Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: MEDTRONIC RECEIVED INFORMATION REGARDING A GUIDANCE SYSTEM BEING USED DURING A SPINAL PROCEDURE. IT WAS REPORTED THAT THERE WERE DEVIATIONS DURING A SCOLIOSIS CORRECTION PROCEDURE FROM T4-L3. THE LEFT SIDE OF THE PATIENT WAS NOTED TO BE CONCAVE. THE FIRST SEGMENT WAS FROM T10-L3 AND A DISPOSABLE CLAMP WAS PLACED ON THE L1 SPINOUS PROCESS. THERE WAS A MEDIAL BREACH AT LEFT L2. THE DEVIATION WAS CONFIRMED WITH AN O-ARM SCAN AND THE PATIENT'S MEP SIGNALS DROPPED SIGNIFICANTLY OVER TIME AFTER FACETECTOMIES WERE DONE. THE SURGEON BELIEVED THE SEGMENT BECAME MOVABLE AND THE MEDIAL SCREW BRUSHED AGAINST THE SPINAL CORD CAUSING THE DROP IN MOTOR RESPONSES. THE SCREW WAS REMOVED. THE SURFACE OF THE BONE WAS FLATTENED PRIOR TO PLACING THE SCREW. ON THE RIGHT SIDE, THERE WAS SOFT TISSUE PRESSURE ON THE L2 AND L3 TRAJECTORIES THAT RESULTED IN THE SURGEON FREE HANDING THOSE TRAJECTORIES. THE SECOND SEGMENT WAS FROM T4-T9 AND A DUAL CLAMP WAS PLACED AT T6 AND T7. ONLY ONE PORTION OF THE CLAMP WAS USED AND THE OTHER PART WAS LOOSE. ALL SCREWS WERE PLACED ACCURATELY ON THE LEFT SIDE, BUT THERE T4-T5 TRAJECTORIES LOOKED MEDIAL. THE SURGEON DECIDED TO FREEHAND T4 AND T5 RIGHT. THE CAUSE OF THE DEVIA

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: ABSTRACT: MANAGEMENT OF DEGENERATIVE DISEASE OF THE SPINE HAS EVOLVED TO FAVOR MINIMALLY INVASIVE TECHNIQUES, INCLUDING NONROBOTIC-ASSISTED AND ROBOTIC-ASSISTED MINIMALLY INVASIVE TRANSFORAMINAL LUMBAR INTERBODY FUSION (MIS-TLIF). VALUE-BASED SPENDING IS BEING INCREASINGLY IMPLEMENTED TO CONTROL RISING COSTS IN THE US HEALTHCARE SYSTEM. WITH AN AGING POPULATION, IT IS FUNDAMENTAL TO UNDERSTAND WHICH PROCEDURE(S) MAY BE MOST COST-EFFECTIVE. TO COMPARE ROBOTIC AND NONROBOTIC MIS-TLIF THROUGH A COST-UTILITY ANALYSIS. WE CONSIDERED DIRECT MEDICAL COSTS RELATED TO SURGICAL INTERVENTION AND TO THE HOSPITAL STAY, AS WELL AS 1-YR UTILITIES. WE ESTIMATED COSTS BY ASSESSING ALL CASES INVOLVING ADULTS UNDERGOING ROBOTIC SURGERY AT A SINGLE INSTITUTION AND AN EQUAL NUMBER OF PATIENTS UNDERGOING NONROBOTIC SURGERY, MATCHED BY DEMOGRAPHIC AND CLINICAL CHARACTERISTICS. WE ADOPTED A WILLINGNESS TO PAY OF $50 000/QUALITY-ADJUSTED LIFE YEAR (QALY). UNCERTAINTY WAS ADDRESSED BY DETERMINISTIC AND PROBABILISTIC SENSITIVITY ANALYSES. COSTS WERE ESTIMATED BASED ON A TOTAL OF 76 PATIENTS, INCLUDING 38 UNDERGOING ROBOT-ASSISTED AND 38 MATCHED PATIENTS UNDERGOING NONROBOTIC MIS-TLIF. USING POINT ESTIMATES,

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: ABSTRACT: ROBOTICS IS A MAJOR AREA FOR RESEARCH AND DEVELOPMENT IN SPINE SURGERY. THE HIGH ACCURACY OF ROBOT-ASSISTED PLACEMENT OF THORACOLUMBAR PEDICLE SCREWS IS DOCUMENTED IN THE LITERATURE. THE AUTHORS PRESENT THE LARGEST CASE SERIES TO DATE EVALUATING 90-DAY COMPLICATION, REVISION, AND READMISSION RATES FOR ROBOT-ASSISTED SPINE SURGERY USING THE CURRENT GENERATION OF ROBOTIC GUIDANCE SYSTEMS. AN ANALYSIS OF A RETROSPECTIVE, MULTICENTER DATABASE OF OPEN AND MINIMALLY INVASIVE THORACOLUMBAR INSTRUMENTED FUSION SURGERIES USING THE MAZOR X OR MAZOR X STEALTH EDITION ROBOTIC GUIDANCE SYSTEMS WAS PERFORMED. PATIENTS 18 YEARS OF AGE OR OLDER AND UNDERGOING PRIMARY OR REVISION SURGERY FOR DEGENERATIVE SPINAL CONDITIONS WERE INCLUDED. DESCRIPTIVE STATISTICS WERE USED TO CALCULATE RATES OF MALPOSITIONED SCREWS REQUIRING REVISION, AS WELL AS OVERALL COMPLICATION, REVISION, AND READMISSION RATES WITHIN 90 DAYS. IN TOTAL, 799 SURGICAL CASES (MAZOR X: 48.81%; MAZOR X STEALTH EDITION: 51.19%) WERE EVALUATED, INVOLVING ROBOT-ASSISTED PLACEMENT OF 4838 PEDICLE SCREWS. THE OVERALL INTRAOPERATIVE COMPLICATION RATE WAS 3.13%. NO INTRAOPERATIVE IMPLANT-RELATED COMPLICATIONS WERE ENCOUNTERED. POSTOP

