全髋关节置换术中髋臼高精度低热损伤铣削机理与方法研究

In the total hip arthroplasty, poor initial stability of the acetabular component and bone ingrowth difficulty lead to early loosening and failure of the acetabular component, resulting in failure of surgery and requiring revision surgery. Acetabular reaming quality is the most important cause of initial stability and bone ingrowth of acetabular prosthesis. The core issues of acetabular reaming are low reaming accuracy, unstable reaming process, and thermal damage to bone tissue. This project proposes that by studying the kinematics mechanism of the surface profile formation during acetabular reaming, the effect of the shape, number, and arrangement of reamer cutting teeth on the irregularity of the reaming surface is obtained. By studying the fracture mode and chip formation mechanism during cutting process of cartilage and subchondral bone in the thickness direction, the cutting mechanism model of cartilage and subchondral bone and the real-time milling force and temperature distribution model during acetabular reaming are obtained. By studying the issues of reamer wobbling, deformation, and thermal necrosis during acetabular reaming, the relationship between reaming quality and acetabular reamer structure parameters, reaming process parameters, and material properties of cartilage and subchondral bone is established. By using genetic algorithm optimization, a well-designed acetabular reamer structure and reaming process method are obtained, and acetabular reaming with high reaming accuracy and low thermal damage is achieved. It provides a theoretical basis for enriching the machining theory of biomaterials, optimal design of surgical instruments, and rational selection of surgical parameters during surgery.

全髋关节置换术中因髋臼假体初期稳定性差和骨组织长入困难，导致其早期松动失效不断发生，造成手术失败和需翻修手术。髋臼铣削质量是影响髋臼假体初期稳定性和骨组织长入的最主要原因。髋臼铣削核心问题是铣削精度低、铣削过程不稳定和骨组织热损伤等问题。本项目提出通过研究髋臼铣削时表面轮廓形成的切削运动学机制，获得髋臼锉上切削齿形状、数量和排布方式对铣削表面平整性的影响规律；通过研究随厚度方向变化的软骨及软骨下骨切削时的材料断裂模式和切屑成形机理，获得软骨及软骨下骨的切削机理模型以及髋臼铣削时实时铣削力和温度分布模型；通过研究髋臼锉铣削时的滑移、变形、发热等问题，建立铣削质量与髋臼锉结构、铣削工艺和材料特性之间的关系；利用遗传算法优化，获得设计合理的髋臼锉刀具结构和铣削工艺方法，实现铣削精度高和热损伤小的髋臼铣削；为丰富生物材料的切削理论，为外科手术器械的优化设计、手术时工艺参数的合理选择提供理论依据。

全髋关节置换术中，髋臼铣削质量差是影响髋臼假体初期稳定性差和骨组织长入困难的最主要原因，进而导致髋臼假体早期松动失效，造成手术失败和需翻修手术。髋臼铣削质量核心问题是铣削精度低、铣削力和温度造成的骨组织机械和热损伤等。本项目通过研究髋臼软骨及软骨下骨的切削机理和切屑成形方式、髋臼锉铣削髋臼时的铣削力和铣削温度分布模型、髋臼铣削的表面轮廓形成的切削运动学机制、铣削精度高和热损伤小的髋臼锉刀具结构，来提高髋臼铣削精度和降低骨组织机械和热损伤等质量问题，并取得了一系列创新性成果。.项目研究的重要成果包括：1）切削力和切屑形态与主要切削工艺参数和刀具参数的影响关系，其中切削深度对切削力和切屑形态具有较大的影响；2）髋臼铣削的铣削力和温度分布与髋臼锉结构参数的分析模型，铣削力模型预测平均误差小于3.37%，铣削力矩模型预测平均误差小于8.2%；3）髋臼锉切削运动学和表面形成机理，建立了髋臼铣削表面质量评价方法，并构建了髋臼铣削表面质量相对于髋臼锉结构参数的分析模型，实验验证发现分析模型精度的预测精度小于6.2%；4）基于分析模型的新型髋臼锉优化设计，并通过增材制造方式快速试制新结构的髋臼锉，通过实验验证发现新结构在不增加切削力的基础上可消除表面环状沟槽，铣削精度大大提高。本项目的研究成果可提升医疗器械的设计能力以及指导创伤骨科医生优选工艺参数，进而改善手术质量提高患者康复水平。