Objective: To compare and analyze the predictive value of two kinds of classification methods, routine magnetic resonance imaging (MRI) and diffusion tensor tractography (DTT), on the diagnosis and prognosis in different degrees of acute cervical spinal cord injury (ACSCI).Methods: A total of 35 patients with ACSCI treated with surgery in our department from January 2013 to December 2014 were included and all patients had received MRI examination and diffusion tensor imaging examination before surgery. The motor score, sensory score and abbreviated injury scale (AIS) of American Spinal Injury Association were used to evaluate the neurological function of patients before and one year after surgery, respectively. Routine MRI was divided into 3 grades according to the compression and signals of spinal cords and DTT was also divided into 3 grades according to continuous levels of fibre bundle. The correlations between routine MRI grades and DTT grades and the neurological function of ACSCI before surgery and after surgery were analyzed, respectively.Results: There were no correlations between MRI grading and the motor score, sensory score and AIS of patients with ACSCI before surgery and after surgery. DTT grading showed no relations with the motor score, sensory score before surgery but were related to AIS before surgery. DTT grading was all related to the motor score, sensory score and AIS after surgery.Conclusions: The noninvasion of DTT showed spinal nerve fibers has a higher predictive value on the diagnosis and prognosis of ACSCI than routine MRI.

Objective To explore the value of the apparent diffusion coefficient(ADC)ratio and fractional anisotropy(FA)ratio of magnetic resonance(MR)diffusion tensor imaging(DTI)in evaluating the clinical symptoms,prognosis of cervical spondylotic myelopathy(CSM).Methods Thirty-six healthy subjects and fifty CSM patients were involved and received MRI examination.Regions of interest(ROIs)were selected in the ventral funiculus(VF),lateral funiculi(LF),dorsal funiculus(DF),and central gray matter(GM)for ADC and FA measurements.In the control group,ADC and FA ratios were calculated using the original values at the C3/4,C4/5,C5/6,and C6/7levels to divide the corresponding values at their C1/2levels.In the CSM group,ADC and FA ratios were calculated using the ADC and FA values at the most compressed levels to divide the corresponding values at their C1/2levels.In the control group,the variances of the two ratios were compared between different cervical levels and ages.CSM patients were divided into mild,moderate,and severe group according to the preoperative Japanese Orthopaedic Association(JOA)scoring system,and were divided into well,moderate,and poor group according to the postoperative JOA recovery rates.Correlations between DTI parameters,DTI ratios of the VF,LF,DF,and GM of the CSM patients and the JOA scores,JOA recovery rates were assessed among different clinical symptom subgroups and prognosis subgroups.Results In control group,DTI ratios(ADC ratios and FA ratios)in VF,LF,DF,and GM were significantly different between C3/4,C4/5,C5/6,and C6/7levels(P0.05),but not found between different age subgroups.Correlations between DTI ratios of the VF,LF,DF,and GM and JOA scores,JOA recovery rates were significantly superior than the correlations between DTI parameters and JOA scores,JOA recovery rates(P0.05 or P0.01),with the FA ratio being superior to the ADC ratio.Compared with normal control group,the ADC ratios increased gradually in order and FA ratios decreased gradually in the mild,moderate,and severe injury subgroups(P0.05).Compared with normal control group,the ADC ratios increased gradually in order and FA ratios decreased gradually in the well,moderate,and poor recovery subgroups(P0.05).Conclusion DTI ratios might eliminate the influence of age in evaluating the clinical symptoms and prognosis of CSM.Therefore DTI ratios,compared with DTI parameters,may better evaluate the clinical symptoms,prognosis of CSM.

