Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: IT WAS NOTED THAT THE L1 SCREW WAS 4.5MM MEDIAL AND THE L2 SCREW WAS 1.5-2MM LATERAL. THE L2 SCREW WAS NOT REDIRECTED OR REVISED. NO PERMANENT HARM WAS DONE TO THE PATIENT DUE TO THE DEVIATIONS.

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 MULTIPLE ACCURATE CASES HAVE BEEN COMPLETED SINCE THE EVENT. THE REPRESENTATIVE HAD MADE SUGGESTIONS ABOUT THE SURGEONS TECHNIQUE, THE POSSIBILITY OF THE SPINE "TORQUING" WITH INSTRUMENTATION AND USING THE CLAMP VERSUS PELVIC FIXATION, BUT THE SURGEON DISAGREED WITH THESE AS THE CAUSE OF THE DEVIATIONS.

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 TECHNICAL ISSUES DURING A RIGHT LEFT L4-L5 TLIF PROCEDURE. THE SURGEON DRILLED PILOT HOLES FOR ALL TRAJECTORIES USING A PERCUTANEOUS TECHNIQUE. SCREWS WERE THEN PLACED. A POST-OP SPIN WAS DONE AND THE SCREWS AT L4 WERE FOUND TO BE SUBOPTIMAL AND WAS SLIGHTLY OFF BY ABOUT 3.5 MM. THE SCREWS WERE SLIGHTLY LATERAL AND COULD HAVE AFFECTED THE RIGIDITY OF THE CONSTRUCT. TROUBLESHOOTING DURING THE INITIAL PROCEDURE INCLUDED CHECKING LANDMARKS. THE PATIENT EXPERIENCED RIGHT SIDE BACK PAIN. A REVISION PROCEDURE WAS DONE AND THE SCREWS WERE REPOSITION FREEHAND. THE SUSPECTED CAUSE OF THE DEVIATION WAS SKIVING AND NON-OPTIMAL ENTRY PLANNING. 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 SCREW WAS MISPLACED BY 1 CM.

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 DURING A T8-T12 TRAUMA BURST FRACTURE, THE LEFT T8 SCREW WAS DEVIATED LATERAL BY ABOUT 5 MM. THE LEFT T8 SCREW WAS PLACED FIRST AND FOUND TO BE DEVIATED ON A POST-OP CT. THE REST OF THE SCREWS WERE PLACED ACCURATELY. THE CAUSE OF THE DEVIATION WAS UNKNOWN. A REVISION WAS SCHEDULED, BUT THE MANUFACTURER REPRESENTATIVE NOTED THAT IT MAY BE CANCELLED DUE TO UNRELATED COMPLICATIONS. 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: MEDTRONIC RECEIVED INFORMATION REGARDING A GUIDANCE SYSTEM BEING USED DURING A SPINAL PROCEDURE. IT WAS REPORTED THAT DURING A T4-S2 CASE WITH THREE SEGMENTS, RIGHT T4 - T9 SCREWS WERE MEDIAL TO PLAN. THIS OCCURRED DURING THE FINAL SEGMENT WITH THE CLAMP PLACED AT T10. THE MANUFACTURER REPRESENTATIVE BELIEVED THE DEVIATIONS WERE DUE TO SKIVING AS THE SURGEON WAS ON THE RIGHT SIDE AND MALLEATING VERY HARD. THE SCREWS WERE DEVIATED LESS THAN 3.5 MM. THE SURGEON WAS NOT WORRIED ABOUT MISPLACED SCREWS DURING THE PROCEDURE SINCE ALL INTRA-OP AP IMAGES APPEARED WITHIN NORMAL LIMITS. AFTER THE PROCEDURE IN POST-OPERATION, THE PATIENT COMPLAINT OF PAIN. A POST-OP CT REVEALED T4-T9 WAS DEVIATED ON THE RIGHT SIDE. THE PATIENT WAS TAKEN BACK TO THE OR TO REPOSITION THE SCREWS WITH NAVIGATION. THERE WERE NO FURTHER SYMPTOMS 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: MEDTRONIC RECEIVED INFORMATION REGARDING A GUIDANCE SYSTEM BEING USED DURING A SPINAL PROCEDURE. IT WAS REPORTED THAT THE PATIENT WENT TO THE CLINIC OVER THE WEEKEND WITH FOOT DROP THAT WAS POTENTIALLY DUE TO A MISPLACED SCREW. FOUR SCREWS WERE PLACED DURING A SINGLE POSITION OLIF PROCEDURE USING THE GUIDANCE SYSTEM ON (B)(6) 2020. AN INTERBODY WAS PLACED PRIOR TO PLACING THE SCREWS. DURING THE PROCEDURE, THE INSTRUMENT ON THE SURGEON SCREEN DID NOT MATCH THE INSTRUMENT IN RELATION TO THE PATIENT. A SECOND SNAPSHOT WAS COMPLETED TO RESOLVE THE ISSUE. THE PATIENT DID NOT HAVE TO BE RE-REGISTER. NO OTHER ISSUES OCCURRED DURING THE PROCEDURE. THE SCREWS LOOKED TO BE MATCHED UP WITH THE PLANNED TRAJECTORIES ACCORDING TO CONFIRMATION IMAGES TAKEN DURING THE PROCEDURE; HOWEVER, AFTER FURTHER EXAMINATION, THE LEFT L5 SCREW WAS MEDIAL BY 3.5-10 MM. THE INITIAL PROCEDURE WAS DELAYED LESS THAN AN HOUR. A REVISION PROCEDURE WAS PLANNED TO REPOSITION THE SCREW, BUT HAD NOT BEEN SCHEDULED.

