· Burst fracture of the ring of C1
· Typically caused by an axial-loading force on the occiput of the head
· Classically, it involves fractures of the anterior arch of C1 on both the right and left sides and the posterior arch of C1 on both the right and left sides (4 fractures)
o But fracture variants may include two or three-part fractures
· There is usually no associated neurologic deficit as the ring of C1 widens when it fractures limiting cord compression
· Mechanism
o Original description in 1920 by Sir Geoffrey Jefferson, an English neurologist and neurosurgeon, in “Fracture of the atlas vertebra: report of four cases, and a review of those previously recorded that appeared in the British Journal of Surgery
o He described the role of axial compression
§ Today, this most frequently occurs when diving into shallow water, the head strikes an obstacle (or the bottom of the pool) and the force is transmitted to the cervical spine
§ It may also occur from motor vehicle accidents in which the head is thrown forcefully against the windshield, frequently producing both hyperextension and compression
§ Another mechanism is falling onto the head from a height
· Associated injuries
o Approx 1/3 of Jefferson fractures are associated with a fracture of C2
· Clinical findings
o Patients usually complain of upper neck pain following trauma
o Neurological examination is usually normal
· Imaging findings
o Conventional radiography
§ Open-mouth (odontoid) view is the most revealing
· Classically there is bilateral, lateral offset of C1 on C2
§ Lateral view:
· May show prevertebral soft tissue swelling anterior to C1
· Pre-dentate space (distance between the anterior tubercle of C1 and the dens) may be widened to greater than 3 mm if there is damage to the transverse ligament
o CT Scan
§ Demonstrates the number of fractures, their locations and degree of displacement of fragments
· Treatment
o Depends in part on whether there is damage to the transverse ligament and the degree of offset of C1 on C2
§ Treatments include collar or brace for 3 months all the way through cranial traction
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