MAUDE Adverse Event Report: STRYKER GMBH LOCKING SCREW,T8 FULL THREAD, 2.7MM/L18MM; SCREW, FIXATION, BONE

Catalog Number 656318

Device Problems Difficult to Remove (1528); Physical Resistance/Sticking (4012)

Patient Problem No Known Impact Or Consequence To Patient (2692)

Event Date 07/18/2019

Event Type  malfunction  

Manufacturer Narrative

Upon completion of investigation, additional information will be provided in a supplemental report.

Event Description

As reported: "variax screws locked into the plate and would not come out" and "needed to completely remove our product and put a different product in".

Event Description

As reported: "variax screws locked into the plate and would not come out" and "needed to completely remove our product and put a different product in." additionally reported: "these each locked into the plate but were spinning as if they weren¿t locked.The heads did not strip but the surgeon was unable to back the screw out from the plate, and had to rip the entire construct out as one.This was the first case with this patient and was not a revision surgery.".

Manufacturer Narrative

The reported event could not be confirmed, however the returned device was found to be damaged.Based on investigation, the root cause was attributed to be user related.The failure was caused by inadequate force during screw insertion.The device inspection revealed the following: the returned plate as well as most of the screws show severe damages / deformations.One screw is still positioned / stuck in the plate hole (spinning though).A close up of this screw shows that the locking thread is indeed badly damaged (unwound), which disables the screw from disengaging from the plate (stuck but still spinning).Similar deformations can be seen on the other screws as well, also most of the screw head interfaces are severely damaged / deformed which clearly indicates that high mechanical force was applied during screw insertion.Therefore the damages were caused during insertion as well as during removal.Note that the bone screw is still intact.Operative technique guide states: "note: when final tightening of the locking screw occurs, take care not to over-torque the screw.Excessive torque may damage the locking mechanism, the screw and/or the screwdriver blade (finger tighten only)." 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,T8 FULL THREAD, 2.7MM/L18MM
• Type of Device: SCREW, FIXATION, BONE
• Manufacturer (Section D): STRYKER GMBH; bohnackerweg 1; postfach; selzach 2545 ; CH 2545
• MDR Report Key: 8889809
• MDR Text Key: 154408345
• Report Number: 0008031020-2019-01038
• Device Sequence Number: 1
• Product Code: HWC
• UDI-Device Identifier: 07613327068696
• UDI-Public: 07613327068696
• Combination Product (y/n): N
• PMA/PMN Number: K180500
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: company representative
• Type of Report: Initial,Followup
• Report Date: 10/16/2019

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 08/13/2019
• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Device Operator: No Information
• Device Catalogue Number: 656318
• Device Lot Number: 1000352545
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 09/18/2019
• Date Manufacturer Received: 09/19/2019
• Is This a Reprocessed and Reused Single-Use Device?: No
• Patient Sequence Number: 1