Objectives:To compare the clinical efficacy and safety of uni-portal endoscopic lumbar interbody fusion by using larger-diameter endoscope for single-level lumbar disease via transforaminal approach versus transfacet approach.Methods:46 patients underwent single-level uni-portal endoscopic lumbar interbody fu-sion from June 2018 to February 2022 were enrolled.18 of the patients were male and 28 were female.The mean age was 60.9±10.5 years old(40-80 years).The follow-up time was 3-47 months.Patients were divided into two groups according to the surgical approach,18 of which were included in the transforaminal group,and the remaining 28 were included in the transfacet group,and a full spinal endoscope of 7.1mm inner-di-ameter working-channel was applied to all the patients.The clinical result was evaluated before surgery,at 3d after surgery and the final follow-up,by Oswestry disability index(ODI),visual analogue scale(VAS)for back pain and leg pain,and Japanese Orthopaedic Association(JO A)score.The decompression and implant were evaluated by anteroposterior and lateral X-ray plain film and lumbar CT at 3d after operation.Bridwell criteria were used to evaluate the fusion rate based on CT images for patients followed up for more than 6 months after surgery.Results:No significant differences were found in age,gender,diagnosis,preoperative in-tervertebral height,surgical segment,preoperative ODI,VAS and JOA score between the two groups(P＞0.05).72.2％of the patients in transforaminal group complained unilateral radicular symptom,while 64.3％of the patients in transfacet group suffered from bilateral radicular symptoms(P=0.020).The average operation time was 327.7±89.9min in the transforaminal group,significantly longer than the 385.9±96.7min in the transfacet group(P=0.047),and the mean length of hospital stay in the transforaminal group was 14.8±6.0d,shorter than that of 19.5±7.8d in the transfacet group(P=0.038).75％of the patients in transfacet group underwent unilater-al laminotomy with bilateral spinal canal decompression(ULBD).The ODI scores,back and leg pain VAS scores and JOA score were significantly improved postoperatively and at the final follow-up in both groups(P＜0.05),while no statistical differences between groups(P＞0.05).Postoperative intervertebral height significantly increased in both group(P＜0.001),but no statistical difference was found between groups(P＞0.05).The compli-cation rate was comparable between two groups,without severe intraoperative or postoperative complication.A-mong the 21 patients who were followed up for more than 6 months and received CT examinations,20(95.2％)presented bony fusion at surgical segment,and there was no statistical difference between the two groups in fusion rate.Conclusions:Both the transforaminal approach and the transarticular protrusion ap-proach are safe and effective for the single-level lumbar interbody fusion under single-hole coaxial large channel endoscopy,and the transforaminal approach results in shorter operation time and shorter hospital stay.

Objectives:To analyze the early clinical efficacy of modified percutaneous transforaminal lumbar interbody fusion(MPTLIF)in the treatment of lumbar degenerative diseases.Methods:The clinical data of 26 patients who underwent MPTLIF at the Second Affiliated Hospital of Army Medical University between Jan-uary 2020 and October 2021 were analyzed retrospectively.There were 12 males and 14 females,aged 44-77 years(58.3±8.4 years);Lumbar spondylolisthesis in 16 cases,lumbar spinal instability with radicular stenosis in 10 cases;3 cases were of L3/4 and 23 cases were of L4/5.The operative time,intraoperative bleeding,post-operative hospital stay,and postoperative drainage were analyzed.The visual analogue scale(VAS)for pain was documented before operation,at 3d and 3 months after operation and at the final follow-up,the Oswestry disability index(ODI)was used for evaluation before operation,at 3 months and the final follow-up after oper-ation,and the modified MacNab efficacy evaluation criteria were used to evaluate the clinical efficacy at the final follow-up.The anteroposterior height of the intervertebral space,lumbar lordosis angle,and lordosis an-gle of the operated segment were measured on X-ray and CT images before surgery and at the final follow-up.Results:All the patients successfully underwent the operation with an operative time of 98.9±6.6min,in-traoperative bleeding of 41.0±12.6mL,postoperative drainage of 38.1±9.5mL,and an average postoperative hos-pital stay of 3.8±0.9d without complications such as epidural hematoma,infection,or muscle paralysis and paralysis.The follow-up time was 17.7±4.2 months,and the VAS scores preoperatively,3d postoperatively,3 months postoperatively,and at final follow-up were 5.85±0.67,2.15±0.54,1.12±0.33,0.54±0.51,respectively.The ODI were(47.38±6.66)％,(11.73±6.73)％,and(6.58±6.51)％before operation,at 3 months and the final follow-up,respectively.The VAS scores and ODI at all time points after operation significantly improved compared with the preoperative values(P＜0.05),and which improved over time(P＜0.05).At final follow-up,ac-cording to the modified MacNab criteria,24 cases were evaluated as excellent and 2 cases were evaluated as good.The anteroposterior height of the intervertebral space(anterior edge 10.95±1.24mm,posterior edge 9.45± 1.13mm),lumbar lordosis(47.38°±4.56°)and lordosis angle of the operated segment(8.62°±1.92°)were higher at final follow-up than before operation(anterior edge 8.85±1.00mm,posterior edge 6.78±1.07mm,43.81°±4.85°,6.62°±2.02°),with significant improvement(P＜0.05).Conclusions:MPTLIF is a safe and effective minimally invasive procedure for the treatment of lumbar degenerative disease in cases selected for strict indications,which can achieve great early clinical efficacy.

