title: Prediction of in vivo joint mechanics of an artificial knee implant using rigid multi-body dynamics with elastic contacts.
abstract: Lower extremity musculoskeletal computational models play an important role in predicting joint forces and muscle activation simultaneously and are valuable for investigating functional outcomes of the implants. However, current computational musculoskeletal models of total knee replacement rarely consider the bearing surface geometry of the implant. Therefore, these models lack detailed information about the contact loading and joint motion which are important factors for evaluating clinical performances. This study extended a rigid multi-body dynamics simulation of a lower extremity musculoskeletal model to incorporate an artificial knee joint, based upon a novel force-dependent kinematics method, and to characterize the in vivo joint contact mechanics during gait. The developed musculoskeletal total knee replacement model integrated the rigid skeleton multi-body dynamics and the flexible contact mechanics of the tibiofemoral and patellofemoral joints. The predicted contact forces and muscle activations are compared against those in vivo measurements obtained from a single patient with good agreements for the medial contact force (root-mean-square error = 215 N, ρ = 0.96) and lateral contact force (root-mean-square error = 179 N, ρ = 0.75). Moreover, the developed model also predicted the motion of the tibiofemoral joint in all degrees of freedom. This new model provides an important step toward the development of a realistic dynamic musculoskeletal total knee replacement model to predict in vivo knee joint motion and loading simultaneously. This could offer a better opportunity to establish a robust virtual modeling platform for future pre-clinical assessment of knee prosthesis designs, surgical procedures and post-operation rehabilitation.
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Zhenxian
authors.initials: Z
authors.lastname: Chen
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Xuan
authors.initials: X
authors.lastname: Zhang
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Marzieh M
authors.initials: MM
authors.lastname: Ardestani
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China menlwang@mail.xjtu.edu.cn.
authors.forename: Ling
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Yaxiong
authors.initials: Y
authors.lastname: Liu
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Lian
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Jiankang
authors.initials: J
authors.lastname: He
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Dichen
authors.initials: D
authors.lastname: Li
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China Institute of Medical and Biological Engineering, School of Mechanical Engineering, University of Leeds, Leeds, UK.
authors.forename: Zhongmin
authors.initials: Z
authors.lastname: Jin
keywords: Musculoskeletal model; contact force; force-dependent kinematics; multi-body dynamics; muscle activation; total knee replacement