A Comparison Study Of MIS-TLIF With The Aid Of Fixed Channel And Expandable Channel In Degenerative Lumbar Spinal Stenosis Treatment

With the development of China's social aging and the increasing demands of the elderly for the quality of life,the incidence of lumbar spinal stenosis(LSS)rises year by year.Degenerative changes are the most common causes of LSS and some patients are characterised by lumbar instability or spondylolisthesis.In the case of failed conservative treatment,spinal decompression and internal fixation fusion is proceeded to reduce the symptoms of low back and leg pain in patients.Currently,in various types of decompression and fusion,minimally invasive transforaminal lumbar interbody fusion(MIS-TLIF)by using a variety of working channels,with small trauma,sufficient decompression and the high fusion rate,has received widespread attention.Objective: The aim of this study was designed to explore MIS-TLIF assisted by MED and Quadrant for the treatment of degenerative lumbar spinal stenosis(DLSS),which was aimed to provide a reference for minimally invasive treatment of DLSS patients.Methods: The clinical data of 59 patients with DLSS treated with MIS-TLIF in the Third Hospital of Hebei Medical University from May 2015 to January 2017 were retrospectively analyzed.According to different methods of minimally invasive surgery,59 patients were divided into MED group(n=27)and Quadrant channel group(n=32).Oswestry disability index(ODI),pain visual analogue scale(VAS)score and serum creatine kinase(CK)level were comparable in the two groups before operation.All patients were followed up for an average of 10.5 months from 6 months to 15 months.The changes of postoperative CK,operative time,intraoperative blood loss,postoperative drainage,postoperative time in bed,fusion rate and the degree of muscle fibrosis shown in MRI after surgery were compared in two groups of patients;at the same time ODI and VAS pain score were used for the evaluation of the clinical efficacy of patients.Results: The duration of operation in MED group was significantly longer than that in Quadrant group [(191.7 ± 32.4)min vs(145.6 ± 19.4)min,P<0.01),but less intraoperative blood loss(138.1 ± 26.9)ml vs 155.6 ± 21.5)ml,P<0.01)and shorter time in bed after surgery(2.3 ± 0.7)d vs(3.5 ± 1.1)d,P<0.01).Compared with Quadrant group,CK levels were risen slightly on the first and third postoperative day(P<0.01).CK on the fifth postoperative day in both groups returned to normal levels.For intraoperative and postoperative complications,1 case of dural sac rupture occurred in both groups.Gelatin sponge immediately with fibrin glue was used for plugging up,no postoperative cerebrospinal fluid leakage.In Quadrant channel group,1 case had less blood supply of skin incision edges and delayed epidermal necrosis and the other case had fat liquefaction.There was no incision-related complications in MED group.VAS score of lower back pain in MED group was lower than that in Quadrant group on the third day after operation(P<0.05).After 3 months,there was no significant difference in VAS score and ODI between the two groups(P>0.05).The fusion rate was 85.2%(23/27)in MED group and 93.8% in Quadrant channel group(30/32).There was no statistical difference in fusion rate of two groups.Some patients underwent MRI examination of lumbar spine one year after operation.Muscle fibrosis of lower back muscle was lighter in MED group.Conclusion: Compared with the aid of Quadrant,MIS-TLIF assisted with MED has less blood loss,less trauma and faster recovery,can reduce the incidence of postoperative incision complication and reduce the risk of doctors' health.