Clinical Outcomes And Imaging Comparison Of Between MIDLF And TLIF/MIS-TLIF In The Treatment Of L4/5 Spinal Stenosis

Background: Lumbar spinal stenosis is one of the most common spinal degenerative diseases in middle-aged and elderly patients,which has a serious impact on the quality of life.When non-surgical treatment is ineffective,surgical treatment is often required to improve the clinical symptoms of patients.Open and minimally invasive decompression and fusion of the lumbar spine is the main treatment.In theory,the midline lumbar fusion（MIDLF）has the advantages of less trauma,stronger screw purchase,and lower risk of intraoperative vascular and nerve injury,especially suitable for the treatment of patients with osteoporosis.It has been gradually recognized in recent years.However,at present,there are few studies on the clinical efficacy of MIDLF in the treatment of single segment lumbar spinal stenosis and its influence on the sagittal parameters of lumbar and pelvic.Therefore,this study discusses the above aspects.Objective: Clarify the clinical value of MIDLF in the treatment of L4/5 lumbar spinal stenosis by comparing the clinical efficacy of MIDLF with open transforaminal interbody fusion（TLIF）and minimally invasive transforaminal interbody fusion（MIS-TLIF）in the treatment of L4/5 lumbar spinal stenosis and its effect on lumbar pelvic sagittal parameters.Methods: The clinical data of L4/5 spinal stenosis patients treated by interbody fusion by the same surgeon in the spine surgery of the First Affiliated Hospital of Dali University from January 2018 to December 2020 were retrospectively analyzed.According to the operation method,they were divided into MIDLF group（49 people）,TLIF group（25 people）and MIS-TLIF group（36 people）.The clinical datas of all patients were collected: age,gender,Body mass index（BMI）,preoperative complications（hypertension,diabetes,urinary tract infection,osteoporosis）,operative time,intraoperative blood loss,C-reactive protein（CRP）,postoperative drainage and drainage tube retention time,postoperative hospital stay,preoperative and final follow-up of third and fifth days after operation,lumbar and leg pain VAS（Visual analogue analogue）,JOA（Japan orthopaedic association scores）and ODI（Oswestry disability index）,operation related adverse events（vascular and nerve injury,dural tear,cerebrospinal fluid leak,poor screw placement,surgical site infection,postoperative blood transfusion etc）;the imaging data of all patients before operation and at the last follow-up were collected: lumbar lordosis（LL）,high of the intervertebral disc（HOD）,segment lordosis（SL）,pelvic incidence（PI）,pelvic tilt（PT）,sacral slope（SS）,at the last follow-up,CT plain scan and reconstruction were performed to evaluate the fusion of L4/5 segments,and the displacement of cage and loosening of internal fixation were recorded.Resutls: All patients were followed up for more than 1 year.The average follow-up time of MIDLF group was 16.90±4.417 months,MIS-TLIF group was 19.58±6.335 months,and that of TLIF group was 19.96±5.674 months,there was no significant difference among the three groups（P > 0.05）.There was no significant difference in baseline data among the three groups（P > 0.05）.The low back and leg pain of VAS,JOA and ODI index in the three groups at the last follow-up were significantly different from those before operation（P < 0.05）,but there was no significant difference in the relief of back and leg pain among the three groups（P > 0.05）.The amount of intraoperative bleeding in MIDLF group was significantly less than that in MIS-TLIF and TLIF（P < 0.05）.The operation time in MIDLF group was longer than that in MIS-TLIF and TLIF（P < 0.05）.The postoperative drainage volume in MIDLF group was less than that in TLIF and more than that in MIS-TLIF（P < 0.05）.The extubation time in MIDLF group was shorter than that in TLIF and longer than that in MIS-TLIF（P < 0.05）.C-reactive protein in MIDLF group was lower than that in TLIF on the 3rd and 5th day after operation（P < 0.05）,but there was no significant difference compared with MIS-TLIF（P > 0.05）.One case in MIDLF group underwent emergency exploration and internal fixation correction due to poor screw position.There were no isthmus and pedicle fracture,vascular and nerve injury,dural tear or cerebrospinal fluid leak and so on;no problems such as cage displacement and screw loosening were found in postoperative follow-up.Conclusion: The clinical outcomes and intervertebral height recovery of MIDLF in the treatment of L4/5 lumbar spinal stenosis are consistent with those of TLIF and MIS-TLIF,and it is a safe and effective interbody fusion.Compared with MIS-TLIF,MIDLF has less intraoperative blood loss,but more postoperative drainage and longer drainage tube indwelling time.Compared with TLIF,MIDLF has the advantages of less intraoperative blood loss,less postoperative drainage,less postoperative inflammatory reactionand and shorter drainage tube indwelling time.