[Comparison of minimally invasive using a tubular retraction system versus open transforaminal lumbar interbody fusion for the treatment of lumbar degenerative diseases].

OBJECTIVE: To compare the clinical effect of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) using a tubular retraction system with traditional transforaminal lumbar interbody fusion (TLIF) for the treatment of lumbar degenerative diseases. METHOD: From June 2009 to June 2013, a total of 96 patients in Department of Orthopaedics, Armed Police Jiangxi Corps Hospital, suffering from lumbar degenerative diseases were divided into 2 groups randomly. 42 patients underwent MIS-TLIF using a tubular retraction system. There were 23 males and 19 females with the age of 64.4 ± 4.9. The preoperative diagnosis included lumbar disc herniation with instability (17 cases), lumbar spinal stenosis (13 cases), lumbar degenerative spondylolisthesis (12 cases). 54 patients underwent traditional TLIF. There were 32 males and 22 females with the age of 66.5 ± 7.6. The preoperative diagnosis included lumbar disc herniation with instability (22 cases), lumbar spinal stenosis (17 cases), lumbar degenerative spondylolisthesis (15 cases). The general data, operating time, blood loss and volume of drainage after operation were compared between two groups. VAS, ODI evaluating standards were applied to evaluate the therapeutic effect. The intervertebral fusion were observed by X ray or CT scan. RESULTS: All patients underwent surgery safely without severe complication occurred. There was no significant difference in operation time between MIS-TLIF group (96±37) min and TLIF group (83 ± 25) min, P>0.05; the blood, volume of drainage after operation in MIS-TLIF group were significantly less than TLIF group (P<0.05). The follow-up time was( 26 ± 7) months in MIS-TLIF group and (27 ± 8) months in TLIF group. Compared with preoperative parameters, the scores of VAS and ODI were significantly decreased after surgery and at the final follow-up in both groups (P<0.05). Compared with TLIF group, VAS in MIS-TLIF group of post-operation and the final follow-up were improved, respectively (P<0.05), but there is no significant difference in ODI score. There occurred cage dislocation with no nerve symptom in MIS-TLIF group in 1 case and fat liquefaction in TLIF group in 1 case. At the follow-up after 6.5 months postoperatively, all the operated segments achieved fusion standard and no internal screw were loose or broken. CONCLUSION: MIS-TLIF technique could provide less operation trauma, blood lose and achieve the similar satisfied short-term effect as traditional TLIF.

Combination of bone marrow concentrate and PGA scaffolds enhance bone marrow stimulation in rabbit articular cartilage repair.

Bone marrow stimulation (BMS) has been regarded as a first-line procedure for the repair of articular cartilage. However, cartilage repair using BMS alone has so far not been ideal because cell homing to the required area has not been sufficient. The aim of this study was to investigate the feasibility of autologous bone marrow concentrate transplantation for the repair of large, full-thickness cartilage defects. Thirty rabbits were divided into five groups: untreated (control); BMS only (BMS); BMS followed by PGA implantation (PGA); BMS followed by a combination of PGA and autologous bone marrow concentrate (BMC); and BMS together with a composite of PGA and cultured bone marrow stem cells (BME). The animals were sacrificed at week 8 after operation, and HE staining, toluidine blue staining and immunohistochemistry were used to assess the repair of defects. The results showed that improved repair, including more newly formed cartilage tissue and hyaline cartilage-specific extracellular matrix, was observed in BMC group relative to the first three groups, in addition similar results were found between BMC and BME groups, however it took longer time for in vitro cell expansion in the BME group. This study demonstrates that the transplantation of autologous bone marrow concentrate is an easy, safe and potentially viable method to contribute to articular cartilage repair.

[Biomechanical study of atlantoaxial fixation for transverse ligament injury leading to atlantoaxial instability].

