Effect Of Internal Fixation On The Stability Of Osteoporotic Lumbar Spine

As an effective way to treat degenerative diseases of human lumbar spine,lumbar internal fixation is widely used in clinical treatment.The common internal fixation methods include traditional pedicle screw fixation and traditional CBT internal fixation.However,osteoporosis often leads to loosening of internal fixation system and failure.Compared with traditional pedicle screw fixation,cortical bone channel technique is more effective Surgery is more and more favored by clinical workers,and it has gradually become an ideal fixation method for patients with osteoporosis.However,some researchers found that there are still many shortcomings in the widely used cortical bone channel screw technology.Based on the improved cortical bone screw technology,the lumbar L4-L5 segment model was reconstructed by mimics medical software,and three kinds of internal fixation models of osteoporotic lumbar L4-L5 segment were simulated under axial load and four working conditions of flexion,extension,lateral bending and torsion.The main contents are as follows:(1)According to the current research status of internal fixation technology,combined with the improvement of cortical bone channel technology,the screw entry trajectory of three internal fixation technologies was compared and analyzed;(2)On the basis of CT image data,we use mimics 17.0 software to reconstruct the three-dimensional model of CT image data,extract the L4-L5 segment lumbar model needed in this study,construct the intervertebral disc model in 3-matic,assemble the model through mimics,establish three kinds of lumbar internal fixation models needed in the study,and mesh the model,and finally combine with the literature Data is used to assign material value to each model;(3)Using the method of numerical simulation,the finite element analysis of L4-L5 segment of osteoporotic lumbar spine was carried out by using ANSYS 15.0 software.The stress and displacement changes of three kinds of osteoporotic lumbar internal fixation models under relevant loads were compared and analyzed.The results showed that the improved cortical bone channel screw technology had better internal fixation effect under axial load;(4)The lumbar L4-L5 segment was used to simulate the influence of four working conditions of flexion,extension,scoliosis and torsion on the range of motion of three lumbar internal fixation models.Through the observation and analysis of the simulation results,it was found that the ROM of mcbt screw model was the smallest under the working conditions of flexion,extension and torsion,and was greater than TT model group and CBT model group under the working conditions of scoliosis.Compared with TT and CBT,mcbt has better mechanical stability,and has more advantages in the treatment of osteoporosis.In this paper,through the construction and material assignment of L4-L5 segment lumbar internal fixation model,three kinds of lumbar internal fixation models were established,and the relevant mechanical analysis was carried out,and the advantages of the improved cortical bone channel screw technology compared with the two traditional internal fixation technologies were obtained.It provides a theoretical basis for future clinical research.