Objective To determine the radiographic feasibility of oblique lumbar interbody fusion (OLIF) corridor to treat lumbar disease at each lumbar disc level,including the corridor's numerical value and the influence of diaphragmatic crura and aorta abdominalis.Methods A retrospective CT study was conducted on 110 patients (including 69 males and 41 females,average age 47.95 years,range 16-83 years) that continuously collected and analyzed in the PACS system.The oblique corridor was defined as the area between the left lateral border of the aorta abdominalis(or iliac artery) and the right lateral border of the left psoas.The distances and angles of L1-2,L2-3,L3-4 and L4-5 levels were measured.Whether the change of diaphragmatic crura and aorta abdominalis affected the building of the corridor was also observed.Results The mean distances of oblique corridor to the levels of L1-L5 discs were:L1-2 15.90 mm,L2-3 14.82 mm,L3-4 17.57 mm,L4-5 11.16 mm.At the levels of L1-2 and L3-4,all of the images could build the corridor.But there were only 97.27％ images allowing operation at both L2-3 and L4-5,and the other 3 cases couldn't build the corridor since the aorta abdominalis was very close to psoas,and the distance was almost 0 mm.The max mean distance was 36.79 mm at L3-4 level.The mean angles were:L1-2 36.98°;L2-3 37.76°;L3-4 40.96°;L4-5 37.85°.The significant difference was at L3-4,ranged from 13.09 to 61.93°.The level of the aortic bifurcation was from the lower third of the L3 vertebral body to the middle third of the L5 vertebral body.The levels of left diaphragmatic crura's ending point in the lumbar was divided into four groups:1) Group L1 vertebral body level:the level at L1 vertebral body and above,5 cases (4.55％);Group L1-2 disc to L2 vertebral body level:at L1-2 disc and L2 vertebral body,67 cases (60.91％);Group L2-3 disc to L3 vertebral body level:at L2-3 disc and L3 vertebral body,36 cases (32.72％);Group L3-4 disc to L4 vertebral body level:at L3-4 disc and L4 vertebral body,2 case (1.81％).Conclusion The OLIF corridor can be built successfully at L1-2 and L3-4.However,it may be difficult at L2-3 and L4-5 for some patients due to the aorta abdominalis which is too close to psoas.The angles of L1-L5 levels were similar.While the left diaphragmatic crura was mainly impact the corridor insertion at L1-2 and L2-3.And the level of the aortic bifurcation was mainly located at the upper endplate of L4 to the L4-5 disc (87％).

Objective To discuss the clinical characteristics and treatment of upper cervical spine injuries in the elderly. Methods A retrospective study was done on clinical data of 28 elderly patients ( > 60 years old) with upper cervical spine injuries treated from January 2003 to December 2007. There were 20 males and 8 females, at age range of 60-86 years (mean 68.1 years). Injury causes included slip in 16 patients, traffic injury in eight and fall from height in four. Atlas fractures occurred in five patients and axis ones in 15,of which there were eight patients with odontoid fractures, six with C2 vertebral arch fractures and one with C2 body fractures. Upper cervical spine injury was combined with lower cervical spine injuries in five patients. There were combined atlantoaxial injuries including odontoid fractures combined with lateral atlas fracture in one and edontoid fractures combined with anterior atlas arch fracture in one. Atlantoaxial dislocation occurred in one patient and combined spinal injury in four. Of all, eight patients were treated conservatively, eight with open surgical operation and 12 with minimally invasive surgery. Results The average hospital stay was 16.5 days, with no statistical difference be-tween conservative treatment group and open surgical operation group ( P > 0.05 ). While the average hos-pital stay in minimally invasive surgery group was shorter than that in conservative treatment and open sur-gical operation groups ( P < 0.05 ). Of all, two patients in conservative treatment group and one in open surgical operation group died and the other 25 patients were followed up for average 16.8 months (9-56 months). The satisfaction rate was 50% in conservative treatment group, 72% in open surgical operation group and 75% in minimally invasive surgery group. Complications occurred in four patients in conserva-tive treatment group, three in open surgical operation group and two in minimally invasive surgery group. Conclusions With odontoid fracture the most common injury type, upper cervical spine injuries arema-inly caused by low-energy force and characterized by low mobidity of spinal cord injuries and high possi-bility of missed diagnosis in the elderly patients. The surgical treatment especially minimally invasive surgery can bring good results compared with conservative methods.

