MAUDE Adverse Event Report: MEDACTA INTERNATIONAL SA M.U.S.T. MINI POLYAXIAL SCREW; MUST MINI CANN.POLY.SCREW-FULL THR-4.0X28+NUT

Model Number	03.75.209
Medical Device Problem Codes	Adverse Event Without Identified Device or Use Problem (2993); Migration (4003)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	07/28/2025
Type of Reportable Event	Serious Injury
Additional Manufacturer Narrative
Batch review performed on 29 jul 2025.Must mini 03.75.209 must mini cann.Poly.Screw-full thr-4.0x28+nut (k171369) lot.2462499: (b)(4) items manufactured and released on 20-sept-2024.Expiration date: 2029-09-04.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 mini 03.75.209 must mini cann.Poly.Screw-full thr-4.0x28+nut (k171369) lot.2460852: (b)(4) items manufactured and released on 16-jul-2024.Expiration date: 2029-06-30.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 mini 03.75.209 must mini cann.Poly.Screw-full thr-4.0x28+nut (k171369) lot 2127542: (b)(4) items manufactured and released on 19-jan-2022.Expiration date: 2026-12-20.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 mini 03.75.209 must mini cann.Poly.Screw-full thr-4.0x28+nut (k171369) lot 2126585: (b)(4) items manufactured and released on 16-dec-2021.Expiration date: 2026-11-29.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 mini 03.75.209 must mini cann.Poly.Screw-full thr-4.0x28+nut (k171369) lot.1922084b: (b)(4) items manufactured and released on 29-oct-2024.Expiration date: 2029-10-14.No anomalies found related to the problem.To date, all items of the same lot have been sold with no similar reported event during the period of review.One of the five screws mentioned above is involved.All batches are being reported, as it is not yet known which one is involved.A conclusion has yet to be established as the devices have not been returned and analyzed.
Event or Problem Description
Primary surgery was performed at c2-c7 with myspine cervical guide on (b)(6).A ct scan two weeks after surgery showed no problems, but three weeks after surgery, it was discovered that the set screw at the right side of c7 had come loose.Revision surgery was performed after two months to replace with the new set screw.
Additional Manufacturer Narrative
Visual inspection performed by r&d project manager.Based on the event description, it was supposed that the threading interface of the device was damaged due to a cross-threading, causing the loosening of the setscrew component.A visual inspection and a functional test were performed on the retrieved device: no visual defects were observed.The threading profile was as good as intact and it was possible to load and fix the setscrew under 3nm torque as per standard procedure.In conclusion, it was not possible to identify the root cause that led to the setscrew loosening from the tulip component.Conclusions: the device was found to be in accordance with specifications, with no defects detected, and the device history record review did not indicate any potentially related manufacturing issue.Although the specific circumstances cannot be verified, it is most likely that unique application-specific factors, such as insufficient tightening torque at the time of device application, contributed to the reported issue.

• Brand Name: M.U.S.T. MINI POLYAXIAL SCREW
• Common Device Name: MUST MINI CANN.POLY.SCREW-FULL THR-4.0X28+NUT
• 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: 22902796
• Report Number: 3005180920-2025-00796
• Device Sequence Number: 8018090
• Product Code: KWP
• UDI-Device Identifier: 07630030863875
• UDI-Public: 07630030863875
• Combination Product (Y/N): N
• Initial Reporter Country: JA
• PMA/510(K) Number: K171369
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2025
• Device Explanted Year: 2025
• Serviced by Third Party (Y/N): Unknown
• Reporter Type: Manufacturer
• Report Source: Company Representative
• Initial Reporter Occupation: Non-Healthcare Professional
• Type of Report: Initial,Followup
• Report Date (Section B): 09/26/2025

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: 03.75.209
• Device Lot Number: 2462499
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 07/28/2025
• Supplement Date Received by Manufacturer: Not provided
• Initial Report FDA Received Date: 08/27/2025
• Supplement Report FDA Received Date: 09/26/2025
• Was Device Evaluated by Manufacturer? (Y/N): Yes
• Date Device Manufactured: 09/20/2024
• 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 Sex: Male
• Patient Ethnicity: Non Hispanic
• Patient Race: Asian