OBJECTIVE: To explore the three-dimensional movement of atlantoaxial joint, complete transverse ligament and cracked transverse ligament after posterior atlantoaxial fixation. METHODS: The fresh upper cervical cadaveric specimens were collected from 6 males dead from active craniocerebral injury. The average age was 39.7 years old (range: 26 - 57). The specimens were divided into 3 groups of intact (Group I), transverse ligament cracked (Group D) and posterior atlantoaxial fixation (Group F). They were tested consecutively. RESULTS: The range of sagittal movement increased when the transverse ligament became cracked. And it had significant difference compared with the Group I (P < 0.05). But the ranges of lateral flexion and rotation showed no significant difference. When posterior atlantoaxial fixation was performed, all three-dimensional movements decreased. And significant differences existed as compared with Group I (P < 0.05). CONCLUSION: Under normal conditions, the main movement of atlantoaxial joint is rotation with lesser sagittal movement and lest lateral flexion. The range of sagittal movement increases significantly when transverse ligament is cracked (P < 0.05), especially so for anteflexion movement. The increase of lateral flexion and rotation has no significant difference compared with Group I. When posterior atlantoaxial Fixation is performed, all three-dimensional movements decrease significantly as compared with Group I (P < 0.05), especially loss of rotation function.

[Effect of siRNA-Cox-2 on the growth inhibition and apoptosis of cartilage endplate chondrocytes].

OBJECTIVE: To investigate the influence of siRNA-COX-2 gene upon the growth inhibition and apoptosis of cartilage endplate chondrocytes and provide new methods and evidence for siRNA in gene therapy of cartilage endplate chondrocytes. METHODS: According to the sequence of COX-2 mRNA, COX-2 siRNA was designed, synthesized, cloned into the GFP reporter pcDNA6.2GW/EmGFPmiR vector and transfected into Hep cell line. The integrity of inset fragment was detected by colony PCR (polymerase chain reaction) and sequencing analysis. The cultured cartilage endplate chondrocytes were divided into 4 groups: control group (untreated), negative siRNA group (treatment with 30 nmol/L negative control siRNA), siRNA1 group (treatment with 15 nmol/L COX-2 siRNA) and siRNA2 group (treatment with 30 nmol/L COX-2 siRNA). The biological activity of recombinants was identified with the interference efficiency of COX-2 siRNA recombinant by real-time PCR and Western blot. And the effects of COX-2 inhibitor on the growth of chondrocytes were detected by WST-8 and the mRNA expressions of survivin, bcl-2 and bax genes measured by real-time PCR. RESULTS: The sequences of inset fragment in 4 siRNA expressing recombinants were correct. After COX-2 transfection, the expression of COX-2 mRNA in chondrocytes was 51.3% ± 7.2% in the siRNA1 group and 35.4% ± 3.6% in the siRNA2 group. Western blot showed that the expression of COX-2 protein decreased, especially in siRNA2 group (P < 0.05). And the cell survival rate was 100.0% ± 8.3% in the control group, 84.9% ± 4.2% in the negative control siRNA group, 52.5% ± 6.7% in the siRNA1 group and 48.9% ± 5.4% in the siRNA2 group (P < 0.05). Meanwhile, the expressions of mRNA of survivin and bcl-2 decreased while the expression of bax mRNA increased in degenerative cartilage endplate chondrocytes transfected with COX-2 siRNA (P < 0.05). CONCLUSION: COX-2-targeting siRNA inhibits the expression of COX-2, suppresses the proliferation of chondrocytes and induces the cell apoptosis. These effects may be attributable to the up-regulation of survivin and bcl-2 and the down-regulation of bax.

[Biological characteristics of human umbilical cord-derived mesenchymal stem cells and their differentiation into chondrogenic and osteogenic cells].

OBJECTIVE: To investigate the isolation and expansion of mesenchymal stem cells (MSCS) from human umbilical cord Wharton's jelly and their biological identities, and explore the possibility of inducing human umbilical cord-derived MSCS to differentiate into chondrogenic and osteogenic cells. METHODS: The hUCMSCs were isolated form human umbilical cord by tissue adherence and digested with collagenase NB4, dispase II and hyaluronidase. The morphology, proliferation and immunophenotype of the 3rd passage cells were analyzed, and then the chondrogenic and osteogenic differentiation was tested and evaluated by specific staining methods.cells were induced to chondrogenic and osteogenic differentiation in vitro. RESULTS: The isolation of hUCMSCs by digestion with collagenase NB4, dispase II and hyaluronidase was efficient. After seeded for 24 hours, the adherent cells showed spindle shape and fibroblast cell-like shape and the size of hUCMSCs was homogeneous. Flow cytometry analysis revealed that the hUCMSCs were positive for CD44, CD105, CD90, CD73, but were negative for CD45, CD34, CD14, CD19 and HLA-DR. These cells could be induced to differentiate into chondrogenic and osteogenic cells under proper inducing conditions. The hUCMSCs retained the appearance and phenotype even after being expanded more than 40 passages in vitro. CONCLUSIONS: The human MSCs could be isolated from human umbilical cord Wharton's jelly, and it was easy to propagate these MSCs. An in vitro method for isolation and purification of hUCMSCs from human umbilical cord has been established. The cultured cells were composed of only undifferentiated cells and their biological properties were stable. The hUCMSCs are expected to be a new type of stem cells of tissue engineering.

