Objective To investigate the clinical features,safety and clinical efficacy of the posterior decompression and interbody fusion with internal fixation for complete thoracolumbar fracture and dislocation.Methods The clinical data of 23 patients with complete thoracolumbar fracture and dislocation treated by posterior decompression and interbody fusion with pedicle screw fixation from August 2011 to October 2014 were retrospectively analyzed.There were 18 males and 15 females,aging from 20 to 50 years old with an average age of 38.2±0.3 years.There were 8 cases of T10,11 vertebral dislocation,8 of T11,12 vertebral dislocation,3 of T12L1 vertebral dislocation,and 4 of L1.2 vertebral dislocation.All the patients had different degrees of multiple rib fractures and pneumothorax complications.Preoperative spinal cord nerve function was evaluated according to the American Spinal Injury Association of spinal cord function (ASIA).There were 10 cases of ASIA grade A and 13 cases of grade B.Operation time,intraoperative blood loss,clinical outcome,imaging X-ray and CT examination,segmental kyphosis angle and bone graft fusion were recorded.Results All the patients were followed up for 13 to 26 months,average 20.2±4.3 months.The operation time ranged from 150 to 260 min with the average time of 180.3± 14.8 min;intraoperative blood loss was 800-1 500 ml with the average of 950.2±98.1 ml.Preoperative sagittal Cobb angle was-13.5° ±6.3° (range,-20.1° to 2.3°);postoperative sagittal Cobb angle was 1.43°±6.4° (range,-7.6° to 3.5°);at the latest follow-up,sagittal Cobb angle was 1.6°±6.3° (range,-8.1° to 10.3°);the dislocation reduced from preoperative 100％ to postoperative 0-15％ (10％±6％).After operation,the ASIA grade of 2 cases improved from A to B,and 5 cases improved from B to C.All of the patients had bone fusion after operation,no false joint or nonunion occurred,no loosening or breakage of internal fixation occurred.Conclusion There are high risks and difficulty of surgery for those who with thoracolumbar fracture dislocation and severe injuries of spine and spinal cord combined with multiple injuries.Proper treatment of preoperative complications is the premise of good curative effect;reliable fusion and long segment internal fixation is the key of operation.Single posterior decompression and reduction with interbody fusion and internal fixation is less invasive and could achieve satisfactory clinical efficacy.

Bone cement leakage is the most common complication in the treatment of thoracolumbar osteoporotic fractures by percutaneous vertebroplasty.The incidence rates of the literatures are different,with the range from 5％ to 80％.There are several different classifications of cement leakage;however there is no uniform classification standard.The classification criteria' s are based on anatomical location and leakage way.The independent risk factors of cement leakage are fracture semiquantitative severity grade and the viscosity of bone cement.The incidence rate of cement leakage increases with high fracture semiquantitative severity grade and low bone cement viscosity.For cortical leakage,the presence of cortical disruption and intravertebral cleft on MRI were identified as additional strong risk factors.The majority of bone cement leakage does not produce clinical symptoms.But some of the patients suffered from new adjacent osteoporotic vertebral compression fractures,neurologic deficits,pulmonary cement emboli,cardiac perforation,and even death.Therefore,we should strictly grasp the indications,select appropriate filling materials,and improve surgical techniques to avoid the occurrence of bone cement leakage.

Objective To evaluate the reliability and reproducibility of the thoracolumbar osteoporotic vertebral compression fracture (OVCF) severity score system (TLOFS),so as to provide basis for clinical decision-making.Methods A total of 320 cases of thoracolumbar OVCF hospitalized between January 2014 and June 2015 were scored by TLOFS.There were 107 male and 213 female patients,aged 52-90 years (mean,63.78 years).All cases presented with a chief complaint of low back pain.Thirty-nine cases (TLOFS ≤3 in 21 cases,TLOFS =4 in 17 cases) were treated non-operatively,while 259 cases (TLOFS =4 in 23 cases,TLOFS ≥ 5 in 259 cases) were treated surgically.Pain was evaluated by the visual analogue scale (VAS).Reliability,reproducibility and content validity of the TLOFS were analyzed.Results Cronbach' sα coefficients of all TLOFS subgroups including evaluation of morphological changes,MRI,bone mineral density,clinical situation and therapy recommendation and total score evaluation were within the range of higher to high reliability (0.76-0.94).Kappa coefficients of all TLOFS subgroups were within the range of higher to high reproducibility (0.84-0.95).Mean content validity of all TLOFS subgroups was 0.916.VAS improved from preoperative(7.8 ± 2.1) to (1.3 ±0.7) at the final follow-up.Rates of correct diagnosis,sensitivity and specificity were 95.7％,87.6％ and 96.5％ respectively.Conclusion TLOFS exhibits good reliability and reproducibility,easy operation,and accurate and comprehensive evaluation,which is effective in guiding the clinical decision making in treatment of thoracolumbar OVCF.