Objectives:To evaluate the value of electromagnetic navigation assisted percutaneous pedicle screw placement in unilateral biportal endoscopic transforaminal lumbar interbody fusion(UBE-TLIF).Methods:The clinical data of 34 patients with single-level lumbar degenerative diseases treated with UBE-TLIF assist-ed with electromagnetic navigation for percutaneous pedicle screw placement between August 2020 and August 2021 were retrospectively analyzed,and there were 18 males and 16 females,aged 43-73 years(58.4±9.4 years)with body mass index of 24.7±2.9kg/m2;1 case was of L2/3,5 cases were of L3/4,17 cases were of L4/5 and 11 cases were of L5/S1(electromagnetic navigation group).A total of 20 patients treated with UBE-TLIF assisted with C-arm X-ray machine fluoroscopy for percutaneous pedicle screw placement during the same period were selected as the control group,which consisted of 11 males and 9 females,aged 35-73 years(58.1±10.2 years),with body mass index of 26.5±3.8kg/m2;1 case was of L1/2,1 case was of L2/3,3 cases were of L3/4,12 cases were of L4/5 and 3 cases were of L5/S1(C-arm fluoroscopy group).The opera-tive time,fluoroscopy times,screw placement time,screw placement accuracy rate,and complications of the two groups were analyzed.Visual analogue scale(VAS)and Oswestry disability index(ODI)were evaluated be-fore and after surgery.The modified MacNab criteria were used to evaluate the clinical effect at final follow-up.Results:All the patients successfully completed operation.The screw placement time,number of fluo-roscopy times and operative time were 30.4±3.3min,3.6±1.0,173.8±23.9min in electromagnetic navigation group and 44.1±6.lmin,22.8±4.9,190.2±12.5min in C-arm fluoroscopy group,which were significantly lower in the electromagnetic navigation group(P＜0.05).The accuracy of pedicle screw placement was comparable be-tween the two groups(97.1％vs 95％,P＞0.05).There were no serious complications and revision surgery.With a mean follow-up of 17.6(6-27)months,the VAS back pain,VAS leg pain and ODI in both groups were significantly improved compared with those before surgery at all time points after operation(P＜0.05),and there was no significant difference between the two groups at the same time point(P＞0.05).According to MacNab criteria,there was no significant difference between the two groups in the rate of excellent and good results at final follow-up(97.1％vs 95％,P＞0.05).Conclusions:UBE-TLIF assisted with electromagnetic navigation for percutaneous pedicle screw placement is feasible and safety in the treatment of single-level lumbar de-generative disease,with few intraoperative fluoroscopy times,high safety,and satisfactory early results.

