Femoral finite element analysis of a novel cementless revision total knee arthroplasty system

Revision total knee arthroplasty (RTKA) is a highly complex procedure challenged by bone defects and compromised biomechanical stability, which may threaten implant fixation and long-term survivorship. This study aimed to introduce a novel cementless RTKA system and evaluate the resulting femoral initial stability. A novel cementless femoral RTKA system based on metaphyseal and biological fixation, comprising a femoral condyle component, metaphyseal cone, and optional intramedullary stems and metal augments, was evaluated using finite element analysis. The initial stability of the system was assessed in a CT-based femoral model under conditions with or without bone defects, at different defect locations, and with or without the use of intramedullary stems and metal augments. Finite element analysis demonstrated that, regardless of the presence of femoral bone defects, the system exhibited favorable interface micromotion and femoral stress distribution, indicating acceptable initial femoral stability. Intramedullary stems reduced micromotion but decreased the proportion of stress within the reference range, whereas metal augments produced only limited numerical improvement without being essential for initial stability. Within the investigated finite element model, the novel cementless RTKA system achieved acceptable initial femoral mechanical stability, even in the presence of femoral bone defects. Adequate initial stability could be obtained through metaphyseal fixation alone, while the additional use of intramedullary stems or metal augments provided limited incremental benefit.