Objective To compare the efficacy of KumaFix posterior spinal screw/rod system (KumaFix system) and posterior U-shape screw/rod system for treatment of thoracolumbar vertebral body fractures.Methods A total of 131 patients with thoracolumbar vertebral body fractures treated from January 2011 to July 2011 were prospectively analyzed.All patients showed thoracolumbar injury classification and severity score (TLICS) more than 5 points and spinal load-sharing classification (LSC) score of 4-6.The patients were assigned to two groups according to the coin toss method:group A (n =72,treated with reduction and fixation with KumaFix system in combination with transpedicular bone grafting of fractured vertebrae) and group B (n =59,submitted to posterior reduction and fixation with U-shaped screw/rod system in combination with transpedicular bone grafting of fractured vertebrae).In group A,there were 41 male and 31 female patients at age of (41.2 ± 4.9) years (range,20-53 years).In group B,there were 33 male and 26 female patients at age of(40.6 ± 4.5)years (range,21-51 years).The two groups were analyzed and compared in aspects of operation time,blood loss,anterior vertebral height ratio,middle vertebral height ratio,posterior vertebral height ratio,kyphosis angle,Oswestry disability index (ODI) and incidence of adjacent segment degeneration.Results All patients were followed up for mean 5.3 years (range,5.1-5.8 years).Operation time and blood loss were (72.5 ±21.8)rain and (320.6 ±90.0)ml in group A,less than (104.3 ±20.7)min and (421.0 ± 84.5) ml in group B (P ＜ 0.05).Both groups achieved obvious improvements in anterior vertebral height ratio,middle vertebral height ratio,posterior vertebral height ratio and kyphosis angle after operation(P ＜ 0.05).At the last follow-up,the middle vertebral height ratio was (92.0 ± 2.8) ％ in group A,better than (84.1 ± 5.1) ％ in group B (P ＜ 0.05).Both groups showed improvement in ODI after operation (P ＜ 0.05).At the last follow-up,ODI and incidence of adjacent segment degeneration were 11.9 ± 7.1 and 0 in group A,decreased compared to 20.9 ± 6.7 and 12％ in group B (P ＜ 0.05).Conclusions For thoracolumbar vertebral body fractures,the KumaFix system has better reduction effect than U-shape screw/rod system.Meanwhile,the KumaFix system can avoid negative effect.

Objective To retrospectively evaluate the safety and efficacy of osteotomy for progressive congenital scoliosis combined with split spinal cord malformation (SSCM).Methods Data of 31 patients,who had undergone osteotomy for progressive congenital scoliosis combined with SSCM from May 2008 to May 2011 in our hospital,were retrospectively analyzed.Twenty-nine patients were followed up successfully,including 11 males and 18 females,aged from 6 to 26 years (average,13 years).Seven patients had tethered cord syndrome (TCS) with progressive neurologic deterioration.Hemivertebrae resection was performed in 7 patients,pedicle subtraction osteotomy (PSO) in 16,and vertebral column resection (VCR) in 6; posterior fusion surgery was performed in all patients after the correction was obtained.Results Twenty-nine patients were followed up for 8 to 24 months (average,18 months).The coronal Cobb angle ranged from 15° to 40°(average,24.4°±18.6°) immediately after operation,with an average correction rate of 63.3％.The coronal apical vertebral translation ranged from 0 to 50 mm (average,21.1±19.2 mm) immediately after operation,with an average correction rate of 59.5％.The coronal thoracic trunk shift ranged from 0 to 28 mm (average,5.5±10.5 mm) immediately after operation,with an average correction rate of 55.0％.There were significant differences between pre-and post-operative coronal Cobb angle,coronal apical vertebral translation and coronal thoracic trunk shift.There was no permanent neurological deterioration in all patients.Pedicle screw break occurred in 4 patients,without permanent neurological compromise.Among 7 patients with TCS,muscle strength was improved in 3 patients,and urination control was improved in 1 patient.Conclusion The osteotomy for congenital scoliosis combined with SSCM is a satisfactory method,which can effectively improve the spinal deformity without significant complications.For patients with TCS,this method also can improve the restoration of neurosurgical function.However,additional large multicenter studies are necessary to further assess the safety and efficacy.

