MAUDE Adverse Event Report: STRYKER GMBH LOCKING SCREW VARIAX 2 T10, FULL THREAD, 3.5MM / L16MM; PLATE, FIXATION, BONE

Model Number 657316S

Device Problems Positioning Failure (1158); Material Deformation (2976)

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

Event Date 03/09/2022

Event Type  malfunction  

Manufacturer Narrative

Once the investigation has been completed any additional information will be reported in a supplemental report.

Event Description

As reported: "the screw did not lock to the plate.The lip of the screw damaged.".

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.Some portions of the crest of the thread flank have separated / have sheared off under significant force.The damage pattern suggests high force application during locking attempts.Related to our post market surveillance activities a potential non-conformity report (nc) was initiated to address similar events related to the variaax2 locking feature.The deep investigation of the nc revealed that the application of over torque during insertion was the root cause of the event.This leads to the damage of the smart lock technology below the head.As a reminder, the operative technique (vax-st-49_rev.5, 05 - 2021) clearly states that the proper use of the screw should prevent this deformation from happening: ¿caution ¿ with the use of variable speed power systems, the surgeon should initially reduce the power to the lowest setting.¿ final tightening of the screw should be performed by hand to avoid damaging the screw-plate interface¿ however, although no product related issue could be detected a preventive action (capa) was nonetheless opened to make the design more robust against a potential over tightening by the user.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.Based on investigation, the root cause was attributed to a user related issue.The failure was caused by over tightening of the locking screw in the final position, which did lead to a deformation of the locking thread.If any further substantial information is provided, the investigation report will be updated.

Event Description

As reported: "the screw did not lock to the plate.The lip of the screw damaged.".

• Brand Name: LOCKING SCREW VARIAX 2 T10, FULL THREAD, 3.5MM / L16MM
• 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: anna jusinski ; 325 corporate drive; mahwah, NJ 07430 ; 2018315000
• MDR Report Key: 14012516
• MDR Text Key: 288874743
• Report Number: 0008031020-2022-00142
• Device Sequence Number: 1
• Product Code: HRS
• UDI-Device Identifier: 07613327086881
• UDI-Public: 07613327086881
• 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: Distributor
• Reporter Occupation: Other
• Type of Report: Initial,Followup
• Report Date: 06/28/2022

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 Model Number: 657316S
• Device Catalogue Number: 657316S
• Device Lot Number: H61377
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 03/23/2022
• Is the Reporter a Health Professional?: No
• Initial Date Manufacturer Received: 03/10/2022
• Initial Date FDA Received: 04/05/2022
• Supplement Dates Manufacturer Received: 06/07/2022
• Supplement Dates FDA Received: 06/28/2022
• Was Device Evaluated by Manufacturer?: Yes
• Date Device Manufactured: 12/21/2021
• 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
• Patient Age: 46 YR
• Patient Sex: Male
• Patient Weight: 70 KG