Objectives:To study the technical notes and clinical outcomes of full-endoscopic interbody fusion via transforaminal approach for hard disc hemiations in thoracolumbar junction.Methods:14 patients with disc herniations involving 20 segments of hard disc hemiations in thoracolumbar junction treated with full-en-doscopic interbody fusion via transforaminal approach between January 2018 and September 2021 were includ-ed in the study.There were 11 males and 3 females with an average age of 43.3±12.6 years;3-segment dis-ease in 2 cases,2-segment disease in 2 cases,and single segment disease in 10 cases.The hard compres-sion were classified as:3 cases of calcified disc hemiation,6 cases of osteophyte protrusion of the posterior edge of the adjacent vertebral body of the diseased disc,3 cases of disc hemiations with atypical Scheuer-mann disease and 2 cases of disc herniation with epiphyseal separation.All patients had symptoms of myelopathy or cauda equina compromise before operation,and 6 of them had radiculopathy.Via transforaminal approach under local anesthesia,full-endoscopic interbody fusion and discectomy were performed firstly,fol lowed with percutaneous pedicle screw system placement and fixation under general anesthesia.Postoperative imaging changes,pain symptoms and recovery of neurological function at 1 week,3 months,6 months and 1 year after operation were observed.Back pain and radicular pain were scored with visual analogue scale(VAS),neurological function was assessed with Nurick score and modified Japanese Orthopaedic Association(mJOA)score,and thoracic spine function was assessed with Oswestry disability index(ODI).Results:All operations were successfully completed,and no intraoperative conversion of surgical methods occurred.Postoperative tho-racolumbar junction MRI and CT examinations of all patients showed that the spinal cord or cauda equina was sufficiently decompressed without any residual compression.At 1 year follow-up,all surgical segments were fused.Back pain and radicular pain were all relieved significantly in all the patients,and neurological function was significantly restored.The Nurick score,mJOA score and ODI all improved compared with the preoperative values(P＜0.01),and the postoperative 1 year values all improved significantly compared with the values at postoperative 1 week,3 months and 6 months(P＜0.01).The average recovery rate of mJOA was 72.5％,with 7 cases excellent,5 cases good and 2 cases fair.Dural tear occurred in 2 cases during opera-tion,but no cerebrospinal fluid leakage and pseudomeningocele occurred during follow-up.No other surgical complications occurred.Conclusions:Full-endoscopic interbody fusion and resection of herniated hard disc vi-a transforaminal approach under local anesthesia followed with percutaneous pedicle screw system fixation un-der general anesthesia are safe and effective minimally invasive spine surgery for the treatment of hard disc herniation located in the thoracolumbar junction.

Objectives:The purpose of this study was to investigate the clinical efficacy of percutaneous endoscopic transforaminal lumbar interbody fusion(PE-TLIF)in patients with single-segment lumbar spinal stenosis and explore the changes of paraspinal muscles and adjacent segmental facet joints of operative segement after PE-TLIF.Methods:28 patients with L4/5 lumbar spinal stenosis treated with PE-TLIF in Beijing Chaoyang Hospital from March 2017 to March 2019 were analyzed retrospectively.The patients consisted of 12 males and 16 females with an average age of 58.0±8.7 years(41-79 years)and were followed up for 40.7±3.6 months(36-58 months).The visual analogue scale(VAS)of low back pain(VAS-LBP)and VAS of leg pain(VAS-LP)were collected at pre-operation,postoperative 1-week follow-up,3-month follow-up,12-month follow-up and the final follow-up;Oswestry disability index(ODI)was evaluated at pre-operation,post-operative 3-month follow-up,12-month follow-up and the final follow-up.CT examination was performed at pre-operation,postoperative 12-month follow-up,24-month follow-up and the final follow-up,the