MAUDE Adverse Event Report: STRYKER GMBH LOCKING SCREW,T8 FULL THREAD, 2.7MM/L22MM; SCREW, FIXATION, BONE

Model Number	656322S
Medical Device Problem Codes	Positioning Failure (1158); Material Twisted/Bent (2981)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	11/05/2020
Type of Reportable Event	Malfunction
Additional Manufacturer Narrative
Upon completion of investigation, additional information will be provided in a supplemental report.
Event or Problem Description
As reported: "variax2 did not lock.The screw head was crushed even though the drill guide fits in the plate screw hole.".
Event or Problem Description
As reported: "variax2 did not lock.The screw head was crushed even though the drill guide fits in the plate screw hole.".
Additional Manufacturer Narrative
The reported event could be confirmed.The device was inspected under a microscope.The threads of the locking mechanism below the screw head saw a plastic deformation which could explain the loss of the angular locking ability.Some portions of the crest of the thread flank have sheared off under significant force.An nc was opened to address this event.Furthermore, as part of the root cause analysis, variax1 and variax 2 screws were sent for analysis to an independent laboratory.The institute carried out surface and microstructure analysis as well as nano-indent hardness measurement of the variax2 and variax1 samples.The institute concluded that there are no significant differences between the screws.The test results were further evaluated by a consulted material specialist while considering the internal manufacturing process.The material expert reconfirmed that there are no significant differences between the screws which could result in the reported complaints.In parallel, investigation efforts were focusing on the anodization color difference between variax1 and variax2 screws.The results revealed no connection between the anodization color and the reported complaints.Excessive in-house handling and bench testing with variax2 screws from various manufacturing batches showed that locking is achieved as intended.We can confirm the desired increase in torque indicating to the customer that the screw is locking in the plate.A review of the device history for the reported lot did not indicate any abnormalities.A review of the labeling did not indicate any abnormalities.If any further information is provided, the investigation report will be updated.

• Brand Name: LOCKING SCREW,T8 FULL THREAD, 2.7MM/L22MM
• Common Device Name: SCREW, FIXATION, BONE
• Manufacturer (Section D): STRYKER GMBH; bohnackerweg 1; postfach; selzach 2545 ; SZ 2545
• MDR Report Key: 10931521
• Report Number: 0008031020-2020-02545
• Device Sequence Number: 14072989
• Product Code: HWC
• UDI-Device Identifier: 07613327070729
• UDI-Public: 07613327070729
• Combination Product (Y/N): N
• Initial Reporter Country: JA
• PMA/510(K) Number: K180500
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Reporter Type: Manufacturer
• Report Source: company representative
• Initial Reporter Occupation: Other
• Type of Report: Initial,Followup
• Report Date (Section B): 04/12/2021

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
• Operator of Device: Health Professional
• Device Expiration Date: 04/15/2025
• Device Model Number: 656322S
• Device Catalogue Number: 656322S
• Device Lot Number: 100404011
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 11/26/2020
• Initial Date Received by Manufacturer: 11/05/2020
• Supplement Date Received by Manufacturer: 03/23/2021
• Initial Report FDA Received Date: 12/02/2020
• Supplement Report FDA Received Date: 04/12/2021
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Patient Sequence Number: 1
• Patient Age: 72 YR