Case 19 – Spinal Fracture
A 42 year old surfer presents to your clinic following a neck injury. He was riding a wave in, lost his balance into the wave, getting thrown head first into the sand. He manages to get ashore and is driven home. He presents the following day to your clinic the following day with severe neck pain.
On exam, no bruising of swelling. He has a restricted range of motion. There is no neurological deficits or spinal muscle tenderness. He has midline tenderness in his upper cervical vertebrae. So you put him in a collar, immobilize his cervical spine and arrange for transfer to the emergency department, a CT of his cervical spine is arranged.
Figure 1: CT coronal view of the cervical spine. The radiograph shows a fracture of the atlas right lateral mass.
Figure 2: CT Sagital view of the cervical spine showing a lateral mass fracture.
Figure 3: CT Axial view of the atlas. The plain radiograph shows a right lateral mass fracture.
The atlas, or C1 vertebra, sits just inferior to the occiput and superior to the axis (C2 vertebra). It articulates with the occiput condyles and the axis to allow for head and upper spine vertical and lateral mobility. The atlas does not have a vertebral body and instead consists of posterior and anterior arches that encircle the spinal cord (see figure 4). The atlas also has two lateral masses with articular surfaces that match the condyles of the occiput, forming the occipito-cervical articulations which join the skull to the spine. The atlas articulates with the axis, via a facet on the anterior ring of the atlas, which is maintained by the transverse ligament, and provides the head with lateral rotation.
Atlas fractures account for 2-13% of acute injuries to the cervical spine and 1-2% of all spinal cord injuries. Injuries to the atlas often involve traumatic axial load to the upper cervical spine. Commonly, patients with injury to the atlas have sustained an injury through diving into shallow water, falling or a motor vehicle accident. Patients present with the symptom of neck pain following a history of trauma.
Radiographs such as plain films or CT can be used to diagnose an isolated fracture, while MRI can identify ligamentous injury most effectively. Without MRI, there are ways to identify ligamentous injury. Lateral displacement of more than 7mm on open-mouth view radiographs is indicative of ligamentous injury. Also, a atlanto-dens interval (ADI), defined as the distance between the atlas and the dens, greater than 3mm is indicative of ligamentous injury.
Once an atlas fracture has been identified, it can be classified into one of three types. Type 1 fractures, considered stable, are isolated to the anterior or posterior arch. Type 2 fractures, also known as Jefferson fractures and are considered unstable, are characterized by bilateral fractures of the anterior and posterior arch. Type 3 fractures involve the lateral mass.
Diagnosis: C1 lateral mass fracture.
Nonsurgical management was recommended in this case. External immobilization of the craniocervical junction and upper cervical spine using a rigid collar is recommended and should be worn for 8-12 weeks (see figure 5). Neurosurgical consultation was obtained, along with follow up. Also, patient should take Vitamin D 2000 units daily.
Figure 4: The bone anatomy of C1 and C2.
Figure 5: Aspen Collar – Rigid neck collar used to immobilize the craniocervical junction and upper cervical spine.
Author Lucas Nugyen Oct 17, 2018 (PRND)