·         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