GMK Total Knee System

Description of Event or Problem

Revision surgery due to tibial loosening after about 1 year and 1 month from primary. The surgeon also noted the complete absence of cement. The surgeon revised all knee implants with GMK-Revision devices.

Additional Manufacturer Narrative

Clinical evaluation The available information is consistent with early loosening and subsidence of the cemented tibial component approximately one year after primary total knee arthroplasty. The available radiographs show prominent radiolucent lines beneath the tibial tray and around the keel, together with subsidence of the tibial component, particularly posteriorly. The valgus alignment observed on the anteroposterior view and the posterior translation of the femur relative to the tibia on the lateral view may represent indirect signs of instability or abnormal knee kinematics. However, functional instability cannot be confirmed on the basis of static radiographs alone. These findings may also be secondary to mobilizatio/migration of the tibial component. The reported absence of cement on the explanted tibial tray raises the clinically and technically relevant possibility of debonding at the implant-cement interface or an issue related to cement application during the primary procedure. However, the exact failure mechanism cannot be established from the available photographs alone. The root cause therefore remains undetermined and is likely multifactorial, with potential contributing factors including cementation technique, implant positioning, bone quality, and patient-related factors. Based on the currently available information, there is no evidence to suggest that the event was caused by a defective or malfunctioning device. Batch review performed on 23 July 2026 Lot. 2431580: (b)(4) items manufactured and released on 07-Apr-2025. Expiration date: 23-Mar-2030. No anomalies found related to the problem. To date, 50 items of the same lot have been sold with no similar reported event during the period of review.