Congratulation to MS Andersen et al. for winning the 2014 Grand Challenge competition!
Congratulation to Michael Skipper Andersen (Aalborg University), Marco Marra (Radbound Univeristy), Valentine Vanheule (Materialise), Rene Fluit (Twente Univeristy), Nico Verdonschot (Radbound Univeristy) and John Rasmussen (Aalborg University) for winning the 2014 Grand Challenge with their paper:
Patient-specific Musculoskeletal Modelling of Total Knee Arthroplasty using Force-dependent Kinematics
Andersen et al. created a patient specific model using MIMICS (Materialise) to segment CT scans and the AnyBody Modeling System to run a musculoskeletal simulation.
The bone geometry of tibia, femur and patella was based on CT images to scale muscle attachments nodes nonlinearly. An optimisation procedure in AnyBody linearly scaled the remaining model segments based on surface marker locations.
A detailed tibiofemoral and patellofemoral joint model, including contact and ligaments, allowed estimation of both muscle, ligament and contact forces, and knee joint kinematics using Force-dependent Kinematics (FDK). By employing quasi-static force-equilibrium, FDK extends inverse dynamics to allow computation of small movements stabilized by soft tissue within joints. In this study, FDK was employed to compute all tibiofemoral and patellofemoral movements except knee flexion/extension, which was prescribed. The muscle strengths were systematically reduced for both knee flexors and extensors as reported for total knee arthroplasty patients, and a strong dependence of the knee contact forces on this strength was observed.
The predicted tibio-femoral contact forces showed a very good correlation to the in-vivo measured data. Medial and lateral forced matched for standard gait and a measured right turn.
Not only the first winner, but also second place was achieved by an AnyBody user:
Congratulation also to Y. Jung and S. Koo for the second place!
“Estimation of knee intra-articular force using distributed force-reaction elements and inverse dynamics simulation”, by Y. Jung, S. Koo; from Chung-Ang University, Seoul, KOREA
Jung et al. used a slightly different approach in the AnyBody Modeling System. Instead of using force dependent kinematics, they used the measured kinematics of the knee and utilized force reaction elements to replace the traditional reaction forces on the knee joint to estimate medial and lateral knee contact forces using the inverse dynamics.
What is the grand challenge competition?
The Grand Challenge is a unique competition using musculoskeletal simulation to predict in vivo knee loads organized by B.J. Fregly (University of Florida), Darryl D’Lima (Scribbs Clinic) and Thor Besier (Auckland Bioengineering Institute). Patient data sets including video motion, ground reaction, muscle EMG, muscle strength, static and dynamic imaging, and implant geometry are used by the participants to create musculoskeletal models to predict tibial contact forces without having access to the corresponding in vivo measured tibial contact forces (Fregly et al. 2012 JOR).
In 2014 several academic groups from all over the world participated in the 2014 challenge. Research groups from France/Luxemburg, Korea, China, USA, Denmark/Belgium/Netherlands participated using different approaches and simulation tools.