MAUDE Adverse Event Report: STRYKER ORTHOPAEDICS-MAHWAH TRIATHLON SYMMETRIC X3 PATELLA; PROSTHESIS, KNEE, PATELLO/FEMOROTIBIAL, SEMI-CONSTRAINED, UNCEMENTED, POROUS, CO

Catalog Number 5550-G-360

Device Problems Break (1069); Loosening of Implant Not Related to Bone-Ingrowth (4002)

Patient Problem Injury (2348)

Event Date 08/21/2018

Event Type  Injury  

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 reported lot.A supplemental report will be submitted upon completion of the investigation.Not returned.

Event Description

It was reported that patient's left knee was revised due to an aseptically loose patella.Intra-operatively, the pegs of the patellar device were found to have sheared off and remained in the cement and bone.Patient did not report any fall or trauma and the surgeon had no theory as to how the implant could have become sheared off.Patient was revised from a size 36 to a size 33 patella.

Event Description

It was reported that patient's left knee was revised due to an aseptically loose patella.Intra-operatively, the pegs of the patellar device were found to have sheared off and remained in the cement and bone.Patient did not report any fall or trauma and the surgeon had no theory as to how the implant could have become sheared off.Patient was revised from a size 36 to a size 33 patella.

Manufacturer Narrative

An event regarding crack/fracture of a triathon patella was reported.The event was confirmed by material analysis of the returned device.Method & results: product evaluation and results: the part was examined with the aid of a stereo microscope at magnifications up to 50x.Burnishing, scratching and third-body indentations were observed on the insert.These are common damage modes of uhmwpe.Damage was observed on the posterior surface, including all three pegs.The damage is consistent with contact against a hard object.The "material" analysis indicated: burnishing, scratching and third-body indentations were observed on the insert.These are common damage modes of uhmwpe.Damage was also observed on the posterior surface of the insert, consistent with contact against a hard object.Based on the given information, no identifiable materials or manufacturing discrepancies were observed on the surfaces examined.Clinician review: soft tissue imbalance across the extensor tendon mechanism of the knee including the patellar due to muscular atrophy and/or possibly rotatory malalignment of knee devices has contributed to lateral shift/tilt of the patellar device with overload across the patellofemoral implant-bone interface with ultimately loosening and disassociation of the patellar device requiring revision.Product history review: indicated all 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.Conclusions: an event regarding crack/fracture of a triathlon patella was reported.The material analysis report revealed: burnishing, scratching and third-body indentations were observed on the patella.These are common damage modes of uhmwpe.Damage was also observed on the posterior surface of the patella, consistent with contact against a hard object.Based on the given information, no identifiable materials or manufacturing discrepancies were observed on the surfaces examined.The medical review indicated: soft tissue imbalance across the extensor tendon mechanism of the knee including the patellar due to muscular atrophy and/or possibly rotatory malalignment of knee devices has contributed to lateral shift/tilt of the patellar device with overload across the patellofemoral implant-bone interface with ultimately loosening and disassociation of the patellar device requiring revision.No further investigation is required at this time.If additional information becomes available to indicate further evaluation is warranted, this record will be reopened.

• Brand Name: TRIATHLON SYMMETRIC X3 PATELLA
• Type of Device: PROSTHESIS, KNEE, PATELLO/FEMOROTIBIAL, SEMI-CONSTRAINED, UNCEMENTED, POROUS, CO
• Manufacturer (Section D): STRYKER ORTHOPAEDICS-MAHWAH; 325 corporate drive; mahwah NJ 07430
• MDR Report Key: 7883075
• MDR Text Key: 120516814
• Report Number: 0002249697-2018-02907
• Device Sequence Number: 1
• Product Code: MBH
• UDI-Device Identifier: 07613327014778
• UDI-Public: 07613327014778
• Combination Product (y/n): N
• PMA/PMN Number: K141056
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: health professional,other
• Type of Report: Initial,Followup
• Report Date: 11/28/2018

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 09/17/2018
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Expiration Date: 01/31/2021
• Device Catalogue Number: 5550-G-360
• Device Lot Number: 5AK8
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 09/06/2018
• Date Manufacturer Received: 10/31/2018
• Is This a Reprocessed and Reused Single-Use Device?: No
• Patient Sequence Number: 1
• Patient Outcome(s): Hospitalization; Required Intervention
• Patient Age: 77 YR
• Patient Weight: 89