Patient specific knee model for post and preoperative simulation and analysis

In this study, we propose a multibody tibiofemoral dynamic model to simulate passive knee motion with the intention of predicting surgical interventions. The knee is a bi-articular joint containing two compartments, tibiofemoral and patellofemoral. Patellofemoral articulation has an important function during active loading of the quadriceps muscle, while tibiofemoral articulation is always involved during both active and passive knee movements. The study focuses on passive knee exion by proposing a multibody dynamic model of the tibiofemoral joint that incorporates ligaments and contact surfaces. The presence of well-established clinical procedures and publicly available data repositories involving passive knee exion enables model validation and supports clinical integration. An anatomical knee model is developed, including bones, cartilage, and fteen ligaments. The ligaments' tensions, the cartilage, and bone contact forces constitute the overall internal force interactions. Passive knee exion is induced in the form of a joint motion function. It repetitively induced in both the cadaver and the model, resulting in ve joint movements: two rotational and three translational. Pearson's correlation resulted in a positive and strong association between the experimental and simulated joint motions (r>0.89). The resulting pairwise linear regression analysis indicates the estimations are statistically signicant (p<0.05) for the clinically dened abduction-adduction, internal-external, medial-lateral, anterior- posterior, and superior-inferior motions. The similarity for internal-external rotation has the highest correlation with R2=0.994. Knee laxity assessment results are consistent with experimental data and literature. The simulated anterior drawer test showed >5mm tibial translation for ACL rupture and <5mm for an intact ACL.