· 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
Jefferson Fracture. There is bilateral offset of both the right and left lateral masses of C1 relative to the lateral masses of C2 on the open-mouth cervical spine view (above-white arrows). This indicates a burst-type injury to the ring of C1. A single axial CT scan through the level of C1 shows fractures involving the right and left anterior ring of C1 and the right posterior ring (yellow arrows).
McQs in Orthopedics and Trauma (Revision MCQs)
