Hybrid fixation versus conventional cage-plate construct in 3-level ACDF: Introduce the "seesaw theory" of stand-alone cage.

STUDY DESIGN: A retrospective study. BACKGROUND: Conventional cage-plate construct (CCP) was widely used in anterior cervical discectomy and fusion (ACDF), but the rigid fixation limits the motion of fused segments. Self-locking stand-alone cage (SSC) was an alternative for ACDF procedures and showed several superiorities. However, the effect of hybrid fixation in 3-level ACDF remains unknown. OBJECTIVE: To assess the clinical and radiological outcomes of hybrid fixation with SSC and CCP against conventional CCP in 3-level ACDF. METHOD: A retrospective review of patients who underwent 3-level ACDF at Renji Hospital between January 2018 and December 2019 was performed. Eighty-three patients met the inclusion and exclusion criteria and were stratified into 2 groups based on the fixation methods. The clinical outcomes, functional outcomes, and radiological parameters were collected and analyzed. RESULTS: No significant difference was observed between the two groups in the mean age, sex, body mass index, hospital stay, and duration of follow-up. The postoperative C2-7 Cobb angle in the CCP group was significantly greater than that in the hybrid group. The rate of cervical proximal junctional kyphosis (CPJK) in the hybrid group was significantly lower than that in the CCP group. The CCP group suffered significantly higher rates of adjacent segment degeneration (ASD) than the hybrid group at 2 years postoperatively. Moreover, the incidence of postoperative dysphagia was lower in the hybrid group. No significant differences were observed in JOA and NDI scores between the two groups. CONCLUSION: The hybrid fixation achieved comparable clinical outcomes against CCP fixation, indicating that hybrid fixation is an alternative procedure in 3-level ACDF.

Is Complete Correction of Cervical Sagittal Malalignment Necessary During 4-Level Anterior Cervical Discectomy and Fusion Surgery in Patients With Kyphosis?

STUDY DESIGN: Retrospective analysis. OBJECTIVE: We investigated whether complete correction of cervical sagittal malalignment is necessary during 4-level anterior cervical discectomy and fusion (ACDF) in patients with kyphosis. METHODS: This retrospective study included 84 patients who underwent 4-level ACDF surgery at a university hospital between January 2010 and December 2015. Based on the degree of cervical lordosis correction, patients were categorized into the following groups: mild (0-10°), moderate (10-20°), and complete correction (>20°). The clinical outcomes, radiological parameters, and functional outcomes were analyzed. RESULTS: We observed no significant intergroup differences in the baseline characteristics. The cervical sagittal vertical axis (CSVA) correction loss at the final follow-up was lesser in the mild- and moderate- than in the complete-correction group. The spinocranial angle (SCA) and T1 slope (T1 S) were significantly higher in the moderate- and complete-correction groups than in the mild-correction group, 3 days postoperatively. The cervical proximal junctional kyphosis (CPJK), adjacent segment degeneration (ASD), and ASD following CPJK rates were higher in the complete-correction group. We observed no significant intergroup differences in postoperative complications; however, 5 patients showed internal fixation failure in the complete-correction group; 4 of these patients required reoperation. No significant intergroup difference was observed in the Japanese Orthopedic Association and neck disability index scores at any time point. CONCLUSIONS: A mild-to-moderate correction of cervical lordosis is superior to complete correction in patients with kyphosis who undergo 4-level ACDF because this approach is associated with lesser axial stress and CSVA correction loss.

Roles of the Neuron-Restrictive Silencer Factor in the Pathophysiological Process of the Central Nervous System.

