) Flexion teardrop fracture
b) Unilateral facet dislocation
c) Hangman’s fracture
d) Jefferson fracture
4) If this patient was uncooperative and combative, the following treatment would be appropriate?
a) Have an individual hold patient’s head in alignment with spine
c) Drug induced paralysis
d) All of the above
Answers and Discussion:
Spinal column injuries are classified according to the mechanism of trauma: flexion, flexion-rotation, extension and vertical compression. When assessing stability of a spinal injury (meaning the spinal cord is protected) it is helpful to view the spine as an anterior and a posterior column. The anterior column consists of alternating vertebral bodies, intervertebral disks, anterior and posterior longitudinal ligaments. The posterior column contains the spinal canal, pedicles, transverse processes, articulating facets, laminae and spinal processes with nuchal ligament complex, capsular ligaments and ligamentum flavum. In a very basic sense you can imagine that if both columns are disrupted, the spine will move as two separate entities whereas if only one column is disrupted the other will resist movement. This can only be applied to injuries below C2.
Unstable flexion injuries
– Flexion teardrop fracture: avulsion of anteroinferior corner of a vertebral body by anterior longitudinal ligament causing anterior displacement of a wedge shaped fragment resembling a teardrop. It commonly involves ligamentous disruption and is often associated with neurologic injury. Of note, this can also occur with extension injury (see below).
– Bilateral facet dislocation: Forces of flexion cause disruption anterior to the annulus fibrosis and anterior longitudinal ligament. This causes anterior displacement of the spine above the level of injury as the upper vertebra passes over superior facets of the lower vertebra
– Alanto-occipital dislocation: This occurs more often in children, partly due to larger relative head size and ligamentous laxity, can also occur non-traumatically in Down syndrome and rheumatoid arthritis.
– Odontoid fracture with lateral displacement: need I say more?
– Subluxation is also potentially unstable
Unstable flexion-rotation injuries
– Rotary atlantoaxial dislocation: In trauma, may occur with forced rotation of the neck with some element of lateral tilt. There are several ways this can occur with respect to placement of atlas on axis including rotation on odontoid or on one of the lateral articular process
Unstable extension injury
– Hangman’s fracture: traumatic spondylolysis of C2. Fracture-dislocation of atlas and axis, specifically of pars interarticularis of C2 and disruption of C2-3 junction.
– Extension teardrop fracture: Same as above flexion teardrop fracture, usually occurs in lower cervical vertebra from diving accidents.
– Posterior atlantoaxial dislocation
– Posterior neural arch fracture (C1): results from compression of the posterior elements between occiput and spinous process of the axis during forced extension. This is unstable primarily due to location.
Unstable vertical compression
– Jefferson fracture: Axial loading results in shattering of the ring of the atlas, associated with disruption of transverse ligament.
Always think of spinal injury in patients presenting with trauma, especially motor vehicle collisions, falls from heights and sports related injuries. Obtain radiographs in patients with suspected injury but don’t let distracting injury prevent you from performing complete physical exam and maintain spinal immobilization until spinal injury has been excluded.