| The rapid development of metal 3D printing technology,it provides new research ideas and technical support for the design and preparation of hip prosthesis stem.Hip,knee and shoulder prostheses with 3D printed titanium alloy bone trabecular structure have been applied in clinic,but most of the applications in joint prostheses are uniformly distributed 3D printed bone trabecular structure,which lacks the bionic characteristics of real human body structure.After implant implantation,the bone tissue in most areas does not meet the conditions for bone growth,or the strain value is too small or too large,which seriously affects the implant stability in the early stage and the long-term stability after implant,resulting in a high rate of secondary revision.This not only increases the suffering of patients,but also increases the economic burden on individuals and the country.Based on the work of homogeneous trabecular prosthesis,this paper studies the mechanical behavior of the femoral shaft of trabecular bone partition based on bone functional adaptability,which is of great significance for improving the long-term stability of the prosthesis implantation and the clinical treatment level of hip prosthesis replacement.The research content of this paper is as follows:(1)The influence of two calculation models and two loading methods on the stress distribution of the femoral stalk was studied.The rigid zone loading method was used for the single femoral shaft,and the displacement loading method was used for the finite element calculation of the femoral shaft ball head.The electrical test method was used for experimental verification,and the position of the measurement point was determined according to the simulation results.The results show that the spherical plate model and displacement loading mode are closer to the experimental results.(2)3D printed tensile and compression specimens of titanium alloy and zirconium niobium alloy were designed and prepared,and the elastic moduli of titanium alloy and zirconium niobium alloy during tensile and compression were tested respectively.The results show that both titanium alloy and zirconium niobium alloy are plastic materials,but the elastic modulus obtained by tensile and compression experiments are different,and the elastic modulus is related to the size of the specimen.(3)A three-dimensional solid model of femur was constructed based on reverse modeling software.Cortical and cancellous bones were reverse-modeled using Mimics,the reverse-modeled components were optimized using Geomagic Studio software,and the components of the prosthetic handle were created using UG,a 3D modeling software,to complete the assembly of the hip joint replacement.(4)Based on ANSYS software,the finite element calculation of the femoral stalk of partitioned bone trabeculae was carried out.Four solid models of bone trabecular structures with different porosity were established for titanium alloy and zirconium niobium alloy respectively.The mechanical properties of different bone trabecular structures and different porosity were studied by finite element calculation.The porous bone trabecular structure was applied to the femoral stem,and four three-dimensional models of the hip prosthesis with uniform porous bone trabecular structure were established.The effects of porous bone trabecular structure with different porosity on the mechanical properties of the hip prosthesis were investigated by numerical simulation.The mechanical properties of the porous structure of homogeneous trabecular bone and zoned trabecular bone were analyzed by numerical simulation through the partition design of uniform trabecular bone with one handle and the combination of handles,and the structural form of bone trabecular bone that can better promote bone ingrowing was determined by comparative analysis.(5)Titanium alloy integrated femoral shaft was printed by Y150 powder electron beam 3D printer,and the dynamic fatigue performance test of the head and neck of 3D printed titanium alloy femoral shaft was carried out.Before the experiment,the surface defects of printed samples were detected by fluorescence.The head and neck of the 3Dprinted titanium alloy integrated handle that met the detection of surface defects were embedded.The fatigue test results showed that the 3D-printed titanium alloy integrated femoral handle could pass 10 million fatigue performance tests of the head and neck of the prosthetic handle under the load of 5340 N. |