The neuron-restrictive silencer factor (NRSF), also known as repressor element 1 (RE-1) silencing transcription factor (REST) or X2 box repressor (XBR), is a zinc finger transcription factor that is widely expressed in neuronal and non-neuronal cells. It is a master regulator of the nervous system, and the function of NRSF is the basis of neuronal differentiation, diversity, plasticity, and survival. NRSF can bind to the neuron-restrictive silencer element (NRSE), recruit some co-repressors, and then inhibit transcription of NRSE downstream genes through epigenetic mechanisms. In neurogenesis, NRSF functions not only as a transcriptional silencer that can mediate the transcriptional inhibition of neuron-specific genes in non-neuronal cells and thus give neuron cells specificity, but also as a transcriptional activator to induce neuronal differentiation. Many studies have confirmed the association between NRSF and brain disorders, such as brain injury and neurodegenerative diseases. Overexpression, underexpression, or mutation may lead to neurological disorders. In tumorigenesis, NRSF functions as an oncogene in neuronal tumors, such as neuroblastomas, medulloblastomas, and pheochromocytomas, stimulating their proliferation, which results in poor prognosis. Additionally, NRSF-mediated selective targets gene repression plays an important role in the development and maintenance of neuropathic pain caused by nerve injury, cancer, and diabetes. At present, several compounds that target NRSF or its co-repressors, such as REST-VP16 and X5050, have been shown to be clinically effective against many brain diseases, such as seizures, implying that NRSF and its co-repressors may be potential and promising therapeutic targets for neural disorders. In the present review, we introduced the biological characteristics of NRSF; reviewed the progress to date in understanding the roles of NRSF in the pathophysiological processes of the nervous system, such as neurogenesis, brain disorders, neural tumorigenesis, and neuropathic pain; and suggested new therapeutic approaches to such brain diseases.

Comparison of Accuracy and Clinical Outcomes of Robot-Assisted Versus Fluoroscopy-Guided Pedicle Screw Placement in Posterior Cervical Surgery.

STUDY DESIGN: This was a prospective controlled study. OBJECTIVE: To compare the accuracy and clinical outcomes of robot-assisted (RA) and fluoroscopy-guided (FG) pedicle screw placement in posterior cervical surgery. METHODS: This study included 58 patients. The primary outcome measures were the 1-time success rate and the accuracy of pedicle screw placement according to the Gertzbein-Robbins scales. The secondary outcome measures, including the operative time, intraoperative blood loss, hospital stay, cumulative radiation time, radiation dose, intraoperative advent events, and postoperative complications, were recorded and analyzed. The Japanese Orthopedics Association (JOA) scores and Neck Disability Index (NDI) were used to assess the neurological function of patients before and at 3 and 6 months after surgery. RESULTS: The rate of grade A was significantly higher in the RA group than in the FG group (90.6% and 71.1%; P < .001). The clinically acceptable accuracy was 97.2% in the RA group and 90.7% in the FG group (P = .009). Moreover, the 1-time success rate was significantly higher in the RA group than in the FG group. The RA group had less radiation time (P < .001) and less radiation dose (P = .002) but longer operative time (P = .001). There were no significant differences in terms of intraoperative blood loss, hospital stay, intraoperative adverse events, postoperative complications, JOA scores, and NDI scores at each follow-up time point between the 2 groups. CONCLUSIONS: The RA technique achieved higher accuracy and 1-time success rate of pedicle screw placement in posterior cervical surgery while achieving comparable clinical outcomes.

Therapeutic Strategy of Percutaneous Transforaminal Endoscopic Decompression for Stenosis Associated With Adult Degenerative Scoliosis.

