Computational modeling: an alternative approach for investigating patellofemoral mechanics.

Computational modeling is commonly used in all engineering disciplines to represent complex systems. A computational model of the patellofemoral joint is a graphical representation of joint anatomy that can be manipulated to simulate knee function. Current models are typically reconstructed from magnetic resonance imaging scans of knees. Force vectors are applied to the patella to represent the quadriceps muscles, while the patella tendon is modeled with force vectors or deformable elements. Although the femur, tibia, and patella are typically modeled as rigid structures, the cartilage is represented with springs or modeled using finite element analysis. Computational models can be created to represent individual patients or general pathologic conditions. The quadriceps muscles and patella tendon can be manipulated to simulate patellofemoral pathology or surgical or nonsurgical treatment methods. The models can be used to characterize patellofemoral loading during knee flexion and characterize the distribution of force and pressure within the patellofemoral joint.