cross-sec-tional area(CSA)and fat infiltration(FI)score of multifidus(MF)were measured,and the degeneration degree of adjacent segmental facet joints was evaluated according to the score of facet joint degeneration.The differ-ences of MF CSA and FI score,as well as adjacent segmental facet joint degeneration were compared be-tween preoperation and postoperation.Results:The VAS-LBP score was 3(2,3)at 1-week follow-up,1(1,2)at 3-month follow-up,1(0,2)at 12-month follow-up,and 1(0,1)at the final follow-up,which was signif-icantly improved compared with the preoperative score of 7(7,8)(P＜0.05);the VAS-LP score was 2(1,3)at 1-week follow-up,1(1,2)at 3-month follow-up,1(0,1)at 12-month follow-up,and 0(0,1)at the final fol-low-up,which were significantly improved compared with the preoperative score of 6(5,7)(P＜0.05);The ODI at 3-month follow-up was 23％(19％,31％),at 12-month follow-up was 12％(8.5％,17.5％),and at the final follow-up was 7％(4％,15.6％),all significantly improved compared with the ODI before operation of 61％(55％,67％)(P＜0.05).The postoperative MF CSAs of 547.12±53.31mm2(12-month follow-up),558.35±52.37mm2(24-month follow-up),and 531.21±56.12mm2(final follow-up)were not significantly changed from the preoper-ative MF CSA of 557.06±46.72mm2(P＞0.05).There was no significant difference in FI score between pre-op-eration of 2(2,3)and 12-month follow-up of 3(2,3),24-month follow-up of 3(2,3)and the final follow-up of 3(3,3)(P＞0.05).The postoperative facet joint degeneration scores of upper segment facet joint(USFJ)of 5(4,6)at 12-month follow-up,5(4,5)at 24-month follow-up,and 5(4,6)at final follow-up were not signifi-cantly changed from the preoperative 5(4,6)(P＞0.05).And there was no significant difference either in facet joint degeneration score of lower segment facet joint(LSFJ)between pre-operation of 5(4,6)and 12-month follow-up of 5(4,5),24-month follow-up of 5(4,6)and the final follow-up of 5(4,7)(P＞0.05).Conclusions:PE-TLIF can achieve satisfactory clinical outcomes in the treatment of single-segment lumbar spinal stenosis,which has no significant effect on multifidus in the surgical segment and adjacent segmental facet joints in the mid-to long-term.

Objectives:To report a V-shape bichannel endoscopy(VBE)system and evaluate the preliminary clinical effects of VBE assisted transforaminal lumbar interbody fusion(VBE-TLIF).Methods:20 patients with lumbar diseases underwent VBE-TLIF surgery in our hospital from January 2020 to April 2021 were retrospectively reviewed.There were 13 males and 7 females,with a mean age of 57.0±11.7 years old(28-77 years old).The operative time and complications were collected,and visual analogue scale(VAS)scores,Oswestry disability index(ODI)before surgery and at 3d,3,6,12 and 18 months after surgery were recorded to evaluate the relief of patients'symptoms.And also,modified MacNab's criteria and radiological examination results at final follow-up were analyzed to to evaluate the overall satisfactory and fusion rate.Results:The average follow-up time of 20 patients was 27.0±3.6 months(22-36 months),and the clinical symptoms of patients relieved significantly.The average VAS leg pain score and VAS back pain score reduced respectively from 6.3±1.6 and 5.7±1.1 before operation to 1.9±0.9 and 2.3±0.8 at 3d postoperatively,and further to 0.7± 0.6 and 0.9±0.7 at 18 months after the surgery,and both with significant differences(P＜0.05).Comparing with the preoperative average ODI[(60.2±15.3)％],the ODI at the 18th month after surgery was(15.0±5.8)％,and the difference was with statistical significance(P＜0.05).There was one patient experienced transient hip flexion weakness and improved after one month of symptomatic treatment;One patient experienced cage immigration causing nerve root irritation and underwent reoperation,the fusion rate was 95％(19/20);No serious operation related complications occurred.The overall excellent and good rate was 95％by modified MacNab's criteria.Conclusions:VBE-TLIF is a safe and effective minimally invasive lumbar fusion technique,and its primary clinical application is satisfactory in outcomes.

