History and Physical Examination
Patients with C1 (atlas) fractures customarily present with a history of trauma and a symptom of pain in the neck. Among the massive number of patients who qualify as having this history and symptom, a few patients have an unstable C1 injury and may present in a neurologically intact state, but they are at grave risk for neurologic compromise if not promptly diagnosed and appropriately stabilized and treated.
Patients with a complete spinal cord injury (SCI) and no neurologic function continue to have only sensation on the face and motor control of the facial muscles from the cranial nerves. A tracheostomy is essential; the patient requires respiratory assistance and a volume respirator. If the C3-C5 area is intact, the phrenic nerve may often be stimulated to contract the diaphragm. If stimulation of the phrenic nerve does not contract the diaphragm, then the spinal cord is no longer functioning; the cell body is dead, and a phrenic electrical stimulator is not effective.
Classification
The Gehweiler classification is commonly used to categorize C1 fractures. This sytem divides fractures of the atlas into the following five types [14] :
-
Fracture of C1 ring may result in lateral displacement and subsequent overhang on open-mouth view in radiographs.
-
Computed tomography is often best for visualizing C1 ring fractures. Note anterior disruption, which must be accompanied by another break in ring.
-
Computed tomography sagittal views can be used to evaluate atlantodental (or atlantodens or atlas-dens) interval or to visualize C1 fractures.
-
Sagittal reformat of CT cervical spine showing posterior displacement and chronic nonunion of the dens.
-
Bilateral posterior arch fractures in the axial plane of the CT cervical spine in the same patient after a second fall.
-
Lateral radiograph after C1-2 posterior fusion.
-
AP radiograph showing hybrid C1-2 posterior fixation with bilateral C1 screws and right sided C2 pedicle screw with a left to right intralaminar or translaminar C2 screw.
-
Lateral radiograph after posterior C1-2 fusion.
