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An event regarding loosening involving a triathlon femoral component was reported.The event was confirmed.Method & results: -device 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: 'this product inquiry concerns a 70-year-old female who underwent a primary cementless right total knee arthroplasty including patellar replacement on (b)(6) 2022.The patient developed pain and it was found that the femoral component had subsided into valgus and was felt to be loose.On (b)(6) 2024 the patient underwent revision with a cemented ps femoral component.The patella component was well fixed at that time.Patient went on again to develop pain and swelling and underwent another revision procedure after she was found to have a fractured patella peg.A new patella was cemented in place.It is unclear whether the tibial component was changed or simply the polyethylene.' confirmation of event: i can confirm that the patient underwent a primary cementless total knee arthroplasty with patella resurfacing, revision total knee arthroplasty for correction of a loose femoral component, and another revision for repair and replacement of a cementless patella component with a broken peg.I can confirm all three of these procedures because i was able to review the operation reports.Root cause analysis: the root cause of these events cannot be determined with certainty.The causes of early failure with subsidence of a cementless beaded pa femoral component, in my experience is quite rare.Contributing causes could be surgical technique in the way the implant is positioned and aligned and implanted, assuring a solid stable press fit.Less likely are other causes such as patient activity level, lifestyle and bmi.I would not attribute any causality to the implant for femoral loosening.Regarding the fractured patella peg on the cementless implant, that is also a rare event especially early on.Factors would include surgical technique again in the alignment, position, and restoration of kinematics of the knee, as well as the ability to gain adequate fixation surrounding all three pegs.If two of the pegs are loose that can put abnormal stress on the remaining peg and cause a stress fracture.Again, less likely contributors are the patient's lifestyle, activity level, and bmi.Implant factors may come into play but this would have to be determined by stryker engineers examining the explanted prosthesis.-device history review: review of the device history records indicate devices were manufactured and accepted into final stock with no relevant reported discrepancies.-complaint history review: there have been no other similar events for the lot referenced.Conclusion: the event was confirmed based on the provided photographs.The reported device was not returned however photographs were provided for review.The photographs show a recently explanted patella.There is evidence of the peg of the patella being fractured from the device.A review of the provided medical records by a clinical consultant indicated: 'i can confirm that the patient underwent a primary cementless total knee arthroplasty with patella resurfacing, revision total knee arthroplasty for correction of a loose femoral component, and another revision for repair and replacement of a cementless patella component with a broken peg.I can confirm all three of these procedures because i was able to review the operation reports.' root cause analysis: 'the root cause of these events cannot be determined with certainty.The causes of early failure with subsidence of a cementless beaded pa femoral component, in my experience is quite rare.Contributing causes could be surgical technique in the way the implant is positioned and aligned and implanted, assuring a solid stable press fit.Less likely are other causes such as patient activity level, lifestyle and bmi.I would not attribute any causality to the implant for femoral loosening.Implant factors may come into play but this would have to be determined by stryker engineers examining the explanted prosthesis.' further information such as device return and analysis are needed to complete the investigation for determining root cause.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.
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