Jefferson Fracture

Pseudo Jefferson fracture, or pseudo spread of the atlas on the axis, can be seen on the open mouth radiographs. The ossification of the lateral masses of Cl in young children often exceeds that of C2. The lateral masses of the atlas therefore may overhang the axis by as much as 6 mm and is commonly seen in children less than 4 years of age and maybe seen up to 7 years of age. 

If symptoms of interruption of the vertebro-basilar circulation are present e.g., in cases of Jefferson fracture) vertebral angiography is mandatory. In severe subluxation of the atlanto-occipital joint damage to the vertebral artery is rather common. 

The lateral masses of Cl and C2 may be offset bilaterally in young children so that the lateral masses of Cl overhang those of C2 on the AP view, simulating a Jefferson burst fracture. This phenomenon is thought to be secondary to disparity in growth rate between the two vertebra and is most commonly... 

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