M.U.S.T. PEDICLE SCREW SYSTEM

Additional Manufacturer Narrative

IT WAS NOT POSSIBLE TO DETERMINE WHICH PEDICLE SCREW WAS DIRECTLY INVOLVED IN THE SET SCREW LOOSENING. THEREFORE, THE HISTORY RECORD REVIEW WAS CONDUCTED FOR ALL POTENTIALLY INVOLVED IMPLANTS. BATCH REVIEW PERFORMED ON 08 JULY 2026 03.52.358 ENH POLY-AXIAL PEDICLE SCREW - CANNULATED 8X80MM (K203482) LOT. 2559942: (B)(4) ITEMS MANUFACTURED AND RELEASED ON 05 MAY 2025. EXPIRATION DATE: 13 APRIL 2030. NO ANOMALIES FOUND RELATED TO THE PROBLEM. TO DATE, (B)(4) ITEMS OF THE SAME LOT HAVE BEEN SOLD WITH NO SIMILAR REPORTED EVENT DURING THE PERIOD OF REVIEW. 03.52.358 ENH POLY-AXIAL PEDICLE SCREW - CANNULATED 8X80MM (K203482) LOT. 2564193: (B)(4) ITEMS MANUFACTURED AND RELEASED ON 09 OCTOBER 2025. EXPIRATION DATE: 22 SEPTEMBER 2030. NO ANOMALIES FOUND RELATED TO THE PROBLEM. TO DATE, (B)(4) ITEMS OF THE SAME LOT HAVE BEEN SOLD WITH ONE SIMILAR REPORTED EVENT DURING THE PERIOD OF REVIEW. 03.52.325 ENH. CANN. PEDICLE SCREW 6X50MM + NUT (1X) STERILE (K141988) LOT. 2658258: (B)(4) ITEMS MANUFACTURED AND RELEASED ON NAN. EXPIRATION DATE: 19 FEBRUARY 2031. NO ANOMALIES FOUND RELATED TO THE PROBLEM. TO DATE, (B)(4) ITEMS OF THE SAME LOT HAVE BEEN SOLD WITH ONE SIMILAR REPORTED EVENT DURING THE PERIOD OF REVIEW. 03.52.324 ENH. CANN. PEDICLE SCREW 6X45MM + NUT (1X) STERILE (K141988) LOT. 2565277: (B)(4) ITEMS MANUFACTURED AND RELEASED ON 17 NOVEMBER 2025. EXPIRATION DATE: 22 OCTOBER 2030. NO ANOMALIES FOUND RELATED TO THE PROBLEM. TO DATE, (B)(4) ITEMS OF THE SAME LOT HAVE BEEN SOLD WITH NO SIMILAR REPORTED EVENT DURING THE PERIOD OF REVIEW. 03.52.324 ENH. CANN. PEDICLE SCREW 6X45MM + NUT (1X) STERILE (K141988) LOT. 2568596: (B)(4) ITEMS MANUFACTURED AND RELEASED ON NAN. EXPIRATION DATE: 19 JANUARY 2031. NO ANOMALIES FOUND RELATED TO THE PROBLEM. TO DATE, (B)(4) ITEMS OF THE SAME LOT HAVE BEEN SOLD WITH NO SIMILAR REPORTED EVENT DURING THE PERIOD OF REVIEW. 03.52.324 ENH. CANN. PEDICLE SCREW 6X45MM + NUT (1X) STERILE (K141988) LOT. 2567478: (B)(4) ITEMS MANUFACTURED AND RELEASED ON NAN. EXPIRATION DATE: 17 DECEMBER 2030. NO ANOMALIES FOUND RELATED TO THE PROBLEM. TO DATE, (B)(4) ITEMS OF THE SAME LOT HAVE BEEN SOLD WITH NO SIMILAR REPORTED EVENT DURING THE PERIOD OF REVIEW. 03.52.324 ENH. CANN. PEDICLE SCREW 6X45MM + NUT (1X) STERILE (K141988) LOT. 2567274: (B)(4) ITEMS MANUFACTURED AND RELEASED ON NAN. EXPIRATION DATE: 08 DECEMBER 2030. NO ANOMALIES FOUND RELATED TO THE PROBLEM. TO DATE, (B)(4) ITEMS OF THE SAME LOT HAVE BEEN SOLD WITH NO SIMILAR REPORTED EVENT DURING THE PERIOD OF REVIEW. 