[Treatment of thoracolumbar mono-segmental fracture with posterior short-segment fixation in combination with intermediate screws: a short-term outcome].

OBJECTIVE: To observe the early clinic outcome of treating thoracolumbar mono-segmental fracture with posterior fixation in combination with intermediate screws. METHODS: From July 2006 to August 2008, 35 of 62 patients with thoracolumbar mono-segmental fracture were treated with in Group A and the remaining 27 with intermediate screw in combination with short segmental fixation in Group B. RESULTS: The relative height of fractured vertebrae and reduction rate showed significant differences [(84.2 +/- 2.8) vs (98.6 +/- 1.9), P < 0.05] between two groups while the change of segmental kyphotic angle showed no difference [(8.5 +/- 1.0) vs (8.1 +/- 1.3), P > 0.05]. CONCLUSION: Intermediate screw in combination with short segmental fixation has a better immediate efficiency in treating thoracolumbar mono-segmental fracture since it reduces the height of fractured vertebrae.

miR­29b promotes the osteogenic differentiation of mesenchymal stem cells derived from human adipose tissue via the PTEN/AKT/ß­catenin signaling pathway.

Accumulating evidence has documented that microRNAs (miRNAs or miRs) function as important post­transcriptional regulators of the differentiation of mesenchymal stem cells (MSCs), including human adipose­derived mesenchymal stem cells (hADSCs); however, their roles in hADSC osteogenic differentiation require further investigation. The present study aimed to investigate the role of miRNAs in the osteogenic differentiation of hADSCs and to elucidate the underlying molecular mechanisms. Using an miRNA microarray, it was found that 24 miRNAs were upregulated and 14 miRNAs were downregulated compared with the undifferentiated cells, and miR­29b­3p (miR­29b) was selected for further experiments. Functional experiments revealed that the upregulation of miR­29b by agomir­29b significantly enhanced alkaline phosphatase (ALP) activity and the mineralization of extracellular matrix (ECM), and led to an increase in the mRNA and protein levels of osteogenic marker genes, including runt­related transcription factor 2 (Runx2), osteopontin (OPN), osteocalcin (OCN) and bone sialoprotein (BSP), whereas the knockdown of miR­29b suppressed these processes. In addition, phosphatase and tensin homolog (PTEN), a negative regulator of the AKT/ß­catenin pathway, was identified as a direct target of miR­29b in the hADSCs. Moreover, it was observed that the overexpression of miR­29b activated the AKT/ß­catenin signaling pathway by inhibiting PTEN expression in the hADSCs. Most importantly, it was also found that the overexpression of PTEN reversed the promoting effects of miR­29b on osteogenic differentiation. On the whole, these findings suggest that miR­29b promotes the osteogenic differentiation of hADSCs by modulating the PTEN/AKT/ß­catenin signaling pathway. Thus, this miRNA may be a promising target for the active modulation of hADSC­derived osteogenesis.

[Application of posterior short-segment fixation combined with intermediate screws in fresh thoracolumbar compressed fracture: short-term outcomes in 27 cases].