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: ABSTRACT: ROBOTICS IS A MAJOR AREA FOR RESEARCH AND DEVELOPMENT IN SPINE SURGERY. THE HIGH ACCURACY OF ROBOT-ASSISTED PLACEMENT OF THORACOLUMBAR PEDICLE SCREWS IS DOCUMENTED IN THE LITERATURE. THE AUTHORS PRESENT THE LARGEST CASE SERIES TO DATE EVALUATING 90-DAY COMPLICATION, REVISION, AND READMISSION RATES FOR ROBOT-ASSISTED SPINE SURGERY USING THE CURRENT GENERATION OF ROBOTIC GUIDANCE SYSTEMS. AN ANALYSIS OF A RETROSPECTIVE, MULTICENTER DATABASE OF OPEN AND MINIMALLY INVASIVE THORACOLUMBAR INSTRUMENTED FUSION SURGERIES USING THE MAZOR X OR MAZOR X STEALTH EDITION ROBOTIC GUIDANCE SYSTEMS WAS PERFORMED. PATIENTS 18 YEARS OF AGE OR OLDER AND UNDERGOING PRIMARY OR REVISION SURGERY FOR DEGENERATIVE SPINAL CONDITIONS WERE INCLUDED. DESCRIPTIVE STATISTICS WERE USED TO CALCULATE RATES OF MALPOSITIONED SCREWS REQUIRING REVISION, AS WELL AS OVERALL COMPLICATION, REVISION, AND READMISSION RATES WITHIN 90 DAYS. IN TOTAL, 799 SURGICAL CASES (MAZOR X: 48.81%; MAZOR X STEALTH EDITION: 51.19%) WERE EVALUATED, INVOLVING ROBOT-ASSISTED PLACEMENT OF 4838 PEDICLE SCREWS. THE OVERALL INTRAOPERATIVE COMPLICATION RATE WAS 3.13%. NO INTRAOPERATIVE IMPLANT-RELATED COMPLICATIONS WERE ENCOUNTERED. POSTOP

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: MEDTRONIC RECEIVED INFORMATION REGARDING A GUIDANCE SYSTEM BEING USED DURING A SPINAL PROCEDURE. IT WAS REPORTED THAT THERE WERE DEVIATIONS AND THE SURGEON COULD NOT INSTRUMENT DUE TO THE PLATFORM DURING A T3-S2 OPEN PROCEDURE. THE SURGEON PLACED SCREWS FROM LEFT S1 TO L1 AND ALL WERE ACCURATE. ON RIGHT L4, THERE WAS AN INFERIOR SKIVE AND THE PATIENT LOST MOTOR CONTROL AND HAD A CSF LEAK. THE RIGHT TIB, RIGHT EHL, AND RIGHT GASTROC HAD FLATLINED AND THE SURGEON WAS UNABLE TO GET A RESPONSE WHEN STIMULATING. RIGHT L5 AND S1 HAD MEDIAL BEACHES OF 1 CM. A NEUROSURGEON WAS CALLED IN TO HELP REPAIR THE CSF LEAD ALONG WITH THE NERVES. THE SURGEON THEN TRIED TO USE THE SPINOUS PROCESS CLAMP ON L2 AND L4 TO REGISTER L1-S2, BUT THEY WERE UNABLE TO DO SO THEY CONTINUED TO THE NEXT SEGMENT. THE NEXT SEGMENT WAS T7-L1 AND GREEN VALUES COULD NOT BE ACHIEVED FOR T11 DURING REGISTRATION. THE SURGEON DECIDED TO CONTINUE WITH THE OTHER BODIES AND THEY FOUND THAT THEY WERE INFERIOR. THE SURGEON DECIDED TO ABORT THE USE OF THE GUIDANCE SYSTEM AND COMPLETE THE PROCEDURE FREEHAND. THE MANUFACTURER REPRESENTATIVE BELIEVED THERE WAS A PATIENT SHIFT THAT RESULTED IN THE ISSUES. THE SURGEON FELT THE SCHANZ

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: MEDTRONIC RECEIVED INFORMATION REGARDING A GUIDANCE SYSTEM BEING USED DURING A SPINAL PROCEDURE. IT WAS REPORTED THAT THE PATIENT HAD SEVERE PAIN TWO DAYS AFTER A L5-S1 TLIF PROCURE WAS COMPLETED. IMAGING WAS DONE AND THE RIGHT L5 SCREW WAS DEVIATED BY 1-2 MM INFERIOR. DURING THE PROCEDURE, A SCHANZ PIN WAS PLACED IN THE RIGHT PSIS TO MOUNT THE SURGICAL SYSTEM TO THE PATIENT. A MIS CT-FLUORO WORKFLOW WAS FOLLOWED. HIGH SKIVE POTENTIAL WAS NOTED ON THE TRAJECTORIES. THE SURGEON STARTED COMPLETED THE SCREWS IN THE FOLLOWING ORDER: LEFT L5, LEFT S1, RIGHT L5 AND RIGHT S1. WHEN DRILLING L5, THE SURGEON HAD TO USE EXCESSIVE FORCE TO DRILL DUE TO HARD BONE AND DIFFICULTY BREAKING THROUGH THE POSTERIOR WALL. WHEN WORKING ON LEFT L5, THE SURGEON HAD TO RE-ADJUST DURING THE PROCEDURE. THE MANUFACTURER REPRESENTATIVE BELIEVED THE HIGH INFERIOR SKIVE POTENTIAL AND DIFFICULTY DRILLING THE BONE CONTRIBUTED TO THE DEVIATION. THE PROCEDURE WAS DELAYED LESS THAN AN HOUR. A REVISION PROCEDURE WAS DONE TO REMOVE BOTH SCREWS AT L5. THE SURGEON DECIDED NOT TO PLACED SCREWS AT THAT POSITION. THE PATIENT WAS DOING WELL AFTER THE REVISION.

