Antinociceptive effect of intrathecal injection of miR-9-5p modified mouse bone marrow mesenchymal stem cells on a mouse model of bone cancer pain.

BACKGROUND: A growing body of studies have indicated that bone marrow mesenchymal stem cells (BMSCs) have powerful analgesic effects in animal models of bone cancer pain. Here, we explored the molecular mechanisms underlying how BMSCs alleviate pain sensation in a mouse model of bone cancer pain. METHODS: C3H/HeN adult male mice were used to generate a bone cancer pain model. BMSCs were isolated from mouse bone marrow, modified by transfection with microRNA-9-5p (miR-9-5p), and infused into the spinal cord. Spontaneous flinches, paw withdrawal latency, limb-use score, and weight-bearing score were used to assess pain-related behaviors. ELISA, RT-PCR, western blot, and luciferase assay were used to assess gene expressions. RESULTS: Our results show that miR-9-5p regulated the expression of both repressor element silencing transcription factor (REST) and µ-opioid receptors (MOR) by targeting REST in primary mouse BMSCs. Overexpression of miR-9-5p reversed the activation of inflammatory pathway in TNF-α- and IL-6-treated BMSCs. In addition, miR-9-5p modified BMSCs alleviated cancer pain in the sarcoma-inoculated mouse model. MiR-9-5p modified BMSCs suppressed cytokine expression in the spinal cord of sarcoma-inoculated mice by suppressing REST gene expression. CONCLUSIONS: Our results indicate that miR-9-5p modified BMSCs can relieve bone cancer pain via modulating neuroinflammation in the central nervous system, suggesting genetically modified BMSCs could be a promising cell therapy in pain management.

Melatonin modulates IL-1ß-induced extracellular matrix remodeling in human nucleus pulposus cells and attenuates rat intervertebral disc degeneration and inflammation.

The inflammatory-associated factors interleukin-1ß (IL-1ß), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) are widely reported to be associated with intervertebral disc (IVD) degeneration (IVDD). N-acetyl-5-methoxytryptamine (melatonin) is a natural hormone secreted by the pineal gland which has been shown to participate in several physiological and pathological progresses, such as aging, anti-inflammation, anti-apoptosis and autophagy regulation. However, the effects of melatonin on IVD remain unclear. In the present study, we treated human nucleus pulposus cells (NPCs) with melatonin and discovered that melatonin could modulate extracellular matrix (ECM) remodeling induced by IL-1ß by enhancing collagen II and aggrecan expression levels and by downregulating matrix metalloproteinase-3 (MMP-3) levels. These findings were verified by western blot and immunofluorescence assays. Intraperitoneal injection of melatonin mitigated IVDD in the rat tail puncture model. X-ray and magnetic resonance imaging (MRI), as well as hematoxylin-eosin (H&E), Safranine O-Green, Alcian blue and Celium red staining methods were adopted to evaluate IVDD grades, the structural integrity of nucleus pulposus (NP) and annulus fibrosus (AF) and the damage and calcification of the cartilage endplate. Melatonin reduced inflammatory cell aggregation and the release of the inflammatory factors IL-1ß, IL-6, TNF-α as determined by immunohistochemistry. In conclusion, the present study demonstrated that melatonin could modulate ECM remodeling by IL-1ß in vitro and attenuate the IVDD and induction of inflammation in a rat tail puncture model in vivo. The data demonstrated that melatonin may contribute to the restoration processs of IVD following damage and may be used as a potential novel therapy for IVDD.

Inflammation-dependent downregulation of miR-194-5p contributes to human intervertebral disc degeneration by targeting CUL4A and CUL4B.