STUDY DESIGN: A retrospective study. OBJECTIVE: To investigate the effects of percutaneous transforaminal endoscopic decompression (PTED) for lumbar stenosis associated with adult degenerative scoliosis and to analyze the correlation between preoperative radiological parameters and postoperative surgical outcomes. METHODS: Two years of retrospective data was collected from 46 patients with lumbar stenosis associated with adult degenerative scoliosis who underwent PTED. The visual analog scale (VAS), Oswestry Disability Index, and modified MacNab criteria were used to evaluate the clinical outcomes. Multiple linear regression analysis was used to analyze the correlation between radiological parameters and surgical outcomes. RESULTS: The mean age of the 33 female and 13 male patients was 73.5 ± 8.1 years. The mean follow-up was 27.6 ± 3.5 months (range from 24 to 36). The average coronal Cobb angle was 24.5 ± 8.2°. There were better outcomes of the VAS for leg pain and Oswestry Disability Index after surgery. Based on the MacNab criteria, excellent or good outcomes were noted in 84.78% of patients. Multiple linear regression analysis showed that Cobb angle and lateral olisthy may be the predictors for low back pain. CONCLUSION: Transforaminal endoscopic surgery may be an effective and safe method for geriatric patients with lumbar stenosis associated with degenerative scoliosis. The predictive factors of clinical outcomes were severe Cobb angle and high degree lateral subluxation. Transforaminal endoscopic surgery may not be recommended for patients with Cobb angle larger than 30° combined with lateral subluxation.

Clinical application of Myelopathy-hand Functional Evaluation System in evaluating the postoperative hand motor function for myelopathy patients.

OBJECTIVE: Recovery of hand motor function after surgical treatment in myelopathy patients is commonly observed. Accurate evaluation of postoperative hand function contributes to assessing the efficacy of surgical treatment. However, no objective and effective evaluation method has been widely accepted in clinical practice. Therefore, the study aimed to explore the value of Myelopathy-hand Functional Evaluation System (MFES) in assessing the postoperative hand function for myelopathy patients. MATERIAL AND METHOD: MFES mainly consist of a pair of wise-gloves and a computer with software. One hundred and thirty myelopathy patients were included and all of them received optimal surgery treatment. The Japanese Orthopaedic Association (JOA) scores were marked at preoperative and at 6 months after surgery. All patients were asked to perform the 10-s grip and release test, and the hand movements were simulated and converted into waveforms by MFES. The waveform parameters were measured and analyzed. RESULTS: The JOA scores and the number of grip-and-release (G-R) cycles significantly increased after surgery. Correspondingly, the waveforms of ulnar three fingers were significantly higher and narrower, along with the significantly declined average time per cycle in postoperative. The a/b ratio (Wave height/wave width) of five fingers were significantly higher in postoperative than that in preoperative. Based on the improvement rate of a/b, the excellent and good rate of surgical outcomes was 62.30 %, which was significantly higher than that (47.69 %) based on the improvement rate of JOA scores (P = 0.019). CONCLUSION: MFES is an effective assessment tool in evaluating the postoperative hand function for myelopathy patients.

Consensus statement on diagnosis and treatment of cervical ossification of posterior longitudinal ligament from Asia Pacific Spine Society (APSS) 2020.

PURPOSE: The study aimed to develop an evidence-based expert consensus statement on diagnosis and treatment of cervical ossification posterior longitudinal ligament (OPLL). METHOD: Delphi method was used to perform such survey, and the panel members from Asia Pacific Spine Society (APSS) 2020 were invited to answer the open-ended questions in rounds 1 and 2. Then the results were summarized and developed into a Likert-style questionnaire for voting in round 3, and the level of agreement was defined as 80%. In the whole process, we conducted a systematic literature search on evidence for each statement. RESULTS: Cervical OPLL can cause various degrees of neurological symptoms, an it's thought to be more common in Asia population. CT reconstruction is an important imaging examination to assist diagnosis and guide surgical choice. Segmental, continuous, mixed, and focal type is the most widely used classification system. The non-surgical treatment is recommended for patients with no or mild clinical symptoms, or irreversible neurological damage, or failed surgical decompression, or condition cannot tolerant surgery, or refusing surgery. As OPLL may continue to develop gradually, surgical treatment would be considered in their course inevitably. The surgical choice should depend on various conditions, such as involved levels, thickness, and type of OPLL, skill-experiences of surgeons, which are listed and discussed in the article. CONCLUSION: In this statement, we describe the clinical features, classifications, and diagnostic criteria of cervical OPLL, and review various surgical methods (such as their indications, complications), and provide a guideline on their choice strategy.

