MAUDE Adverse Event Report: MEDACTA INTERNATIONAL SA M.U.S.T. PEDICLE SCREW SYSTEM; MUST LT 15MM SHORT - PEDICLE SCREW Ø7X35 CANN

Model Number	03.57.033
Medical Device Problem Code	Migration (4003)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	08/20/2025
Type of Reportable Event	Serious Injury
Event or Problem Description
Fixation l4-l5.After surgery, it was recognised that a set screw came off.The patient was immediately reoperated and the setscrew replaced.
Additional Manufacturer Narrative
Batch review performed on 04 september 2025: must lt 03.57.033 must lt 15mm short - pedicle screw ø7x35 cann lot 2562202: (b)(4) items manufactured and released on 16/07/2025.Expiration date: 22/06/2030.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.Additional devices involved, batch review performed on 04 september 2025: must lt 03.57.033 must lt 15mm short - pedicle screw ø7x35 cann (k203482) lot 2561628: (b)(4) items manufactured and released on 20/06/2025.Expiration date: 05/06/2030.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.Must lt 03.57.034 must lt 15mm short - pedicle screw ø7x40 cann (k203482) lot 2560859: (b)(4) items manufactured and released on 28/05/2025.Expiration date: 13/05/2030.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.Must lt 03.57.034 must lt 15mm short - pedicle screw ø7x40 cann (k203482) lot 2559466: (b)(4) items manufactured and released on 11/04/2024.Expiration date: 24/03/2030.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.Pedicle screw 03.51.10.0625 torque limiter handle 9nm - extension compatible lot 2156153: (b)(4) items manufactured and released on 17-mar-2022.No anomalies found related to the problem.To date, no similar events have been reported on the same lot.Clinical evaluation performed by medical affairs department: a set screw disengaged immediately after an l4-l5 spinal fusion surgery.Postoperative radiographic images clearly confirmed the occurrence.The final tightening was reportedly performed correctly, and stability was checked before wound closure.Identifying a definitive explanation remains challenging.One hypothesis is that the left rod, being slightly long, may have interfered with the proximal anatomical structures, preventing complete seating into the tulip.Consequently, removal of the extended tap may have exposed the last thread of the set screw, leading to loosening of the fixation.Further analysis of the instruments used and retrieved components may provide additional insights.The patient was successfully reoperated on immediately, with the loose set screw removed and replaced without complications.Preliminary investigation performed by r&d spine director: as discussed with the surgeon, the left rod looks long; a potential scenario could be that the rod interfered with the anatomy/bone, which did not allow to get the rod to be fully seated inside the tulip when applying the final tightening.As a consequence, the set screw potentially came off when they removed the extended tap.Visual inspection performed by r&d project manager: the setscrew has been measured and is compliant with the drawing.It has been tested in a pedicle screw, and final tightening was successfully achieved.One of the tabs shows small burrs on the external surface.Another tab has one deformed thread.The torque limiter has been tested using a calibrated torque testing machine, and the measured values are within the specified tolerance range.A possible cause of the issue is that the rod interfered with the anatomy/bone, preventing it from being fully seated inside the tulip during final tightening and/or the setscrew may have been in a cross-threaded position.As a result, when the extension tab broke, the setscrew came off.The possibility of the tulip opening during tab breakage is considered less likely, as in that case, final tightening would not have been achievable the second time.Conclusion: a plausible intraoperative scenario is that the rod impinged on the adjacent bony or anatomical structures, hindering its complete seating within the tulip during the final tightening step.Consequently, upon removal of the extended tap, the set screw may have disengaged.

• Brand Name: M.U.S.T. PEDICLE SCREW SYSTEM
• Common Device Name: MUST LT 15MM SHORT - PEDICLE SCREW Ø7X35 CANN
• Manufacturer (Section D): MEDACTA INTERNATIONAL SA; strada regina; castel san pietro, switzerland 6874 ; SZ 6874
• Manufacturer (Section G): MEDACTA INTERNATIONAL SA; strada regina; castel san pietro, switzerland 6874 ; SZ 6874
• Manufacturer Contact: marco giannessi ; strada regina; castel san pietro, switzerland 6874 ; SZ 6874
• MDR Report Key: 23081977
• Report Number: 3005180920-2025-00846
• Device Sequence Number: 17304458
• Product Code: NKB
• UDI-Device Identifier: 07630971278448
• UDI-Public: 07630971278448
• Combination Product (Y/N): N
• Initial Reporter Country: JA
• PMA/510(K) Number: K203482
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2025
• Device Explanted Year: 2025
• Serviced by Third Party (Y/N): N
• Reporter Type: Manufacturer
• Report Source: Company Representative
• Initial Reporter Occupation: Non-Healthcare Professional
• Type of Report: Initial
• Report Date (Section B): 09/18/2025

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: No
• Operator of Device: Health Professional
• Device Model Number: 03.57.033
• Device Lot Number: 2562202
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 09/16/2025
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 08/20/2025
• Initial Report FDA Received Date: 09/18/2025
• Was Device Evaluated by Manufacturer? (Y/N): No
• Date Device Manufactured: 07/16/2025
• Is the Device Labeled for Single Use? (Y/N): Yes
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Usage of Device: Initial
• Patient Sequence Number: 1
• Outcome Attributed to Adverse Event: Required Intervention
• Patient Age: 60 YR
• Patient Sex: Male
• Patient Weight: 69 KG
• Patient Ethnicity: Non Hispanic
• Patient Race: Asian