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: ABSTRACT: ACCURATE PEDICLE SCREW PLACEMENT IS CRITICAL TO SURGICALLY CORRECT PEDIATRIC HIGH-GRADE SPONDYLOLISTHESIS (HGS). THE RECENT ADVENT OF ROBOTICS COUPLED WITH COMPUTER-ASSISTED NAVIGATION (RAN) MAY REPRESENT A NOVEL OPTION TO IMPROVE SURGICAL OUTCOMES OF HGS, SECONDARY TO ENHANCED PEDICLE SCREW PLACEMENT SAFETY. THIS SERIES PRESENTS THE HGS-RAN TECHNIQUE ADOPTED BY OUR SITE, DESCRIBING ITS SURGICAL OUTCOMES AND FEASIBILITY. CONSECUTIVE PATIENTS WITH A DIAGNOSIS OF HGS (MEYERDING GRADE III TO V), OPERATED ON USING RAN FROM 2019 TO 2020 AT A SINGLE-CENTER WERE REVIEWED. DEMOGRAPHICS, SCREW ACCURACY, SAGITTAL L5-S1 PARAMETERS, COMPLICATIONS, AND PERIOPERATIVE OUTCOMES WERE DESCRIBED. ALL PATIENTS WERE TREATED WITH INSTRUMENTATION, DECOMPRESSION, POSTERIOR LUMBAR INTERBODY FUSION, AND REDUCTION. ROBOTIC TIME INCLUDED ANATOMIC REGISTRATION TO END OF SCREW PLACEMENT. SCREW ACCURACY, DEFINED AS A SCREW PLACED SAFELY WITHIN THE PLANNED INTRAPEDICULAR TRAJECTORY WAS CHARACTERIZED BY THE GERTZBEIN-ROBBINS SYSTEM FOR PATIENTS WITH ADDITIONAL 3-DIMENSIONAL IMAGING. TEN HGS PATIENTS, WITH AN AVERAGE AGE OF 13.7 YEARS OLD, WERE INCLUDED IN THE SERIES. ALL 62 SCREWS WERE PLACED WITHOUT NEU

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: MEDTRONIC RECEIVED INFORMATION REGARDING A GUIDANCE SYSTEM BEING USED DURING A SPINAL PROCEDURE. IT WAS REPORTED THAT A SINGLE LEVEL MIS TLIF AT L4-L5 PROCEDURE WAS PLANNED. AFTER THE RIGHT L5 GUIDEWIRE WAS INSERTED, THE SURGEON REALIZED THERE WAS SOMETHING WRONG WHEN INSERTING THE RIGHT L4 GUIDEWIRE. IMAGING WAS DONE WITH THE C-ARM AND THE SURGEON FOUND THEY WERE NOT IN THE PLANNED TRAJECTORIES. THE SCREWS INTENDED FOR L5 WERE AT L4 AND THE SURGICAL ARM WAS SENT TO THE WRONG LEVEL. TROUBLESHOOTING INVOLVED CHECKING THE PLAN AND LABELING AND RESENDING THE SURGICAL ARM TO THE TRAJECTORY. THE SURGEON DECIDED TO ABORT THE USE OF THE GUIDANCE SYSTEM AND COMPLETE THE PROCEDURE FREEHAND USING THE C-ARM. THE PATIENT'S L3 EXITING NERVE ROOT WAS DAMAGED, BUT THE PATIENT'S MOTOR FUNCTION WAS NOT IMPACTED. THE PATIENT WAS STILL UNDER OBSERVATION. THE PROCEDURE WAS DELAYED TWO HOURS.

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: ABSTRACT: PEDICLE SCREW INSERTION FOR STABILIZATION AFTER LUMBAR FUSION SURGERY IS COMMONLY PERFORMED BY SPINE SURGEONS. WITH THE ADVENT OF NAVIGATION TECHNOLOGY, THE ACCURACY OF PEDICLE SCREW INSERTION HAS INCREASED. ROBOTIC GUIDANCE HAS REVOLUTIONIZED THE PLACEMENT OF PEDICLE SCREWS WITH 2 DISTINCT RADIOGRAPHIC REGISTRATION METHODS, THE SCAN AND PLAN METHOD AND CT-TO-FLUOROSCOPY METHOD. IN THIS STUDY, THE AUTHORS AIMED TO COMPARE THE ACCURACY AND SAFETY OF THESE METHODS. A RETROSPECTIVE CHART REVIEW WAS CONDUCTED AT 2 CENTERS TO OBTAIN OPERATIVE DATA FOR CONSECUTIVE PATIENTS WHO UNDERWENT ROBOT-ASSISTED LUMBAR PEDICLE SCREW PLACEMENT. THE NEWEST ROBOTIC PLATFORM (MAZOR X ROBOTIC SYSTEM) WAS USED IN ALL CASES. ONE CENTER USED THE SCAN-AND-PLAN REGISTRATION METHOD, AND THE OTHER USED CT-TO-FLUOROSCOPY FOR REGISTRATION. SCREW ACCURACY WAS DETERMINED BY APPLYING THE GERTZBEIN-ROBBINS SCALE. FLUOROSCOPIC EXPOSURE TIMES WERE COLLECTED FROM RADIOLOGY REPORTS. OVERALL, 268 PATIENTS UNDERWENT PEDICLE SCREW INSERTION, 126 PATIENTS WITH SCAN-AND-PLAN REGISTRATION AND 142 WITH CT-TO-FLUOROSCOPY REGISTRATION. IN THE SCAN-AND-PLAN COHORT, 450 SCREWS WERE INSERTED ACROSS 266 SPINAL LEVELS (MEAN