Inflammation is one of the major causes of intervertebral disc degeneration (IDD). Emerging evidence has revealed that increase in the levels of pro-inflammatory cytokines, such as interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α), can activate a variety of signaling pathways, eventually resulting in IDD. Here, we show that the two cullin family genes, CUL4A and CUL4B, but not other cullins, are specifically overexpressed in IDD samples compared with healthy controls, and the CUL4A and CUL4B levels are positively correlated with the severity of IDD. In vitro analyses in human osteoblast cells (hFOB1.19), nucleus pulposus cells (hNPCs), and annulus fibrosus cells (hAFCs) indicated that treatment with IL-6 and TNF-α can increase CUL4A and CUL4B levels. By performing a microRNA-based microarray analysis, we found a set of microRNAs (miRNAs) that were differentially expressed in IDD samples compared with samples from healthy controls. Of these miRNAs, miR-194-5p, was significantly downregulated in IDD samples and could bind to the three prime untranslated regions (3'-UTRs) of both CUL4A and CUL4B, thereby downregulating their expression. The in vitro overexpression or downregulation of miR-194-5p, with a miR-194-5p-mimic or with anti-miR-194-5p, can cause the repression or induction of both CUL4A and CUL4B, respectively. Interestingly, treatment with IL-6 and TNF-α inhibitors in primary hNPCs and hAFCs that were isolated from patients with IDD led to the downregulation of CUL4A and CUL4B. Together, these findings provide insight into how the inflammation-dependent downregulation of miR-194-5p contributes to the pathogenesis of IDD, which may aid in the development of new therapeutic approaches for IDD by directly targeting miR-194-5p or CUL4A and CUL4B.

Retracted Article: Melatonin protects spinal cord injury by up-regulating IGFBP3 through the improvement of microcirculation in a rat model.

The present study was aimed at the investigation of the effects of melatonin on spinal cord injury (SCI) and the role of IGFBP3 in SCI both in vivo and in vitro. The rats received treatment with 100 mg kg-1 melatonin or both melatonin and pGenesil-1-si-IGFBP3 (50 µg per g bw) after SCI surgery. The motor function in rats was measured using the Basso-Beattie-Bresnahan (BBB) scale score; perfusion vessel area was determined by injecting FITC-conjugated lycopersicon esculentum agglutinin lectin (FITC-LEA), whereas the blood-spinal cord barrier permeability was measured using Evans blue. The pericytes were isolated, and the cells were cultured under hypoxia, treated with melatonin or transfected with si-IGFBP3. RT-qPCR and western blotting were conducted for the determination of IGFBP3, VEGF, MMP-2, ICAM-1 and Ang1. The expression of IGFBP3 was significantly down-regulated in the SCI rats, and melatonin significantly enhanced the IGFBP3 level. Melatonin improved the motor function, reduced the neuron injury, and improved the microcirculation in rats. However, the down-regulation of IGFBP3 significantly reversed these effects. Moreover, in both the SCI rat spinal cord tissues and the in vitro pericytes under hypoxia, the expressions of IGFBP3 and Ang1 were significantly down-regulated, whereas those of the proteins MMP-2, VEGF and ICAM-1 were significantly up-regulated, and melatonin dramatically inhibited these changes. Melatonin could protect the rats from SCI by improving the microcirculation through the up-regulation of IGFBP3.

Bone cement distribution is a potential predictor to the reconstructive effects of unilateral percutaneous kyphoplasty in OVCFs: a retrospective study.

