MAUDE Adverse Event Report: STRYKER GMBH BONE SCREW VARIAX2 T10, FULL THREAD, 3.5MM / L20MM; SCREW, FIXATION, BONE

Model Number	657420
Medical Device Problem Code	Positioning Failure (1158)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	08/20/2022
Type of Reportable Event	Malfunction
Additional Manufacturer Narrative
The reported event regarding the locking feature could be not confirmed, since the returned bone screw is not designed to be locked into the plate.The device inspection revealed the following: there is no failure of a bone screw mentioned in the event description.However, the evaluation of the screw has shown that the device is extremely damaged.The last thread flank below the screw head is completely flattened.The screw head is very strong deformed, a piece of the head is even sheared off on one site.Due to this damage the lot number is not present anymore.The t10 recess is deformed in, caused by very high forces in clockwise direction.All these damages are an indication for an extremely heavy contact between the screw and the plate.Afterwards it cannot be defined why such tremendous forces where applied onto this bone screw, the most likely explanation could be that the user thought it was a locking screw and tried to lock it in the plate.The damage pattern of the bone screw corresponds to the damage pattern of the proximal hole of the plate.By the corresponding marks at the screw and the plate it can be simulated in which extreme angle the screw was inserted into the plate during implantation.A review of the device history was not possible because the lot number was not communicated.No corrective actions are required at this time.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 an extreme insertion angle of the screws, this did lead to an undue contact between the screws and the plate.This contact caused in this case a strong deformation of the locking hole at the plate and the bone screw.No indications of material, manufacturing or design related problems were found during the investigation.If more information is provided, the case will be reassessed.
Event or Problem Description
It was reported that as the screw progressed, it would not engage the locking mechanism.It was further reported that it spun freely losing all compression on the bone.A surgical delay of 45-minutes was reported.

• Brand Name: BONE SCREW VARIAX2 T10, FULL THREAD, 3.5MM / L20MM
• Common Device Name: SCREW, 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: 15825065
• Report Number: 0008031020-2022-00618
• Device Sequence Number: 20389098
• Product Code: HWC
• UDI-Device Identifier: 07613327073874
• UDI-Public: 07613327073874
• Combination Product (Y/N): N
• Initial Reporter Country: CA
• 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
• Report Date (Section B): 11/18/2022

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
• Operator of Device: Health Professional
• Device Model Number: 657420
• Device Catalogue Number: 657420
• Device Lot Number: UNKNOWN
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 09/01/2022
• Type of Report(Section G): Initial
• Initial Date Received by Manufacturer: 10/25/2022
• Initial Report FDA Received Date: 11/18/2022
• Was Device Evaluated by Manufacturer? (Y/N): Yes
• Is the Device Labeled for Single Use? (Y/N): Yes
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Usage of Device: Initial
• Patient Sequence Number: 1
• Patient Sex: Female