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Daniel Felix Ritchie School of Engineering and Computer Science, Center for Orthopaedic Biomechanics, Mechanical and Materials Engineering


Total knee arthroplasty (TKA), Patellofemoral mechanics, Tibiofemoral mechanics, Model


Contemporary total knee arthroplasty (TKA) has not fully restored natural patellofemoral (P-F) mechanics across the patient population. Previous experimental simulations have been limited in their ability to create dynamic, unconstrained, muscle-driven P-F articulation while simultaneously controlling tibiofemoral (T-F) contact mechanics. The purpose of this study was to develop a novel experimental simulation and validate a corresponding finite element model to evaluate T-F and P-F mechanics. A commercially available wear simulator was retrofitted with custom fixturing to evaluate whole-knee TKA mechanics with varying patella heights during a simulated deep knee bend. A corresponding dynamic finite element model was developed to validate kinematic and kinetic predictions against experimental measurements. Patella alta reduced P-F reaction forces in early and midflexion, corresponding with an increase in T-F forces that indicated an increase in extensor mechanism efficiency. Due to reduced wrapping of the extensor mechanism in deeper flexion for the alta condition, peak P-F forces in flexion increased from 101% to 135% of the applied quadriceps load for the baja and alta conditions, respectively. Strong agreement was observed between the experiment and model predictions with root-mean-square errors (RMSE) for P-F kinematics ranging from 0.8 deg to 3.3 deg and 0.7mm to 1.4 mm. RMSE for P-F forces ranged from 7.4N to 53.6 N. By simultaneously controlling dynamic, physiological loading of the T-F and P-F joint, this novel experimental simulation and validated model will be a valuable tool for investigation of future TKA designs and surgical techniques.

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Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

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Copyright is held by ASME. User is responsible for all copyright compliance. This article was originally published as:

Behnam, Y. A., Anantha Krishnan, A., Wilson, H., and Clary, C. W. (2024). Simultaneous evaluation of tibiofemoral and patellofemoral mechanics in total knee arthroplasty: A combined experimental and computational approach. Journal of Biomechanical Engineering, 146(1), 011007.

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Received from author

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English (eng)


42 pgs

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1.8 MB

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Journal of Biomechanical Engineering





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