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: ABSTRACT: PEDICLE SCREW INSERTION FOR STABILIZATION AFTER LUMBAR FUSION SURGERY IS COMMONLY PERFORMED BY SPINE SURGEONS. WITH THE ADVENT OF NAVIGATION TECHNOLOGY, THE ACCURACY OF PEDICLE SCREW INSERTION HAS INCREASED. ROBOTIC GUIDANCE HAS REVOLUTIONIZED THE PLACEMENT OF PEDICLE SCREWS WITH 2 DISTINCT RADIOGRAPHIC REGISTRATION METHODS, THE SCAN AND PLAN METHOD AND CT-TO-FLUOROSCOPY METHOD. IN THIS STUDY, THE AUTHORS AIMED TO COMPARE THE ACCURACY AND SAFETY OF THESE METHODS. A RETROSPECTIVE CHART REVIEW WAS CONDUCTED AT 2 CENTERS TO OBTAIN OPERATIVE DATA FOR CONSECUTIVE PATIENTS WHO UNDERWENT ROBOT-ASSISTED LUMBAR PEDICLE SCREW PLACEMENT. THE NEWEST ROBOTIC PLATFORM (MAZOR X ROBOTIC SYSTEM) WAS USED IN ALL CASES. ONE CENTER USED THE SCAN-AND-PLAN REGISTRATION METHOD, AND THE OTHER USED CT-TO-FLUOROSCOPY FOR REGISTRATION. SCREW ACCURACY WAS DETERMINED BY APPLYING THE GERTZBEIN-ROBBINS SCALE. FLUOROSCOPIC EXPOSURE TIMES WERE COLLECTED FROM RADIOLOGY REPORTS. OVERALL, 268 PATIENTS UNDERWENT PEDICLE SCREW INSERTION, 126 PATIENTS WITH SCAN-AND-PLAN REGISTRATION AND 142 WITH CT-TO-FLUOROSCOPY REGISTRATION. IN THE SCAN-AND-PLAN COHORT, 450 SCREWS WERE INSERTED ACROSS 266 SPINAL LEVELS (MEAN

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: ABSTRACT: PEDICLE SCREW INSERTION FOR STABILIZATION AFTER LUMBAR FUSION SURGERY IS COMMONLY PERFORMED BY SPINE SURGEONS. WITH THE ADVENT OF NAVIGATION TECHNOLOGY, THE ACCURACY OF PEDICLE SCREW INSERTION HAS INCREASED. ROBOTIC GUIDANCE HAS REVOLUTIONIZED THE PLACEMENT OF PEDICLE SCREWS WITH 2 DISTINCT RADIOGRAPHIC REGISTRATION METHODS, THE SCAN-AND-PLAN METHOD AND CT-TO-FLUOROSCOPY METHOD. IN THIS STUDY, THE AUTHORS AIMED TO COMPARE THE ACCURACY AND SAFETY OF THESE METHODS. A RETROSPECTIVE CHART REVIEW WAS CONDUCTED AT 2 CENTERS TO OBTAIN OPERATIVE DATA FOR CONSECUTIVE PATIENTS WHO UNDERWENT ROBOT-ASSISTED LUMBAR PEDICLE SCREW PLACEMENT. THE NEWEST ROBOTIC PLATFORM (MAZOR X ROBOTIC SYSTEM) WAS USED IN ALL CASES. ONE CENTER USED THE SCAN-AND-PLAN REGISTRATION METHOD, AND THE OTHER USED CT-TO-FLUOROSCOPY FOR REGISTRATION. SCREW ACCURACY WAS DETERMINED BY APPLYING THE GERTZBEIN-ROBBINS SCALE. FLUOROSCOPIC EXPOSURE TIMES WERE COLLECTED FROM RADIOLOGY REPORTS. OVERALL, 268 PATIENTS UNDERWENT PEDICLE SCREW INSERTION, 126 PATIENTS WITH SCAN-AND-PLAN REGISTRATION AND 142 WITH CT-TO-FLUOROSCOPY REGISTRATION. IN THE SCAN-AND-PLAN COHORT, 450 SCREWS WERE INSERTED ACROSS 266 SPINAL LEVELS (MEAN

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: ABSTRACT: MULTIPLE-ROD CONSTRUCTS (MRCS) ARE OFTEN USED IN DEFORMITY CORRECTION FOR INCREASED STABILITY AND RIGIDITY. THERE ARE CURRENTLY NO REPORTS SHOWING MINIMALLY INVASIVE PLACEMENT OF MRCS IN ADULT DEFORMITY SURGERY AND ITS TECHNICAL FEASIBILITY THROUGH PREOPERATIVE SOFTWARE PLANNING. DATA WERE COLLECTED RETROSPECTIVELY FROM MEDICAL RECORDS OF SIX CONSECUTIVE PATIENTS WHO UNDERWENT MINIMALLY INVASIVE MRCS WITH ROBOTICS PLANNING BY A SINGLE SURGEON AT AN ACADEMIC CENTER BETWEEN MARCH¿AUGUST 2020. A TOTAL OF SIX PATIENTS (4 FEMALES, MEAN AGE 69.7 YEARS) UNDERWENT MINIMALLY INVASIVE LONG-SEGMENT (6 +) POSTERIOR FIXATION WITH MULTIPLE RODS (3 +) USING THE MAZOR X STEALTH EDITION ROBOTICS PLATFORM. AVERAGE FOLLOW-UP WAS 14.3 MONTHS. ALL PATIENTS UNDERWENT OBLIQUE LUMBAR INTERBODY FUSION (OLIF) AS A FIRST STAGE, FOLLOWED BY SECOND STAGE POSTERIOR FIXATION IN THE SAME DAY. THE MEAN NUMBER OF LEVELS POSTERIORLY INSTRUMENTED WAS 8.8. ONE PATIENT UNDERWENT 3 ROD FIXATION (1 ILIAC, 2 S2AI) AND 5 PATIENTS UNDERWENT QUAD ROD FIXATION (2 ILIAC, 2 S2AI). THE MEAN TIME TO SECURE ALL RODS WAS 8 MIN 36 S. MEAN IMPROVEMENT IN SPINOPELVIC PARAMETERS WAS -4.9 CM SAGITTAL VERTICAL AXIS, 18.0° LUM B

