MAUDE Adverse Event Report: STRYKER ORTHOPAEDICS-MAHWAH X3 TRIATHLON INSERT CS NUM5 10MM; PROSTHESIS, KNEE, PATELLOFEMOROTIBIAL, SEMI-CONSTRAINED, CEMENTED, POLYMER/METAL

Catalog Number	5531-G-510-E
Medical Device Problem Code	Unstable (1667)
Health Effect - Clinical Code	Joint Laxity (4526)
Date of Event	01/30/2026
Type of Reportable Event	Serious Injury
Event or Problem Description
It was reported that the patient's right knee was revised due to instability.A 5 x 10 cs insert was exchanged for a 5 x 12 cs insert.Rep confirmed that no further information will be released by the hospital or surgeon.
Additional Manufacturer Narrative
Review of the device history records indicate devices were manufactured and accepted into final stock with no relevant reported discrepancies.There have been no other similar events for the lot referenced.An evaluation of the device cannot be performed as the device was not returned to the manufacturer.Should additional information become available it will be reported in a supplemental report upon completion of the investigation.
Additional Manufacturer Narrative
Reported event:\ an event regarding instability involving a triathlon insert was reported.The event was confirmed via clinician review of the provided medical records.\ \ method & results:\ -product evaluation and results: material analysis, visual, functional and dimensional inspections could not be performed as the device was not returned.\ -clinician review: a review of the provided medical records by a clinical consultant indicated:\ \"confirmation of event: i can confirm that the patient had the primary total knee arthroplasty since i was able to view x-rays with the implant in place.I can also confirm that there was rather severe instability with polyethylene wear since i was able to see sequential x-rays showing progression.\ root cause analysis: the root cause of this event cannot be determined with certainty.The causes of instability and severe polyethylene where are multifactorial including surgical technique especially in the way the knee is balanced and the kinematics are restored.Patient factors including lifestyle, activity level and bmi can be considered as well, as can implant factors.Having said that it appears from the x-rays that the lateral side was most likely left tight which resulted in stretching of the medial side and abnormal wear patterns.Given my observation i would not assign any causality to the implant itself, but rather due to abnormal stresses on the implant.\"\ -product history review: review of the product history records indicate the reported device was manufactured with no reported relevant discrepancies.\ -complaint history review: there have been no other similar events for the lot referenced.\ \ conclusions:\ it was reported that the patient was revised due to instability.A review of the provided medical records by a clinical consultant indicated: \"confirmation of event: i can confirm that the patient had the primary total knee arthroplasty since i was able to view x-rays with the implant in place.I can also confirm that there was rather severe instability with polyethylene wear since i was able to see sequential x-rays showing progression.Root cause analysis: the root cause of this event cannot be determined with certainty.The causes of instability and severe polyethylene where are multifactorial including surgical technique especially in the way the knee is balanced and the kinematics are restored.Patient factors including lifestyle, activity level and bmi can be considered as well, as can implant factors.Having said that it appears from the x-rays that the lateral side was most likely left tight which resulted in stretching of the medial side and abnormal wear patterns.Given my observation i would not assign any causality to the implant itself, but rather due to abnormal stresses on the implant.\" no further investigation for this event is possible at this time.If devices and/or additional information become available to indicate further evaluation is warranted, this record will be reopened.
Event or Problem Description
No new information.

• Brand Name: X3 TRIATHLON INSERT CS NUM5 10MM
• Common Device Name: PROSTHESIS, KNEE, PATELLOFEMOROTIBIAL, SEMI-CONSTRAINED, CEMENTED, POLYMER/METAL
• Manufacturer (Section D): STRYKER ORTHOPAEDICS-MAHWAH; 325 corporate drive; mahwah NJ 07430
• Manufacturer (Section G): STRYKER ORTHOPAEDICS-MAHWAH; 325 corporate drive; mahwah NJ 07430
• Manufacturer Contact: anna ryan ; raheen business park; limerick NA ; EI NA ; 61498200
• MDR Report Key: 25159417
• Report Number: 0002249697-2026-00400
• Device Sequence Number: 9453245
• Product Code: JWH
• UDI-Device Identifier: 07613327390636
• UDI-Public: 07613327390636
• Combination Product (Y/N): N
• Initial Reporter State: MA
• Initial Reporter Country: US
• PMA/510(K) Number: K173849
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2020
• Device Explanted Year: 2026
• Reporter Type: Manufacturer
• Report Source: Health Professional
• Initial Reporter Occupation: Physician
• Type of Report: Initial,Followup
• Report Date (Section B): 06/25/2026

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: No
• Operator of Device: Health Professional
• Device Expiration Date: 07/31/2024
• Device Catalogue Number: 5531-G-510-E
• Device Lot Number: TL288V
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: Yes
• Type of Report(Section G): Follow-Up
• Initial Date Received by Manufacturer: 01/30/2026
• Supplement Date Received by Manufacturer: 05/29/2026
• Initial Report FDA Received Date: 05/13/2026
• Supplement Report FDA Received Date: 06/25/2026
• Was Device Evaluated by Manufacturer? (Y/N): No
• Date Device Manufactured: 07/26/2019
• 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
• Outcome Attributed to Adverse Event: Hospitalization; Required Intervention
• Patient Age: 70 YR
• Patient Sex: Male