BACKGROUND: Osteoporotic vertebral compression fracture (OVCF) is a common type of fracture, and percutaneous kyphoplasty (PKP) is an eligible solution to it. Previous studies have revealed that both the volume and filling pattern of bone cement correlate with the clinical outcomes after PKP procedure. However, the role of bone cement distribution remains to be illustrated. METHODS: To retrospectively evaluate the relationship between the bone cement distribution and the clinical outcomes of unilateral PKP, we enrolled 73 OVCF patients receiving unilateral PKP treatment. All the intervened vertebrae were classified into three groups based on the bone cement distribution observed on postoperative X-ray films. Preoperative and postoperative radiographic parameters including the vertebral height and kyphotic Cobb angle were recorded, and anterior vertebral height restoration rate (AVHRR) and Cobb angle correction (CR) were then calculated to assess the vertebral height reconstruction. Preoperative and postoperative Oswestry Disability Index (ODI) and visual analogue scale (VAS) were adopted by interviewing patients to assess the mobility improvement and pain relief. Demographic data, body mass index (BMI), lumbar bone mineral density (evaluated by BMD T-score) of each patient, bone cement volume (BV), and bone cement extravasation (BE) were also recorded. Between- and within-group comparisons and multivariable correlation analysis were carried out to analyze the data. RESULTS: VAS and ODI scores were both significantly improved in all of the enrolled cases with no significant differences between groups. Among the three groups, the average age, AVHRR, and BV were significantly different. Occurrence of BE was significantly different between two of the three groups. AVHRR was demonstrated to correlate negatively with preoperative anterior vertebral height ratio and positively with preoperative Cobb angle, CR, diffusion score, and ODI changes. CONCLUSIONS: Bone cement distribution is a potential predictor to the reconstructive effects in unilateral PKP for OVCFs. Bone cement distribution is associated with AVHRR and BV, as well as the risk of BE occurrence. Greater bone cement distribution may indicate better vertebral restoration along with a higher BE risk.

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.

Outcome of Bilateral C1 Laminar Hooks Combined With C2 Pedicle Screw Fixation for the Treatment of C1-C2 Instability: A Report of 18 Cases From a Single Chinese Center.

STUDY DESIGN: A retrospective technical report. OBJECTIVE: To assess the effect of bilateral C1 laminar hooks combined with C2 pedicle screw fixation for the treatment of C1-C2 instability. SUMMARY OF BACKGROUND DATA: Various posterior atlantoaxial fixations for C1-C2 instability have been developed. However, due to anatomic anomalies of the vertebral artery, the smallness of the pedicle, trajectories of broken screws, or a lack of surgical experience, a simple atlantoaxial fixation technique with good safety and effectiveness is urgently needed. MATERIALS AND METHODS: From January 2007 to September 2012, 18 patients with C1-C2 instability who underwent posterior bilateral C1 laminar hooks combined with C2 pedicle screw fixation were evaluated. Six patients had acute odontoid fractures (Anderson IIc type), 8 patients had odontoid pseudarthrosis, 3 had os odontoideum, and 1 had a traumatic rupture of the transverse ligament. The mean age at the time of surgery was 34.1 years. The clinical and radiographic analyses were performed before and after the operation and at follow-up. RESULTS: The follow-up period was 12-78 months (with an average follow-up period of 25.6 mo). All patients were relieved of pain and their neurological symptoms were substantially improved. The postoperative JOA score improved significantly (t=-7.234, P<0.001). No neurological or vascular complications occurred in these cases. The device was placed well and had not loosened or broken and plain radiographs revealed bony fusion in 17 patients. One patient had C1 posterior arch fracture 3 weeks postoperatively and she was followed up for 18 months without revision surgery. CONCLUSIONS: When appropriate patients were selected, bilateral C1 laminar hooks combined with C2 pedicle screw fixation can be an alternative method to treat C1-C2 instability effectively with a relatively simple procedure. Preoperative planning and evaluation were crucial for the solid atlantoaxial fusion.

CRL4BDCAF11 E3 ligase targets p21 for degradation to control cell cycle progression in human osteosarcoma cells.

