Safety and Efficacy of Cortical Bone Trajectory Screw Fixation Combined with Facet Fusion for the Treatment of Lumbar Degenerative Disease.

OBJECTIVE: The mainstream lumbar fusion surgeries have various shortcomings, such as complex operation, much invasion, and loss of lumbar function. How to minimize the surgical injury and to achieve better therapeutic effects has become the goal pursued by spine surgeons. This study introduces a cortical bone trajectory (CBT) screw fixation combined with facet fusion (FF), evaluates its safety and efficacy, and explores its advantages, in order to provide a reference for treatment of patients with single-level lumbar stenosis or grade I degenerative spondylolisthesis. METHODS: We retrospectively analyzed the clinical, radiological, and operative data of 167 patients with single-level lumbar stenosis or grade I degenerative spondylolisthesis who underwent FF or transforaminal lumbar interbody fusion (TLIF) from January 2013 to September 2019 in the spine surgery department of the Second Hospital of Shandong University. Patients were divided into four groups according to surgical method: group CBT-FF, CBT screw combined with FF; group PS-FF, pedicle screw (PS) combined with FF; group CBT-TLIF, CBT screw combined with TLIF; and group PS-TLIF, PS combined with TLIF. The operation time, estimated intraoperative blood loss, complications after surgery, visual analog scale (VAS), and Oswestry disability index (ODI) of the four groups were compared. The fusion was evaluated by anteroposterior and lateral X-ray, CT scan, and three-dimensional reconstruction. RESULTS: Twelve months after surgery, the fusion rate of four groups had no significantly statistical differences (p = 0.914). VAS and ODI scores were lower after surgery than before. Low back pain VAS scores 1 week after surgery in group CBT-FF and group CBT-TLIF were significantly lower than those in group PS-FF and group PS-TLIF (pCF/PF = 0.001, pCF/PT = 0.000, pPF/CT = 0.049, pCT/PT = 0.000). Low back pain VAS score 3 months after surgery was significantly lower in group CBT-FF than group PS-FF and group PS-TLIF (pCF/PF = 0.045, pCF/PT = 0.008). ODI score 1 week after surgery was significantly lower in group CBT-FF than group PS-FF, group CBT-TLIF, and group PS-TLIF (pCF/PF = 0.000, pCF/CT = 0.005, pCF/PT = 0.000, pCT/PT = 0.015). ODI score 3 months after surgery was significantly lower in group CBT-FF than group PS-FF, group CBT-TLIF, and group PS-TLIF (pCF/PF = 0.001, pCF/CT = 0.002, pCF/PT = 0.000). Incidence of complications did not significantly differ among the groups. CONCLUSION: CBT screw fixation combined with FF is a safe and efficacious procedure for patients with single-level lumbar stenosis or grade I degenerative spondylolisthesis. This minimally invasive approach of lumbar fusion can be simply and easily performed. Patients who undergo CBT screw fixation combined with FF recovered faster than TLIF.

C1-ring osteosynthesis versus C1-2 fixation fusion in the treatment of unstable atlas fractures: a multicenter, prospective, randomized controlled study with 5-year follow-up.

OBJECTIVE: The aim of the present study was to compare the long-term effects of posterior C1-ring osteosynthesis and C1-2 fixation fusion in the treatment of unstable atlas fractures. METHODS: A multicenter, prospective, randomized controlled trial was conducted to analyze 73 patients with atlas fractures who underwent posterior fixation. The intervention group was treated with C1-ring osteosynthesis, and the control group was treated with C1-2 fixation fusion. The patients were followed up for 6 months, 1 year, 2 years, and 5 years after the operation. RESULTS: Fifty-two patients had complete data at the last follow-up. The visual analog scale (VAS) score for neck pain in the intervention group was lower than that in the control group (p < 0.001). The operation time, intraoperative blood loss, radiation dose, bedridden period, hospital stay, and cost in the intervention group were significantly lower than those in the control group (p < 0.001). At the last follow-up, the Neck Disability Index in the intervention group was higher than that of the control group, and the angle of flexion-extension and axial rotation in the intervention group were greater than those in the control group (p < 0.001). CONCLUSIONS: In this study, the authors found that posterior C1-ring osteosynthesis is superior to C1-2 fixation fusion in terms of long-term relief of neck pain and preservation of the physiological function of the cervical vertebrae. This technique is a reliable choice for the treatment of unstable C1 fractures.