OBJECTIVE: To observe the short-term outcomes of the application of posterior short-segment fixation combined with intermediate screws in fresh thoracolumbar fracture. METHODS: Posterior short-segment fixation combined with intermediate screws was used in 27 patients suffering from fresh thoracolumbar fracture, 19 males and 8 females, aged 45 (22-71). X-ray photography was conducted before and after operation. RESULTS: The height of fractured vertebra was 57.6%+/-16.5% of the normal value before operation, and was restored to 93.8%+/-11.9% after operation; the segmental kyphosis angle on the sagittal plane was 20.8+/-9.4 degrees before operation, and decreased to 5.9+/-7.4 degrees after operation (both P<0.001). CONCLUSION: Using pedicle screws on the fractured vertebra via posterior approach conditionally helps reduce the fractured vertebra and correct the kyphosis, and enhance the stiffness of the internal fixation system as well.

[Comprehensive typing and surgical treatment of axial fracture with adjacent section instability: analysis of 17 cases].

OBJECTIVE: To study the clinical and radiographic characteristics of axial fracture with adjacent section instability and the diagnosis and surgical treatment thereof. METHODS: Seventeen patients of axial fracture with adjacent section instability, 11 males and 7 females, aged 34 (23-56) underwent different treatment patterns depending on the fracture type and stability of the atlanto-axial joint and C2-3: resection of C2-3 intervertebral disk and bone grafting, anterior interbody fusion and plate internal fixation, odontoid screw fixation, posterior C2 pedicle screw fixation, odontoid screw fixation combined with bilateral C-2 pedicle screw fixation. Follow-up was conducted for 12 (6-36) months. RESULTS: Postoperatively all patients were immobilized in a hard collar for 3 months. Bony fusion was obtained in all patients in 3 months. There were no operation-related complications, such as spinal cord injury, cerebrospinal fluid leakage, vertebral artery injury, etc. No re-dislocation was found. Neurological recovery was observed in the 3 patients who presented neurological deficits. CONCLUSION: The type of atlas fracture with adjacent section instability and the impact thereof on the stability of the atlanto-axial joint and C2/3 neck joint should be identified early. Surgical treatment results in better outcome.

[Posterior fusion versus posterior interbody fusion in segmental spinal fixation for aged spondylolisthesis].

OBJECTIVE: Clinical and radiographic results in 30 consecutive patients undergoing posterior lumbar fixation and posterior facet joint or posterior interbody fusion for Meyerding Grade II/III spondylolisthesis were assessed: (1) to address the suitability of a dynamic stabilization; and (2) to investigate whether there are differences in terms of clinical and functional results between these two types of arthrodesis. METHODS: Fourteen patients underwent posterior interface fusion (PLF) and implantation of TSRH-3D system. Posterior lumbar interbody fusion (PLIF) and placement of the same system were performed in 16 patients. Clinical, economic, functional and radiographic data were recorded both pre- and postoperatively. RESULTS: The average changes in Prolo Scale of economic and functional scores were 1.25 and 1.64 respectively, in patients undergoing posterior fusion; the average measured vertebral slippage was 48.6% (range 32%-65%) preoperatively and 17.5% (range 15%-25%) postoperatively. In patients undergoing PLIF, the average changes in economic and functional score were 1.18 and 1.39 respectively, and the average preoperative vertebral slippage was 44.2% (range 30%-55%) versus 20.3% (range 18%-26%) postoperatively. CONCLUSION: The use of a segmental pedicle screw fixation with TSRH-3D was able to successfully combine the goal of solid fusion with the requirements of nerve root decompression. When these two fusion techniques were compared, PLIF was superior to PLF because of an overall superior reliability and system resistance. But their clinical outcomes did not differ greatly (P > 0.05).

[Clinical analysis of surgical treatment of odontoid fracture].

OBJECTIVE: To evaluate the therapies and clinical outcome for different types of odontoid process fracture. METHODS: Twenty-one patients with odontoid process fracture were treated with different therapies for different Anderson-D'Alonzo classifications: three cases of type I were treated by traction of occipital-jaw band and fixed with head-neck-chest plaster at 6 weeks; thirteen cases of type II were treated by cannulated screws following skull traction and reduction; and for the cases of type III, one was fixed with screw when the fracture was reduced by skull traction, and four with atlantoaxial pedicle screw. RESULTS: All cases were followed up for a mean of 9 months (range: 3 - 48). All cases achieved bony union. No post-operative complication was found. CONCLUSION: Odontoid process fracture should be treated according to different types. Conservative treatment for type I fracture and cannulated screws for type II and low type III fracture can obtain a satisfactory outcome. Atlantoaxial pedicle screw should be chosen if the superficial type III fracture is not suitable for cannulated screw.

