Research On The Technology Of Metal Bone Implants Based On 3D Printing

In recent years,the replacement of broken bone tissue with metal implants in recent years is one of the main methods for the treatment of bone injury,tumor,and functional degradation.At present,the domestic application of metal implant mostly imports.Because the skeleton structure of the human body in the European and American countries is a little larger than that of the Chinese.The implant will cause great damage to the human skeleton in the process of implantation.In addition,the common implants have no grid-less structure,so it is inconvenient to combine with bone tissue and muscle tissue.Therefore,it is particularly necessary to develop suitable metal implants for Chinese.This study is mainly divided into three aspects:1.The mechanical properties of the grid with different structures are studied and the best grid shape and dimensions are obtained through simulations and pressure tests.2.The stress-strain-related simulation of grid and grid-less implants with femurs are studied.3.A bio-mechanical experiment is carried out to verify the simulation results.Two grids of square and circular are used in this paper and each grid is designed to compare four different grid areas of 1mm2?1.22mm2?1.42mm2?1.62mm2.The maximum stress value of each model is obtained by finite element analysis of the 0 degrees,15 degrees,30 degrees and 45 degrees of the angle between the force and the vertical direction respectively with 100N.It is concluded that the circular grid is more easily destroyed under the same grid area.In order to verify the simulation results,the circular grid of 1mm2 is produced by 3D printing,and the pressure test is carried out to verify the simulation conclusion.The final result is a 1mm2 square grid with the best comprehensive strength.For the simulation,the CT data of adult male patients in the department of orthopedics are provided by the Jilin University.Through the providing CT data,mimics is applied for three-dimensional reconstruction of the right femur and measure the data inside the marrow cavity.By geomagic software,the model reverse reverse processing and then import it to UG.The handle and neck of the implant are designed through the three-dimensional structure of the femur and the internal data of the bone marrow cavity.The designed grid and grid-less implants combine with femurs for finite element analysis in ABAQUS.It was finally concluded that grid implants perform better than grid-less implants.The Machined grid implants were inserted into the femoral cavity.The corresponding loads were applied to measure the strain at three points at the same simulated position.Combining simulations and experiments,it is result that with the increase of load,the strain of cortical bone is linear with load.Cortical bones and cancellous bones have a greater stress near the mid-bottom,especially at the bottom of the 1/3.The stress at the tip of the implant is most pronounced and prone to wear,thus result the postoperative bone marrow cavity friction heat,shake and other phenomena,which affect the stability of the replacement surgery.