MAUDE Adverse Event Report: SMITH & NEPHEW, INC. LGN OX CONSTRAINED FEM 6 LT; PROSTHESIS, KNEE, PATELLOFEMOROTIBIAL, SEMI-CONSTRAINED, CEMENTED, POLYMER/METAL

Catalog Number	71421166
Medical Device Problem Code	Adverse Event Without Identified Device or Use Problem (2993)
Health Effect - Clinical Code	Joint Dislocation (2374)
Date of Event	02/26/2026
Type of Reportable Event	Serious Injury
Additional Manufacturer Narrative
Internal complaint reference: (b)(4).This complaint was opened by smith+nephew to document a patient complication reported that includes reference to the use of a smith+nephew product without evidence about a specific product problem.The reported complication relates to known inherent procedural risks that are appropriately documented in our risk files.Smith+nephew will continue to monitor trends in accordance with our post-market surveillance process and take necessary action as required if anticipated severity and/or occurrence rates are exceeded.Smith+nephew has no reason to suspect that the product failed to meet any specifications at the time of manufacture.Based on our review of all currently available information, we are unable to confirm a relationship between the reported event and the device or identify a definitive root cause.However, as the use of our product cannot be excluded as a potential cause or contributory factor to the reported issue, we are submitting this report in accordance with applicable regulations.If additional investigative findings or information becomes available that alters the conclusions of this report, a follow-up report will be submitted as required.
Event or Problem Description
It was reported that, after a tka revision surgery had been performed on (b)(6) 2025, the patient experienced patella dislocations.This adverse event was treated by a second revision surgery on (b)(6) 2026, in which the implants were explanted and replaced with full legion revision construct.The current health status of the patient is unknown.

• Brand Name: LGN OX CONSTRAINED FEM 6 LT
• Common Device Name: PROSTHESIS, KNEE, PATELLOFEMOROTIBIAL, SEMI-CONSTRAINED, CEMENTED, POLYMER/METAL
• Manufacturer (Section D): SMITH & NEPHEW, INC.; 1450 brooks rd.; memphis TN 38116
• Manufacturer (Section G): SMITH & NEPHEW, INC.; 1450 brooks rd.; memphis TN 38116
• Manufacturer Contact: holly topping ; 1450 brooks rd.; memphis, TN 38116 ; 5123913905
• MDR Report Key: 24649358
• Report Number: 1020279-2026-00376
• Device Sequence Number: 9797345
• Product Code: JWH
• UDI-Device Identifier: 03596010543851
• UDI-Public: 3596010543851
• Combination Product (Y/N): N
• Initial Reporter Country: AS
• PMA/510(K) Number: K230653
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2025
• Device Explanted Year: 2026
• Serviced by Third Party (Y/N): N
• Reporter Type: Manufacturer
• Report Source: Other,Foreign,Health Professional,Company Representative
• Initial Reporter Occupation: Physician
• Type of Report: Initial
• Report Date (Section B): 03/20/2026

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 Catalogue Number: 71421166
• Device Lot Number: 25BM10507
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: Yes
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 02/26/2026
• Initial Report FDA Received Date: 03/20/2026
• Date Device Manufactured: 02/25/2025
• 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
• Concomitant Medical Products and Therapy/Usage Dates: 71421753, 23LSM0838B; 71421753, 24BSM0346; 71424005, 24HM16384; 71424047, 22KSM0590; 71424048, 23KSM0651; 71424225, 25EM05686; 71453223, 23FM01469
• Outcome Attributed to Adverse Event: Required Intervention; Hospitalization
• Patient Sex: Unknown