Zhang Qida, Chen Zhenxian, Zhang Jing, Hu Jiayu, Peng Yinghu, Fan Xunjian, Jin Zhongmin
State Key Laboratory for Manufacturing System Engineering, School of Mechanical Engineering, Xi'an Jiaotong University, No.28, Xianning West Road, Xi'an, 710049, China.
Key Laboratory of Road Construction Technology and Equipment (Ministry of Education), School of Mechanical Engineering, Chang'an University, Middle-section of Nan'er Huan Road, Xi'an 710064, China.
Clin Biomech (Bristol). 2019 May;65:19-25. doi: 10.1016/j.clinbiomech.2019.03.016. Epub 2019 Mar 29.
The insert conformity is a critical factor for successful total knee replacement which must be considered in design of the implant. However, the effects of conformity on knee kinematics and wear under physiological environment are often neglected in previous studies. The present study involved evaluating the biomechanics and wear performance with regard to different insert conformity in total knee replacement.
Different tibial inserts with different sagittal and coronal conformity levels were created and analyzed using a previously developed wear prediction framework, coupling a patient-specific musculoskeletal multibody dynamics simulation, finite element and wear analysis. The contact mechanics, kinematics, and wear performance were compared during 10 million cycles of wear simulation.
The findings revealed that the knee kinematics was affected by sagittal conformity design variables, which further influenced the wear of insert bearing surface. Additionally, kinematics and wear of artificial knee joint were much more sensitive to sagittal than coronal conformity of tibial insert. The lower sagittal conformity designs had lower wear rates, worn area and contact area. In turn, the wear of insert bearing surface also changed insert conformity, and further impacted on knee kinematics.
The present study indicated that the sagittal conformity design of insert surface played a crucial role to improve contact mechanics and kinematics performance and minimize wear of total knee replacement. The optimization of insert conformity should be considered carefully in implant design and surgical procedures.
假体衬垫适配性是全膝关节置换成功的关键因素，在植入物设计中必须予以考虑。然而，以往研究常常忽视生理环境下适配性对膝关节运动学及磨损的影响。本研究旨在评估全膝关节置换中不同假体衬垫适配性的生物力学及磨损性能。
制作具有不同矢状面和冠状面适配水平的不同胫骨假体衬垫，并使用先前开发的磨损预测框架进行分析，该框架结合了患者特异性肌肉骨骼多体动力学模拟、有限元分析及磨损分析。在1000万次磨损模拟过程中，对接触力学、运动学及磨损性能进行比较。
结果显示，膝关节运动学受矢状面适配性设计变量的影响，进而影响假体衬垫表面的磨损。此外，人工膝关节的运动学及磨损对胫骨假体衬垫矢状面适配性的敏感度远高于冠状面适配性。矢状面适配性较低的设计具有较低的磨损率、磨损面积及接触面积。反过来，假体衬垫表面的磨损也会改变衬垫适配性，并进一步影响膝关节运动学。
本研究表明，假体衬垫表面的矢状面适配性设计在改善接触力学及运动学性能、最小化全膝关节置换磨损方面起着关键作用。在植入物设计及手术操作中应仔细考虑假体衬垫适配性的优化。
