I will briefly provide some definitions here for those of you, including my self, retrospectively, that might have been lost along the way.
Odontoid process, or dens, is a toothlike piece of the axis (C2) which projects into the atlas (C1) anteriorly (toward the inner part of the body) and is, though not attached to C1, the bone responsible for the majority of its movement.
It is easy now to see and understand why the procedure I had is called a Posterior atlanto-axial Arthrodesis. Posterior is rear, atlanto and axial are the atlas and axis respectively, and arthrodesis is the artificial joining of bone as would be done my surgical methods.
My MRI showed an old type II odontoid fracture which left my odontoid practically non-existent as the doctors have since advised. Because the odontoid controls (for lack of a better word) the movement of C1, which bears the weight of the skull (think of the Greek Atlas holding the weight of the globe on his shoulders), the tranverse ligaments have been holding my skull in place. These are two ligaments that run parallel to each other on opposite sides of the odontoid process and connect to the skull and C2. Each vertebrae has similar ligaments. I thought if they were supporting my skull for so long, they must have only become stronger over time. The opposite is true. In fact, from bearing the load of my skull, they have actually stretched and weakened.
Without the odontoid holding the atlas, or C1, in place, C1 wandered on it?s own as my head was flexed and extended. Either direction, the atlas rested on my spinal cord, basically fraying it and causing the condition of myelomalcia (spoken of on the other page).
The purpose of the surgery was to add stability to the spine, targeting the atlas. The atlas would need to be attached to the axis to prevent it from further rupturing the spinal cord which eventually would have frayed it until it was severed. Two 3.5" transarticular screws were drilled and fitted through the bottom section of C2 and bored through C1, bonding them together while the graft of bone taken from my hip fused itself to the two vertebrae, ultimately forming one solid bone out of C1 and C2, thus eliminating the lack of stability and the chance of future damage to my spinal cord which the previous condition had begun to cause. The halo placement is necessary to not only completely immobilize the cervical spine, but to transfer the weight of the head from the atlas to the chest and back, eliminating any pressure from resting on the spine and allowing it to heal. Despite what that cute little kid in "Jerry Maguire" said, my head actually weighs closer to 15 pounds, not eight.
The shortest way of wording the results of my injury is: I fractured C2 and dislocated C1.
Hope this solved any left over questions as far as the injury and procedure go.
