MAUDE Adverse Event Report: STRYKER GMBH BONE SCREW VARIAX2 T10, FULL THREAD, 3.5MM / L50MM; PLATE, FIXATION, BONE

Model Number 657450S

Device Problem Material Fragmentation (1261)

Patient Problems No Known Impact Or Consequence To Patient (2692); No Clinical Signs, Symptoms or Conditions (4582)

Event Date 08/13/2020

Event Type  malfunction  

Manufacturer Narrative

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

Event Description

The customer reported that during the case the screw thread on 3 screws appears to have stripped off in places.

Manufacturer Narrative

The reported event could be confirmed since the device was returned for evaluation and matches the alleged failure.The device inspection revealed the following: the received screw was found to be having damaged threads around the middle moving towards proximal, covering approximately 6-8 threads.A metal splinter/wire was also formed which is most likely to have emerged from one of the middle threads and continued to form as the screw was pushed inside.The wire and the thread surface were found to be flat and plastically deformed.These damages and wire formation indicates towards excessive force that was applied to screw in the screw with some misalignment/angulation with the plate, leading to strip-off.A review of the device history for the reported lot did not indicate any abnormalities.No corrective actions are required at this time.No indications of manufacturing or design related problems were found during the investigation.A review of the labeling did not indicate any abnormalities.Based on the above investigation, the root cause of the failure is determined to be user related.There was a definite overtightening and misalignment of the screw involved as observed through the manner of deformation and stripping in the returned screw.The operative technique clearly provides a caution in inserting bone screws: ¿note: during bone screw insertion in an oblong hole, the surgeon should rely on tactile feedback to prevent excessive torque which may result in thread / bone stripping, screw damage / pull through, or screwdriver damage.Proper observation of bone quality, screw size, and instrumentation can help determine the appropriate insertion torque during insertion and final tightening of the screw in the plate.When the screw is fully seated during final tightening, an increase of resistance indicates sufficient screw fixation.¿ if any additional information is provided, the investigation will be reassessed.

Event Description

The customer reported that during the case the screw thread on 3 screws appears to have stripped off in places.

• Brand Name: BONE SCREW VARIAX2 T10, FULL THREAD, 3.5MM / L50MM
• Type of Device: PLATE, FIXATION, BONE
• Manufacturer (Section D): STRYKER GMBH; bohnackerweg 1; postfach; selzach 2545 ; SZ 2545
• MDR Report Key: 10485319
• MDR Text Key: 206568176
• Report Number: 0008031020-2020-02205
• Device Sequence Number: 1
• Product Code: HRS
• UDI-Device Identifier: 07613327074277
• UDI-Public: 07613327074277
• Combination Product (y/n): N
• PMA/PMN Number: K132502
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: health professional
• Type of Report: Initial,Followup
• Report Date: 11/10/2020

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 09/02/2020
• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Model Number: 657450S
• Device Catalogue Number: 657450S
• Device Lot Number: D41940
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 09/29/2020
• Date Manufacturer Received: 10/15/2020
• Is This a Reprocessed and Reused Single-Use Device?: No
• Patient Sequence Number: 1