Cryogel biocomposite containing chitosan-gelatin/cerium-zinc doped hydroxyapatite for bone tissue engineering.

The present examination includes manufacture and portrayal of cryogel bio-composite implants containing chitosan-gelatin (CS-GT), cerium-zinc doped hydroxyapatite (CS-GT/Ce-Zn-HA) by cryogelation technique. The prepared cryogel biocomposites (CS-GT/HA and CS-GT/Ce-Zn-HA) were described by scanning electron microscope (SEM) and X-Ray diffraction (XRD) contemplates. The expansion of Ce-Zn in the CS-GT implants essentially expanded growing, diminished swelling, expanded protein sorption, and expanded bactericidal movement. The CS-GT/Ce-Zn-HA biocomposite had non-toxic towards rodent osteoblast cells. So the created CS-GT/Ce-Zn-HA biocomposite has favorable and potential applications over the CS-GT/HA platforms for bone tissue engineering.

Source apportionment and source-to-sink transport of major and trace elements in coastal sediments: Combining positive matrix factorization and sediment trend analysis.

Major and trace elemental concentrations in coastal marine sediments were incorporated into positive matrix factorization (PMF) to identify potential sources and source contributions. Transport pathways of fine-grained sediments and sediment-bound elements were inferred from sediment trend analysis (STA). The spatial distribution patterns of 21 elements (Co, Cu, Ni, Sr, Zn, V, Ba, Sc, Ga, Pb, Cr, Zr, SiO2, Al2O3, Fe2O3, MgO, CaO, K2O, MnO, TiO2, and P2O5) coupled with sediment grain sizes were investigated. The natural and anthropogenic sources of the elements were distinguished by their medium enrichment factors (EFs). Seven sources were recognized by PMF: weathering products, anthropologic emissions, sand, older sediment, biogenic carbonates, products of siliceous organisms, and mine exploitation. Some land-derived elements, including weathering products, anthropogenic-related elements, and mining-related elements, had a significant positive correlation with sediment silt, clay, and organic carbon contents. The spatial patterns of the land-derived elements' concentrations and source contributions were consistent with the sediment transport pathways inferred from the STA. This result revealed that the delivery of the land-derived elements was determined by marine current flows and the associated sediment transport processes. Conversely, elements originating from marine sources, such as sand and older sediment, and from the biological activities of calcareous and siliceous organisms showed little response to sediment transport and deposition processes. Our study links the outputs of statistically oriented approaches (e.g., PMF) to a process-based understanding of elemental transport in marine environments.

Using self-organizing map for coastal water quality classification: Towards a better understanding of patterns and processes.

Self-organizing map (SOM) was used to explore the spatial characteristics of water quality in the middle and southern Fujian coastal area. Nineteen water quality variables (temperature, salinity, pH, dissolved oxygen, alkalinity, chemical oxygen demand, nutrients NH4-N, H2SiO3, PO4-, NO2-, and NO3-, heavy metals/metalloid Cu, Zn, As, Cd, Pb, Hg, and Cr6+, and oil) were measured in the surface, middle, and bottom water layers at 94 different sampling sites. Patterns of water quality variables were visualized by the SOM planes, and similar patterns were observed for those variables that correlated with each other, indicating a common source. pH, COD, As, Hg, Pb, and Cr6+ likely originated from industries, while nutrients NH4-N, NO2-, NO3-, and PO43- were mainly attributed to agriculture and aquaculture. The k-means clustering in the SOM grouped the water quality data into nine clusters, which revealed three representative water types, ranging from low salinity to high salinity with different levels of heavy metal/metalloid pollution and nutrient pollution. Spatial changes in water quality reflected the impacts of natural factors (riverine outflows, tides, and alongshore currents), as well as anthropogenic activities (mariculture, industrial and urban discharges, and agricultural effluents). Principal component analysis (PCA) confirmed the clustering results obtained by SOM, while the latter provides a more detailed classification and additional information about the dominant variables governing the classification processes. The results of this study suggest that SOM is an effective tool for a better understanding of patterns and processes driving water quality.

FLVCR1 promotes the proliferation and tumorigenicity of synovial sarcoma through inhibiting apoptosis and autophagy.