Clinical Application of a New Assessment Tool for Myelopathy Hand Using Virtual Reality.

STUDY DESIGN: A cross-sectional study. OBJECTIVE: To assess the effectiveness of a new assessment tool, myelopathy-hand functional evaluation system (MFES), in evaluating the hand dysfunction of patients with cervical myelopathy in the 10-second grip-and-release test (10 second G-R test). SUMMARY OF BACKGROUND DATA: Clumsy fingers movement is a common symptom of myelopathy patients. Evaluating the impaired hand function can provide a strong basis in assessing the severity of myelopathy. Currently, no objective and effective evaluation method is widely accepted in clinical practice. METHODS: MFES mainly consists of a pair of wise-gloves and a computer with software. One hundred and ninety-eight consecutive participants were asked to wear the wise-gloves and then perform 10 seconds G-R test. The movements of each finger were recorded by MFES and converted into waveforms. Relevant waveform parameters were measured and analyzed. The Japanese Orthopedics Association (JOA) scores of each patient were marked and the maximum spinal cord compression (MSCC) was measured on midsagittal T2-weighted magnetic resonance imaging (MRI). RESULTS: Myelopathy patients had a lower number of G-R cycles and a longer time per cycle than healthy subjects. There were significant differences in adduction and abduction time in patients with JOA scores greater than 6, but not in healthy subjects and patients with JOA scores less than 6. The waveforms of ulnar three fingers in myelopathy patients were lower and wider than those in healthy individuals. The average ratio value of wave height to wave width (a/b) could quantitatively reflect such differences of waveforms. According to receiver operating characteristic (ROC) curve analysis, the optimal threshold value of the normal average ratio was more than 1.92. The average a/b value was correlated with the JOA scores of the motor function in the upper extremities (r = 0.842). CONCLUSION: MFES appears to be an objective and quantitative assessment tool for patients with cervical myelopathy. LEVEL OF EVIDENCE: 3.

Different Surgical Strategy for Patients with Cervical Angina: A Potential Role of Luschka's Joint Osteophyte.

OBJECTIVE: Cervical angina is an underrecognized type of noncardiac chest pain and its mechanism of pain remains obscure. The objective of the current study was to investigate the clinical outcomes of different surgical strategies for patients with cervical angina and to analyze the potential pathogenesis of Luschka's joint osteophyte. METHODS: From February 2013 to March 2018, a prospective study on cervical angina was performed in our hospital. All patients who were diagnosed with both noncardiac chest pain and cervical pathology were identified. During admission, they consulted with a cardiologist and underwent strict cardiac workups to exclude true angina pectoris. The included 41 patients were randomly divided into two groups according to different surgical strategies of whether or not to remove Luschka's joint osteophyte during anterior cervical decompression surgery: the osteophyte resection (OR group) and the nonresection (NR group). RESULTS: The OR group consisted of 21 patients (8 men and 13 women) with a mean age of 54.7 years (range, 41-65 years). The NR group was composed of 20 patients (9 men and 11 women) with an average age of 56.3 years (range, 43-68 years). Before surgery, the mean duration of symptoms was 6.1 months (range, 4-20 months). The Luschka's joint osteophytes were located at C6 -C7 (19 cases, 46.3%), C5 -C6 (17 cases, 41.5%), and C4 -C5 (4 cases, 12.2%). Their average area was 34.85 mm2 and the average length were 5.09 mm. No statistically significant differences in demographic characteristics were detected between the two groups (P > 0.05). After operation, there were significant improvements in the Japanese Orthopedic Association score and the Neck Disability Index score in both groups (P < 0.05). However, the visual analogue scale score for chest pain in the OR group was statistically lower than that in the NR group (1.4 ± 1.0 vs 2.1 ± 1.6, P < 0.05). In the OR group, the results of cervical spine surgery were excellent in 18 patients (85.7%), and fair in 3 patients (14.3%). In the NR group, there were 10 patients (50.0%) with excellent results, 9 patients with fair results (45.0%), and 1 patient with poor results (5.0%). Notably, there were statistically significant differences between the two groups (χ2 = 6.265, P = 0.044). The average follow-up was 31 months (24-52 months). CONCLUSION: Anterior cervical decompression surgery with resection of Luschka's joint osteophyte can effectively reduce cervical angina symptom and improve the patient's quality of life. In addition to nerve root compression, Luschka's joint osteophyte may be another pathogenic factor in cervical angina.

