Atlanto-occipital dissociation (Traynelis type 1), C2 teardrop fracture, C6/7 facet joint dislocation

The head is rotated to the right. Even allowing for this, there is subluxation of the atlanto-occipital articulations bilaterally. On the right, the occipital condyle is impacted against the right lateral mass of C1, with fractures of both articular surfaces. Fracture arising from the right occipital condyle is mildly displaced medially. On the left, there is impaction without definite fracture line or displaced fracture fragments.

Triangular fracture arising from the anteroinferior aspect of C2, with up to 7 mm anterior fracture displacement into the prevertebral soft tissues. There is slight retropulsion of C1 on C2. The right C2/C3 facet joint is mildly widened.

Small density at the posterior aspect of the C4/C5 disc is likely longstanding.

Grade 1 anterolisthesis of C6 on C7, with uncovering of the C6/C7 disc. Unilateral subluxation of the right C6/C7 facet joint. Bilateral intra-articular fractures of the inferior articular surfaces of C7.

The posterior longitudinal ligament is elevated between C1 to C7, with mildly reduced AP dimension of the cervical canal at C6/C7.

Impression

• Bilateral atlanto-occipital subluxation (Traynelis type 1) with impaction, with displaced fracture fragment on the right.
• Teardrop fracture of the C2 vertebral body, with widening of the right C2/C3 facet joint.
• Unilateral right C6/C7 facet joint dislocation, with fractures of the C6 inferior articular processes bilaterally. Anterolisthesis of C6 on C7 with uncovering of the intervertebral disc.
• Elevation of the posterior longitudinal ligament between C1 and C6.