Cell cycle progression in mammals is strictly controlled by a number of cyclin-dependent kinases (CDKs) and CDK inhibitors (CKIs), the expression of which is often dysregulated in cancer cells. Our previous work revealed that Cullin 4B (CUL4B), a critical component of the Cullin4B-RING E3 ligase complex (CRL4B), is overexpressed in human osteosarcoma cells through an unknown mechanism. Here, we demonstrated that CUL4B forms an E3 ligase with RBX1 (RING-box 1), DDB1 (DNA damage binding protein 1), and DCAF11 (DDB1 and CUL4 associated factor 11) in human osteosarcoma cells. In vitro and in vivo ubiquitination analyses indicated that CRL4BDCAF11 E3 ligase was able to specifically ubiquitinate a CDK inhibitor-p21Cip1 at K16, K154, K161 and K163 but not at K75 and K141. Knocking down any component of the CRL4BDCAF11 complex, including CUL4B, DDB1 or DCAF11, using short hairpin RNAs (shRNAs) attenuated the ubiquitination level of p21Cip1, inhibited osteosarcoma cell proliferation, led to cell cycle arrest at S phase, and decreased colony formation rate. Taken together, our data suggest that the CRL4BDCAF11 complex represents a unique E3 ligase that promotes the ubiquitination of p21Cip1 and regulates cell cycle progression in human osteosarcoma cells.

Secreted Phosphoprotein 24 kD Inhibits Growth of Human Prostate Cancer Cells Stimulated by BMP-2.

BACKGROUND/AIM: Secreted phosphoprotein 24 kD (spp24) has been shown to inhibit bone morphogenetic protein 2 (BMP2)-induced cancer growth in several tumor models. In this study, we aimed to investigate the effects spp24 on the growth of prostate cancer caused by BMP2 in vitro and in vivo. MATERIALS AND METHODS: The effects of BMP2 and spp24 on PC-3 cell viability were analyzed using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay. A subcutaneous tumor model and intratibial tumor model was established using PC-3 cells. Tumor growth was assessed through gross examination and radiography during the experiment. Then, after sacrifice, tumor cell apoptosis and tumor cell proliferation were assessed by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay and immunochemical analysis. RESULTS: BMP2 stimulated the PC-3 cell proliferation in vitro and spp24 could abolish the effect of BMP2. In a xeneograft tumor model, BMP2 promoted the subcutaneous and intratibial tumor growth, while spp24 dramatically inhibited the tumor growth induced by BMP2. Histological examination showed that spp24 also abolished the BMP2-induced proliferating cell nuclear antigen (PCNA) expression and promoted tumor cell apoptosis. CONCLUSION: Spp24 can inhibit the growth of prostate cancer and its bone metastasis induced by BMP2; spp24 may have great potential to be a therapeutic agent in clinical situations.

Cyclic stretch enhances apoptosis in human lumbar ligamentum flavum cells via the induction of reactive oxygen species generation.

OBJECTIVE: The lumbar ligamentum flavum (LF) is an important part of the spine to maintain the stability of the spine. In this study we aimed to examine whether mechanical force by cyclic stretch could induce apoptosis in human LF cells and investigate the underlying mechanism. METHODS: LF cells were isolated from six young patients undergoing spinal surgery and then cultured in vitro. LF cells were subjected to cyclic stretch and the poptosis was detected by flow cytometry. The level of intracellular reactive oxygen species (ROS) and caspase-9 activity were measured. RESULTS: Cyclic stretch at a frequency of 0.5 Hz with 20% elongation induced the apoptosis of human LF cells in vitro, and this was correlated with increased ROS generation and activation of caspase-9. CONCLUSION: Our study suggests that cyclic stretch-induced apoptosis in human LF cells may be mediated by ROS generation and the activation of caspase-9.

Application of a stand-alone anchored spacer in noncontiguous anterior cervical arthrodesis with radiologic analysis of the intermediate segment.