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 FIXATION IN PEDIATRIC SPINE SURGERY HAS BECOME COMMON PRACTICE GIVEN THE FIXATION STABILITY AND IMPROVED CURVE CORRECTION. HOWEVER, DUE TO PROXIMITY TO VITAL STRUCTURES, ACCURACY IS PARAMOUNT. LITERATURE HAS REPORTED ACCURACY RATES FROM 87.5 TO 90% USING TRADITIONAL FREEHAND TECHNIQUES. THIS STUDY PRESENTS OUR INITIAL EXPERIENCE WITH PEDICLE SCREW PLACEMENT USING THE NEWEST GENERATION OF SPINAL ROBOTICS FOR TREATMENT OF PEDIATRIC SPINAL DEFORMITY. A COHORT OF PATIENTS, AGED 8¿21 YEARS, UNDERGOING SPINAL FUSION SURGERY USING ROBOTIC-ASSISTED TECHNOLOGY WAS REVIEWED. DIAGNOSES, COBB ANGLES, SURGICAL TIME, ROBOT TIME, NUMBER OF SCREWS PLACED, AND COMPLICATIONS WERE RECORDED. ACCURACY OF SCREW PLACEMENT WAS ASSESSED BASED ON ANALYSIS OF SUCCESSFUL SCREW EXECUTION, EVALUATION SCREW POSITION USING INTRAOPERATIVE FLUOROSCOPY AND POST-OPERATIVE RADIOGRAPHS, AND CLINICAL EVALUATION. THE AVERAGE AGE WAS 14.5 YEARS. PREVALENT DIAGNOSES INCLUDED IDIOPATHIC (65%) AND NEUROMUSCULAR SCOLIOSIS (13%). MEAN PREOPERATIVE CURVE MEASURED 66.8°. THE MEDIAN TIME FOR OPERATION WAS 235 MINUTES WITH MEDIANS OF 8 LEVELS FUSED AND 5 SCREWS PLACED PER PATIENT. OF THE 314 SCREWS PLACED,

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 TO TREAT DEGENERATIVE DISC WITH FIXATION. IT WAS REPORTED THAT THE LEFT L4 SCREW WAS DEVIATED DURING AN OPEN L4-L5 TLIF. THE SURGEON OPERATED ON THE RIGHT L4 AND L5 WITHOUT ISSUE SO THEY PROCEEDED TO THE LEFT SIDE. L4 WAS FIRST, FOLLOWED BY L5. WHEN EXECUTING L5, THE SURGEON FOUND THAT THE INCISION WAS NOT LARGE ENOUGH. THIS CAUSED EXCESSIVE LATERAL PRESSURE ON THE SURGICAL ARM FROM THE SOFT TISSUE AND LED TO THE SHOULDER UNLOCKING. THE SURGEON DECIDED TO ABORT THE USE OF THE GUIDANCE SYSTEM FOR LEFT L5. DURING THE PROCEDURE, THERE WAS AN ISSUE WITH AIR PRESSURE IN THE GUIDANCE SYSTEM. THE PNEUMATIC MOTOR WOULD NOT BOOT ON BY ITSELF. ONCE DURING THE OPERATION STEP AND ONCE AFTER THE PROCEDURE, A LOW PRESSURE ERROR MESSAGE WAS DISPLAYED AND THE SYSTEM HAD TO BE REBOOTED TO GET THE PRESSURE TO BE RESTORED. AFTER THE PROCEDURE, THE CONFIRMATION IMAGES SHOWED THAT L4 LEFT WAS MEDIAL BY 3 MM. THE SURGEON BELIEVED THIS WAS DUE TO THE EXCESSIVE PRESSURE PLACED ON THE SURGICAL ARM. L5 LEFT WAS ACCURATE. THE PATIENT WAS EXPERIENCING NERVE DAMAGE. 