Biomechanical Consequences of Tibial Insert Thickness after Total Knee Arthroplasty: A Musculoskeletal Simulation Study

The thickness of the tibial polyethylene (PE) insert is a critical parameter to ensure optimal soft-tissue balancing in intraoperative decision-making procedure total knee arthroplasty (TKA). However, there paucity information about kinetic response PE variations tibiofemoral (TF) joint, and subsequently, secondary effects on patellofemoral (PF) biomechanics. Therefore, purpose this study was investigate influence varying ligament TF compressive forces, as well PF forces kinematics, after cruciate-retaining TKA. A previous patient-specific musculoskeletal model TKA adapted simulate chair-rising motion which varied with 2 mm increments or decrements compared reference case (9 mm), from 5 up 13 mm. Greater resulted higher concurrently increased force by 21% (13 but slightly unloaded joint 7% mm) while shifting patella distally trochlear groove, case. Thinner inserts showed an opposite trend. Our findings suggest that selection trade-off between outcomes joints.