Efficacy of percutaneous transforaminal endoscopic decompression treatment for degenerative lumbar spondylolisthesis with spinal stenosis in elderly patients.

The efficacy of fusion combined with decompression for the treatment of spinal stenosis with degenerative lumbar spondylolisthesis (DLS) has been debated. Percutaneous transforaminal endoscopic decompression (PTED) under local anesthesia is an ultra-minimally invasive procedure. The present study aimed to evaluate whether PTED is an effective alternative therapy for spinal stenosis associated with DLS in elderly patients. PTED was performed in elderly patients exhibiting lumbar stenosis and low-grade (Meyerding grades I and II) DLS; these patients also exhibited leg-dominant symptoms and had tolerable or absent mechanical back pain. Administration of general anesthesia may be considerably hazardous in patients when combined with comorbid conditions that result from aging. Therefore, the present procedure was performed under local anesthesia. No obvious radiographic lumbar intervertebral instability was identified prior to surgery. Pre- and post-operative visual analogue scale (VAS) score, Oswestry Disability Index (ODI) and walking distance data were collected. The clinical global outcomes following surgery were evaluated using modified MacNab criteria. A total of 18 elderly patients underwent surgery using PTED techniques. The mean follow-up time was 27.7 months (range, 24-33 months) and the mean estimated blood loss was 18.33 ml (range, 10-35 ml). The mean pre-operative ODI, VAS score of the back and VAS score of the leg were 68.2±6.5, 2.8±1.4 and 6.6±1.2, respectively. All average scores improved post-operatively to 31.7±5.2, 1.5±0.6 and 1.7±0.8, respectively, at the latest follow-up. A statistically significant improvement was observed for all scores at 1 month and that the scores remained relatively stable after that. According to modified MacNab criteria, the good-to-excellent rate was 83.3%. Only 1 patient required micro-decompression surgery due to poor rating. The present study indicated that PTED may be an effective alternative therapeutic option for elderly patients with low-grade DLS associated with spinal stenosis. However, PTED techniques continue to evolve and further follow-up studies are required to determine the long-term outcomes of this treatment technique.

Endoscopic Ventral Decompression for Spinal Stenosis with Degenerative Spondylolisthesis by Partially Removing Posterosuperior Margin Underneath the Slipping Vertebral Body: Technical Note and Outcome Evaluation.

BACKGROUND: Decompression alone is a treatment option in patients with lumbar spinal stenosis (LSS) and degenerative lumbar spondylolisthesis (DLS). This study aims to describe the procedure of percutaneous transforaminal endoscopic ventral decompression technique and to demonstrate the clinical outcomes. METHODS: Two years of retrospective data were collected from 26 patients with predominant unilateral leg pain caused by LSS and low-grade DLS (Meyerding grades I and Ⅱ). All patients underwent endoscopic ventral decompression by removing the posterosuperior margin underneath the slipping vertebral body, combined with dorsal decompression without excessive resection of facet joints. The surgical outcomes were assessed using the visual analog scale (VAS), Oswestry Disability Index (ODI), modified MacNab criteria, and walking distance improvement evaluation. RESULTS: The mean age of the 18 women and 8 men was 69.2 years. The mean preoperative ODI and VAS of the leg and the back scores were 64.7 ± 8.1, 7.0 ± 1.4, and 3.0 ± 1.2, respectively. All mean scores improved postoperatively to 31.4 ± 5.6, 2.4 ± 1.1, and 1.7 ± 1.1 at the final follow-up. In 88.5% of cases, patients' estimated walking distance improved. The outcomes of the modified MacNab criteria showed that 81.3% of patients obtained good-to-excellent rate. There were no statistically significant differences between the percent slip of spondylolisthesis before surgery and at the end of follow-up. CONCLUSIONS: Based on the initial short-term follow-up results, transforaminal endoscopic ventral decompression by partially removing the posterosuperior margin underneath the slipping vertebral body, combined with dorsal decompression, might be an efficient alternative treatment for leg dominant symptoms in patients with LSS and low-grade DLS.

