人工关节生物固定界面微动刺激下的骨生长促进机制及微动损伤行为研究

The loosening of artificial joint fixation interface is one of the major cause for the failure of artificial joint. Due to the longer recovery time and lower fixation intensity in the early stage, the development of noncemented fixation has been greatly restricted. Basing on reconstruction of bone trauma under mechanical stimulation, this project proposes to apply fretting stimulation on the noncemented fixation interface after replacement of artificial joint which can accelerate the growth and binding strengthen of the bone tissues in the interface. Based on the 3D model of artificial joint, the mechanical stimulation parameters that are suitable for the growth of bone tissue in vitro are calculated in this project. The aseptic experimental platform for fretting stimulation of bone tissue growth in vitro is constructed. Besides, the promoting mechanism of bone growth mechanism on the inactive joint surface under the fretting stimulation is studied. In addition, the relationships between the growth rate of bone tissue, the steady fixation quality of the interface and the fretting stimulation parameters, the joint materials as well as micro-porous structures are built. The mechanism of fretting damage and cell damage in the noncemented fixation interface are studied on the basis of the tribology and biomedicine. Additionally, the promoting mechanism of bone growth under the fretting stimulation is verified in vivo animals experiments. Furthermore, the artificial joint prosthesis materials and fretting stimulation parameters which could reduce the fretting damage in the noncemented fixation interface are obtained. The research results have great significance for shortening the rehabilitation time after artificial joint replacement, improving the quality of the joint fixation interface and prolonging the life of artificial joint prosthesis.

人工关节固定界面松动是引起人工关节失效的主要原因之一。由于生物固定较长的康复时间和前期较低的固定强度，造成其发展受到极大限制。基于力学刺激下骨创伤的重建功能，本项目提出在人工关节置换术后的生物固定界面施加微动刺激，加速界面的骨组织生长和牢固结合。项目基于人工关节的3D模型，计算获得适于体外骨组织生长的力学刺激参数，构建无菌性体外骨组织生长微动刺激试验平台，研究微动刺激下骨组织在非活性关节表面的生长促进机制，建立骨组织生长速率和界面稳固质量与微动刺激参数、人工关节假体材料及微孔结构的关系；从摩擦学和生物医学研究生物固定界面的微动损伤机理和细胞组织损伤机制，结合动物体内实验验证微动刺激下骨组织生长促进机制，提出减少生物固定界面微动损伤的人工关节假体材料及微动刺激参数。所取得的研究成果将对缩短人工关节置换术后康复时间，提高人工关节固定界面稳固质量，延长人工关节假体寿命具有重要研究意义。

人工关节固定界面松动是引起人工关节失效的主要原因之一。针对人工关节固定界面长期稳定性差、机械松动、术后康复时间长等问题，本项目提出了在人工关节生物固定界面施加微动刺激可加速界面的骨组织生长和牢固结合的学术思路。项目构建了人体内人工关节假体与骨接触界面的3D模型并进行有限元分析，确定了在体外环境下骨组织-人工关节固定材料间的微动力学刺激参数；构建了无菌化骨组织体外培养体系，优化配制了体外骨组织培养基，发明了探究生物固定界面微动刺激骨生长的实验装置及方法；选择临床常用的钛基钛珠涂层和羟基磷灰石涂层人工关节固定材料为对象，研究了其在体外环境下交变压缩和交变切向微动刺激下不同力学刺激参数对骨组织-固定材料界面的生长速率和界面稳固的影响，获得了最佳的微动力学刺激参数，揭示了交变压缩和交变切向微动刺激下骨组织在人工关节固定材料表面的促进骨生长机制；研究了频率、间歇加载周期、微动幅值等参数对人工关节固定材料骨生长结合的影响，探明了微动刺激参数与微损伤之间的关联关系，优化了利于生物固定的微动刺激参数，揭示了骨组织-钛珠涂层界面间的骨生长机制及微动损伤机理；研究了骨组织与钛基钛珠涂层和羟基磷灰石涂层间的切向微动和扭动磨损行为，探究了微动幅值、法向载荷等微动参数对骨组织微动磨损行为的影响，建立了骨组织与生物固定界面间的微动-松动-骨损伤的关联关系，揭示了其切向微动磨损和扭动微动磨损机理；研发了具有拓扑结构的、生物活性强的掺铜和掺锶HA涂层多孔结构钛合金支架，优化了最佳的涂层配比和工艺；基于体外人工关节生物固定界面的促进骨生长数据，开展了人工关节固定材料在动物体内微动刺激对骨生长的影响研究，验证了适当的微动刺激有利于促进动物体内人工关节固定材料与骨组织界面间的骨生长。所取得的研究成果对于缩短人工关节置换术后康复时间，提高人工关节固定界面稳固质量，延长人工关节假体寿命具有重要的指导意义。