MAUDE Adverse Event Report: STRYKER GMBH LOCKING SCREW VARIAX2 T10, FULL THREAD, 3.5MM / L16MM; SCREW, FIXATION, BONE

Catalog Number	657316
Medical Device Problem Code	Difficult to Insert (1316)
Health Effect - Clinical Code	No Known Impact Or Consequence To Patient (2692)
Date of Event	09/13/2019
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
It couldn't lock on the plate.Another screw was used and could lock.No adverse consequences or surgical delay reported.
Event or Problem Description
It couldn't lock on the plate.Another screw was used and could lock.No adverse consequences or surgical delay reported.
Additional Manufacturer Narrative
The reported event could be confirmed.The device inspection revealed the following: the thread below the head of the screw is plastically deformed, in a way that the pitch between two consecutive threads diminishes.This naturally results in an inability to lock the screw on the plate, since there is not enough space for the lip on the plate to engage the screw head.As a result, the screw can not be locked into a plate.The root cause of the deformation of the screw is most probably an introduction of the screw with an improper angle.Indeed, note that the insertion angle of the locking screw should be a cone with 30° angle.Any excesses in the angulation might lead to the non function of the locking mechanism and even the damage of the thread of the screw.Operative technique guide states: ¿the polyaxial locking technology works by using two different grades of titanium.Locking screws are made of titanium alloy (ti6a14v) which is stronger than the pure titanium plate.When a screw is driven into a plate hole, the locking threads on the underside of the screw head engage the circular ¿lip¿ in the hole.This technology allows the surgeon to aim and lock the screw within a 30° cone." as a summary, this case can be classified as user related.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.If any further information is provided, the investigation report will be updated.

• Brand Name: LOCKING SCREW VARIAX2 T10, FULL THREAD, 3.5MM / L16MM
• Common Device Name: SCREW, FIXATION, BONE
• Manufacturer (Section D): STRYKER GMBH; bohnackerweg 1; postfach; selzach 2545 ; CH 2545
• MDR Report Key: 9188155
• Report Number: 0008031020-2019-01433
• Device Sequence Number: 3094921
• Product Code: HWC
• UDI-Device Identifier: 07613327086874
• UDI-Public: 07613327086874
• Combination Product (Y/N): N
• PMA/510(K) Number: K180500
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Reporter Type: Manufacturer
• Report Source: health professional
• Initial Reporter Occupation: Physician
• Type of Report: Initial,Followup
• Report Date (Section B): 12/30/2019

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: 02/29/2024
• Device Catalogue Number: 657316
• Device Lot Number: D20023
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 10/29/2019
• Initial Date Received by Manufacturer: 09/24/2019
• Supplement Date Received by Manufacturer: 12/04/2019
• Initial Report FDA Received Date: 10/14/2019
• Supplement Report FDA Received Date: 12/30/2019
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Patient Sequence Number: 1