Objective To investigate the feasibility of preparing individualized navigation templates for pedicle screw insertion using a three-dimensional printing forming technique,and to evaluate the accuracy of template-assisted pedicle screw insertion.Methods Five male Chongming goats were selected and total spine CT-scan was performed.After the original Dicom data were imported into the Mimics software,the C3-6,T3-6and L3-6spinal column models were created to design and generate the cavity models based on a three-dimensional printing forming technique.The navigation template was created with a wellestablished pedicle screw path using a free-hand procedure,and then bilateral pedicle screw insertion was done assisted by the navigation templates.CT-scan was taken again postoperatively to access the position of the screws.Results Totally 60 navigation templates were prepared and 119 pedicle screws were implanted under the assistance of these templates,with one pedicle screw insertion failed due to a congenital deformity.CT-scan axial images indicated that 114 pedicle screws were completely contained within the pedicles,while 5screws perforating the pedicle walls.Sagittal images showed accurate screw placement except for 2screws perforating into the foramen.Conclusion The present study indicates that Mimics software is a feasible and precise method for establishing spinal column and related cavity model based on CT-scan images.Pedicle screw insertion assisted by a three-dimensional printing model is highly accurate and easy to perform,which may be a new alternative to conventional technique.

Chronic spinal cord compression is the result of mechanical pressure on the spinal cord, which in contrast to traumatic spinal cord injury, leads to slowly progressing nerve degeneration. These two types of spinal cord injuries may trigger similar mechanisms, including motoric nerve cell apoptosis and autophagy, however, depending on differences in the underlying injury severity, nerve reactions may predominantly involve the conservation of function or the initiation of functions for the removal of irreversibly damaged cells. p62 is a multidomain adapter protein, which is involved in apoptosis and cell survival as well as autophagy, and is a common component of protein aggregations in neurodegenerative diseases. In the present study, a rat chronic spinal cord compression model was used, in which the spinal cord was progressively compressed for six weeks and then constantly compressed for another 10 weeks. As a result Basso, Beattie and Bresnahan locomotor scaling revealed a gradual score decrease until the 6th week followed by constant recovery until the 16th week after spinal cord compression was initiated. During the first eight weeks of the experiment, p62 and nuclear factor-κB (NF-κB) were increasingly expressed up to a constant plateau at 12-16 weeks, whereas caspase 3 exhibited a marginally enhanced expression at 8 weeks, however, reached a constant maximum peak 12-16 weeks after the beginning of spinal cord compression. It was hypothesized that, in the initial phase of spinal cord compression, enhanced p62 expression triggered NF-κB activity, directing the cell responses mainly to cell survival and autophagy, whereas following eight weeks of spinal cord compression, caspase 3 was additionally activated indicating cumulative elimination of irreversibly damaged nerve cells with highly activated autophagy.

OBJECTIVES:To investigate the feasibility of establishing an individualized navigation template for occipital condyle screws insertion using a fused deposition modeling based three-dimensional printing forming technique, and to evaluate the accuracy and safety of template-assisted condyle screw insertion.METHODS:Thirty adult occipitocervical specimens were selected to take a CT-scan. After original Dicom data imported into the Mimics software, the craniocervical junction models were created, which were used to evaluate anatomic structures and define the screw-related parameters. Design and generate the cavity models of the occipital condyle based on a three-dimensional printing forming technique. After using a free-hand procedure to create a navigation template with a well-established screw path, finish bilateral condyle screws insertion assisted by the navigation template. Anatomy study and CT-scan were taken postoperatively to access the position of the screws.RESULTS:Sixty condyle screws were implanted assisted by 30 individualized navigation templates with an average time cost of (91.4 ± 8.2) s. The axial medial angle, sagittal cranial angle and distance between the entry point to atlantooccipital joint surface were (33.2 ± 6.4)°, (8.9 ± 3.4)°, (3.9 ± 0.9) mm, respectively. The variations due to different sex and sides resulted in a statistically insignificant difference of the parameters. Anatomy study and CT-scan indicated no intrusion of the vertebral artery, hypoglossal canal, condyle emissary vein canal or atlantooccipital joint. Fifty-nine condyle screws were completely contained within the condyle, while only 1 screw perforated lateral condyle wall.CONCLUSIONS:Using the Mimics software for establishing the occipital condyle and related cavity model based on CT-scan images proves to be a feasible and precise method.Occipital condyle screws insertion assisted by a three-dimensional printing model is highly accurate and simple, which could be a new alternative to conventional technique.