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: MEDTRONIC RECEIVED INFORMATION REGARDING A GUIDANCE SYSTEM BEING USED DURING A SPINAL PROCEDURE. IT WAS REPORTED THAT THE PATIENT WAS HAVING A REVISION SURGERY DUE TO A SCREW BEING PLACED INFERIORLY DURING A PROCEDURE ON (B)(6) 2020. THE S1 SCREW WAS DEVIATED. THE MANUFACTURER REPRESENTATIVE NOTED THAT IT WAS UNKNOWN HOW THE PLACEMENT BECAME INFERIOR AS ALL OTHER SCREW PLACEMENTS WERE NOTED TO BE FINE AND THERE WERE NO ISSUES WITH SKIVING OF THE SCREW. THE 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: MEDTRONIC RECEIVED INFORMATION REGARDING A GUIDANCE SYSTEM BEING USED DURING A SPINAL PROCEDURE. IT WAS REPORTED THAT A POST-OP SCAN SHOWED THAT LEFT L1-L3 SCREWS WERE DEVIATED LATERALLY BETWEEN 3.5-10 MM. DURING THE IMPLANT PROCEDURE, A SINGLE SCHANZ PIN WAS USED TO MOUNT THE SURGICAL SYSTEM TO THE PATIENT. THE LEFT SIDE WAS DONE FIRST AND THE RIGHT SIDE WAS SECOND. THE THORACIC SCREWS ON THE RIGHT SIDE WERE ACCURATE. INTRA-OP IMAGING WAS DONE AND THE IMAGES LOOKED GOOD. THE MANUFACTURER REPRESENTATIVE THOUGHT THERE COULD BE A SHIFT THAT CAUSED THE DEVIATION. THE PATIENT EXPERIENCED SOME DISCOMFORT AFTER THE PROCEDURE AND THEY WERE BROUGHT BACK IN FOR A REVISION TO REPOSITION THE SCREWS ON THE FOLLOWING DAY. 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: MEDTRONIC RECEIVED INFORMATION REGARDING A GUIDANCE SYSTEM BEING USED INTRA-OPERATIVELY OF A SPINAL PROCEDURE. IT WAS REPORTED THAT A SCREW DEVIATION WAS DISCOVERED. THE SCREWS WERE IMPLANTED DURING A L3-L4 CASE ON (B)(6) 2020 WITH NO ISSUES. THE SITE HAD TAKEN AP SHOTS TO CONFIRM SCREW PLACEMENT AFTER THE CASE; HOWEVER, THEY WERE UNABLE TO IDENTIFY THE DEVIATION FROM THOSE SHOTS. ON (B)(6) 2020, IT WAS DISCOVERED THAT THERE WAS A DEVIATION WHEN THE PA DID A FOLLOW UP VISIT WITH THE PATIENT SINCE THEY WERE STILL EXPERIENCING NERVE PAIN AND WEAKNESS IN THEIR LEGS. IT APPEARS THAT THE LEFT AND RIGHT L3 SCREWS ARE LATERAL BY 6 MM AND ARE NOT WITHIN THE PEDICLE. THE RIGHT L4 IS LATERAL BY 6 MM. BOTH MEASUREMENTS ARE APPROXIMATE FROM THE DISTAL END OF THE SCREW. THE REVISION PROCEDURE HAD NOT BEEN SCHEDULED. 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: ADDITIONAL INFORMATION RECEIVED FROM A MANUFACTURER REPRESENTATIVE REPORTED THAT L5 WAS ACTUALLY S1 AND THE L4 AND S1 SCREWS HAD EQUAL SHIFTS OFF THE CENTER OF THE PEDICLE.