Paclitaxel Induce Apoptosis of Giant Cells Tumor of Bone via TP53INP1 Signaling.

OBJECTIVE: To evaluate the antitumor capability and to investigate the underlying molecular mechanism of paclitaxel. METHODS: First, cck-8 and apoptosis assays were used to determine survival and apoptotic effects of HS 737.T cells under treatment of paclitaxel. Next, RNA-seq and bioinformatics were used to determine the differentially expressed genes and to analyze the pathway involved. Quantitative real-time polymerase chain reaction was used to verify the accuracy of some differentially expressed genes (DEG). ClueGO was used to decode and visualize functionally grouped GO terms of differentially expressed genes, and to map the DEG protein-protein interactions (PPI) network. Western blotting was used to check the expression of target genes, the cleavage of Caspase-3 and PARP1, and the phosphorylation level of p53. Finally, transcriptomics, bioinformatics, and RNAi were used to estimate the antitumor capability and to identify the underlying mechanisms of paclitaxel in GCTB. RESULTS: Our data revealed that paclitaxel had significant time-dependent effects on the viability and induced apoptosis of HS 737.T cells. RNA-seq and bioinformatics analysis showed that apoptosis, death receptor signaling pathway, TNF signaling pathway, and TP53 regulated transcription of cell death genes pathway were closely associated with paclitaxel in the treatment of GCTB. Western bolt results revealed that paclitaxel induced cleavage of Caspase-3 and PARP1, and increased the phosphorylation level of p53 in HS 737.T cells. RNAi results showed that the expression level of TP53INP1 was significantly decreased in HS737.T cells (the decrease was more than 70%). In addition, we found that the inhibitory ratios of paclitaxel on HS737.T cells deficient in TP53INP1 were less than in HS737.T cells with empty vector (19.88 and 40.60%, respectively). Hence, our data revealed that TP53INP1 regulated paclitaxel-driven apoptosis in HS737.T cells. CONCLUSION: Paclitaxel can significantly repress cell proliferation and induce apoptosis of HS 737.T cells through activating Caspase-3, PARP1, p53, and TP53INP1. Paclitaxel may be an effective drug in the management of GCTB.

Arteriovenous Fistula Inside Cervical Spinal Canal Associated with Neurofibromatosis Type 1.

BACKGROUND: Neurofibromatosis type 1 (NF-1) is an autosomal dominant disease caused by mutation on chromosome 17, which affects the skin, vascular system, nervous system, and skeleton system. Arteriovenous fistula (AVF) is one of the recognized complications of NF-1. CASE DESCRIPTION: We report a case of a 33-year-old woman with NF-1 with cervical spine AVF inside the cervical spinal canal who presented with progressive spinal cord compression which was abnormal. After sufficient preparation, the patient underwent vascular embolization, and then symptoms of spinal cord compression significantly improved. CONCLUSIONS: This report reminds readers of the possibility of AVF if there is a space-occupying lesion inside the cervical spinal canal and to do computed tomography angiography examination when necessary.

Estradiol Alleviates Intervertebral Disc Degeneration through Modulating the Antioxidant Enzymes and Inhibiting Autophagy in the Model of Menopause Rats.

