Design And Simulation Analysis Of Novel Extensible Pedicle Screw

With our country's aging population and the pressure of people's lives,the incidence of lumbar spinal stenosis also improved obviously,and become a common disease of bone surgery.Traditional surgical procedures need to remove the vertebral plate and expand the vertebral canal in order to achieve the effect of decompression.The risk of this approach is greater,and the surgical trauma is bigger.It is prone to appear the instability of the lumbar spine,epidural scar adhesions,adjacent segment degeneration and other complications after operation,and surgery often does not achieve the desired results.We proposed a new method for the treatment of LSS by cutting the pedicle of vertebrae,moving the posterior column backward to enlarge the spinal and foreman and reduce the destruction of the tissue around the lumbar spine,and provide a good guarantee for the stability of the spine.The volume of vertebral canal is equal to the product of the sectional area and the length of extended distance.The volume of vertebral canal with different extended distance is definitely different,and the influence of the spinal stability is different.So the section of a reasonable expanded distance to meet the requirement of reducing spinal canal pressure and also provide sufficient stability and activity of the lumbar spine which is the focus of clinical application.By using the finite element analysis method,this paper makes a biomechanical analysis and evaluation of a new adjustable pedicle screw.The main research contents and results of this paper mainly include the following aspects:(1)By using many kinds of image processing software and finite element analysis software,this paper established a 3D finite element model of normal human lumbar spine of L1-L5 segment.The effectiveness of the model is verified and get the activity of the normal lumbar spine compared with Famous external lumbar biomechanics experimental data at home and abroad.It provides a good foundation for the following analysis and research.(2)On the basis of traditional pedicle screw structure,this paper proposes the design of a new type of adjustable pedicle screw so as to expand the area of the intervertebral foramen and reduce the pressure of the spinal canal.Then establishing the finite element model of pedicle screw,and to integrate it with the normal lumbar spine model.(3)In this paper,we used reasonable finite element analysis method,applying load and constraints to obtain the activity of lumbar,the maximum Von Mises stress value of the screw and faced joint.Through the above three kinds of analysis index,a reasonable analysis and evaluation of the pedicle screw fixation was carried out to provide a basis for the clinical application of percutaneous pedicle screw fixation.