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: MEDTRONIC RECEIVED INFORMATION REGARDING A GUIDANCE SYSTEM BEING USED DURING A SPINAL PROCEDURE. IT WAS REPORTED THAT THE LEFT T3 TRAJECTORY WAS MEDIAL BY LESS THAN 3.5 MM DURING AN OPEN T3 - L2 PROCEDURE. THE SURGEON PLANNED THE CASE WITH THE MANUFACTURER REPRESENTATIVE PRIOR TO THE CASE. A DUAL CLAMP WAS USED TO MOUNT THE SURGICAL SYSTEM TO THE PATIENT. REGISTRATION WAS COMPLETED SUCCESSFULLY AND NO SHIFTS WERE NOTICED. THE SURGEON STARTED THE CASE AT L2 AND ALL SCREWS WERE PLACED ACCURATELY PRIOR TO REACHING RIGHT T3. MULTIPLE ADJUSTMENTS WERE MADE ON THE RIGHT SIDE DUE TO DUAL-CLAMP INTERFERENCE WITH THE PLANNED TRAJECTORIES. NAVIGATION WAS USED AND CHECKED REGULARLY DURING THE CASE. THE SURGEON CHECKED INSTRUMENTS ON THE ARM GUIDE AND PATIENT ANATOMY. WHEN THE SURGEON WAS DRILLING THE RIGHT T3 SCREW, THEY NOTICED CSF FLUID AND THE DRILL HAD BREACHED IN THE MEDIAL DIRECTION. NO SCREW WAS PLACED. NAVIGATION WAS CHECKED PRIOR TO DRILLING T3 DUE TO POSSIBLE SOFT TISSUE PRESSURE AT THE TOP OF THE INCISION. THE PATIENT EXPERIENCED TEMPORARY LOSS OF MOTOR FUNCTION ON THE RIGHT SIDE. THE SURGEON ABORTED THE USE OF THE GUIDANCE SYSTEM, REMEDIED THE CSF LEAK, REPAIRED THE DURA, AND THEN

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: MEDTRONIC RECEIVED INFORMATION REGARDING A GUIDANCE SYSTEM BEING USED DURING A SPINAL PROCEDURE. IT WAS REPORTED THAT TWO WEEKS AFTER AN L3-L5 PROCEDURE, THE PATIENT EXPERIENCED FOOT DROP SYMPTOMS. AFTER IMAGING, THE RIGHT L4 SCREW WAS FOUND TO BE MEDIAL BY 4-5 MM. THE MANUFACTURER REPRESENTATIVE STATED THAT THE PATIENT HAD HIGH BMI AND THERE WAS SOFT TISSUE PRESSURE ON THE TOOLS DURING THE PROCEDURE. THERE WAS NO SKIVE POTENTIAL IN THE PLANNING FOR THE TRAJECTORIES. A REVISION PROCEDURE TO REPOSITION THE SCREW USING NAVIGATION WAS PLANNED. THERE WAS NO DELAY TO THE PROCEDURE.

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: ADDITIONAL INFORMATION RECEIVED FROM A MANUFACTURER REPRESENTATIVE REPORTED THAT FLUORO IMAGES WERE TAKEN DURING THE PROCEDURE AND THE SURGEON CONFIRMED ACCURACY. NO PROBLEMS WERE EXPERIENCED DURING THE INITIAL PROCEDURE. THE CAUSE OF THE DEVIATION WAS DETERMINED TO BE A MEDIAL SKIVE POTENTIAL AND A DRILL BIT TAKING THE PATH OF LEAST RESISTANCE DOWN THE JOINT. THE PATIENT EXPERIENCED FOOT DROP AFTER THE PROCEDURE.

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: ADDITIONAL INFORMATION RECEIVED FROM A MANUFACTURER REPRESENTATIVE REPORTED THAT THE SURGICAL ARM HIT THE BONE MOUNT BRIDGE DURING REGISTRATION. AN AP IMAGE WAS TAKEN AND THE BRIDGE WAS HIT WHEN MOVING THE SURGICAL ARM TO THE OBLIQUE POSITION. THE 3D MARKER WAS REMOVED FROM THE ARM GUIDE PRIOR TO THE SURGICAL ARM BEING SENT TO THE OBLIQUE TRAJECTORY. A NAVIGATION ACCURACY TEST WAS DONE AFTER THE ANATOMICAL ACCURACY TEST. THE PASSIVE PLANAR PROBE WAS USED AND PLACED ON THE PATIENT'S ANATOMY AND THEN THE ARM GUIDE. ADDITIONAL ANATOMICAL CHECKS WERE DONE THROUGHOUT THE CASE SINCE AN INSTRUMENT WAS SHOWN TO BE SLIGHTLY MEDIAL DURING THE PROCEDURE. NAVIGATION ACCURACY AND GUIDANCE SYSTEM ACCURACY WERE DISCUSSED WITH THE SURGEON. THE SURGEON DECIDED TO DO ADDITIONAL SNAPSHOTS AND ACCURACY TESTS WERE PERFORMED AFTERWARDS TO AVOID RE-REGISTERING THE PATIENT. THE ADDITIONAL ANATOMICAL ACCURACY CHECKS WERE ACCURATE. THE REVISION PROCEDURE WAS COMPLETED. AFTER THE PROCEDURE, THE PATIENT STILL HAD WEAKNESS AND IMMOBILITY ON THEIR LEFT SIDE.

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: ABSTRACT: ROBOT-ASSISTED SPINE SURGERY CONTINUES TO RAPIDLY DEVELOP AS EVIDENCED BY THE GROWING LITERATURE IN RECENT YEARS. IN ADDITION TO DEMONSTRATING EXCELLENT PEDICLE SCREW ACCURACY, EARLY STUDIES HAVE EXPLORED THE IMPACT OF ROBOT-ASSISTED SPINE SURGERY ON REDUCING RADIATION TIME, LENGTH OF HOSPITAL STAY, OPERATIVE TIME, AND PERIOPERATIVE COMPLICATIONS IN COMPARISON TO CONVENTIONAL FREEHAND TECHNIQUE. RECENTLY, THE MAZOR X STEALTH EDITION WAS INTRODUCED IN 2018. THIS ROBOTIC SYSTEM INTEGRATES MEDTRONIC¿S STEALTH NAVIGATION TECHNOLOGY INTO THE MAZOR X PLATFORM, WHICH WAS INTRODUCED IN 2016. IT IS UNCLEAR WHAT THE IMPACT OF THESE ADVANCEMENTS HAVE MADE ON CLINICAL OUTCOMES. TO COMPARE THE OUTCOMES AND COMPLICATIONS BETWEEN THE MOST RECENT ITERATIONS OF THE MAZOR ROBOT SYSTEMS: MAZOR X AND MAZOR X STEALTH EDITION. AMONG FOUR DIFFERENT INSTITUTIONS, WE INCLUDED ADULT (=18 YEARS OLD) PATIENTS WHO UNDERWENT ROBOT-ASSISTED SPINE SURGERY WITH EITHER THE MAZOR X (NON-NAVIGATED ROBOT) OR STEALTH (NAVIGATED ROBOT) PLATFORMS. PRIMARY OUTCOMES INCLUDED ROBOT TIME PER SCREW, FLUOROSCOPIC RADIATION TIME, SCREW ACCURACY, ROBOT ABANDONMENT, AND CLINICAL OUTCOMES WITH A MINIMUM 90 DAY FOLLOW UP.