OBJECTIVE: To investigate the effects of menopause on redox balance in the intervertebral disc and to examine whether oxidative stress and autophagy were associated with disc degeneration in menopause rats. METHODS: Thirty female Sprague-Dawley rats were randomly divided into three groups (sham, ovariectomized with vehicle, and ovariectomized with estrogen). At the end of the 3-month treatment, the rats were examined by 3.0 T MRI. Serum estradiol (E2) level was measured. Redox balance of nucleus pulposus was determined by measuring total antioxidant capacity (T-AOC), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione (GSH), and oxidized glutathione (GSSG). Transmission electron microscopy (TEM), immunohistochemical staining, and Western blot were used to determine the nucleus pulposus autophagy level. At the same time, Spearman's correlation coefficient was used to describe the relationship between intervertebral disc grade, oxidative stress status, serum E2, and autophagy level. RESULTS: The level of serum E2 was significantly decreased by ovariectomy and can be corrected by the estrogen replacement therapy (ERT). In OVX rats, an increased oxidative stress and high level of autophagy were observed in nucleus pulposus tissue. ERT prevented the intervertebral disc degeneration (IVDD), restored the redox balance, and reduced autophagy level. CONCLUSION: Ovariectomy induced oxidative stress, autophagy, and intervertebral disc degeneration. Autophagy of the intervertebral disc was negatively correlated with oxidative stress, and the level of autophagy can be reduced by ERT through modulating the redox balance and downregulating the autophagy level. Regulating the redox balance of IVD may be a potential therapeutic option for degeneration of the disc in the postmenopausal women.

Effects of Low Bone Mineral Status on Biomechanical Characteristics in Idiopathic Scoliotic Spinal Deformity.

BACKGROUND: Low bone mass in patients with adolescent idiopathic scoliosis has been well reported. Poor bone quality was regarded as a new and unique prognostic factor in aggravating curve progression. However, the potential biomechanical correlation between them remains unclear. METHODS: Three-dimensional finite element models of idiopathic scoliotic spine with different bone mineral status were created for axial loading simulation. An axial load of 3 different body weights was applied on different bone mineral mass models. The mechanical responses of the vertebral cortical and cancellous bone, facet joints, end plate, and intervertebral disc were analyzed. RESULTS: Accompanied with the low bone mineral status, thoracic scoliosis produced asymmetric and higher stress in the cortical bone, lumbar facet joints, and end plate at the concave side of the thoracic structure curve. Stress increased in the disc at the apex of the scoliosis, whereas it mildly decreased in the L4-5 and L5-S1 disc. Body weight gain increased the stress in scoliotic spine structures in all bone mineral statues. CONCLUSIONS: Biomechanical simulations indicated that low bone mineral mass might aggravate curve progression and induce more serious lumbar compensatory scoliosis in patients with adolescent idiopathic scoliosis. Weight gain was also a risk factor for curve progression.

Effectiveness of tranexamic acid in reducing blood loss in spinal surgery: a meta-analysis.

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.

[A modified goat model of acute spinal cord compression injury from a percutaneous balloon catheter: method feasibility and preliminary observation].

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.

Pseudarthrosis in multilevel anterior cervical fusion with rhBMP-2 and allograft: analysis of one hundred twenty-seven cases with minimum two-year follow-up.

