MAUDE Adverse Event Report: STRYKER TRAUMA KIEL UNKNOWN T2 ALPHA FEMUR IMN LOCKING SCREW; IMPLANT

Catalog Number UNK_KIE

Device Problem Migration (4003)

Patient Problems Failure of Implant (1924); Osteopenia/ Osteoporosis (2651)

Event Date 07/05/2021

Event Type  Injury  

Manufacturer Narrative

The device will not be returned.If additional information becomes available, it will be provided in a supplemental report.Device disposition is unknown.

Event Description

It was reported there was distal screw migration, requiring revision surgery.The patient was (b)(6) years old with severe osteoporosis.

Event Description

It was reported there was distal screw migration, requiring revision surgery.The patient was 80 years old with severe osteoporosis.

Manufacturer Narrative

The reported event could be confirmed since x-rays were reported and show the backing out of the distal screw.Since x-rays were provided, the opinion of a medical expert was request and is the following: [.] the x-ray show a periprosthetic fracture proximal to a knee arthroplasty.The bone shows, that there has been a plate (or at least there are some screw holes in the ml-plane) adjusted to the distal femur.The op-report says that there was a liss-plate before and that the plate and cerclage construct dislocated seven weeks after the initial operation.It was decided to perform the revision with an antegrade nailing system.[.]" to the question of " is there any particular reason the als screws would have backed out in this case?", the answer of the medical expert was: "[.] the fracture is just proximal to the most proximal of the distal screws and thus very unstable.The ap-screw has been positioned exactly proximal to the femoral shield of the prosthesis.In this case the shield acts as a lever arm to the ap-screw and therefore it is not a surprise, that the screw backed out of the construct.This distal ap locking screw is the only distal fixation in the ap plane.As the epiphysis widens here to the distal femoral condyles, a lack of stability results.The distal fragment which has a long spike in the ap view with the fracture line in the frontal plane can despite of the three mediolateral distal screws pretty easily move like a windshield wiper around the ap-screw.The advanced locking screw which is positioned most proximal mediolaterally has a high intrinsic stability, but, in contrast to the locking screws of a plate is not firmly linked with the implant.It cannot be proven the x-rays only, but it seems as if the moving forces resulting from this instability on the screw were higher then the locking forces and as a result the screw migrated forward (as can be seen in the 14 d.Post op x-ray) [.]" in summary, based on investigation, the complex situation with a highly instable fracture led to the reported event.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.No indications of material, manufacturing or design related problems were found during the investigation.If the device is returned or if any additional information is provided, the investigation will be reassessed.

• Brand Name: UNKNOWN T2 ALPHA FEMUR IMN LOCKING SCREW
• Type of Device: IMPLANT
• Manufacturer (Section D): STRYKER TRAUMA KIEL; prof. kuentscher-strasse 1-5; schoenkirchen/kiel D-242 32; GM D-24232
• Manufacturer (Section G): STRYKER TRAUMA KIEL; prof. kuentscher-strasse 1-5; schoenkirchen/kiel D-242 32; GM D-24232
• Manufacturer Contact: kristen canter ; 325 corporate drive; mahwah, NJ 07430 ; 2018315000
• MDR Report Key: 12239050
• MDR Text Key: 264029588
• Report Number: 0009610622-2021-00625
• Device Sequence Number: 1
• Product Code: HSB
• Combination Product (y/n): N
• Reporter Country Code: GM
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: Health Professional
• Reporter Occupation: Physician
• Type of Report: Initial,Followup
• Report Date: 11/16/2021

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 07/28/2021
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Device Operator: Lay User/Patient
• Device Catalogue Number: UNK_KIE
• Device Lot Number: UNKNOWN
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: Yes
• Date Manufacturer Received: 10/22/2021
• Was Device Evaluated by Manufacturer?: Device Not Returned to Manufacturer
• 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 Outcome(s): Required Intervention
• Patient Age: 80 YR