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: ABSTRACT: ROBOT-ASSISTED SPINE SURGERY CONTINUES TO RAPIDLY DEVELOP AS EVIDENCED BY THE GROWING LITERATURE IN RECENT YEARS. IN ADDITION TO DEMONSTRATING EXCELLENT PEDICLE SCREW ACCURACY, EARLY STUDIES HAVE EXPLORED THE IMPACT OF ROBOT-ASSISTED SPINE SURGERY ON REDUCING RADIATION TIME, LENGTH OF HOSPITAL STAY, OPERATIVE TIME, AND PERIOPERATIVE COMPLICATIONS IN COMPARISON TO CONVENTIONAL FREEHAND TECHNIQUE. RECENTLY, THE MAZOR X STEALTH EDITION WAS INTRODUCED IN 2018. THIS ROBOTIC SYSTEM INTEGRATES MEDTRONIC¿S STEALTH NAVIGATION TECHNOLOGY INTO THE MAZOR X PLATFORM, WHICH WAS INTRODUCED IN 2016. IT IS UNCLEAR WHAT THE IMPACT OF THESE ADVANCEMENTS HAVE MADE ON CLINICAL OUTCOMES. TO COMPARE THE OUTCOMES AND COMPLICATIONS BETWEEN THE MOST RECENT ITERATIONS OF THE MAZOR ROBOT SYSTEMS: MAZOR X AND MAZOR X STEALTH EDITION. AMONG FOUR DIFFERENT INSTITUTIONS, WE INCLUDED ADULT (=18 YEARS OLD) PATIENTS WHO UNDERWENT ROBOT-ASSISTED SPINE SURGERY WITH EITHER THE MAZOR X (NON-NAVIGATED ROBOT) OR STEALTH (NAVIGATED ROBOT) PLATFORMS. PRIMARY OUTCOMES INCLUDED ROBOT TIME PER SCREW, FLUOROSCOPIC RADIATION TIME, SCREW ACCURACY, ROBOT ABANDONMENT, AND CLINICAL OUTCOMES WITH A MINIMUM 90 DAY FOLLOW UP.

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: ABSTRACT: ROBOT-ASSISTED PLATFORMS IN SPINE SURGERY HAVE RAPIDLY DEVELOPED INTO AN ATTRACTIVE TECHNOLOGY FOR BOTH THE SURGEON AND PATIENT. ALTHOUGH CURRENT LITERATURE IS PROMISING, MORE CLINICAL DATA IS NEEDED. THE PURPOSE OF THIS PAPER IS TO DETERMINE THE EFFECT OF ROBOT-RELATED COMPLICATIONS ON CLINICAL OUTCOMES THIS MULTICENTER STUDY INCLUDED ADULT (=18 YEARS OLD) PATIENTS WHO UNDERWENT ROBOT-ASSISTED LUMBAR FUSION SURGERY FROM 2012-2019. THE MINIMUM FOLLOW-UP WAS 1 YEAR AFTER SURGERY. BOTH BIVARIATE AND MULTIVARIATE ANALYSES WERE PERFORMED TO DETERMINE IF ROBOT-RELATED FACTORS WERE ASSOCIATED WITH REOPERATION WITHIN 1 YEAR AFTER PRIMARY SURGERY. A TOTAL OF 320 PATIENTS WERE INCLUDED IN THIS STUDY. THE MEAN (STANDARD DEVIATION) CHARLSON COMORBIDITY INDEX WAS 1.2 (1.2) AND 52.5% OF PATIENTS WERE FEMALE. INTRAOPERATIVE ROBOT COMPLICATIONS OCCURRED IN 3.4% OF PATIENTS AND INCLUDED INTRAOPERATIVE EXCHANGE OF SCREW (0.9%), ROBOT ABANDONMENT (2.5%), AND RETURN TO THE OPERATING ROOM FOR SCREW EXCHANGE (1.3%). THE 1-YEAR REOPERATION RATE WAS 4.4%. ROBOT FACTORS, INCLUDING ROBOT TIME PER SCREW, OPEN VS. PERCUTANEOUS, AND ROBOT SYSTEM, WERE NOT STATISTICALLY DIFFERENT BETWEEN THOSE WHO RE

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: MEDTRONIC RECEIVED INFORMATION REGARDING A GUIDANCE SYSTEM BEING USED DURING A SPINAL PROCEDURE. IT WAS REPORTED THAT A SCAN & PLAN CASE FOR L3-L4 OLIF WITH PERC SCREWS WAS COMPLETED. THE PROCEDURE STARTED BY TAKING A SPIN WITH THE O-ARM AND SENDING THE IMAGES TO THE GUIDANCE SYSTEM FOR PLANNING. WHILE PLANNING FOR THE SCREWS WAS DONE, THE SURGEON DID THE EXPOSURE FOR THE OLIF. THE SURGEON THEN EXECUTED THE SCREWS, PERFORMED THE OLIF, AND THEN WENT BACK TO PLACE RODS. SCOUT SHOTS TAKEN DURING THE PROCEDURE SHOWED THE SCREWS LOOKED OK IN THE LATERAL VIEW. ANOTHER LATERAL IMAGE WAS DONE AND THE SCREWS LOOKED TO BE IN A DIFFERENT POSITION. AN AP IMAGE WAS TAKEN AND THE SCREWS ON THE LEFT SIDE WERE FOUND TO BE LATERAL BY 3.5-10 MM. THE LEFT L3 AND L4 SCREWS WERE REMOVED DURING THE PROCEDURE. A POST OPERATIVE CT SCAN WAS DONE OF THE RIGHT SIDE AND THE SCREWS WERE MEDIAL IN THE CANAL. A REVISION WAS DONE TO REMOVE THE RIGHT SIDE SCREWS. NO TROUBLESHOOTING WAS DONE DURING THE PROCEDURE SINCE THE SURGEON THOUGHT THE DEVIATION MAY HAVE BEEN CAUSED WHEN TRYING TO TIGHTEN THE RODS. IMAGING WAS NOT DONE PRIOR TO THAT. THE PROCEDURE WAS DELAYED LESS THAN AN HOUR.