The purpose of this study was to describe the clinical features of noncontiguous cervical degenerative disc disease (cDDD), investigate the efficacy and complications of a stand-alone anchored spacer (SAAS) for patients with noncontiguous cDDD, and present radiologic analysis of the intermediate segment (IS) after skip-level fusion. Nineteen consecutive patients with noncontiguous cDDD who underwent skip-level anterior cervical discectomy and fusion (ACDF) with SAAS from January 2010 to December 2012 were enrolled in this study. Clinical outcomes were assessed preoperatively and at 24 months postoperatively using the Japanese Orthopaedic Association score, Neck Disability Index, and Visual Analog Scale. Overall cervical alignment (OCA) of the cervical spine, and the range of motion (ROM), intervertebral disc height (IDH), disc signal intensity and disc protrusion of IS were measured and compared before and after surgery. Clinical outcomes significantly improved compared to preoperative scores. The OCA was corrected and maintained at 24 months postoperatively compared with preoperative values (p<0.05). There were no significant differences in the ROM and IDH of the IS at each follow-up (p>0.05). However, decreased signal intensity on T2-weighted MRI was evidenced in three mobile IS at final follow-up (20.0%). Skip-level ACDF with SAAS may be an efficacious option for the treatment of noncontiguous cDDD.

Comparison of plate-cage construct and stand-alone anchored spacer in the surgical treatment of three-level cervical spondylotic myelopathy: a preliminary clinical study.

BACKGROUND CONTEXT: Although stand-alone cages were advocated to be superior to plate-cage construct (PCC) because of comparable clinical outcomes and fewer plate-related complications, cage dislocation and subsidence were frequently mentioned in multilevel fusion. There are some concerns about whether these issues can be effectively prevented in multilevel anterior cervical discectomy and fusion (ACDF) by stand-alone anchored spacer (SAAS). PURPOSE: The aim was to compare clinical outcomes, radiologic parameters, and complications of PCC and SAAS in the treatment of three-level cervical spondylotic myelopathy (CSM). STUDY DESIGN/SETTING: This was a retrospective comparative study. PATIENT SAMPLE: A total of 38 consecutive patients with three-level CSM (ACDF with PCC, 20 patients; ACDF with SAAS, 18 patients) were reviewed. OUTCOME MEASURES: Clinical outcomes were assessed using Japanese Orthopaedic Association and Neck Disability Index. The radiologic evaluations included cervical alignment (CA), segmental angle (SA), postoperative curvature loss (PCL), and incidence of subsidence. METHODS: All the aforementioned parameters were compared before and after surgery between two groups. Besides, the aforementioned results were also compared between the two groups. The complications were also recorded. RESULTS: The mean follow-up period was 30.3 months. No significant differences were observed in clinical outcomes between the two groups (p>.05). Additionally, no significant differences existed in fusion rate between the two groups. There were significant differences in PCL of SA and CA and correction of SA between the two groups (p<.05). Besides, the incidence of subsidence (9 of 54 levels, 16.7%) was recorded in the SAAS group, and the potential of SAAS to reduce the incidence of postoperative dysphagia was not proven. No other complications were observed in this study. CONCLUSIONS: In the surgical treatment of three-level CSM, PCC is superior to SAAS in correction and maintenance of SA and avoiding cage subsidence, although the technique of ACDF with SAAS yielded encouraging clinical outcomes and high fusion rate.

Lever reduction using polyaxial screw and rod fixation system for the treatment of degenerative lumbar spondylolisthesis with spinal stenosis: technique and clinical outcome.

