Medtronic received information regarding a guidance system being used during a spinal procedure.It was reported that the case was planned and reviewed preoperatively for three vertebrae on levels l2 - l4.The manufacturer's representative noted that screws at l2 would not fit into a single incision with the rest of the trajectories and the surgeon understood.The hover-t platform was chosen for this case based on clinical indication and surgeon preference.Two ap and three oblique images were taken.Automatic registration was successful using advanced algorithm with labeling off of l3.Good values were seen at each level.Four out of six trajectories were achieved successfully.No red screws were seen.The trajectories at left l3 right were not correct.When the surgeon planned the trajectories, he planned them with the screws angled upwards towards the superior endplate of l3.When l3 left and l3 right were sent using the guidance system, the angulation for both was towards the inferior endplate.The surgeon noted this for l3 initially.The surgeon decided to move forward with l4 left and comeback to l3 left.The trajectory for l4 left looked as planned.The trajectory at l3 left was resent and the trajectory was still towards the inferior endplate.The surgeon put a k-wire at l3 left.L2, l3 and l4 right were then sent and k-wires inserted.The same deviated trajectory was seen at l3 right.L2 and l4 left and right were the correct trajectories.No patient harm was reported.
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