Feline leukemia virus subgroup C receptor 1 (FLVCR1) has been reported to have a crucial role in variety of biological processes, including cell proliferation, cell death, apoptosis, oxidative stress response, cellular differentiation and metabolism. However, little is known about its role in synovial sarcoma (SS). In the current study, FLVCR1 expression was analyzed in two SS cell lines (SW982 and HS-SY-II), and in eight SS tissues and paired adjacent non-tumor tissues using reverse transcription-quantitative polymerase chain reaction, western blot analysis and immunohistochemistry. Lentivirus-mediated short hairpin RNAs were used to knock down FLVCR1 expression in SW982 and HS-SY-II cells. The effects of FLVCR1 knockdown on the cell proliferation, clonogenicity, cell cycle and apoptosis in SS cells were evaluated by MTT, colony formation assay, flow cytometry analysis, western blotting and in vivo tumorigenesis in nude mice. In the current study, gene expression of FLVCR1 was upregulated in SS cell lines (SW982 and HS-SY-II) and SS tissues from patients. The protein levels of FLVCR1 in SS tissues were also significantly higher than in adjacent non-tumor tissues. Furthermore, suppressing the expression of FLVCR1 in SS cells using short hairpin RNA effectively attenuated cell proliferation, colony formation and impaired the cell cycle, and also significantly induced apoptosis and autophagy. In accordance with this, an in vivo tumorigenicity assay in mice demonstrated that suppression of FLVCR1 expression inhibited the growth of SS tumors implanted subcutaneously. Collectively, these results demonstrated that FLVCR1 may act as an oncoprotein, and have key roles in promoting proliferation and tumorigenicity of SS, and this may shed new light on finding novel therapeutic strategies against SS.

Identification of SHCBP1 as a novel downstream target gene of SS18-SSX1 and its functional analysis in progression of synovial sarcoma.

The SS18-SSX1 fusion gene has been shown to play important roles in the development of synovial sarcoma (SS), but the underlying molecular mechanisms and its downstream target genes are still not clear. Here SHC SH2-domain binding protein 1 (SHCBP1) was identified and validated to be a novel downstream target gene of SS18-SSX1 by using microarray assay, quantitative real-time (qPCR) and western blot. Expression of SHCBP1 was firstly confirmed in SS cell line and SS tissues. The effects of SHCBP1 overexpression or knockdown on SS cell proliferation and tumorigenicity were then studied by cell proliferation, DNA replication, colony formation, flow cytometric assays, and its in vivo tumorigenesis was determined in the nude mice. Meanwhile, the related signaling pathways of SHCBP1 were also examined in SS cells. The results indicated that SHCBP1 was significantly increased in SS cells and SS tissues compared with adjacent noncancerous tissues. The expression of SHCBP1 was demonstrated to be positively correlated with the SS18-SSX1 level. Overexpression and ablation of SHCBP1 promoted and inhibited, respectively, the proliferation and tumorigenicity of SS cells in vitro. SHCBP1 knockdown also significantly inhibited SS cell growth in nude mice, and lowered the MAPK/ERK and PI3K/AKT/mTOR signaling pathways and cyclin D1 expression. Our findings disclose that SHCBP1 is a novel downstream target gene of SS18-SSX1, and demonstrate that the oncogene SS18-SSX1 promotes tumorigenesis by increasing the expression of SHCBP1, which normally acts as a tumor promoting factor.

Inferring sources of polycyclic aromatic hydrocarbons (PAHs) in sediments from the western Taiwan Strait through end-member mixing analysis.

Concentration, spatial distribution, composition and sources of polycyclic aromatic hydrocarbons (PAHs) were investigated based on measurements of 16 PAH compounds in surface sediments of the western Taiwan Strait. Total PAH concentrations ranged from 2.41 to 218.54ngg-1. Cluster analysis identified three site clusters representing the northern, central and southern regions. Sedimentary PAHs mainly originated from a mixture of pyrolytic and petrogenic in the north, from pyrolytic in the central, and from petrogenic in the south. An end-member mixing model was performed using PAH compound data to estimate mixing proportions for unknown end-members (i.e., extreme-value sample points) proposed by principal component analysis (PCA). The results showed that the analyzed samples can be expressed as mixtures of three end-members, and the mixing of different end-members was strongly related to the transport pathway controlled by two currents, which alternately prevail in the Taiwan Strait during different seasons.