BACKGROUND: The management for degenerative lumbar spondylolisthesis with spinal stenosis remains controversial. Reduction of lumbar spondylolisthesis has been performed via numerous techniques. Most of them need extra reduction assembly. METHODS: In this retrospective analysis, 27 patients of degenerative lumbar spondylolisthesis with spinal stenosis underwent reduction using polyaxial screw and rod constructs and posterolateral fusion. The average age at the time of surgery was 53 ± 3.23 years. The outcome measures consisted of a radiographic assessment of deformity and fusion rate and a clinical assessment of perioperative improvement in low back pain and function. Preoperative and postoperative radiographic evaluation included the percent slip, slip angle, and the lumbar lordosis between L1 and the sacrum measured using the Cobb method. Before surgery and at the final follow-up, the Oswestry Disability Index (ODI) and the visual pain analog scale (VPAS) between 0 (no pain) and 10 (maximal pain) were quantified. RESULTS: The average follow-up period more than 5 years was available. The mean operative time was 90.19 ± 14.51 min, and the mean blood loss during surgery was 152.59 ± 45.71 ml. The mean length of incision was 4.83 ± 0.63 cm. The average percent slippage and the mean slip angle were, respectively, 19.8 ± 4.49% and 9.69 ± 3.79° before surgery, 5.09 ± 3.40% and 6.39 ± 3.16° after surgery, and 5.67 ± 3.92% and 7.21 ± 3.05° at the last follow-up. The average lumbar lordosis was 36.88 ± 2.64° before surgery, 41.96 ± 1.64° after surgery, and 40.27 ± 1.19° at the final follow-up. No neurologic deficit occurred. Solid fusion was achieved for all cases. Compared with the outcome preoperation, the data improved from 6.56 ± 1.40 to 2.48 ± 1.16 for VPAS pain scores and from 32.22 ± 3.57 to 10.93 ± 4.93 for the ODI at the final follow-up. CONCLUSIONS: Lever slip reduction maneuver techniques using polyaxial screw and rod fixation system was simple and practicable. The treatment outcomes showed satisfactory radiographic characteristics and clinical results. The length of the incision was relatively small with a low intraoperative blood loss and short operation time.

Surgical treatment for cervical spondylotic myelopathy in elderly patients: a retrospective study.

OBJECTIVE: To analyze perioperetive clinical features and outcomes of surgical treatment for cervical spondylotic myelopathy (CSM) in elderly patients. METHODS: From 2006 to 2013, we retrospectively reviewed 136 patients with CSM who underwent surgery. The patients were divided into two groups: 70 years or older (elderly group, 58 patients) and younger than 70 years (younger group, 78 patients). The course of disease, surgical outcome, morbidities, and postoperative complications were analyzed. RESULTS: In the elderly group, follow-up lasted 9-76 months (mean 39.6 months), the course of disease was 23.7 months (range 4-72 months). Anterior cervical decompression and fusions and posterior laminectomy and fixation were performed in 24 and 34 patients, respectively. The operative time averaged 103 min (range 48-210 min). In the younger group, follow-up lasted 10-71 months (mean 37.8 months), the course of disease was 12.6 months (range 2-58 months). Anterior cervical decompression and fusions and posterior laminectomy and fixation were performed in 75 and three patients, respectively. The prevalence of chronic diseases and postoperative complications were higher in the elderly group than the younger group. The recovery rates of JOA score were 40.82 ± 11.20% in the elderly group and 64.10 ± 22.61% in the younger group. The therapeutic effects of surgery were significantly better for the young patients than for the elderly. CONCLUSION: Elderly patients with CSM present long period and serious symptoms, and the degeneration of multiple organs. Surgical decompression for CSM appears to be a beneficial and safe procedure for older patients if properly handled, although the recovery rate is poorer than that of younger patients.

Comparison of the safety and efficacy of anterior 'skip' corpectomy versus posterior decompression in the treatment of cervical spondylotic myelopathy.

BACKGROUND: The aim of this study was to compare the therapeutic effects of anterior 'skip' corpectomy with posterior decompression for treating four-level cervical spondylotic myelopathy. METHODS: Operation time and blood loss during the operation for the anterior and posterior approach groups were recorded. Patients were examined with cervical lateral radiography before and after the operation to measure Cobb's angle and postoperatively to monitor bony fusion. Surgery-, instrumentation-, and graft-related complications were assessed and recorded. RESULTS: The surgical aspects of both anterior 'skip' corpectomy and posterior decompression went smoothly, with mean durations of 2.5 and 2.1 h, respectively, and mean blood loss volumes of 250 and 380 mL, respectively. In the anterior approach group, the complications included axial pain in five cases and transient hoarseness in two. Radiography revealed titanium mesh subsidence in two cases and plate or screw dislodgement in one case. In the posterior approach group, C5 nerve root palsy was present in 2 patients, axial pain in 15, and cerebrospinal fluid leakage in 3. The mean Japanese Orthopaedic Association scores showed that the recovery rate was significantly higher in the anterior approach group than in the posterior approach group (p < 0.05). CONCLUSIONS: 'Skip' corpectomy has comparable safety and better efficacy than posterior decompression in the treatment of four-level cervical spondylotic myelopathy.

