Medtronic received information from a healthcare professional (hcp) via a manufacturer representative (rep) regarding a guidance device being used in a spinal procedure. It was reported that the plan for the case was to perform a scan and plan and execute screws at t11, t12, l2, and l3. This was to back up a l1 burst fracture. Once the surgeon exposed the region of interest, the rep suggested using the dual clamp and clamping at t12 and l2 spinous processes. This was to avoid the instability of l1. The dual clamp was placed, 3define performed, snapshot taken and then star marker placed. Due to the size of the patient and height of the dual clamp, it took three spins of the o-arm to achieve registration. Screws were then planned and reviewed with the surgeon.
Thoracic screws were planned between 8-10 degrees off midline to account for any soft tissue problems, with lumbar screws planned slightly more lateral. The rep noted the small pedicles to the surgeon and asked if they would like to adjust to 4. 5mm screws and they opted to keep them at 5. 5mm. The screws were then executed starting with t11 on the right and working down, followed by t11 on the left and working down. Navigation showed all trajectories to be accurate to plan and surgeon was very pleased with how the case was progressing. It was noted that neither rep noticed any soft tissue pressure on any trajectory, and the surgeon was well aware to watch out for this as well. Once all screws were in place however, the surgeon noted that t12 on the right appeared to be slightly medial to corresponding tulip heads. The rep requested that the surgeon take an ap image to confirm that the screw was in fact medial. Imaging showed the screw was in fact medial to plan and pedicle. The surgeon then pulled the screw and informed the reps that the screw had breached the canal.
They then took the passive planar inside the screw hole and this also showed a medial deviation. The surgeon told the reps to remove the robot from the room as they called another physician to devise a plan. The surgeon then had the o-arm come back in for another spin to proceed with the case. After the spin, the rep scrolled through the images on the o-arm outside the room to confirm all other screws were accurate. Every single screw was100% accurate to plan except for the screw hole at t12 right, which was medial by roughly 5mm and the screw at t12 left, which was slightly lateral to plan but acceptable. The rep went on to perform a 10 point accuracy test, and shoulder calibration test to be sure all was well with the robot and passed both. The spine rep informed the rep that there was a slight dural leak and they believed it occurred during the screw placement and not the 3. 0 drill or 4. 5mm tap. The rep later informed the reporter that surgeon believed they had repaired the leak. It was also noted that during initial drilling of right l2, the black nav lock and long drill appeared to become "fused" somehow.
The rep thought that it was due to bone density at this level the nav lock became torqued and thus resulted in the drill and nav lock becoming locked together. The surgeon was unable to disengage the black nav lock from the drill regardless of force applied. At this point the rep had an hcp attach a back up long drill with the blue nav lock. The blue nav lock was then switched between long drill and long tap accordingly. The power ease rpms were continually adjusted between 250rpm for the drill and 150rpm for tap and driver. It was noted that changes to the course of the surgery included the removal of the right t12 screw, fixing the dural tear and reinserting the screw freehand.
The procedure was delayed for over an hour. It was reported that they had issues with the black nav lock ¿fusing¿ to the long drill guide. It was noted that the surgeon worked on the right side of the patient for the entire procedure. However it was also noted that they believed the surgeon switched sides. The surgeon technique was well within protocol with them malleting lightly, followed by a heavier malleting. There was no bone removal prior to the trajectories. The screws were off by approximately 5 mm. There were no additional complications reported or anticipated as a result of the event.