STUDY DESIGN: Consecutive case series. OBJECTIVE: The purpose of this study was to analyze the pseudarthrosis rate in a large series of recombinant human bone morphogenetic protein-2 (rhBMP-2) augmented multilevel (> or =3 levels) anterior cervical fusions. SUMMARY OF BACKGROUND DATA: The reported pseudarthrosis rate following anterior cervical fusion varies from 0% to 20% for single-level and up to 50% for multilevel fusions. It has been postulated that the use of rhBMP-2 may decrease the pseudarthrosis rate. METHODS: A consecutive series of patients with cervical spondylosis and/or disc herniation who underwent anterior cervical fusion with rhBMP-2, structural allograft, and plate fixation with a minimum 2-year follow-up were analyzed by experienced, independent spine surgeons. RESULTS: A total of 127 patients (54 men and 73 women with mean age of 54 +/- 10 years [range, 32-79]) were examined. Seventy-five (59.1%) patients underwent a 3-level fusion, 34 (26.7%) underwent a 4-level fusion, and 18 (14.2%) underwent a 5-level fusion. Of the 451 fusion segments, 14 segments (3.1%) in 13 of 127 patients (10.2%) had evidence of pseudarthrosis at 6 months following surgery. Of the 13 patients with a pseudarthrosis, 3 had a 3-level fusion (3/75 patients [4.0%]), 6 had a 4-level fusion (6/34 patients [17.4%]), and 4 had a 5-level fusion (4/18 patients [22.2%]). Five patients were asymptomatic and were not revised, but the remaining 8 patients required additional surgery. In 12 of 13 patients with a pseudarthrosis, the nonunion occurred at the lowest fusion level and at the cervicothoracic junction. The only statistically significant risk factor for developing a pseudarthrosis was the number of fusion levels. CONCLUSION: In a large series of rhBMP-2 augmented multilevel fusions, the pseudarthrosis rate was 10.2% at 6 months following surgery. Since the risk of pseudarthrosis increases with the number of fusion levels, a long fusion lever arm may biomechanically overwhelm the biologic advantage of rhBMP-2. While rhBMP-2 is known to enhance fusion rates, it does not guarantee fusion in all situations.

Position of increased signal intensity in the spinal cord on MR images: does it predict the outcome of cervical spondylotic myelopathy?

BACKGROUND: Increased signal intensity (ISI) in the spinal cord on T2-weighted MR images has been reported in some previous researches, however no study focused on the position of the ISI in the spinal cord and its potential value. The aim of this study was to investigate the correlation between ISI position and the outcome of surgical treatment for cervical spondylotic myelopathy (CSM) patients. METHODS: A retrospective study was conducted. Pre- and post-operative clinical status was evaluated by modified Japanese Orthopaedic Association (JOA) score. ISI was evaluated according to the T2-weighted sequences. The JOA score and the recovery ratios among patients with ISI in gray matter (group A), in both gray and white matter (group B), and ISI-negative group were compared. RESULTS: Totally 64 patients were enrolled in this retrospective study. Preoperative JOA score of ISI positive and negative group had significant difference, but the recovery ratios had no significant difference (the recovery ratios of the two groups in week 1, week 26, and week 104 were (21.54 +/- 14.65)%, (50.56 +/- 14.76)%, (59.23 +/- 13.08)% and (20.25 +/- 14.32)%, (54.46 +/- 23.16)% and (61.26 +/- 29.4)%, respectively; P > 0.05). The recovery ratios of negative group and group A in week 104 were superior to group B (the recovery ratios of negative group, group A, and group B in week 104 were (61.26 +/- 29.49)%, (65.35 +/- 11.36)%, and (50.33 +/- 10.20)%, respectively; P < 0.05). CONCLUSIONS: Patients with ISI in the gray matter alone on T2-weighted MR images did not have significantly different surgical outcomes compared with those without ISI. Patients with ISI in both gray and white matter had surgical outcomes that were worse than those without ISI.

Cervical spine clearance in obtunded patients after severe polytrauma.

OBJECTIVE: To provide clinicians with data supporting three different clearance techniques in the obtunded patients after severe polytrauma. METHODS: This study gave an overview of the available and pertinent literature regarding cervical spine clearance in obtunded patients after severe polytrauma. RESULTS: Currently, there were three accepted techniques for clearance of the cervical spine in obtunded patients after severe polytrauma. Each of these methods has advantages and disadvantages to both of the patients and the clinicians. CONCLUSIONS: There are continuous improvements in both computed tomography (CT) and magnetic resonance imaging (MRI) techniques that increase their sensitivities. The continued use of plain radiographs is called into question with respect to cost and time requirements. An algorithmic approach to the evaluation of the cervical spine in the obtunded patients will lead to fewer missed injuries.