TKA前后功能运动中膝关节接触力变化的仿真研究

The knee is one of the biggest and most complex joints in body, which also has the highest requirement for the motion function. The total knee arthroplasty (TKA) can reduce the pain and improve the function of knee and is an effective way to cure the advanced knee osteoarthritis. The knee contact force is an important factor for the long-term success after TKA. Abnormal knee contact force can affects the stability of knee joint, accelerate the wear and loosening of the implant. Therefore, accurate prediction of knee contact force during functional activities has a significant meaning for TKA population. In this project, we plan to compare among healthy individuals, and those with cruciate-retaining TKA and posterior-stabilized TKA. Subject-specific musculoskeletal model developed based on the CT and MRI scanning data, combined with 3D motion capture system will be used to simulate the knee kinematics during functional activities. The optimization algorithm will be recruited to predict knee ligament forces and muscle forces of lower limb. The change of knee contact force and underlying biomechanical mechanism will be investigated before and after cruciate-retaining TKA and posterior-stabilized TKA. The findings may benefit the design of knee implant, offer objective and quantitative indices and reference basis for the evaluation of knee motion function and rehabilitation after TKA.

膝关节是人体最大、解剖最复杂，对运动功能要求最高的关节之一。全膝关节置换术（total knee arthroplasty, TKA）能够减轻疼痛，改善膝关节功能，是治疗终末期膝关节骨关节炎的有效措施。膝关节接触力是直接影响TKA术后远期成功的重要因素，接触力异常可导致聚乙烯垫片加速磨损、假体松动并破坏膝关节稳定性。因此，准确预测术后功能活动中膝关节接触力对TKA患者有着十分重要的意义。本项目拟以后交叉韧带保留型及后稳定型假体置换的TKA患者和正常人为对比研究对象，利用CT和MRI图像获取建立个体肌骨模型所需的参数信息，并结合三维运动捕捉技术还原个体功能活动中的膝关节运动。应用优化算法预测膝关节韧带力和下肢肌肉力，以揭示手术前后不同时间点上TKA患者运动中膝关节接触力的变化及其生物力学机理。以期为膝关节的假体设计、TKA术后运动功能评定及康复治疗提供客观量化指标及参考依据。

全膝关节置换术（total knee arthroplasty, TKA）能够减轻疼痛，改善膝关节功能，是治疗终末期膝关节骨关节炎的有效措施。膝关节生物力学的改变，尤其是膝关节接触力的变化，是影响TKA术后远期成功的重要因素，本课题对TKA术后步态中的膝关节的生物力学进行了研究。结果发现TKA后患侧的支撑期、步时大于健侧，患侧髋、膝、踝关节的屈伸范围、地反力纵向峰值小于正常人。通过医学影像数据建立个体化肌骨模型，计算了行走过程中下肢肌肉力情况并通过表面肌电数据加以验证。实现了对模拟仿真过程中的误差控制。通过肌骨模型预测膝关节接触力发现，相比于健侧和正常组，TKA术后患侧膝关节轴向接触力第一峰值偏小，第二峰值偏大。股四头肌肌力对膝关节轴向接触力峰值贡献比重偏大，而腘绳肌肌力的贡献比重偏小。患侧的股四头肌-腘绳肌协同收缩程度升高，提示患侧膝关节在稳定性方面仍需加强。研究结果对TKA术后的运动功能评定及康复治疗具有较大的指导意义。