Design Of Auxiliary Mechanism And Postoperative Fixation System For High Tibial Osteotomy

The osteotomy process in medial tibial high osteotomy is often cumbersome,and the stability of the tibial fixation system after surgery is not ideal.In view of these two problems,this thesis designs the auxiliary osteotomy mechanism and force line correction mechanism,which reduces the cumbersome osteotomy process.Design and optimize the tibial fixation system,effectively improve the stability of the tibia fixation system,and provide more accurate and effective help for the diagnosis and treatment of knee joints.(1)Design of auxiliary osteotomy mechanism and force line correction mechanism.Based on the reverse design theory and the digital measurement of the lower limb force line,the back and knife edge position of the auxiliary osteotomy module are individually designed,and the osteotomy can be completed at one time with the use of a scale,accurately measuring the proximal center point of the tibia,the distal center point of the femur,the center point of the ankle joint and the center point of the femur,and determine the mechanical axis and load-bearing line of the lower limb,so as to accurately predict the depth of surgical osteotomy and the height of the osteotomy area,which greatly reduces the cumbersome osteotomy process of tibial high osteotomy.(2)Design and study of postoperative fixation systems.Preoperative knee joint static analysis.According to the threshold segmentation method,reverse engineering software and elastic mechanics principle,the three-dimensional solid model of the knee joint was established and analyzed,and the displacement,stress and strain analysis of the model was carried out to obtain the stress distribution,and the preoperative analysis data was used as the basic data for the stability analysis and verification of the postoperative tibial fixation system.Determination of the stability of the tibial fixation system after surgery.For the bone plates with different bends,five models of bone plates with different curves and postoperative tibial fixation were established according to the equal gradient,and the static simulation calculation of each model was carried out based on Workbench 18.0,and the optimal fixation scheme was obtained by comparative analysis,that is,the 3.0mm internal bending of the bone plate was the most stable.The variation of tibial contact stress with the degree of bone plate bending and the distribution characteristics of screw shear stress and screw tensile stress were obtained.The tibial contact stress is negatively correlated with the degree of internal bending of the bone plate.The maximum shear stress of screws occurs at screw 2 and screw 4 that are perpendicular to the osteotomy surface and closest to the osteotomy surface,and the maximum tensile stress of the screw is distributed at the upper end of the osteotomy surface.It provides a theoretical basis for subsequent fixed system research.