Objectives:To systematically evaluate the clinical efficacies of unilateral biportal endoscopic lumbar interbody fusion(ULIF)and minimally invasive transforaminal lumbar interbody fusion(MIS-TLIF)in the treatment of lumbar degenerative diseases(LDD).Methods:Clinical controlled studies on ULIF and MIS-TLIF in the treatment of LDD were systematically retrieved from Chinese and English databases,including CNKI,VIP,WanFang,SinoMed,PubMed,Cochrane Library,Embase,and Web of Science.The retrieval time limit was from the establishment of the database to September 2023.The quality of the included studies was evaluated by the Newcastle-Ottawa scale(NOS).The indexes of operation time,surgical bleeding,hospitalization time,visual analog scale(VAS),Oswestry disability index(ODI),incidence of complications,disc height,and fusion rate were extracted,and Meta-analysis was performed by RevMan 5.4.1 software.Results:A total of 11 studies were included,all of which were cohort studies,and all of which were evaluated as medium-high quality by NOS.There were 800 patients,including 380 in the ULIF group and 420 in the MIS-TLIF group.The results of Meta analysis showed that the hospitalization time[WMD=-0.75,95％CI(-1.33,-0.17)],low back pain VAS(1-3 months after operation)[MD=-0.43,95％CI(-0.70,-0.15)],low back pain VAS(final follow-up＞l year)[MD=-0.09,95％CI(-0.18,-0.00)],ODI(1-3 months after operation)[MD=-1.37,95％CI(-2.46,-0.28)],and intraoperative bleeding[MD=-78.72,95％CI(-113.20,-44.23)]in the ULIF group were better than those in the MIS-TLIF group.The operation time[MD=30.28,95％CI(13.86,46.71)]in the MIS-TLIF group was better than that in the ULIF group.There were no significant differences in leg pain VAS(1-3 months after operation)[MD=-0.12,95％CI(-0.30,0.06)],leg pain VAS(final follow-up＞1 year)[MD=-0.04,95％CI(-0.15,0.07)],ODI(final follow-up＞1 year)[MD=-0.46,95％CI(-1.02,0.11)],lumbar lordosis angle[MD=0.39,95％CI(-1.12,1.90)],disc height[MD=0.03,95％CI(-0.24,0.30)],fusion rate[MD=0.97,95％CI(0.92,1.03)]and complication rate[MD=0.82,95％CI(0.45,1.48)].Conclusions:Compared with MIS-TLIF,ULIF has advantages in improving low back pain symptoms and early recovery of function,reducing intraoperative blood loss,shortening hospital stay,which is less in surgical trauma and faster in recovery.There is no significant difference in long-term efficacy,complications,and fusion rate between the two methods.

Objectives:To analyze the safety of the assistance of microscope in lumbar interbody decompres-sion,fusion and internal fixation in the treatment of recurrent lumbar disc herniation.Methods:Retrospective analysis was made on 73 patients recurred lumbar disc herniation after percutaneous endoscopic lumbar dis-cectomy(PELD)and underwent a revision surgery of single-segment lumbar decompression and fusion in our hospital from January 1,2020 to April 1,2022.Among the patients,42 received microscope-assisted opera-tion(microscope group),including 31 males and 11 females,aged 53.4±16.4 years;the other 31 received an operation without microscope assistance(conventional group),including 18 males and 13 females,aged 49.6± 11.4 years.There were no significant differences between the two groups in general data such as gender,age and BMI(P＞0.05).Data such as the surgical approach and surgical segment of initial PELD,and operative time,intraoperative bleeding volume,total postoperative drainage volume,postoperative length of stay,dural tears,nerve injury and superficial infection of the revision surgery were collected and compared between the two groups.Results:All the operations were successful.In the microscope group,the operative time was 168.0±33.1min,intraoperative bleeding volume was 125.0±40.2mL,total drainage volume was 379.6±220.6mL and postoperative length of stay was 5.2±1.3d,and dural tears occurred in 2 patients,none nerve injury or superficial wound infection was found.In the conventional group,the operative time was 155.8±29.4min,in-traoperative bleeding volume was 133.9±59.7mL,total drainage volume was 452.2±464.5mL,and postoperative length of stay was 5.0±1.7d,and dural tears occurred in 4 patients,nerve injury was noticed in 1 patient,and none superficial wound infection was found.There was no statistical difference in perioperative and com-plication data between the two groups(P＞0.05).Conclusions:Microscope does not increase the operative time,intraoperative bleeding volume,postoperative length of stay,and the rate of infection,dural tears and nerve injury in the revision surgery after PELD.

