Anatomical Study of the Posterior Ascending Artery: Application to C2 Pedicle Screw Placement

Anatomy of the posterior ascending artery (PAA) has been well documented. The PAA forms an apical arcade, which supplies the small branches to the tip of the dens. However, morphometrics of this artery such as diameter and distance from the midline, which could be applied to the diagnosis and surgical procedure, are scant. We aimed to investigate the anatomy of the PAA in order to apply our findings to surgical procedures such as C2 pedicle screw placement.

Ten sides from 5 Caucasian cadaveric heads in which red latex was injected were used. The origin of the PAA, diameter of the PAA and apical arcade, and the distance from midline were recorded.

Diameters of the PAA and apical arcade were approximately 1 mm and 0.7 mm, respectively. Distance from the midline to the PAA was approximately 7 mm. In 1 specimen, the os odontoideum was observed on top of the dens.

The result of this study could provide anatomic knowledge, which is important for C2 pedicle screw placement to the spine surgeon.