Development of a personalized parametric finite element model of the knee: Evaluation of geometric variables affecting osteoarthritis progression.

Background: Osteoarthritis is a degenerative condition that impacts synovial joints, particularly the knee joint. Researchers regard Finite Element Analysis as a promising technique for managing knee osteoarthritis. However, these models often depend on input geometry from one or more individuals, feature complex interfaces, and require a significant amount of time, which makes them unsuitable for clinical use and reduces their reliability. Purpose: This study aims to assess the effectiveness of the personalized parametric model technique in predicting the knee joint's mechanical response, taking into account anatomical variables that influence osteoarthritis. Methods: A 3D model of the knee was created from CT images of a patient with knee osteoarthritis. Lateral, anterior, and posterior knee radiographs were obtained from twenty-six subjects to customize the geometric parameters of the developed parametric model. The knee geometry was parameterized using Ansys software. The models used six parameters to represent the articular surface of the tibial plateau, its slope, and variables attached to the medial and lateral femoral condyles. Parametric FE models were created individually by applying the ground reaction force diagram to each model. Results: Mean maximum von Mises stress was higher in the OA group than in the control group. Simulations of the patients in the OA group indicated that the mean von Mises stress at the articular surfaces diminished with an increase in tibial plateau tilt. Also, individual geometry-specific models exhibited varying responses, thereby confirming the significance of taking personalized geometry into account. Conclusion: Personalized models can be used to simulate mechanical responses and specifically evaluate the effect of the tibial plateau tilt. This work presented an innovative method for creating individualized finite element models of osteoarthritic knees, which can be used as a practical and effective tool in clinical environments.