Objective To investigate complications associated with Coflex interspinous process device for degenerative lumbar disc diseases and methods to treat.Methods Clinical data of 121 patients with degenerative lumbar disc diseases,who had undergone surgical decompression and additional fixation of Coflex between November 2007 and June 2011,was analyzed retrospectively.There were 76 males and 45 females,aged from 37 to 75 years (average,54.6 years).Surgery-related complications and sequelae were recorded and analyzed.Results Surgery-related complications occurred in 10 patients,and the incidence was 8.3％ (10/121).There were 3 cases of device-related complications,including wing break in 1 case,prosthetic loosening in 1 case and spinal process fracture in 1 case; all 3 cases were treated conservatively and received good results.There were 7 cases of non-device-related complications,including dura mater dilaceration in 2 cases,superficial wound infection in 1 case,insufficient decompression of spinal canal in 2 cases,recurrence of disc herniation in 1 case,and intraspinal hematoma in 1 case; the former 3 patients recovered after corresponding treatment,and the latter 4 patients also recovered after re-operation.Conclusion The incidences of complications and re-operation associated with application of Coflex are low,and the incidence of device-related complications is also low.The precise intraoperative manipulation is the key to reduce incidence of device-related complications.It's absolutely necessary to strictly master surgical indications and perform sufficient decompression in order to receive good surgical results and avoid non-device-related complications.

Objective Retrospective study and report on cases of "symptomatic facet of residual bone mass" caused by percutaneous transforaminal endoscopic discectomy (PTED),to analysis of its causes and revision strategies.Methods Seven cases of "symptomatic facet of residual bone mass" after PTED were found in six medical centers from July 2015 to November 2017.Weintroduced the course of diagnosis and treatment,to analysis of the causes,clinical features and revision strategies of the rare complication.Results Seven patients came from different medical centers (2 cases in Ningbo No.6 Hospital and 1 case in each of the other medical centers).The average age of the subject is 67.29±9.64 years (range from 57-83 years).Among them there were 1 male and 6 female.PTED was performed for all cases with lumbar disc herniation or stenosis.The operative segments were 1 of L2,3,2 of L3,4,3 of L4,5,1 of L5S1.Symptoms occurred immediately after surgery in all cases except one after a week of operation and another one month later.Two cases were appeared symptom of contralateral irritation,and the rest were aggravated by the original symptoms.Two cerebrospinal fluid leakage caused by bone mass piercing the dural sac.The bone mass compressed the nerve root and caused 1 case of lower limb muscle weakness.Foraminoplasty was performed during PTED in all patients.After CT scan,5 cases of bone mass were found on the same side of operation,and 2 cases were in the contralateral side.The shortest time for revision was 2 days and the longest 3 months.After conservative treatment,the symptoms were relieved in only one case.Revision surgeries were performed for all the other 6 cases,2 with microendoscopic discectomy (MED),1 mobile microendoscopic discectomy (MMED),1 small incision operation,1 PTED and 1 with minimal invasive surgery of transforaminal lumbar intervertebral fusion (MIS-TLIF).The VAS scores of low back pain and leg pain was significantly relieved from 8.67±0.52 to 1.50±0.55.Conclusion FTED may lead to residual bone mass in lumbar foraminoplasty.The penetration of the bone mass block into the spinal canal can cause the compression symptoms of the corresponding segment.The patients showed the corresponding spinal canal stenosis and nerve root irritation symptoms.A revision operation is required to remove the oppressed bone mass to relieve the symptoms as soon as possible if the conservative treatment not effective.