Laminoplasty versus laminectomy for multi-level cervical spondylotic myelopathy: a systematic review of the literature.

BACKGROUND: There is considerable controversy as to which posterior technique is best for the treatment of multi-level cervical spondylotic myelopathy. The aim of this study was to compare the clinical and radiographic results and complications of laminoplasty (LAMP) and laminectomy (LAMT) in the treatment of multi-level cervical spondylotic myelopathy. METHODS: We reviewed and analyzed papers published from January 1966 and June 2013 regarding the comparison of LAMP and LAMT for multi-level cervical spondylotic myelopathy. Statistical comparisons were made when appropriate. RESULTS: Fifteen studies were included in this systematic review. There was no significant difference in the incidence of surgical complications between LAMP and LAMT. Compared to conventional LAMT and skip LAMT, postoperative ROM was more limited in LAMP, but this was still superior to postoperative ROM following LAMT with fusion. Postoperative kyphosis occurred in 8/180 (4.44%) in LAMP and 13/205 (6.34%) in LAMT, whereas no cases of kyphosis were reported for skip LAMT. Skip LAMT appears to have better clinical outcomes than LAMP, while the outcome was similar between LAMP and LAMT with fusion. CONCLUSIONS: Based on these results, a claim of superiority for laminoplasty or laminectomy was not justified. In deciding between the two procedures, the risks of surgical and neurological complications, and radiologic and clinical outcome, must be taken into consideration if both options are available in multi-level cervical spondylotic myelopathy.

[Unilateral pedicle screw fixation through the pedicle of fractured vertebra in combination with the short segment of pedicle screw in the treatment of thoracolumbar fracture of mild to moderate instability].

OBJECTIVE: To evaluate the efficacy of unilateral pedicle screw fixation through the pedicle of fractured vertebra in combination with the short segment of pedicle screw in the treatment of thoracolumbar fracture of mild to moderate instability. METHODS: Twenty-six patients with single segment thoracolumbar fracture received unilateral pedicle screw fixation through the pedicle of fractured vertebra in combination with the short segment of pedicle screw from January 2008 to December 2009. There were 16 patients were male and 10 were female with an average age of 47.3 years (range from 39 to 60 years). Fracture severity score was constructed by using the load-sharing classification (4 points for 2 cases, 5 points for 14 cases, 6 points for 10 cases). By Frankel assessment system, 2 cases were in grade C, 3 in grade D, 21 in grade E. The assessment included anterior vertebral body height, the sagittal Cobb angle, the restoration of nervous function, visual analogue score (VAS) and Oswestry disability index (ODI). RESULTS: The follow-up after the surgery was 13 - 26 months, with an average of 18.6 months. There were no fixation failure, defined as implant failure or ≥ 10° correction loss. The neurological status of 4 patients, who had an associated neurologic deficit preoperatively, was completely recovered. The Frankel grade of another case was re-rated D from the original C. The mean anterior vertebral body height increased from 57.0% ± 6.3% before the surgery to 93.1% ± 1.7% at the last follow-up(F = 455.276, P < 0.05). The sagittal Cobb angle decreased from 15.6° ± 4.7° before the surgery to 2.6° ± 5.2° at the last follow-up (F = 34.623, P < 0.05). VAS and ODI were 1.0 ± 0.7 and 17.0 ± 5.9 at the last follow-up. CONCLUSION: Unilateral pedicle screw fixation through the pedicle of fractured vertebra combined with the short segment of pedicle screw is effective for thoracolumbar fracture with mild to moderate instability.