[Treatment of thoracic vertebrae fracture with vertebral pedicle-screw placement in selected injured vertebrae].

OBJECTIVE: To study the clinical effects of vertebral pedicle-screw placement in selected thoracic vertebrae with fresh fracture in reduction and fixation. METHODS: Twenty-five patients with thoracic vertebrae fracture, involving 1 vertebra in 13 cases, 2 vertebrae in 7 cases, and 3 vertebrae in 5 cases, underwent vertebral pedicle-screw placement in selected unilateral or bilateral injured vertebrae with relatively complete pedicle of vertebral arch. Pedicle-screw was inserted into the pedicle of the injured vertebra guided by fluoroscopy to achieve posterior pedicle screw fixation, the height of the collapsed vertebral body was recovered by popping up or extruding the vertebral pedicle-screw. The patients were followed up for 18 - 24 months. RESULTS: The postoperative X-films showed that the direction and length of the screws were satisfying without screw looseness and breakage of the internal fixation. No loss of spinal height of the injured vertebrae was seen after reduction. CONCLUSION: Pedicle-screw fixation of the injured thoracic vertebrae is effective in treatment of fresh thoracic vertebrae fracture.

Investigation of candidate genes for osteoarthritis based on gene expression profiles.

OBJECTIVE: To explore the mechanism of osteoarthritis (OA) and provide valid biological information for further investigation. METHODS: Gene expression profile of GSE46750 was downloaded from Gene Expression Omnibus database. The Linear Models for Microarray Data (limma) package (Bioconductor project, http://www.bioconductor.org/packages/release/bioc/html/limma.html) was used to identify differentially expressed genes (DEGs) in inflamed OA samples. Gene Ontology function enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enrichment analysis of DEGs were performed based on Database for Annotation, Visualization and Integrated Discovery data, and protein-protein interaction (PPI) network was constructed based on the Search Tool for the Retrieval of Interacting Genes/Proteins database. Regulatory network was screened based on Encyclopedia of DNA Elements. Molecular Complex Detection was used for sub-network screening. Two sub-networks with highest node degree were integrated with transcriptional regulatory network and KEGG functional enrichment analysis was processed for 2 modules. RESULTS: In total, 401 up- and 196 down-regulated DEGs were obtained. Up-regulated DEGs were involved in inflammatory response, while down-regulated DEGs were involved in cell cycle. PPI network with 2392 protein interactions was constructed. Moreover, 10 genes including Interleukin 6 (IL6) and Aurora B kinase (AURKB) were found to be outstanding in PPI network. There are 214 up- and 8 down-regulated transcription factor (TF)-target pairs in the TF regulatory network. Module 1 had TFs including SPI1, PRDM1, and FOS, while module 2 contained FOSL1. The nodes in module 1 were enriched in chemokine signaling pathway, while the nodes in module 2 were mainly enriched in cell cycle. CONCLUSION: The screened DEGs including IL6, AGT, and AURKB might be potential biomarkers for gene therapy for OA by being regulated by TFs such as FOS and SPI1, and participating in the cell cycle and cytokine-cytokine receptor interaction pathway.

Impact of ischemic preconditioning on ischemia-reperfusion injury of the rat sciatic nerve.

The aim of this study was to assess the preventive effects of ischemic preconditioning (IPC) on ischemia-reperfusion (IR) injury in the sciatic nerve of the rat hind limb. This study included two experiments. For Experiment 1, 40 Sprague-Dawley (SD) rats were randomly divided into 4 equal groups that received different IPC treatments prior to IR. Serum concentrations of aspartate aminotransferase (AST), lactate dehydrogenase (LDH), malondialdehyde (MDA), and superoxide dismutase (SOD) were assessed following reperfusion. Furthermore, we tested the electrophysiological response and ultrastructural changes in the ipsilateral sciatic nerve after IR. After determining the best IPC protocol for protection, we performed a second experiment with 30 SD rats randomly divided into 3 equal groups. Each group underwent 1, 2, or 3 IPC cycles before prolonged ischemia and reperfusion. The same analyses as in Experiment 1 were performed. In Experiment 1, the AST, LDH, and MDA concentrations were decreased in all IPC groups compared with the control group. Concentration of these enzymes showed decreases with increasing IPC cycle number in Experiment 2; however, the difference between 2 and 3 cycles of IPC did not reach significance. Conversely, SOD activity increased in the rapid and delayed groups, and with increasing cycles of IPC. The electrophysiological test showed a decrease in amplitude and increase in conduction velocity with increasing IPC cycles. Moreover, ultrastructural damage decreased with increasing IPC cycles. IPC protected against IR injury in the peripheral nerves. This effect was positively correlated with the number of IPC cycles.

