MAUDE Adverse Event Report: MEDACTA INTERNATIONAL SA AMISTEM-P; AMISTEM-P LAT. SIZE2

Model Number	01.18.412
Medical Device Problem Code	Fracture (1260)
Health Effect - Clinical Code	Insufficient Information (4580)
Date of Event	10/29/2025
Type of Reportable Event	Serious Injury
Additional Manufacturer Narrative
Batch review performed on 11 november 2025.Stem: amistem p 01.18.412 amistem-p lat.Size 2 (k173794) lot 2200388: (b)(4) items manufactured and released on 22-apr-2022.Expiration date: 08-apr-2027.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.Ball heads: mectacer 01.29.209 mectacer head biolox delta dia.36 12/14-m (k112115) lot 2213125: (b)(4) items manufactured and released on 06-sep-2022.Expiration date: 22-aug-2027.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.Clinical evaluation: about 3 years after primary cementless tha, the stem fractured at stem-neck junction with no traumatic event.Through further enquiry, it was ascertained that after primary tha, the same day, a second operation was carried out on the same hip due to instability, and a ceramic head with a metal internal sleeve was used, as appropriate.This second operation was most probably done to increase soft tissue tension, as they changed from length m to xl.However, when re-accessing the joint, it is very likely that a small superficial damage may have been done, for instance by inadvertently touching the metallic stem with the electrocauter.This may create a small indentation that can act as a stress raiser, and limit the fatigue resistance of the stem, as widely published in literature and reported in the instructions for use.These damages are often very difficult, if not impossible, to be seen by the naked eye, but their effect can be deleterious, if by misfortune they happen to be in the most stressed area of the construct.Detailed analysis of the explant may confirm the origin of the fracture.
Event or Problem Description
Revision surgery performed about 3 years after the primary surgery due to stem neck breakage while the patient was getting out of the car.On the same day of the primary surgery, the patient was brought back into the operating room to stabilize the joint.Ceramic head size m was removed and biolox option and xl sleeve were implanted to stabilize the joint.
Additional Manufacturer Narrative
Fu1: the device was received on 03 dec 2025.Further analysis results will be provided at a later stage, as more in-depth evaluations are currently ongoing.
Additional Manufacturer Narrative
External laboratory analysis conclusions: on the distal side, the final part of the fracture shows dimple ductile features typical of overload.Multiple origins were detected in the neck surface on the proximal side.Irregular areas with melted morphologies were highlighted by sem (scanning electron microscope) examinations on the proximal side, in correspondence and in proximity to the area of origin.The principal origin is indicated in image 1 by a red dot, but several probable origins can be detected (blue dots).Two "indentations" are probably due to removal surgery.Based on the results of the analyses carried out, it is possible to affirm that the prosthesis yielded due to mechanical fatigue propagation of a crack (ca.90% of the fracture surface area) initiated by surface damages due to very localized heat exposure.The localized exposure to high temperatures could have led to the genesis of brittle microstructures.It is possible that these damages originated during the first surgery.The propagation of the crack occurred, during time, for monodirectional flexure, compatible to the common walking load.Root cause: the prosthesis breakage was caused by fatigue crack propagation initiated by surface damage associated with a very localized heat exposure, which probably occurred during the primary surgery or when revising the prothesis as reported on the day of the primary surgery, with progressive expansion over time under physiological cyclic loading.The investigation does not indicate any potential manufacturing or design related issue.

• Brand Name: AMISTEM-P
• Common Device Name: AMISTEM-P LAT. SIZE2
• 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: 23669496
• Report Number: 3005180920-2025-01129
• Device Sequence Number: 13186593
• Product Code: LZO
• UDI-Device Identifier: 07630040720113
• UDI-Public: 07630040720113
• Combination Product (Y/N): N
• PMA/510(K) Number: K173794
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2022
• 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,Followup
• Report Date (Section B): 03/24/2026

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: 01.18.412
• Device Lot Number: 2200388
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 10/29/2025
• Supplement Date Received by Manufacturer: Not provided; Not provided
• Initial Report FDA Received Date: 11/28/2025
• Supplement Report FDA Received Date: 12/19/2025; 03/24/2026
• Was Device Evaluated by Manufacturer? (Y/N): No
• Date Device Manufactured: 04/22/2022
• 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: 63 YR
• Patient Sex: Male
• Patient Race: White