Background The aim of present meta-analysis was to evaluate the effectiveness of tranexamic acid (TXA) use in reducing blood loss and the related thrombotic complications in spinal surgery. Methods Three databases (MEDLINE, EMBASE, and the Cochrane Library) were searched through October 2012 to identify the relevant randomized controlled trials (RCTs) regarding the TXA effective in spinal surgery. Mean differences (MDs) of blood loss, blood transfusions, and postoperative partial thromboplastic time (PTT), odds ratios (ORs) of blood transfusion and thrombotic complication in TXA-treated group compared to placebo group were extracted and combined using random-effect meta-analysis. Results A total of 6 RCTs comprising 411 patients were included in the meta-analysis according to the pre-defined selection criteria. TXA-treated group had significantly less amount of blood loss and blood transfusions per patient, and had smaller proportion of patients who required a blood transfusion compared with the placebo group. The use of TXA can significantly reduce the postoperative PTT with weighted MD of -1.59 [(95% confidence interval (CI):-3.07, -0.10] There is a null association between thrombosis complications and the use of TXA. Conclusion We conclude that the use of TXA in patients undergoing spinal surgery appears to be effective in reducing the amount of blood loss, the volume of blood transfusion, the transfusion rate, and the postoperative PTT. However, data were too limited for any conclusions regarding safety. More high-quality RCTs are required before recommending the administered of TXA in spinal surgery.

Background: The diffusion tensor imaging (DTI) parameters of the cervical spinal cord (CSC) changes with age. However, previous studies only examined specific CSC areas. Objectives: To analyze the DTI parameters in all intervertebral space levels of the whole normal CSC and to study the impact of age on these parameters in a Chinese population.Methods: Thirty-six healthy subjects aged 20-77 years were recruited. DTI parameters were calculated for gray matter (GM) and white matter (WM) funiculi in all the CSC intervertebral spaces (C112-C617). Age-related changes of DTI parameters were analyzed for the GM and WM funiculi.Results: Fractional anisotropy (FA) and mean diffusivity (MD) were lower in GM than in WM. MD and FA values were lower in the WM in the lower CSC compared with the upper CSC (all P< 0.05), but no difference was observed in GM. In ventral funiculi, MD increased with age, while FA decreased (all P< 0.001). In lateral and dorsal funiculi, MD and FA decreased with age (all P< 0.001). In GM, MD and FA decreased with age (all P< 0.001). Significant age-related changes were observed in FA and MD from GM and WM funiculi. FA was correlated with age in all funiculi (ventral: r = -0.733; lateral: r = -0.468; dorsal: r = -0.607; GM: r= -0.724; all P < 0.01).Conclusion: Important changes in MD and FA were observed with advancing age at all levels of CSC in Chinese patients. DTI parameters may be useful to assess CSC pathology, but the influence of age and segments need to be taken into account in diagnosis. (C) 2014 Elsevier Ireland Ltd. All rights reserved.

OBJECTIVE:To establish a goat model of acute spinal cord compression injury through a modified percutaneous technique with a Foley double-lumen urine catheter and explore the method feasibility and preliminary observation.METHODS:Twelve adult male Chongming goats were randomly divided into 3 groups:control (A, n = 4), 0.5 ml compression (B, n = 4) and 1 ml compression (C, n = 4). After local anesthesia, all animals received epidural balloon catheter (5Fr) insertion via a percutaneous trans-lumbosacral interlaminar space technique that mimicked the method used in vascular access for angiography. The balloon catheter was advanced under fluoroscopic guidance until its distal tip reached the middle of T6 level.One week later, for groups B and C, the balloon was inflated by half-strength contrast material, 0.5 ml and 1 ml, respectively. The balloon was left inflated for 30 min and then deflated. The images of computed tomography (CT) and magnetic resonance (MR) were taken before and after surgical procedures.Quantitative assessment of spine canal occupying rate was accomplished by an off-line software program based on CT results. Motor function was assessed by the modified Tarlov scale. Two animals of each group were sacrificed after a total observation period of 48 h and 72 h respectively.Spinal cords from the injured level were then obtained for pathologic examinations.RESULTS:All animals underwent successful catheterization occupying 6.8%±0.7% (Group A), 6.7%±0.7% (Group B) and 6.6%±0.6% (Group C) of spine canal respectively. After inflation, the occupying rate of groups B and C achieved 43.4%±2.5% and 88.1%±2.3% respectively.Ventral compression of spinal cord was noted on MR images.Hindlimb movement remained normal after catheter insertion in all groups. All animals in group B and C became paraplegic after inflation. And a positive correlation existed between injection volume and Tarlov score. Pathological findings confirmed neuron atrophy, increased gap around neurons, mild demyelination and vacuolar degeneration both in groups B and C at 48 h after injury. Pathological changes deteriorated at 72 h after injury.CONCLUSION:The results of behavioral evaluation, radiographic images and pathological examination reveal an evidence of acute spinal cord injury. Percutaneous epidural balloon catheter insertion differs from previous techniques by avoiding surgical exposure and associated artifacts, yet it offers injury mechanisms similar to those of human spinal cord injury. As a new means of modeling spinal cord injury in animals, this technique has many potential applications.