Objective:To investigate the feasibility of transplantation of neural stem cells (NSCs) modified by hypoxia-regulated nerve growth factor (NGF) gene to treat acute spinal cord injury (SCI) and observe the functional repair after SCI.Methods:Adeno-associated virus (AAV) was used as the vector to construct gene-modified NSCs. Three days after SCI attack on the animal model, the NSCs modified by hypoxia-regulated NGF were transplanted to the site of SCI as the NGF group. The GFP-modified neural stem cell group (GFP group), sham group, SCI group were set up. Hindlimb motor function was assessed by Basso-Beattie-Bresnahan (BBB) Locomotor Rating Scale, inclined plane tests and footprint analysis at 10 time points on day 1, 3, 7, 10, 14, 21, 28, 35, 42 and 60 after transplantation. The video cassette recorder (VCR) image and quantitative measurement of the height of the rat from the ground, the foot error and plantar steps were used to test the hindlimb support and flexibility of the rats. The degree of spinal cord injury in rats was roughly measured by observing the visual map of the spinal cord. The neuronal repair and morphological changes in SCI area were evaluated by Nissl staining, HE staining and immunofluorescence. CM-DiI was used to trace neural stem cells and to analyze the differentiation of NSCs by immunofluorescence.Results:Two months after transplantation of genetically modified NSCs, the BBB, inclined plane tests and footprint Analytical scores of NGF group rats were higher than those of SCI group and GFP group ( P<0.05); Through VCR image analysis, the hindlimb support and mobility of the rats in the NGF group were better than those in the SCI group and GFP group, and the difference was statistically significant ( P<0.05). Visual analysis showed that the spinal cord of the rats in each group was visually compared to the NGF group, and the spine did not show significant atrophy and color deepening, and the degree of injury was lower than that of the SCI group and GFP group; Through Nissl staining, HE staining and immunofluorescence detection, obviously positive in NeuN at the transplant site was noted at NGF group, and evidently regenerated neural structure can be seen at the morphological level. The cavity in SCI was obviously reduced, neurons and Nissl bodies were distinctly increased ( P<0.05). CM-DiI was used to track NSCs, NeuN was used to mark neurons, and GFAP was used to mark astrocytes. It was found that neural stem cells could differentiate into neurons and astrocytes. Neural stem cells in GFP group were more differentiated into astrocytes, and neural stem cells in NGF group were more differentiated into neurons. Conclusion:NSC transplantation with oxygen-regulated NGF gene mediated by adeno-associated virus can treat SCI, NSCs can differentiate into neural stem cells and astrocytes to fill the damaged cavity, NSCs secrete NGF as the carrier, playing the protective role on adjacent damaged nerve cells and reducing the death of neurons, which is expected to provide new ideas for the treatment of acute spinal cord injury, and at the same time make new attempts for the development of NGF protein drugs.

Objective:To investigate the characteristics and causes of endplate injury in the oblique lateral interbody fusion for the treatment of lumbar diseases, and summarize the precaution of endplate injury.Methods:Thirty-five cases of endplate injury were observed, which were originally treated with oblique lateral interbody fusion with or without pedicle screw fixation from October 2014 to December 2017. There were 7 males and 28 females, and the age ranged from 51 to 78 years old (averagely 62.8±8.13 years). There were 2 cases of lumbar disc degeneration, 10 cases of lumbar canal stenosis, 17 cases of lumbar degenerative spondylolisthesis, 2 cases of lumbar spondylolysis with or without spondylolisthesis, and 4 cases of lumbar degenerative scoliosis. Lesion sites contained L 3,4 in 2 cases, L 4,5 in 21 cases, L 2-4 in 3 cases, L 3-5 in 4 cases, L 2-5 in 3 cases and L 1-5 in 2 cases. Preoperative bone mineral density examination revealed there were 7 cases of T>-1 SD, 24 cases of -2.5 SD

Objective To reduce the risk of cervical spinal cord injury,the most medial point of the cervical intervertebral disc that the posterior percutaneous endoscopic sheath could reach was evaluated.And that could help to determine the indication of posterior percutaneous endoscopic cervical discectomy for cervical intervertebral disc herniation.Methods Cervical MRI images for 50 randomly selected patients,21 males and 29 females with ages from 20 to 60(average 33.5± 10.03 years),were analysed.All 50 patients underwent MRI examination at our institution between January 2014 and December 2017.As 50％ of the zygapophyseal joint was preserved,on the cross-section T2-weighted MRI images,when the sheath just touched the spinal cord,the intersection point of the medial wall of sheath and cervical spinal cord (Point L) was the most medial point of the posterior percutaneous endoscopy could get.The distance between Point L and the line through and tangent to the most lateral point of cervical disc border was the length of the line section DL.The distance between the middle sagittal line of the cervical disc and the line through and tangent to the most lateral point of cervical disc border was the length of the line section D.D1/D was the most medial distance ratio of the posterior percutaneous endoscopic cervical discectomy when 50％ of the lateral zygapophyseal joint was preserved.In the same way,D'1/D was the most medial distance ratio of the posterior percutaneous endoscopic cervical discectomy when 75％ of the lateral zygapophyseal joint was preserved.Results When 50％ of the lateral zygapophyseal joint was preserved,the upper limit of 95％ confidence intervals of the most medial distance ratio that the posterior percutaneous endoscopy could get were 78％,76％,81％,93％ in C3,4,C4,5,C5,6,C6,7 respectively.This meant that the most medial distance the posterior percutaneous endoscopy could get were the 78％,76％,81％,0.93％ of the length of the line section D in C3,4,C4,5,C5,6,C6,7 respectively.The most medial distance the posterior percutaneous endoscopy could get in C5,6 or C6,7 was longer than that in C3,4,C4,5.Conclusion When 50％ of the lateral zygapophyseal joint was preserved,the upper limit of the most medial distance ratio that the posterior percutaneous endoscopy should get were 78％,76％,81％,93％ in C3,4,C4,5,C5,6,C6,7 respectively.This meant that the most medial distance the posterior percutaneous endoscopy could get were the 78％,76％,81％,93％ of the length of line section D in C3,4,C4,5,C5,6,C6,7 respectively.If the resected disc was beyond this range,the cervical spinal cord should be in the risk of being injured.

