Clinical Efficacy Of Extreme Lateral Interbody Fusion And Development Of A Novel XLIF Cage

OBJECTIVE:1.Analyze the subsidence rate after Extreme Lateral Interbody Fusion(XLIF)through clinical data,and evaluate the fusion rate by using autologous bone marrow mixed with allograft bone as bone graft material;2.Proving the advantages of single level XLIF in the treatment of lumbar degenerative scoliosis by analyzing a case of LDS surgery,and proposing a new design idea of novel XLIF cage accordingly;3.Completed the related imaging anatomical measurement and preliminary design of the novel XLIF cage design;4.Establish the LDS finite element model and verify the validity of the model;5.Based on the LDS finite element model,a lumbar posterior cage,a traditional lumbar lateral cage and a novel lumbar lateral cage combined with pedicle screw internal fixation model were established by using the finite element analysis method,and the mechanical characteristics of the novel XLIF cage were analyzed.METHODS:1.According to the fixation type,107 patients(126 operations segment)were divided into four groups,stand-alone group,lateral fixation group,unilateral pedicle screw and bilateral pedicle screw group.Preoperative and postoperative imaging data including intervertebral disc height,lumbar lordosis angle and segmental lordosis angle.Meanwhile,the subsidence rate was calculated according to the height of intervertebral disc at the different time points.Fusion rate was collected according to the postoperative CT;2.Collect the imaging data and health-related quality of life(HRQOL)score of a LDS patient before and after surgery;3.Select CT scan images of 100 normal adult lumbar vertebrae,50 males and 50 females,aged 21-75 years.Use PACS system to review images and measure relevant data;4.A patient with LDS was selected and scanned to obtain CT image data.Mimics 13.0,Geomagic Studio 2012 and ANSYS 13.0 software were used to construct a three-dimensional finite element model of LDS,and special constraints and loading conditions were imposed.5.Finite element analysis was used to calculate the activity and stress of the three internal fixation models under different working conditions.RESULTS:1.The postoperative height of the vertebral space in the four groups was significantly increased compared with that before the surgery.The influence of the bilateral pedicle screw group on the lumbar lordosis Angle was statistically different from that of the other three groups;2.The LDS patient was operated with single level XLIF surgery,preoperative and postoperative coronal cobb Angle is 21.1 ° and 4.8 ° respectively,while preoperative and postoperative lumbar lordosis angle is 1.5 ° and 5.6 °,proving that the orthopedic effect is satisfied.HRQOL scores also showed good clinical curative effect;3.Collected CT data of 100 Chinese lumbar vertebrae,proposed new specifications of XLIF fusion cage,and preliminarily designed the fusion cage with computer software;4.The LDS finite element model was established and the results were verified to be effective;5.ANSYS software analysis results show that the stress of the two side fusion devices is smaller than that of the back fusion device,and the new XLIF fusion device has more obvious orthopedic effect than the other two.CONCLUSION:1.No matter what kind of internal fixation is performed,XLIF can obtain good imaging images,and the fusion rate 2 years after the surgery is satisfactory;2.A new XLIF cage is preliminarily designed,and the LDS finite element model is proved to be effective;3.The new XLIF fusion cage has both stability and safety,and its orthopedic effect is the most obvious.