Objective To observe the expression of SRY(sex determining region Y)-box 9(SOX9) and collagen type Ⅱalpha 1(COL2A1) in human cervical intervertebral disc nucleus pulposus(NP) tissues of various degeneration degrees,so as to discuss the role of their expression during cervical intervertebral disc degeneration(CIDD).Methods Totally 36 human cervical intervertebral disc specimens and their pre-operation MRI findings were obtained from surgical patients or patients with cervical trauma,and they were classified into five grades according to the Miyazaki grading system.The expression of SOX9 and COL2A1 was examined by fluorescence quantitative RT-PCR,Western blotting analysis and immunohistochemistry staining.The relationship between SOX9,COL2A1 expression and the degrees of CIDD was analyzed,and the relationship between SOX9 and COL2A1 was also discussed.Results Both SOX9 and COL2A1 were expressed in NP tissues,with SOX9 seen in the nucleus and COL2A1 in the extracellular matrix. The expression of SOX9 and COL2A1 mRNA and protein gradually decreased as Miyazaki Ⅰprogressed to Miyazaki Ⅴ. We also found a linear relationship between COL2A1(Y) and SOX9(X) expression: Y=0.923X-0.059 (P0.001).Conclusion The expression of SOX9 and COL2A1 mRNA decrease with the increase of CIDD severity,with SOX9 and COL2A1 mRNA having a similar decreasing tendency.SOX9 positively regulate COL2A1 expression,indicating that changes of SOX9 and COL2A1 gene might be one of the molecular mechanisms of CIDD.

Objective To establish a new animal model of chronic cervical compressive myelopathy and to assess its feasibility.Methods Eighteen Chongming goats were divided into two groups: control group(n=3) and experimental group(n=15).The balloon was placed into the C3 intervertebral space by anterior approach operation,and the syringe valve was fixed subcutaneously.Contrast agent was injected percutaneously into the valve(0.1 ml/week) to inflate the balloon progressively to produce chronic compression.In the control group,the balloon compression system was placed and immediately removed;percutaneous puncture was performed each week without injecting anything.The Tarlov scores were assessed in each group every four weeks.The goats underwent X-ray,CT and MRI under general anesthesia every four weeks.The spinal cord specimens were pathologically examined at test level at the end of experiment.Results The Tarlov scores were 5(normal) at all time points in the control group.Tarlov scores were not changed in the experimental group four weeks after surgery(n=13);at eight weeks after surgery(n=11) the Tarlov scores were 4 in 2 goats and 5 in 9 goats;and at twelve weeks after surgery(n=9) the Tarlov scores were 2 in 3 goats,3 in 4 goats and 4 in 2 goats.The balloon compression system was stable in the experimental group.Radiological findings showed that the cervical spinal cord compressed progressively in the experimental group as time went by,and those in the control group underwent no noticeable change.Pathological examination showed neuronatrophy,increased gap around the neurons,mild demyelinated and vacuolar degeneration in the experimental group at eight weeks after surgery,and these changes were deteriorated twelve weeks after surgery.There were no noticeable pathological changes in the control group and four weeks after surgery in the experimental group.Conclusion The postoperative behavior,radiological and pathological findings of the animals consist with the character of chronic cervical compressive myelopathy,indicating that the balloon compression system in the present study can be used to establish a reliable and stable animal model of chronic cervical spinal cord compression.