AP is anterior/posterior.... the dimensions are the diameter? of the canal in millimeters.
Your C2-3 sounds like my C3-4:
http://www.ispine.org/forum/ispine/6...y-results.html
I'm so sorry that you are experiencing more pain. I have a client who's in the same boat as you after a series of cervical fusions.
Say more about your pain... neck, arm, back? Dull ache? Sharp? Electric? Nerve pain?