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 TO TREAT DEGENERATIVE DISC USING FIXATION. IT WAS REPORTED THAT A JOINT 6 SHIFT OCCURRED DURING THE PROCEDURE. THE JOINT BROKE WHILE ON THE THIRD OUT OF FOUR TRAJECTORIES. THE TOOLS WERE ALREADY IN POSITION AND THE HOLE HAD BEEN DRILLED WHEN IT BROKE SO THE SURGEON RESUMED WITH THE WIRE. THE MANUFACTURER REPRESENTATIVE TRIED DOING A FULL SHUTDOWN OF THE SYSTEM 2-3 TIMES TO SEE IF THE ERROR WOULD DISAPPEAR, BUT THE ISSUE WAS NOT RESOLVED. THE SURGICAL ARM COULD NOT BE SENT TO THE RIGHT L5 TRAJECTORY. THE CASE WAS ABORTED DUE TO THE SHIFT AND THE FOURTH SCREW WAS PLACED FREEHAND. THE REPRESENTATIVE LATER REPORTED THAT THE THIRD SCREW WAS DETERMINED TO BE MISPLACED BY LESS THAN 3.5 MM. THE PATIENT HAD NEW RIGHT LEG PAIN AFTER THE SURGERY SO A CT WAS DONE AND THAT WAS WHEN THE SCREW WAS DETERMINED TO BE MEDIAL. A REVISION PROCEDURE USING THE GUIDANCE SYSTEM WAS DONE ON (B)(6) 2020 TO REPOSITION THE SCREW. THE SCREW WAS ACCURATELY PLACED DURING THE REVISION. THE INITIAL 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: MEDTRONIC RECEIVED INFORMATION REGARDING A GUIDANCE SYSTEM BEING USED DURING A SPINAL PROCEDURE TO TREAT DEGENERATIVE DISC WITH FIXATION. IT WAS REPORTED THAT DURING A L4-S1 REVISION CASE, THE RIGHT L5 SCREW DEVIATED FROM THE PLANNED TRAJECTORY. THE SCREW WAS DEVIATED APPROXIMATELY TWO MM INFERIOR. THE MANUFACTURER REPRESENTATIVE THOUGHT SURGICAL TECHNIQUE OF WORKING ON THE OPPOSITE SIDE OF SCREW PLACEMENT CAUSED THE DEVIATION. THE PATIENT DID EXPERIENCE SOME DISCOMFORT AND THEY HAD DEVELOPED A CYST IN THE SAME AREA OF THE SCREW AFTER THE SURGERY. THE SCREWS WERE REPOSITIONED ON (B)(6)2020 USING NAVIGATION TO ASSIST WITH THE DISCOMFORT. THE SURGEON INDICATED THAT IT WAS UNKNOWN WHETHER IT WAS THE SCREW, CYST OR BOTH THAT CAUSED THE PROBLEM. THERE WAS NO PATIENT HARM AND 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: MEDTRONIC RECEIVED INFORMATION REGARDING A GUIDANCE SYSTEM BEING USED INTRA-OPERATIVELY OF A SPINAL PROCEDURE TO TREAT DEGENERATIVE DISC WITH FIXATION. IT WAS REPORTED THAT A DAY AFTER THE SURGERY THEY DISCOVERED THAT THE L4 LEFT WAS MEDIAL TO PLAN. THE SUSPECTED CAUSE OF THE DEVIATION WAS SOFT TISSUE PRESSURE. A REVISION WAS DONE TO CORRECT THE SCREW. IT WAS UNKNOWN HOW MUCH THE SCREW WAS DEVIATED. THE MANUFACTURER REPRESENTATIVE HAD COMPLETED A 10 POINT ACCURACY CHECK TWICE AND THE SHOULDER CALIBRATION WAS IN SPECIFICATION AFTER THE PROCEDURE. THE GUIDANCE SYSTEM WAS USED IN TWO CASES WITHOUT ANY FURTHER ISSUE. THERE WAS NO PATIENT HARM AND THE 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: MEDTRONIC RECEIVED INFORMATION REGARDING A GUIDANCE SYSTEM BEING USED DURING A SPINAL PROCEDURE. IT WAS REPORTED THAT A T9-PELVIS CASE WAS BEING DONE. TWO PINS WERE PLACED IN THE PSIS TO MOUNT THE SURGICAL SYSTEM TO THE PATIENT. THE MANUFACTURER REPRESENTATIVE NOTED THAT THERE WAS A ROTATION IN THE SPINE. FOR THE T9-L2 SCREWS, THE LEFT SIDE WAS MEDIAL AND THE RIGHT SIDE