The Clinical Efficacy And Finite Element Analysis Of MIS-TLIF Combined With Unilateral Fixation In The Treatment Of Double-segment Lumbar Intervertebral Disc Herniation

Objective(1)To analyze the efficacy comparison of minimally invasive transforaminal interbody fusion(MIS-TLIF)combined with unilateral fixation and bilateral fixation in the treatment of unilateral two-level lumbar degeneration.(2)The finite element analysis of TLIF combined with unilateral fixation and bilateral fixation for the treatment of unilateral two-segment lumbar degenerative disease of the vertebral body and internal fixation displacement.Methods(1)A retrospective analysis of 140 patients with lumbar degenerative disease admitted to our hospital from August 2015 to August 2018 were divided into unilateral fixation group and bilateral fixation group according to different treatment methods,with70 cases in each group.The unilateral fixation group was fixed with MIS-TLIF+unilateral pedicle screw,and the bilateral fixation group was fixed with MIS-TLIF+bilateral pedicle screw.The perioperative indexes,preoperative and postoperative VAS scores,ODI scores and surgery were compared between the two groups.Complications later.(2)Establish a normal L3-L5 finite element model based on the CT scan data of the normal person L3-L5 segment,and establish a two-segment TLIF combined with unilateral pedicle screw fixation and double-segment pedicle screw fixation on this basis model.Under the set load conditions,simulate the lumbar spine flexion,extension,left flexion,right flexion,left rotation,right rotation,and observe the maximum displacement of the lumbar spine and internal fixation of the two models under various conditions.Results(1)There was no statistically significant difference in general information between the two groups(P>0.05).The operation time(149.99±20.91)min,intraoperative blood loss(82.50±12.00)m L,and postoperative drainage volume(81.53±9.94)m L in the unilateral fixation group were better than those in the bilateral fixation group,and the difference was statistically significant(P<0.05)).The postoperative VAS score and ODI score of the two groups improved compared with preoperatively,the difference was statistically significant(P<0.05),but the difference between the two groups of postoperative VAS score and ODI score was not statistically significant(P>0.05).There was no significant difference between the two groups of complications such as fusion cage displacement and incision infection(P>0.05).(2)The maximum displacement of the unilateral fixed vertebral body is 0.271 mm for forward flexion,0.456 mm for posterior extension,0.634 mm for left side,0.547 mm for right side,and 0.817 mm for left rotation.The right hand is 0.727 mm.The maximum displacement of the internal fixation was0.181 mm for flexion,0.304 mm for extension,0.422 mm for the left,0.365 mm for the right,0.545 mm for left rotation,and 0.485 mm for right rotation.The maximum displacement of the bilateral fixed vertebral body is 0.119 mm for flexion,0.196 mm for extension,0.276 mm for the left side,0.275 mm for the right side,0.394 mm for left rotation,and 0.354 mm for right rotation.The maximum displacement of the internal fixation was 0.092 mm for flexion,0.153 mm for extension,0.214 mm for the left side,0.214 mm for the right side,0.306 mm for left rotation,and 0.275 mm for right rotation.Conclusion(1)In the treatment of MIS-TLIF for two consecutive segments of lumbar degenerative disease,both unilateral fixation and bilateral fixation have certain effects.However,unilateral fixation has more advantages than bilateral fixation in terms of operation time,intraoperative blood loss,and postoperative drainage.,(2)Two-segment TLIF combined with unilateral pedicle screw fixation has a firm and effective treatment from a biomechanical point of view.