仿生表面髋关节假体生物力学性能的有限元分析

Finite element analysis of biomechanical properties of bionic surface hip prosthesis

目的比较传统表面髋关节假体和仿生表面髋关节假体的生物力学性能。方法选用Sawbone数字模型(型号3908,左侧,中号)作为研究对象,通过Mimics 21.0软件重建股骨实体化模型,利用Solidworks 16.0软件建立假体模型,包括传统和仿生(1~4型)表面髋关节股骨侧假体的三维模型并装配,其中仿生1~4型假体螺钉交叉位置距压力螺钉顶部分别为20.22 mm、30.12 mm、32.17 mm和37.76 mm。在Workbench 18.2软件中划分网格并对材料赋值,模拟缓慢行走单足负重下的受力,测量整个模型的力学分布特征并得到应力分布云图。结果传统和1~4型仿生表面髋关节股骨侧假体的骨-假体柄交界处峰值应力分别为32.18 MPa、13.80 MPa、15.01 MPa、23.46 MPa和34.51 MPa。随着交叉处远离股骨顶部,1~4型仿生表面髋关节股骨侧假体的交叉处峰值应力分别为37.98 MPa、48.60 MPa、54.80 MPa和53.87 MPa。传统假体和1~4型仿生表面髋关节假体股骨颈上方应力峰值分别为8.00 MPa、7.80 MPa、7.04 MPa、7.03 MPa和7.51 MPa,股骨颈下方应力峰值分别为15.38 MPa、14.20 MPa、11.11 MPa、13.10 MPa和12.18 MPa,股骨大转子应力峰值分别为13.08 MPa、11.61 MPa、13.09 MPa、11.02 MPa和39.51 MPa。结论与传统表面髋关节假体相比,基于杠杆平衡重建理论设计的类型1仿生表面髋关节假体通过仿生重建主张力骨小梁和主压力骨小梁、合理的置钉角度和更接近股骨头中心的支点内移,弥补了传统表面髋关节假体的设计缺陷,优化了股骨近端的应力分布,提高了置换术后假体的稳定性,有助于降低股骨颈骨折和假体松动的风险,延长假体使用寿命。

Objective:To compare the biomechanical properties of traditional surface hip prosthesis and bionic surface hip prosthesis.Methods:The Sawbone digital model(#3908,Left,Medium)was selected as the research object.Mimics 21.0 software was used to reconstruct the physical model of femur.Solidworks 16.0 software was used to build the model of prostheses,including the traditional and bionic(type 1-4)protheses and their assembly.The distances from the screw cross position to the top of pressure screw of type 1 to type 4 protheses were 20.22 mm,30.12 mm,32.17 mm and 37.76 mm,respectively.The mechanical distribution characteristics of the whole model were measured and the stress distribution cloud map was obtained.Results:The peak stresses at bone-stem junction of traditional prosthesis and type 1-4 hip prostheses were 32.18 MPa,13.80 MPa,15.01 MPa,23.46 MPa and 34.51 MPa,respectively.With the fulcrums away from the top of the femur,the peak stresses at the fulcrums of type 1-4 hip protheses were 37.98 MPa,48.60 MPa,54.80 MPa,and 53.87 MPa,respectively.The maximum stress above femoral neck of traditional prosthesis and type 1-4 hip prostheses were 8.00 MPa,7.80 MPa,7.04 MPa,7.03 MPa and 7.51 MPa,respectively.The maximum stresses under femoral neck was 15.38 MPa,14.20 MPa,11.11 MPa,13.10 MPa and 12.18 MPa,respectively.The maximum stresses in the greater trochanter region of femur were 13.08 MPa,11.61 MPa,13.09 MPa,11.02 MPa and 39.51 MPa,respectively.Conclusion:Compared with the traditional surface hip prosthesis,the type I bionic surface hip prosthesis is designed based on the lever balance reconstruction theory.With the bionic reconstruction of the tension trabeculae and compression trabeculae through reasonable screw placement angles and the inward movement of the fulcrum closer to the center of the femoral head,the new type prothesis make up for the design defects of the traditional surface hip prosthesis,optimize the stress distribution in the proximal femur,and improve the stability of the prosthesis after replacement,which help reduce the risk of femoral neck fracture and prosthesis loosening,and extend the service life of the prosthesis.