FEM modeling of lateral collateral & medial collateral ligaments for use in total knee arthroplasty surgery simulation.

The objective of this study is to model the lateral collateral ligament (LCL) and medial collateral ligament (MCL) around the artificial knee joint in such a way that the virtual ligaments have the same behavior as the native ligaments around the artificial knee joint in reality. This study provides more accuracy in knee biomechanical simulation by introducing a nonlinear model for MCL and LCL ligaments and improved the modeling of ligaments by assigning nonlinear elastic behavior through achieving the force-displacement relationship in nonlinear form and assigned this relationship to the uniaxial connectors that represent the ligament bundles. The results showed that the virtual ligaments can only bear tensile loads and have the same behavior as the native ligaments that surround the artificial knee joint. In addition, the results obtained for tibiofemoral contact forces and ligament forces have been compared with the reference data and have shown significant agreement. This model serves as a biomechanical platform for simulating soft tissue balancing strategies in TKA. While the current study does not implement specific surgical techniques, the validated ligament representation enables future simulations involving clinical interventions such as ligament release, alignment adjustments, and gap balancing procedures and helps the surgeon to evaluate the result of treatment plan on the knee joint before the surgery.