MAUDE Adverse Event Report: STRYKER GMBH GAMMA4 - RC LAG SCREW D10.5X100MM; ROD, FIXATION, INTRAMEDULLARY AND ACCESSORIES

Catalog Number	81660100S
Medical Device Problem Code	Migration (4003)
Health Effect - Clinical Codes	Pain (1994); Perforation (2001)
Date of Event	10/08/2025
Type of Reportable Event	Serious Injury
Additional Manufacturer Narrative
Once the investigation has been completed any additional information will be reported in a supplemental report.
Event or Problem Description
As reported: "a gamma4 u-lag screw perforated the pelvis.The patient reported pain and this resulted in a revision surgery.".
Event or Problem Description
As reported: "a gamma4 u-lag screw perforated the pelvis.The patient reported pain and this resulted in a revision surgery." additional information: around (b)(6), the pain in the left hip joint gradually worsened and increased during rehabilitation.When the surgeon re-checked the x-ray, it revealed that the lag screw had perforated the pelvis.It was reported that during primary surgery, the set screw was not tightened when inserting the u-lag, and the u-blade was inserted without x-ray confirmation.
Additional Manufacturer Narrative
The reported event could be confirmed, since the migrated lag screw can be confirmed on the received x-rays as described in the event description.The device inspection revealed the following: the nail and the disassembled lag screw were returned for evaluation.The returned lag screw is in a very used condition, there are different very strong stress marks visible.One prong of the u-blade is excessively bent outwards.The reason for this deformation can in retrospective not be defined as it is unknown if this occurred during the insertion, in-situ or during the extraction.On none of the received x-rays is the position of the blade visible.The inspection of the lag screw has shown that we have on two sides on the top of one set screw groove excessive stress marks.The only explanation for this marks is a strong contact with the set screw.A microscopic inspection of the set screw grooves was made.Both grooves do not have the typical mark that occurs when the set screw is tightened in the groove.There is no indication that the set screw was ever in contact with one of the grooves.Based on these findings is can be concluded that the set screw was placed on top of the groove and not in the grooves as intended.The visual inspection of the nail set screw tips, which are placed in the grooves of the lag screw, has shown that both tips are damaged, one tip is partially flattened on one side and the other tip is completely flattened.The damages indicate that there was a strong contact between the set screw and the lag screw, but with a flat surface and not with the rounded groove as intended.The damage to the set screw matches the damage observed on the side of the lag screw grooves.Functional inspection: a functional test with the returned devices was performed.Despite the extensive damage to the devices it was still possible to place the set screw in the grooves as intended and the lag screw could be moved back and forth after the set screw was unscrewed for a quarter (1/4) of a turn as described in the operative technique.A review of the device history for the reported lot did not indicate any abnormalities.No corrective actions are required at this time.A review of the labeling did not indicate any abnormalities.No indications of material, manufacturing or design related problems were found during the investigation.Based on investigation, the root cause was attributed to a user related issue.The event was by an incorrect placement of the nail set screw, the screw was placed in one of the grooves of the lag screw as intended.In this relation following statements of the gamma4 hip fracture nailing system operative technique can be pointed out: - caution the set screw has to be placed before u-blade insertion.- warning the set screw must be used.Insufficient set screw placement could lead to loss of lag screw fixation and postoperative complications.If more information is provided, the case will be reassessed.

• Brand Name: GAMMA4 - RC LAG SCREW D10.5X100MM
• Common Device Name: ROD, FIXATION, INTRAMEDULLARY AND ACCESSORIES
• Manufacturer (Section D): STRYKER GMBH; bohnackerweg 1; postfach; selzach 2545 ; SZ 2545
• Manufacturer (Section G): STRYKER TRAUMA KIEL; prof. kuentscher-strasse 1-5; schoenkirchen/kiel D-242 32; GM D-24232
• Manufacturer Contact: dannielle stap ; 325 corporate drive; mahwah, NJ 07430 ; 2018315000
• MDR Report Key: 23477346
• Report Number: 0008031020-2025-02040
• Device Sequence Number: 10526557
• Product Code: HSB
• UDI-Device Identifier: 07613327591897
• UDI-Public: (01)07613327591897(17)341130(10)K0FA147
• Combination Product (Y/N): N
• Initial Reporter Country: JA
• PMA/510(K) Number: K230512
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2025
• Device Explanted Year: 2025
• Reporter Type: Manufacturer
• Report Source: Health Professional
• Initial Reporter Occupation: Physician
• Type of Report: Initial,Followup
• Report Date (Section B): 01/21/2026

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?: Yes
• Operator of Device: Lay User/Patient
• Device Catalogue Number: 81660100S
• Device Lot Number: K0FA147
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 10/23/2025
• Is the Reporter a Health Professional?: Yes
• Type of Report(Section G): Follow-Up
• Initial Date Received by Manufacturer: 10/08/2025
• Supplement Date Received by Manufacturer: 12/23/2025
• Initial Report FDA Received Date: 11/05/2025
• Supplement Report FDA Received Date: 01/21/2026
• Was Device Evaluated by Manufacturer? (Y/N): Yes
• Date Device Manufactured: 12/12/2024
• 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 Age: 72 YR
• Patient Sex: Male