体内生物力学环境诱导的人工颈椎间盘磨损机理研究

Prosthesis wear and aseptic loosening resulted from wear particles are the two key factors limiting the clinical lifetime and performance of artificial cervical disc arthroplasty. The in vivo biomechanical environment directly determines the motion pattern and load condition of the joint interface, thus determining its wear behavior and mechanism. Therefore, in order to solve the wear problem of artificial cervical disc in the in vivo biomechanical environment, this project proposes a de-coupling and coupling approach based on musculoskeletal multibody dynamics to reveal the friction and wear mechanism of the joint interface. More specifically, by establishing a flexible musculoskeletal multi-body dynamics model based on inverse dynamics analysis, the current proposal aims to analyze the in vivo biomechanical environment of artificial cervical disc, to de-couple the three typical single motion modes including sliding, rolling and twisting of the joint interface, and to study the wear behavior and mechanism in single mode through experimental analysis and simulation. On this basis, the current project also aims to investigate the joint interface wear behavior under two modes and multi-modes, and to finally reveal the wear mechanism and key factors of artificial cervical joint interface and come up with the wear mechanism map of joint interface induced by the in vivo biomechanical environment, that laying a theoretical and experimental basis for improving the design of artificial cervical disc and improving its service performance and life.

假体磨损及磨粒导致的无菌性松动是制约人工颈椎间盘假体服役性能和寿命的关键原因，而假体的磨损行为很大程度上取决于体内生物力学环境下关节界面的运动模式与载荷条件。因此，针对体内生物力学环境下人工颈椎间盘的磨损问题，本项目拟提出基于柔性骨肌多体动力学的关节界面摩擦模式解析与耦合分析方法，揭示关节界面的磨损机理：主要通过建立基于逆向动力学分析的柔性骨肌多体动力学模型，分析人工颈椎间盘的体内生物力学环境，解析关节界面“平动、滚动、扭动”三种典型的单一运动模式及其载荷条件，并通过实验分析和仿真计算，研究单一模式下的磨损行为与机理，在此基础上研究两两模式间相互作用及多模式耦合作用下的关节界面磨损行为，最终揭示颈椎关节界面的磨损机理与关键作用机制，构建体内生物力学环境诱导的关节界面磨损机理图谱，为改善人工颈椎间盘设计、提高其服役性能与寿命奠定理论和实验基础。

假体磨损及磨粒导致的无菌性松动是制约人工颈椎间盘假体服役性能和寿命的关键原因，而假体的磨损行为很大程度上取决于体内生物力学环境下关节界面的运动模式与载荷条件。骨肌多体动力学研究方法能够对各种运动状态下的假体关节（包括邻近关节和小关节等）的运动、接触力、肌肉力和韧带力进行准确预测，并已在人工髋、膝等关节假体置换中得到了很好的模拟效果。因此，本项目首先建立了自然颈椎间盘的柔性骨肌多体动力学模型，该模型可以考虑关节运动、肌肉、韧带、小关节以及软骨组织变形，从关节力和运动、几何结构等方面研究了自然颈椎的在体生物力学环境。其次，建立了人工颈椎间盘假体置换后的柔性骨肌多体动力学模型，解析了关节界面的不同运动模式和载荷条件。最后，搭建了人工颈椎间盘的磨损试验平台，开展了单模式以及复合模式下不同配副材料的磨损机理实验研究，考察了载荷条件、材料配副等条件对颈椎间盘界面生物力学和摩擦学行为的影响规律，揭示了颈椎关节界面的磨损机理与关键作用机制，为临床治疗、术后康复和假体优化设计等提供理论依据。