Efficient terahertz emission by mid-infrared laser pulses from gas targets.

It is shown by simulations that terahertz (THz) radiation can be produced more efficiently by a mid-infrared laser pulse from a gas target. The THz amplitude is enhanced by 35 times as the laser wavelength increases from 1 µm to 4 µm; a 4 µm laser at 10(15) W cm(-2) produces 5 MV/cm THz radiation. The THz amplitude changes oscillatingly with increasing laser intensity for a given laser wavelength. In addition, the laser intensity threshold for the THz emission is lower for a longer laser wavelength.

Direct posterior c1 lateral mass screws compression reduction and osteosynthesis in the treatment of unstable jefferson fractures.

STUDY DESIGN: Technical case report. OBJECTIVE: To investigate a new concept and surgical technique in the treatment of unstable Jefferson fractures, which preserves the motion of upper cervical spine, avoiding fusion. SUMMARY OF BACKGROUND DATA: The management of unstable Jefferson fractures remains controversial. Conservative treatment usually involves a long time of immobilization in halo vest, whereas surgical intervention generally performs fusion, eliminating the range of motion of upper cervical spine. METHODS: Two patients with unstable Jefferson fractures were surgically treated via direct posterior C1 lateral mass screws compression reduction and osteosynthesis technique, aiming at restoring the C0-C2 height and maintaining the vertical ligamentous tension for C0-C1-C2 complex stability despite the incompetent transverse ligament, achieving physiologic repair instead of traditional fusion. The clinical and radiographic results were documented. RESULTS: The postoperative CT showed that C1 lateral mass screws were well positioned. At 1-year follow-up, plain radiographs, and CT scan revealed no implant failure, good cervical alignment, and bony healing of the fractures; no C1-C2 instability was observed on the flexion-extension radiographs. The patients were completely pain-free, with full range of motion of the cervical spine. CONCLUSION: The ideal treatment of unstable Jefferson fractures is expected to preserve the function of C0-C1-C2. Unstable Jefferson fractures involve the concomitant failure of the vertical ligamentous tension because of the loss of C0-C2 height. Reduction of the displaced lateral masses to restore the C0-C2 height and maintain the ligamentous tension is the key to the surgery. Direct posterior C1 lateral mass screws compression reduction and osteosynthesis is a valid technique, avoiding fusion of upper cervical spine.

Intradural cervical disc herniation: report of two cases and review of the literature.

STUDY DESIGN: Case report and review of the literature. OBJECTIVE: To report two additional cases with intradural cervical herniation and review the pertinent literature. SUMMARY OF BACKGROUND DATA: Intradural cervical disc herniation is rare and a total of 22 cases were reported in 2007. In searching the world literature on this topic, we found 27 cases of intradural cervical disc herniation in all. METHODS: Clinical history, physical examination, and radiographic findings of two patients with intradural cervical disc herniation were described, and corpectomy was performed in both cases. A review of the literature was completed. RESULT: The outcome of one case was gratifying, and at a 36-month follow-up, nearly a full recovery was obtained. But the other's condition was disappointing, whose postoperative MRI demonstrated high signal intensity in the spinal cord and adhesion of spinal cord to the posterior margin at C4 level. CONCLUSION: Intradural cervical disc herniation is relatively rare, and the two additional cases updated the number of this condition to 29. It remains difficult to definitively diagnose the disease before surgery, but some indirect signs may indicate the cases. Corpectomy under a microscope as the first option in treatment of this disease is recommended once it is highly diagnosed. The pathogenesis of intradural cervical disc herniation remains to be further investigated. We presume that biochemical factors may play an important role in the pathogenesis.