Non-spinal-associated injuries with lumbar transverse process fractures: influence of segments, amount, and concomitant vertebral fractures.

BACKGROUND: Lumbar transverse process fractures (LTPFs) are often with concomitant non-spinal-associated injuries (NSAIs). The purpose of this study was to analyze the correlation between the NSAIs and the LTPFs of different segments, amount, and concomitant thoracolumbar/lumbar vertebral fractures. METHODS: A total of 1,181 patients with LTPFs or thoracolumbar/lumbar vertebral fractures were chosen between September 2006 and June 2010. The patients were divided into three groups: thoracolumbar/lumbar vertebral fractures without LTPFs, with associated LTPFs, and isolated LTPFs (iLTPFs). The correlation of the NSAIs of different sites and the LTPFs of different segments, amount, and concomitant thoracolumbar/lumbar vertebral fractures were analyzed between and within groups by χ test and logistic regression analysis. RESULTS: The incidence of NSAIs with iLTPFs and aLTFP groups were significantly higher than that of vertebral fractures without LTPF group (55.73% and 64.49% vs. 21.32%, respectively, p = 0.000). However, the incidence was not significantly different between the iLTPFs and the aLTFP groups (p = 0.106). The results with NSAIs of different sites were almost the same. L5TPFs were a stronger risk factor to NSAIs (relative risk [RR] = 15.72; 95% confidence interval [CI], 4.47-55.37; p = 0.000) in the iLTPF group (RR = 21.92; 95% CI, 6.68-71.92; p = 0.000) and in the vertebral fractures with associated LTPF group (RR = 9.42; 95% CI, 1.19-74.72; p = 0.034). L5TPFs were also a very important risk factor for pelvic injuries (RR = 46.10; 95% CI, 22.40-94.88; p = 0.000); 65.1% in L5iTPFs were accompanied with Tile-C pelvic injuries, slightly higher than in L5aTPFs (46.7%). L4TPFs were a risk factor to abdominal injuries within iLTPFs (RR = 2.27; 95% CI, 1.23-4.20; p = 0.009). CONCLUSIONS: The incidence of NSAIs is very high in cases with LTPFs, particularly with L5TPFs. A detailed investigation should be performed to search for NSAIs once LTPFs are identified so that appropriate treatment can be initiated. LEVEL OF EVIDENCE: Level III.

Surgical treatment of complex axis fractures with adjacent segment instability.

This study investigates the clinical and radiographic characteristics of complex axis fractures with adjacent segment instability and describes the outcome of surgical treatment. Twenty-one patients (14 male, seven female; mean age=34 years) with complex axis fractures and adjacent segment instability who were treated between August 2003 and June 2009 were retrospectively reviewed. Treatment selection was based on fracture type and stability of the upper cervical segments. All patients were immobilized with a hard collar for three months after surgery. The mean follow-up period was 12 months (range=6-36 months). No intraoperative surgery-related complications were observed and fusion was achieved in all patients. The outcome was excellent for 17 patients, good for two patients, fair for one patient, and poor for one patient. The upper cervical segments that can become unstable due to complex axis fractures include the atlantoaxial and C2-3 joints. Recommended surgical treatments produce good results.

Combined single-level subtotal corpectomy and decompression for cervical spondylotic myelopathy treatment.

