Atypical unstable burst fracture of the atlas. Treated by primary atlantoaxial fusion.

Burst fracture of the atlas with concomitant disruption of the transverse ligament is presented by the author because it demonstrated an atypical fracture pattern on computed tomography that has bearing on the treatment modalities. The integrity of the posterior arch was preserved, except for a fracture in the proximity of one of the lateral masses. The patient underwent a posterior C1-C2 fusion before there was evidence of healing of the posterior arch fracture. The fracture healed, and a good C1-C2 fusion was noted.