Objective:To investigate the role of MicroRNA-9-1 in inducing epidermal stem cells(ESCs) differentiation into neurons.Methods:The lentiviral of MicroRNA-9-1 was constructed and transfected into rats epidermal stem cells.The experiment was divided into transfected group,non-transfected group and the negative control group.The β-mercaptoethanol was as an inducer for triggering the ESCs to differentiate into neurons.The GFP fluorescence expression of epidermal stem cells after transfection was observed under inverted fluorescence microscope.The protein and mRNA expression level of microtuble-associated protein 2 (MAP-2) was detected by immunocytochemical method and RT-PCR,respectively.Results:The result of Positive clone PCR confirmed successful construction of MicroRNA-9-1 in rats.Transfection after 48 h,the expressing of GFP fluorescence at peak in transfected group,and transfection efficiency reached (85.6+1.9)％.Most ESCs differentiated into neurons in transfected group after β-mercaptoethanol induction 7 h,and the effect was significantly better than non-transfected group and the negative control group.The protein ((87.3± 0.6)％) and mRNA (about twice over) expression levels of MAP-2 in transfected group was higher than those in non-transfected group and the negative control group (P＜0.05).Conclusion:The lentiviral of MicroRNA-9-1 has high transfection efficiency in rats ESCs,and could promoted ESCs differentiate into neurons under β-mercaptoethanol induced.

Objective To investigate the incidence and treatment of posttraumatic cauda equina herniation associated with lumbar fracture.Methods A retrospective analysis was performed on 416 patients admitted due to lumbar burst fracture between June 1,2008 and June 1,2011.All the patients had been operated on via anterior or posterior approaches.Data collected included demographics,injury mechanism,radiographs,surgical procedures,outcomes and follow-up.Incidence of cauda equina herniation was documented.Results All surgeries were uneventful.Cauda equina herniation was observed in 49 patients (11.8％) during surgical exploration.Anterior surgery was done on 115 patients and found 7.8％ incidence of cauda equina herniation (9/115).Posterior surgery was done on 301 patients and found 13.3％ incidence of cauda equina herniation (40/301).There were 40 patients combined with laminar fracture and 38 of them had cauda equina herniation with the incidence rate of 95％.Among the 49 patients with cauda equina herniation,44 (90％) had neurological deficit and 5(10％) were found with good neurological function but significant proportion of cauda equina rootlets entrapped in the lamina fracture.Conclusions Lumbar burst fracture combined with neurological deficit and laminar fracture may increase the risk of posttraumatic cauda equina herniation and should be paid attention.Operations should be performed with caution to avoid further nerve damage.

Objective To observe the efficacy of posterior atlantoaxial fusion for C1/C2 fractures combined with ponticulus posticus.Methods A retrospective case series review was performed on data of 12 cases of C1/C2 fractures combined with ponticulus posticus treated from January 2008 to January 2014.There were 7 males and 5 females,aged 35.5 (23.5-49.25) years.Three cases were diagnosed with C1 lateral mass fractures combined with other injury,seven type Ⅱ odontoid fractures,and two type Ⅲ odontoid fractures.Nine cases whose C1 pedicle height ≥4 mm in both sides underwent posterior C1-C2 screw-rod fixation and fusion,and three cases whose C1 pedicle height was ＜ 4 mm underwent posterior C1-C2 hook-screw fixation and fusion.Operation time,blood loss and complications were recorded.Variations in American Spinal Injury Association (ASIA) grade and Visual Analogue Scale (VAS) were compared before operation and at final follow-up.Position of internal implant,fracture healing and fusion were observed.Results Surgery was successful in all cases.Operation time was 145 (120-160) min,and blood loss was 200 (200-300)ml.No intraoperative injury to the vertebral artery injury,venous plexus,spine and nerve root occurred,and no cases showed ponticulus posticus after operation.Follow-up period was 24 (12-33) months.Postoperative imaging demonstrated satisfactory implant placement in all eases.Before operation,one case was rated as ASIA grade A,two as grade D and nine as grade E.One case was rated as ASIA grade A and 11 as grade E at the final follow-up.VAS was improved from preoperative 7 (6-8) points to 0(0-1) points at the final follow-up (P ＜ 0.05).Fracture healing and fusion were observed in all cases at the final follow-up.Conclusion Posterior atlantoaxial fusion for C1/C2 fractures combined with ponticulus posticus is a safe and effective procedure that can promote fracture union without increasing the risk of vertebral artery injury.