BACKGROUND: The purpose of this study was to summarize outcomes of patients with refractory multisegmental cervical spondylotic myelopathy (CSM) who were treated by combined single-level subtotal corpectomy and decompression of the intervertebral space using the anterior approach. METHODS: Forty-five consecutive patients with multisegmental CSM were included; their ages ranged from 37 to 72 years. Seventeen (37.8%) patients had noncontiguous or 'jumping' multisegmental CSM and 28 (62.2%) had contiguous multisegmental CSM. The mean preoperative Japanese Orthopedic Association (JOA) score was 8.1 points. All patients underwent combined single-level decompression of the involved intervertebral space and subtotal corpectomy together with subsequent fusion and internal fixation. An anterior approach was used for all patients. A cage filled with bone graft was inserted and internal fixation was performed after single-level intervertebral space decompression. Mesh filled with bone graft was inserted and plate internal fixation was performed after subtotal corpectomy. RESULTS: Follow-up data (average follow-up, 14 months) were available for all 45 patients; the mean postoperative JOA score was 13.2 points, which was significantly different from the preoperative JOA score. Bony fusion was achieved in all patients based on postoperative radiography, and no pseudoarthrosis was observed during follow-up. CONCLUSIONS: An excellent outcome can be achieved with the combination of single-level subtotal corpectomy and decompression of the intervertebral space using the anterior approach to treat multisegmental CSM.

RNAi-mediated knockdown of cyclooxygenase2 inhibits the growth, invasion and migration of SaOS2 human osteosarcoma cells: a case control study.

BACKGROUND: Cyclooxygenase2 (COX-2), one isoform of cyclooxygenase proinflammatory enzymes, is responsible for tumor development, invasion and metastasis. Due to its role and frequent overexpression in a variety of human malignancies, including osteosarcoma, COX-2 has received considerable attention. However, the function of COX-2 in the pathogenesis of cancer is not well understood. We examined the role of COX-2 in osteosarcoma. METHODS: We employed lentivirus mediated-RNA interference technology to knockdown endogenous gene COX-2 expression in human osteosarcoma cells (SaOS2) and analyzed the phenotypical changes. The effect of COX-2 treatment on the proliferation, cell cycle, invasion and migration of the SaOS2 cells were assessed using the MTT, flow cytometry, invasion and migration assays, respectively. COX-2, vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), basic fibroblast growth factor (bFGF) mRNA and protein expression were detected by RT-PCR and western blotting. RESULTS: Our results indicate that a decrease of COX-2 expression in human osteosarcoma cells significantly inhibited the growth, decreased the invasion and migration ability of SaOS2 cells. In addition, it also reduced VEGF, EGF and bFGF mRNA and protein expression. CONCLUSIONS: The COX-2 signaling pathway may provide a novel therapeutic target for the treatment of human osteosarcoma.

Posterior short-segmental fixation combined with intermediate screws vs conventional intersegmental fixation for monosegmental thoracolumbar fractures.

Posterior short-segmental fixation is reliable for the management of thoracolumbar fractures; however, it is associated with recurrence of kyphosis and failure of fixation. This study compared the short-term results of short-segmental fixation combined with intermediate screws with those of conventional intersegmental fixation in the treatment of monosegmental thoracolumbar fractures. The records of 62 consecutive patients with thoracolumbar monosegmental fractures who underwent conventional 4-screw intersegmental fixation (35 patients) or short-segmental fixation combined with intermediate screws (27 patients) were reviewed. The study population included 43 men and 19 women (mean age, 44.1±13.6 years). The majority of fractures were L1 (28 [45.1%]) and T12 (21 [33.9%]) fractures. There were no significant differences between the 2 groups with respect to the preoperative relative height of the fractured vertebra or the segmental kyphotic angle. There was a significant difference in the restoration rate between the conventional and short-segmental fixation groups (62.6±38.7% vs 100.4±25.4%, respectively; P<.001). However, a statistically significant decrease in postoperative segmental kyphotic angle was noted in both groups (P<.001). The mean change of segmental kyphotic angle in the short-segmental fixation group was greater than in the conventional fixation group (14.4±6.8° vs 8.3±7.9°, respectively; P<.002). Patients in the short-segmental fixation group ambulated an average of 10 days earlier than those in the conventional fixation group. These findings indicate that compared to conventional intersegmental fixation, short-segmental fixation combined with intermediate screws more effectively restores fractured vertebral height, is associated with a decrease in the segmental kyphotic angle, and allows earlier ambulation.