03.52.324 ENH. CANN. PEDICLE SCREW 6X45MM + NUT (1X) STERILE (K141988) LOT. 2566075: (B)(4) ITEMS MANUFACTURED AND RELEASED ON 09 DECEMBER 2025. EXPIRATION DATE: 06 NOVEMBER 2030. NO ANOMALIES FOUND RELATED TO THE PROBLEM. TO DATE, (B)(4) ITEMS OF THE SAME LOT HAVE BEEN SOLD WITH NO SIMILAR REPORTED EVENT DURING THE PERIOD OF REVIEW. 03.52.316 ENH. CANN. PEDICLE SCREW 5X50MM + NUT (1X) STERILE (K141988) LOT. 1923079F: (B)(4) ITEMS MANUFACTURED AND RELEASED ON 18 MARCH 2025. EXPIRATION DATE: 26 FEBRUARY 2030. NO ANOMALIES FOUND RELATED TO THE PROBLEM. TO DATE, (B)(4) ITEMS OF THE SAME LOT HAVE BEEN SOLD WITH NO SIMILAR REPORTED EVENT DURING THE PERIOD OF REVIEW. CLINICAL EVALUATION PERFORMED BY MEDICAL AFFAIRS DEPARTEMENT THE COMPLAINT CONCERNS A REVISION SURGERY PERFORMED DUE TO LOOSENING / BACK-OUT OF THREE PROXIMAL SET SCREWS ON THE RIGHT ROD OF A POSTERIOR SPINAL FIXATION CONSTRUCT. THE AVAILABLE RADIOGRAPHS CLEARLY CONFIRM UNSCREWING OF THE SET SCREWS. THE SURGEON PERFORMED A REOPERATION, RECOVERED ALL THREE COMPONENTS, AND RE-LOCKED THE ROD PROXIMALLY. THE FAILURE PATTERN IS COMPATIBLE WITH MECHANICAL LOSS OF LOCKING AT THE SET SCREW-TULIP INTERFACE. A TIGHTENING-RELATED ISSUE DURING THE PRIMARY SURGERY REPRESENTS A PLAUSIBLE HYPOTHESIS, PARTICULARLY IF THE SET SCREWS WERE NOT TIGHTENED TO THE REQUIRED TORQUE, IF THE ROD WAS INCOMPLETELY SEATED WITHIN THE TULIPS, OR IF THE TORQUE-LIMITING SCREWDRIVER DID NOT PERFORM AS INTENDED. PERSISTENT CYCLIC LOADING RELATED TO DELAYED OR ABSENT FUSION MAY ALSO HAVE CONTRIBUTED; HOWEVER, FUSION STATUS IS NOT AVAILABLE. AT THIS STAGE, NO DEFINITIVE ROOT CAUSE CAN BE DETERMINED. TECHNICAL INVESTIGATION OF THE TORQUE-LIMITING SCREWDRIVER WOULD BE USEFUL TO ASSESS WHETHER THE INSTRUMENT DELIVERED THE REQUIRED TIGHTENING TORQUE AND TO SUPPORT ROOT-CAUSE EVALUATION. ROOT CAUSE:ALTHOUGH A DEFINITIVE ROOT CAUSE COULD NOT BE ESTABLISHED BASED ON THE AVAILABLE INFORMATION, THE HISTORICAL RECORDS OF ALL POTENTIALLY INVOLVED PEDICLE SCREWS DID NOT REVEAL ANY DISCREPANCIES. THEREFORE, BASED ON THE AVAILABLE EVIDENCE, THE EVENT MAY BE RELATED TO INADEQUATE TIGHTENING DURING THE PRIMARY SURGERY.

Description of Event or Problem

REVISION SURGERY WAS PERFORMED DUE TO LOOSENING OF THE SET SCREWS. THE SURGERY WAS COMPLETED SUCCESSFULLY BY REPLACING THE SET SCREWS.