Table 1.

Comparison of C2 anatomic variation based on sagittal computed tomography cuts assuming placement of a long pedicle screw.

Analysis	No. of Pedicals at Risk/ Total No. of Pedicles	%
Low risk bilaterally	5/46	11
Moderate risk bilaterally	9/46	20
High risk bilaterally	7/46	15
Low risk/moderate risk	8/46	17
Low risk/high risk	8/46	17
Moderate risk/high risk	9/46	20
Total low risk	26/92	28
Total moderate	35/92	38
Total high risk	31/92	34