Ahn o-T1  

The patient was brought into the Operating Room.  Anesthesia had seen the 

patient.  Preop Decadron was administered 10 mg IV for stress dosing. 

She received preoperative 2 g of IV Ancef along with Cipro for wound prophylaxis 

and UTI prophylaxis. 

She then got a general anesthetic with awake fiberoptic intubation.  Once 

asleep, she was then positioned on the Jackson table supine, Mayfield pins were 

utilized along with the Mayfield adapter.  She was then sandwiched into place 

and the table was rotated prone.  We took the dorsal part of the table off and 

the body was padded as required in all regions of her body including the chest, 

pelvis, legs and arms.  Arms were tucked at the sides. 

We then prepped and draped the occipital and cervical spine in the usual sterile 

fashion.  We dissected open the skin from the occiput all the way down to C7. 

We lifted the muscle off the lamina from C3 down to C6, and we also took muscle 

off the C2 vertebral arch along with the C1 arch very carefully staying away 

from the vertebral artery on the cephalic end.  We exposed the skull also at the 


We then brought in the intraoperative navigation and we clamped onto C3 and we 

registered five points on C2.  We then confirmed our accuracy.  We then further 

refined this with surface matching.  Our error margin was 0.2 mm on the surface 

match combined with the pairwise matching of five points.  We confirmed our 

registrations of C2 by correlating it with well known points on the C2 dorsal 

surface.  Once this was completed, we then cannulated the C2 pedicle on the 

right and left-hand sides. 

We had to avoid the vertebral artery.  As a result, on the one slide we decided 

to place a short 14 mm length screw, however on the other side where we got nice 

clearance above the arch of the vertebral artery, we were able to get an 18 mm 

length 4.0 diameter pedicle screw of C2.  We got excellent bony purchase despite 

her osteopenia from the rheumatoid disease and Prednisone use.  We then drilled 

pilot holes for lateral mass screws using the navigation from C3 down to C6.  We 

then drilled with sequential drilling and drilled 14 mm length screws and tapped 

and inserted appropriate length screws for the lateral masses.  We then applied 

our midline plate and we then ensured that it would be in good position. 

We then proceeded under microscope and we did a high-speed bur of the C1 arch. 

We were careful to stay away from the vertebral artery and we were able to burr 

down the whole arch and the arch was removed for bone graft.  No complications 

occurred.  We then drilled the midline plate onto the bone using sequential 

drilling.  The middle screws on the top end we were able to drill 10 mm length 

screws, 10 x 4.0 mm diameter bone screws were inserted on the north end and 

ventrally we went down to 6 mm.  We were careful to get just past the bicortical 

surface.  No CSF leaks occurred during bone plate insertion.  We then applied 

two rods that were contoured into cervical lordosis to provide her a nice 

cervical arch.  We then placed in our blocking caps and we did our final 

tightening with the torque antitorque.  We then brought in our high-speed bur 

along with the microscope and we drilled two troughs going from C2 all the way 

down to C6 bilaterally.  We then lifted off the laminas bilaterally, and we then 

morselized the bone graft.  We brought in the intraoperative ultrasound.  There 

was a nice cord pulsation and the spinal cord was free of any compression from 

the ventral surface.  We then packed in our bone graft.  We washed the spine out 

thoroughly.  We also burred down the facet joints for spinal fusion from the 

occiput all the way down to C6. 

It was decided to not go all the way down to T2 given that she would have no 

movement whatsoever, especially with her young age of 66. 

We then closed the fascia with a subfascial drain and we then closed the 

subcutaneous layer with 2-0 with deep interrupted stitches followed by a running 

to reinforce it, staples for the skin.  Dressings were applied.  The patient 

tolerated the procedure well.  We applied a collar onto her neck and she was 

then taken out of the Mayfield pins.  She can be activity as tolerated in the 

Aspen collar. 




250 cc. 

Henry Ahn, MD, FRCSC 

University of Toronto 

Spine   Orthopaedic Surgery 

T: 416-864-6005 F:416-864-5340 

cc:   Henry Ahn, MD, FRCSC 

      55 Queen Street East 

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      Toronto ON M5C 1R6