Objective To investigate the clinical efficacy and complications of minimally invasive transforaminal lumbar-interbody fusion (TLIF) in the treatment of lumbar spondylolisthesis. Methods Total 142 patients with single level spondylolis-thesis who treated by TLIF from 2010.01 to 2015.06 were included in this study, with 68 cases in minimally invasive TLIF (MIS-TLIF) group and 74 cases in traditional open TLIF group. The general information (age, gender, isthmic or degenerative type, per-centage of slip degree, levels), operative time, blood loss, length of postoperative hospital stay, Visual Analogue Scale (VAS) of low-back pain and leg pain, and Oswestry Disability Index (ODI) were recorded and collected. The posterior height of the interverte-bralpace and segmental lordosis, reduction of spondylolisthesis and cross-sectional area of spinal canal were measured. Results There was no statistically significant difference between the two groups in age, gender ratio, percentage of slip degree, and sur-gicallevels distribution. Total of 66 cases in MIS-TLIF group and 71 cases in Open TLIF group finished 2 years follow up, and 25 cases in MIS-TLIF group and 31 cases in Open TLIF group finished 5 years follow up. The blood loss of the MIS-TLIF group was 164.7±51.7 ml, significantly lower than the open TLIF group of 239±69.3 ml(P<0.001). The length of postoperative hospital stay was 5.9 ± 1.5 days in MIS-TLIF group, significantly shorter than the open TLIF group of 7.3 ± 3.1 days(P<0.001). The operative time of MIS-TLIF and Open TLIF was 146.3±21.9 mins, 152.0±20.4 mins, respectively, and no significant differ-ence was found between them. The VAS ofback pain, leg pain, ODI in MIS-TLIF group was 1.76±1.16, 1.91±1.36 and 23.5± 7.3 at 2 years follow up, and in Open TLIF was 1.73±1.10, 1.83±1.36 and 23.8±6.7, respectively, all of them were significant-ly different to pre-operation, however, no significant difference was found between two groups. The VAS of back pain, leg pain, ODI in MIS-TLIF group was 1.73±1.21, 1.93±1.48, and 25.4±6.8 at 5years follow up, and in Open TLIF was 1.85±1.02, 1.85± 1.33 and 26.1 ± 6.5, respectively, no significant difference between twogroups. The posterior height of the intervertebral space and segmental lordosis of MIS-TLIF was 9.52±1.67 mm and 12.11°±3.44° at 2 years follow up, while the open TLIF was 9.88± 1.54 mm and 12.98 ± 3.83° , all of them were significantly different to pre-operation,however, no significant difference between two groups. The posterior height of the intervertebral space and segmental lordosis of MIS-TLIF was 9.37 ± 1.46 mm and 11.55° ± 2.77° , while the open TLIF was 9.66 ± 1.68 mm and 12.59° ± 4.23° , no significant difference between two groups. The percentage of slip degree was reduced to 5.2％±4.6％ in MIS-TLIF and 5.6％±4.3％ in open TLIF, the cross-sectional area of spinal canal was enlarged to 139.7±19.5 mm2 and 141.7±20.7 mm2, no significant difference between two groups either. Con-clusion MIS-TLIF has less blood loss, shorter postoperative hospital stay than open TLIF, and similar clinical pain and function-al outcomes. MIS-TLIF is suggested to be a safe and effective choice in the treatment of lower grade lumbar spondylolisthesis (Grade II or less).