MAUDE Adverse Event Report: MEDACTA INTERNATIONAL SA M.U.S.T. MINI POLYAXIAL SCREW; MUST MINI CANN.POLY.SCREW-FULL THR-4.0X22+NUT

Model Number	03.75.206
Medical Device Problem Code	Adverse Event Without Identified Device or Use Problem (2993)
Health Effect - Clinical Code	Aseptic loosening (4883)
Date of Event	07/30/2025
Type of Reportable Event	Serious Injury
Event or Problem Description
At 4 months from the primary, the patient came in reporting cervical spine instability attributed to loosening of a 4.0 x 22 mm screw at the c2 vertebral level.The surgeon revised the 4.0 x 22mm screw with a 4.5 x 26mm screw and the surgery was completed successfully.
Additional Manufacturer Narrative
Batch review performed on 04 aug 2025: lot 2229123: (b)(4) items manufactured and released on 15-feb-2023.Expiration date: 2028-01-22.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 department: a revision surgery was performed approximately 4 months after a cervical procedure, due to cervical spine instability.The surgeon attributed this instability to loosening of a c2 screw (laterality not specified).Based on the single available amplioscopic image, however, it is very difficult to confirm this type of failure.With the current imaging and limited information, it is challenging to determine the exact cause of the reported failure.In general, screw loosening occurring a few months after surgery may result from the absence of osseous fusion, which exposes the implants to incongruous stress even under physiological mechanical loading.However, at present, there is insufficient evidence to draw definitive conclusions.Conclusions: based on the information available, no definitive root cause can be established.The most plausible contributing factor is the lack of solid osseous fusion postoperatively, which may have led to screw loosening under physiological loading conditions.There is no evidence to suggest that any device-related issue caused or contributed to the event, and the device history record review did not reveal any manufacturing-related nonconformities.

• Brand Name: M.U.S.T. MINI POLYAXIAL SCREW
• Common Device Name: MUST MINI CANN.POLY.SCREW-FULL THR-4.0X22+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: 22894882
• Report Number: 3005180920-2025-00784
• Device Sequence Number: 5986459
• Product Code: NKG
• UDI-Device Identifier: 07630030863844
• UDI-Public: 07630030863844
• Combination Product (Y/N): N
• Initial Reporter Country: US
• 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): N
• Reporter Type: Manufacturer
• Report Source: Other
• Initial Reporter Occupation: Non-Healthcare Professional
• Type of Report: Initial
• Report Date (Section B): 08/26/2025

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: 03.75.206
• Device Lot Number: 2229123
• Was Device Available for Evaluation?: No
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 07/30/2025
• Initial Report FDA Received Date: 08/26/2025
• Was Device Evaluated by Manufacturer? (Y/N): No
• Date Device Manufactured: 02/15/2023
• 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: 79 YR
• Patient Sex: Female
• Patient Race: White