Objectives:To observe and analyze the relationship between thoracolumbar vertebral fractures and vertebral bone structure,as well as stress distribution within ligaments,in order to explore the mechanical mechanisms underlying thoracolumbar vertebral fractures.Methods:Eight healthy young male volunteers were recruited for the study.X-ray and CT examinations of the entire spine were conducted to rule out spinal deformity,tumor,and bone disease.Bone mineral density(BMD)measurements were taken for each vertebral body and femur to exclude osteoporosis.CT thin layer scan was performed from the upper endplate of T11 to lower edge of L2 vertebra,and the CT image parameters were imported to ABAQUS 2016 software to standardize and perform finite element mesh construction.The thoracolumbar spine finite element model was developed using MIMICS 17.0,GEOMAGICS 15.0,and PRO/ENGINEER 5.0 softwares to measure relevant parameters,and its efficacy was validated.Seven motion states,including vertical compression,flexion,extension,left and right lateral bending,and left and right rotation,were simulated.ABAQUS software was employed to analyze stress distribution patterns and variations in the seven motion states of the finite element model,allowing for the observation of the relationship between stress distribution and thoracolumbar fracture.Results:The validated three-dimensional finite element model utilized in this study consisted of 309,583 nodes and 428,760 elements,encompassing anatomical structures such as four vertebral bodies,three intervertebral discs,and various ligaments including the anterior longitudinal ligament,posterior longitudinal ligament,intertransverse ligament,and interspinous ligament.Analysis of the data across seven different motion states revealed no significant deviations from the findings reported by other literature,confirming the accuracy and reliability of the model.The cross-sectional areas of T11-L2 pedicle were 135mm2,154mm2,105mm2,and 139.2mm2,respectively.High stress areas presented within the cancellous bone of the vertebral body,the pedicle and surrounding cortex of the vertebral body during various states of motion according to the stress cloud map analysis.Specifically,the T12 vertebral body exhibited the highest stress level(617.4MPa)under vertical compression,while the T11 vertebral body experienced the highest stress level(200.7MPa)during forward flexion.Additionally,the maximum stress levels recorded for the L1 vertebral body were 314.2MPa,574.4MPa,626.2MPa,641.3MPa,and 527.1MPa during extension,left and right lateral bending,and left and right rotation,respectively.The stress experienced by the L1 vertebral body was found to be minimal in the flexion position and maximal in the left rotation position.T12 vertebral fracture was observed under vertical compression,while T11 vertebral fracture occurred during flexion.L1 vertebral fracture,in combination with ligament injury,was observed during extension,left and right lateral bending,and left and right rotation.High stress areas were identified in anterior longitudinal ligament during extension and left and right lateral bending and in posterior longitudinal ligament during flexion.High stress areas were observed in the intertransverse and interspinous ligaments during movements involving forward flexion,left and right lateral bending,and left and right rotation.Conclusions:In the three-dimensional model of thoracolumbar spine,in-corporating key ligaments,intervertebral discs,and other soft tissue structures,notable areas of high stress were identified within the cancellous bone of vertebral body,pedicle and surrounding cortical bone,and liga-ments.Variations in maximum stress levels were observed in vertebral body under different conditions,result-ing in varying degrees of vertebral body fracture and ligament injury;L1 pedicle exhibited the smallest cross-sectional area and was prone to fracture.

Objectives:To establish a cadaveric model of ossification of posterior longitudinal ligament(OPLL)in thoracic spine and explore the feasibility of performing the endoscopic sink boat technique(SBT)for OPLL decompression on the cadaveric model.Methods:A fresh frozen cadaveric specimen was utilized.Under the guidance of a navigation robotic arm and CT,a puncture was made through the lateral thoracic wall into the posterior edge of the T9 vertebra,mimicking the pre-planned surgical trajectory.Once the puncture reached the midpoint of the venebral body,bone cement was injected to penetrate the spinal canal along the posterior longitudinal ligament.CT scans confirmed successful cement distribution behind the T9 vertebra,simulating OPLL preparation.Subsequently,the endoscopic SBT was performed by entering the vertebral body through the ipsilateral intervertebral foramen and the contralateral partial pedicle.Bilateral center-directed resection of the vertebral body created a trough-like defect accommodating the simulated OPLL.Using suture anchors,the OPLL mass was anchored,sunk,and secured within the vertebral trough to achieve ventral decompression of the spinal canal.Results:A bone cement model of thoracic OPLL in cadaveric specimen was successfully established with the simulated OPLL occupying 49％of the posterior margin of the T9 vertebra.Endoscopic SBT surgery smoothly decompressed the ventral side of the thoracic spinal cord,and postoperative CT scans confirmed the simulated OPLL was successfully embedded and fixed within the vertebra using the endoscopic SBT technique,with a sagittal diameter restoration rate of 218％.Conclusions:Endoscopic SBT is an innovative thoracic endoscopic technique,which has demonstrated in cadavers to achieve decompression of the spinal canal by sinking simulated segmental thoracic OPLL into the vertebral body.