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: ADDITIONAL INFORMATION RECEIVED FROM A MANUFACTURER REPRESENTATIVE REPORTED THAT THE CASE WAS MINIMALLY INVASIVE. THE CASE WAS STARTED SUCCESSFULLY, BUT AT THE SECOND SCREW, THE SCREWDRIVER WAS STUCK ON THE SCREW AND THE SURGEON PULLED OUT THE SCREW WITH TOO MUCH FORCE CAUSING A SHOULDER SHIFT. AT THIS POINT, S1 AND L5 RIGHT SIDE SCREWS WERE ALREADY PLACED. A NEW REGISTRATION WAS DONE, BUT THE SURGICAL ARM HAD PROBLEMS REACHING THE OTHER TRAJECTORIES DUE TO THE SCREW EXTENDERS. THE SURGEON WAS ALSO NOT HAPPY WITH THE RIGHT L5 SCREW SO THEY REMOVED THEY REMOVED BOTH L5 SCREWS AND DECIDED TO START FROM THE BEGINNING. THE RIGHT L5 WAS TOO MEDIAL AND THE LEFT L5 WAS TOO LATERAL AND SUPERIOR. THE S1 LEFT SCREW WAS DEVIATED SO THE PLANNING WAS CHANGED INTRAOPERATIVELY DUE TO THE PATIENT BEING OBESE AND THE COLLISION WITH THE EXTENDERS OF L5 AND PELVIS. THE PATIENT EXPERIENCED ISSUES TWO WEEKS AFTER SURGERY. NAVIGATION WAS CHECKED AND EVERYTHING WAS OKAY.

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: MEDTRONIC RECEIVED INFORMATION REGARDING A GUIDANCE SYSTEM BEING USED DURING A SPINAL PROCEDURE. IT WAS REPORTED BY THE PATIENT THAT THEIR LIFE WAS RUINED AND THEY EXPERIENCED A SIGNIFICANT LIFE CHANGING INJURY THROUGH USE OF THE GUIDANCE SYSTEM FOR SPINAL SURGERY. THE PATIENT REPORTED HAD TWO SEPARATE PROCEDURE USING THE GUIDANCE SYSTEM.

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: ADDITIONAL INFORMATION RECEIVED REPORTED THE PATIENT WAS UNABLE TO PROPERLY MOVE THEIR FOOT AND THEY WERE UNABLE TO VOID THEIR BLADDER AFTER THE PROCEDURE. THE PATIENT'S HOSPITAL STAY WAS EXTENDED.

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: ABSTRACT: TO COMPARE THE PATIENT-REPORTED OUTCOMES (PROS) BETWEEN PATIENTS UNDERGOING MULTILEVEL LUMBAR FUSION WITH ROBOT-ASSISTED VS. FREEHAND TECHNIQUES. THIS WAS A SINGLE-INSTITUTION COHORT STUDY OF ADULT PATIENTS (=18 YEARS OLD) UNDERGOING ROBOT-ASSISTED SPINE SURGERY FROM 2016 TO 2018 WITH MINIMUM 2-YEAR FOLLOW-UP. A PROPENSITY-SCORE MATCHING (PSM) ALGORITHM ACCOUNTED FOR SEVERAL PERIOPERATIVE FACTORS. PROS WERE MEASURED USING THE OSWESTRY DISABILITY INDEX (ODI). THE MINIMUM CLINICALLY IMPORTANT DIFFERENCE (MCID) BETWEEN GROUPS WERE ASSESSED AT EACH FOLLOW-UP PERIOD (6-WEEKS/6-MONTHS/1-YEAR/2-YEARS). CHI-SQUARE/FISHER EXACT TEST AND T-TEST/ANOVA WERE USED FOR CATEGORICAL AND CONTINUOUS VARIABLES, RESPECTIVELY. AFTER PSM, A TOTAL OF 70 PATIENTS REMAINED. THE MEAN (STANDARD DEVIATION) CHARLSON COMORBIDITY INDEX WAS 1.4 (1.0) AND 57% OF PATIENTS WERE FEMALE. THE MOST COMMON DIAGNOSES INCLUDED DEGENERATIVE DISC DISEASE (37.1%), DEGENERATIVE SCOLIOSIS (27.1%), AND HIGH GRADE SPONDYLOLISTHESIS (GRADE > 2) (19%), AND THE MEAN NUMBER OF INSTRUMENTED LEVELS WAS 4.6 (4.4). RATES FOR INTRAOPERATIVE/POSTOPERATIVE COMPLICATIONS, AND ANY REOPERATION WITHIN 2 YEARS AFTER SURGERY WERE LOW AND

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: MEDTRONIC RECEIVED INFORMATION REGARDING A GUIDANCE SYSTEM BEING USED DURING A SPINAL PROCEDURE. IT WAS REPORTED THAT A T11-L3 PSF WAS COMPLETED. THE CASE WAS MINIMALLY INVASIVE AND A SCHANZ ARM WAS USED TO MOUNT THE SURGICAL SYSTEM TO THE PATIENT. L1 WAS FRACTURED SO THE SCREWS AND RODS WERE PLACED MIS AND THEN THE PATIENT WAS FLIPPED LATERAL FOR THE CORPECTOMY. INTRA-OP IMAGES LOOKED GOOD AND PLACEMENT WAS CONFIRMED BY THE SURGEON. A FEW DAYS AFTER THE PROCEDURE, POST-OP SCANS SHOWED THAT LEFT T11 WAS LATERAL 4MM AND RIGHT T11 WAS MEDIAL BY 4 MM. THE SURGEON PLANNED TO REVISE THE SCREWS. THE CAUSE OF THE DEVIATION WAS NOT DETERMINED. THE INITIAL PROCEDURE WAS NOT DELAYED.