WAS LATERAL. FOR THE SECOND SEGMENT, L3 TO S2AI, REGISTRATION WAS DONE AND THE SCREWS WERE PLACED. THE SCREWS ON THE LEFT SIDE WERE LATERAL AND MEDIAL ON THE RIGHT SIDE. THE REPRESENTATIVE DID NOT BELIEVE THERE WAS A TECHNIQUE ISSUE. THE S2 SCREWS WERE ACCURATE, BUT ALL OTHER SCREWS WERE SUPERIOR TO PLAN. A REVISION HAD TO BE DONE TO REPOSITION THE SCREWS. THERE WAS NO PATIENT HARM AND THE PROCEDURE WAS NOT 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: ABSTRACT: COMPUTERIZED NAVIGATION IS CURRENTLY WIDE SPREADING AROUND THE WORLD IN SPINE SURGERY, AIMING TO ALLOW MORE ACCURATE AND SAFE PROCEDURES. SINCE THE END OF THE 20TH CENTURY, NAVIGATION APPEARED TO BE SUPERIOR TO TRADITIONAL FREE-HAND TECHNIQUE TO INSERT PEDICLE SCREWS. THUS ITS USE IS BECOMING A GOLD STANDARD IN MANY FACILITIES. ROBOTIC GUIDANCE AIMS TO STABILIZE A ROBOTIC ARM AFTER SURGICAL PLANNING OF SCREW TRAJECTORY. THE MAZOR X STEALTH IS A RECENT DEVICE WHICH COMBINES ROBOTIC GUIDANCE AND NAVIGATION. THE AIM OF THE STUDY WAS TO COMPARE OPERATIVE AND RADIOLOGIC RESULTS AND ALSO RADIATION EXPOSURE BETWEEN THE MAZOR X STEALTH AND THE O-ARM NAVIGATION FOR PEDICLE SCREW INSERTION. MATERIAL AND METHODS: ALL PATIENTS WHO REQUIRED PEDICLE SCREW INSERTION FOR POSTERIOR LUMBAR FUSION WERE PROSPECTIVELY INCLUDED AND DIVIDED INTO TWO GROUPS: RG WHEN OPERATED WITH THE MAZOR X STEALTH, AND NV WHEN OPERATED WITH THE O-ARM AND NAVIGATION AS A CONTROL GROUP. AGE, OPERATIVE DATA SUCH AS NUMBER OF LEVELS OPERATED, NUMBER OF SCREWS INSERTED, OPERATIVE TIME IN MINUTES (MIN), ESTIMATED BLOOD LOSS (EBL IN MILLILITERS, ML), TIME TO INSERT SCREWS (IN MIN). SATISFACTION OF SCREW POSITIONING W

Mazor X — Injury report filed with FDA (MAUDE). A MAUDE report does not establish that the device caused the outcome. Reported narrative: DE BIASE, G., GRUENBAUM, B. F., BOJAXHI, E., PATTERSON, J. S., SABETTA, K., QUINONES-HINOJOSA, A., ABODE-IYAMAH, K. (2025). AWAKE MINIMALLY INVASIVE SURGERY TRANSFORAMINAL LUMBAR INTERBODY FUSION UNDER SPINAL ANESTHESIA: SCREW PLACEMENT ACCURACY AND 1 YEAR FOLLOW-UP. WORLD NEUROSURGERY, 194(123478), 1¿7. HTTPS://DOI.ORG/10.1016/J.WNEU.2024.11.061 OBJECTIVE: WE ASSESSED THE ACCURACY OF PEDICLE SCREWS PLACED DURING AWAKE MINIMALLY INVASIVE SURGERY (MIS) TRANSFORAMINAL LUMBAR INTERBODY FUSION (TLIF) UNDER SPINAL ANESTHESIA AND ANALYZED OUTCOMES AT THE 1-YEAR FOLLOW-UP. METHODS: WE INCLUDED PATIENTS WHO UNDERWENT AWAKE MIS-TLIF UNDER SPINAL ANESTHESIA AT AN ACADEMIC CENTER FROM FEBRUARY 2020 TO FEBRUARY 2022. THE GERTZBEIN-ROBBINS CLASSIFICATION WAS USED FOR SCREW ACCURACY RATING. RESULTS: A TOTAL OF 100 PEDICLE SCREWS WERE INSERTED IN 24 PATIENTS, WITH THE MOST COMMON LEVEL BEING L4-5. MEDIAN AGE WAS 63.5 ±16.5 (INTERQUARTILE RANGE) YEARS, 42% MALE, MEDIAN BODY MASS INDEX 28 ± 6 KG/M2, AND MEDIAN AMERICAN SOCIETY OF ANESTHESIOLOGISTS CLASS WAS 2 ± 1. TWO PATIENTS UNDERWENT A 2-LEVEL FUSION, AND 22 PATIENTS UNDERWENT A 1-LEVEL FUSION. MEDIAN ESTIMATED BLOOD LOSS WAS 35 ± 25 ML, MEDIAN