An anatomy-based dynamic model of total knee arthroplasty

The present study aims at developing a three-dimensional forward dynamics methodology to compute the micro- and macro-motion of the tibiofemoral joint where the ligament behavior is simulated employing an asymmetric nonlinear elastic model. Point clouds associated with the knee components are smoothed using the Laplacian smoothing technique. A specific contact detection is also developed in which a bounding box procedure, one-by-one surface function based scheme, and a memory module along with a minimum distance technique are integrated, leading to a significant reduction of computational time while the accuracy is preserved. External loads and moments imposed on the femoral bone from all surrounding soft issues are acquired using a musculoskeletal modeling approach, fed into the forward dynamic model for the in-detail modeling of the total knee arthroplasty. Archard wear law is in turn embedded in the presented dynamic model allowing for wear prediction of total knee arthroplasty. A mesh density analysis is performed and the developed approach is assessed against outcomes available in the literature. The efficiency of the proposed approach is evaluated and consequently, it can be concluded that the model is promising, robust, and efficient. The dynamic model is subsequently employed to study the trajectory of the knee joint under different friction coefficients. Predicted wear values and distribution are also acquired showing friction can cause changes in both of them along with the knee motion.