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: ABSTRACT: TO REPORT OUR EXPERIENCE USING THE SCAN-AND-PLAN WORKFLOW AND REVIEW CURRENT LITERATURE ON SURGICAL EFFICIENCY, SAFETY, AND ACCURACY OF NEXT-GENERATION ROBOT-ASSISTED (RA) SPINE SURGERY. THE RECORDS OF PATIENTS WHO UNDERWENT RA PEDICLE SCREW FIXATION WERE REVIEWED. THE ACCURACY OF PEDICLE SCREW PLACEMENT WAS DETERMINED BASED ON THE RAVI CLASSIFICATION SYSTEM. TO EVALUATE WORKFLOW EFFICIENCY, 3 DEMOGRAPHICALLY MATCHED COHORTS WERE CREATED TO ANALYZE DIFFERENCES IN TIME PER SCREW PLACEMENT (DEFINED AS OPERATING ROOM [OR] TIME DIVIDED BY NUMBER OF SCREWS PLACED). GROUP A HAD 4 SCREWS PLACED, GROUP B HAD 4 SCREWS PLACED, AND GROUP C HAD >4 SCREWS PLACED. INTRAOPERATIVE ERRORS AND POSTOPERATIVE COMPLICATIONS WERE COLLECTED TO ELUCIDATE SAFETY. EIGHTY-FOUR RA CASES (306 PEDICLE SCREWS) WERE INCLUDED FOR ANALYSIS. THE MEAN NUMBER OF SCREWS PLACED WAS 2.1 +- 0.3 IN GROUP A AND 6.4 +- 1.2 IN GROUP C; 4 SCREWS WERE PLACED IN GROUP B PATIENTS. THE ACCURACY RATE (RAVI GRADE I) WAS 98.4%. SCREW PLACEMENT TIME WAS SIGNIFICANTLY LONGER IN GROUP A (101 +- 37.7 MINUTES) THAN GROUP B (50.5 +- 25.4 MINUTES) OR C (43.6 +- 14.7 MINUTES). THERE WERE NO INTRAOPERATIVE COMPLICATIONS, ROBOT FAILU

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: MEDTRONIC RECEIVED INFORMATION REGARDING A GUIDANCE SYSTEM BEING USED DURING A SPINAL PROCEDURE. IT WAS REPORTED THAT THERE WERE DEVIATIONS DURING A L5-S1 CASE. A SCHANZ PIN WAS CONNECTED TO A SCHANZ ARM TO MOUNT THE SURGICAL SYSTEM TO THE PATIENT. THE SURGEON BEGAN WITH LEFT L5 AND LEFT S1 AND A ROD WAS INSERTED WITH NO MOVEMENT DETECTED. RIGHT L5 AND S1 TRAJECTORIES WERE COMPLETED NEXT AND A ROD WAS PLACED. THE MANUFACTURER REPRESENTATIVE NOTED THAT THE SCREW TRAJECTORIES WERE ALTERED DURING THE PROCEDURE TO ACCOMMODATE SOFT TISSUE PRESSURE. AP AND LATERAL IMAGES WERE TAKEN AND PLACEMENT WAS APPROVED BY THE SURGEON. THE DEVIATION COULD NOT BE SEEN ON THE IMAGES. AFTER THE CASE, THE PATIENT EXPERIENCE RIGHT SIDED FOOT DROP AND CHANGES IN SENSATIONS. THE SCREWS WERE REMOVED LATER IN THE DAY DUE TO BEING MISPLACED ON THE RIGHT SIDE IN THE SPINAL CANAL. THE SCREWS WERE DEVIATED BY MORE THAN 10 MM. THE PATIENT EXPERIENCED SOME RECOVERY WITH FORCED EVERSION AND SOME IMPROVEMENT IN SENSATION. THE REPRESENTATIVE SUSPECTED THE DEVIATION WAS CAUSED BY ANATOMY SHIFT, PLATFORM MOUNTING AND SOFT TISSUE PRESSURE. THE PROCEDURE WAS DELAYED MORE THAN AN HOUR.

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: MEDTRONIC RECEIVED INFORMATION REGARDING A GUIDANCE SYSTEM BEING USED DURING A SPINAL PROCEDURE. IT WAS REPORTED THAT THE PATIENT EXPERIENCED A NEAR DEATH EXPERIENCE.

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: MEDTRONIC RECEIVED INFORMATION REGARDING A GUIDANCE SYSTEM BEING USED DURING A SPINAL PROCEDURE. IT WAS REPORTED THAT THERE WAS A DEVIATION DURING A L4-S1 CASE. THE SCREWS WERE PLACED ACCURATELY ON THE LEFT SIDE OF THE PATIENT. ON THE RIGHT SIDE, THERE WAS A SUSPECTED MEDIAL SKIVE AT L5. WHEN THE SURGEON WAS TAPPING AT L5, THE TAP WAS PLACED MEDIAL AND DEVIATED 10 MM MEDIALLY FROM PLAN. THE TAP WAS INSERTED INTO THE CANAL AND THERE WAS NOTICEABLE CEREBROSPINAL FLUID (CSF) COMING FROM FROM THE TRAJECTORY. THE SURGEON REPAIRED THE CSF LEAK AFTER REMOVING ABORTING THE USE OF THE GUIDANCE SYSTEM AND REMOVING IT FROM THE TABLE. THERE WAS NO PATIENT HARM AND THE PROCEDURE WAS DELAYED LESS THAN AN HOUR.