MAUDE Adverse Event Report: STRYKER GMBH LOCKING SCREW VARIAX 2 T10, FULL THREAD, 3.5MM / L65MM; PLATE, FIXATION, BONE

Model Number 657365S

Device Problem Positioning Failure (1158)

Patient Problem No Clinical Signs, Symptoms or Conditions (4582)

Event Date 10/12/2021

Event Type  malfunction  

Manufacturer Narrative

Upon completion of the investigation any additional information will be communicated in a supplemental report.

Event Description

It was reported there were three screws that did not lock, and each time the surgeon had them replaced with screws of the same size or 2 mm shorter.The replaced screws locked without any problem.

Event Description

It was reported there were three screws that did not lock, and each time the surgeon had them replaced with screws of the same size or 2 mm shorter.The replaced screws locked without any problem.

Manufacturer Narrative

The reported event could be confirmed.The returned locking screw was inspected under a microscope.The thread below the screw head which is intended to lock the screw in the plate, shows plastic deformation which could explain the loss of the angular locking ability.The damage pattern suggests high force application during locking attempts.A potential non-conformity report was initiated to address this event.The comprehensive root cause analysis of the potential ncr included a surface and microstructure analysis as well as nano-indent hardness measurement of variax1 and variax2 screw samples by the fraunhofer institute on behalf of stryker.Further internal investigation efforts were focusing on the anodization color difference between variax1 and variax2 screws.Significant differences between the screws which could result in the reported complaints have not been revealed in either fraunhofer or stryker investigations.Excessive in-house handling and bench testing with variax2 screws from various manufacturing batches showed that locking is achieved as intended.The desired increase in torque indicating to the customer that the screw is locking in the plate, can be confirmed.A review of the device history for the reported lot did not indicate any abnormalities.No deviation from the specifications was noted.No indications of material, manufacturing or design related problems were found during the investigation.A review of the labeling did not indicate any abnormalities.Considering the information given and based on the above investigations a root cause of the reported event could not be determined.If any further substantial information is provided, the investigation report will be updated.

• Brand Name: LOCKING SCREW VARIAX 2 T10, FULL THREAD, 3.5MM / L65MM
• Type of Device: PLATE, FIXATION, BONE
• Manufacturer (Section D): STRYKER GMBH; bohnackerweg 1; postfach; selzach 2545 ; SZ 2545
• Manufacturer (Section G): STRYKER GMBH; bohnackerweg 1; postfach; selzach 2545 ; SZ 2545
• Manufacturer Contact: marilyne chaumont ; 325 corporate drive; mahwah, NJ 07430 ; 2018315000
• MDR Report Key: 12777489
• MDR Text Key: 284899133
• Report Number: 0008031020-2021-00447
• Device Sequence Number: 1
• Product Code: HRS
• UDI-Device Identifier: 07613327087475
• UDI-Public: 07613327087475
• Combination Product (y/n): N
• Reporter Country Code: JA
• PMA/PMN Number: K132502
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: Health Professional
• Reporter Occupation: Physician
• Type of Report: Initial,Followup
• Report Date: 12/16/2021

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Expiration Date: 07/31/2023
• Device Model Number: 657365S
• Device Catalogue Number: 657365S
• Device Lot Number: Y21616
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 10/28/2021
• Is the Reporter a Health Professional?: Yes
• Initial Date Manufacturer Received: 10/12/2021
• Initial Date FDA Received: 11/09/2021
• Supplement Dates Manufacturer Received: 11/18/2021
• Supplement Dates FDA Received: 12/16/2021
• Was Device Evaluated by Manufacturer?: Yes
• Date Device Manufactured: 08/29/2018
• Is the Device Single Use?: Yes
• Is This a Reprocessed and Reused Single-Use Device?: No
• Type of Device Usage: Initial
• Patient Sequence Number: 1