Objective To determine the clinical efficacy of limited internal fixation with posterior titanium plates for unstable atlas fractures.Methods A retrospective case series analysis was performed for 29 patients with unstable atlas fractures immobilized using the posterior titanium plate from January 2011 to November 2014.There were 22 males and seven females,with a mean age of 41.5 years (range,17-68 years).Ten patients were diagnosed with 1/2 ring Jefferson fractures,12 anterior 1/2 Jefferson fractures and seven patients posterior 3/4 Jefferson fractures.Frankel neurological performance scale was grade E in all patients.Operation time,amount of bleeding during operation and postoperative complications were recorded.X-ray and CT were performed to identify the fusion,internal fixation location and atlantoaxial stability.Visual Analogue Scale (VAS) for craniocervical pain and cervical range of motion were evaluated.Results Mean duration of procedure was (86.6 ± 7.8) min (range,68-122 min) and mean blood loss was (120.0 ± 25.3) ml (range,90-400 ml).No vascular and neurologic complications were noted.All patients were followed up for (22.5 ± 18.0)months (range,12-32 months).CT scans confirmed bony union in all patients 6 months after operation.No plate-related complications,implant lessening and implant breakage occurred during the follow-up.Postoperative VAS [(1.9 ± 1.1) points] was significantly lower than that before operation [(7.2 ± 1.4) points] (P ＜ 0.05).At the last follow-up,the ranges of cervical flexion-extension [(81.3 ± 22.2) °] and rotation [(152.4 ±38.7) °] were close to the normal range.Conclusion Limited internal fixation with posterior titanium plates is a safe and effective surgical method that contributes to good reduction and maximal preservation of cervical physiological motion.

Objective To analyze reasons of open operation after percutaneous vertebroplasty.Methods From January 2008 to January 2012,516 patients (587 vertebrae) underwent percutaneous vertebroplasty in our hospital.Among them,13 patients occurred serious complications after operation:9 cases of spinal cord injury and 4 cases of nerve root injury.There were 5 males and 9 females,aged from 53 to 72 years (average,64.5 years).There were 10 cases of osteoporotic fracture,2 cases of vertebral metastases and 1 case of vertebral hemangioma.The lesion segments were as follows:T7 in 1 case,T8 in 1 case,T9 in 2 cases,T10 in 1 case,T11 in 1 case,T12 in 2 cases,L1 in 3 cases,L3 in 1 case and L4 in 1 case.According to the American Spinal Injury Association (ASIA) classification,9 patients with spinal cord injury were rated as follows:grade A in 2 cases,grade B in 1 case and grade C in 6 cases.Four patients with nerve root injury had skin hypesthesia,and the muscle strengths of them were grade Ⅱ.All patients underwent posterior open operation 4-12 h after definite diagnosis.Results Thirteen patients were followed up for 3 to 47 months (average,14.1 months).The reasons of open operation were as follows:bone cement leakage in 6 cases (46.2％,6/13),puncture failure in 3 cases (23.1％,3/13) and indication select error in 4 cases (30.8％,4/13).All 6 cases of bone cement leakage were non vascular leakage,including 2 cases of leakage into the spinal canal and 4 cases of leakage into the nerve root canal.At final follow up,the muscle strength was improved to grade V in 3 patients with nerve root injury and grade Ⅳ in remaining 1 patient.And skin sensation was also improved.The ASIA grade of 7 patients with spinal cord injury was improved:grade D in 4 cases and grade E in 3 cases.For remaining 2 patients,there was no change in ASIA grade.Conclusion The reasons of open operation after percutaneous vertebroplasty include bone cement leakage,puncture failure,and indication select error.And bone cement leakage is the most common.