Inhibition of monocyte chemoattractant peptide-1 decreases secondary spinal cord injury.

Previous studies have suggested that impairment secondary to mechanical injury is a major cause of irreversible damage to the spinal cord. Inflammatory chemokines have been shown to play an important role in the pathological and physiological consequences of secondary spinal cord injury (SCI). The aim of the present study was to evaluate how changes in the expression levels of the cellular chemokine, monocyte chemoattractant peptide-1 (MCP-1), and the chemotaxis of inflammatory cells (monocytes and macrophages) are involved in the process of SCI. RNA interference methods were used to study the mechanisms that protect residual neurons after SCI in an attempt to explore novel, early interventions for managing SCI. Our results suggested that inhibiting inflammation alleviates nerve cell injury caused by apoptosis and provides a potentially important approach for the future treatment of secondary SCI.

Sciatic nerve regeneration using a nerve growth factor-containing fibrin glue membrane.

Our previous findings confirmed that the nerve growth factor-containing fibrin glue membrane provides a good microenvironment for peripheral nerve regeneration; however, the precise mechanism remains unclear. p75 neurotrophin receptor (p75(NTR)) plays an important role in the regulation of peripheral nerve regeneration. We hypothesized that a nerve growth factor-containing fibrin glue membrane can promote neural regeneration by up-regulating p75(NTR) expression. In this study, we used a silicon nerve conduit to bridge a 15 mm-long sciatic nerve defect and injected a mixture of nerve growth factor and fibrin glue at the anastomotic site of the nerve conduit and the sciatic nerve. Through RT-PCR and western blot analysis, nerve growth factor-containing fibrin glue membrane significantly increased p75(NTR) mRNA and protein expression in the Schwann cells at the anastomotic site, in particular at 8 weeks after injection of the nerve growth factor/fibrin glue mixture. These results indicate that nerve growth factor-containing fibrin glue membrane can promote peripheral nerve regeneration by up-regulating p75(NTR) expression in Schwann cells.

[Promoting of angiogenesis and osteogenesis in radial critical bone defect regions of rabbits with nano-hydroxyapatite/collagen/PLA scaffolds plus endothelial progenitor cells].

OBJECTIVE: To explore the roles of nano-hydroxyapatite/collagen/PLA (nHAC/PLA) plus endothelial progenitor cells (EPCs) in repairing segmental bone defects of rabbit radius and enhancing angiogenesis and new bone formation. METHODS: EPCs isolated from New Zealand white rabbit bone marrow were cultured, identified and seeded into nHAC/PLA scaffolds. And the growth of EPCs in scaffolds was observed under scanning electron microscopy (SEM). Thirty-six were randomly divided into 3 groups to establish segmental bone defect models in radii. Two groups were implanted with EPCs/scaffolds constructs (group A, n = 16) and scaffolds alone (group B, n = 16) respectively. The remaining four rabbits were used as negative control (group C) and nothing was implanted. Animals were sacrificed at different timepoints and radii harvested to undergo radiological examination, histological examination and microvessle density test. RESULTS: These cells isolated from bone marrow were confirmed as EPCs. SEM showed that EPCs attached to the nHAC/PLA scaffolds, grew and proliferated well. Animal experiments revealed that radiological scores (5w: 2.25 ± 0.50 vs 1.00 ± 0.00; 10w: 2.75 ± 0.50 vs 1.75 ± 0.50; 15w: 4.25 ± 0.50 vs 3.0 ± 0.0; each P < 0.05), percentage of new bone formation area in bone defect regions (5w: 29.0% ± 3.5% vs 8.1% ± 0.8%; 10w: 63.4% ± 5.5% vs 16.6% ± 1.3%; 15w: 96.0% ± 4.3% vs 34.0% ± 6.6%; each P < 0.05) and microvessel density (2w: 13.5 ± 0.9 vs 4.3 ± 1.0; 5w:9.8 ± 0.7 vs 4.8 ± 0.3; 10w: 7.0 ± 0.4 vs 4.5 ± 0.4; each P < 0.05) in group A were significantly higher than those in group B. No new bone formation occurred in group C. CONCLUSION: The composite structure of EPCs-nHAC/PLA can enhance angiogenesis and new bone formation in segmental bone defects in rabbit radii. It may become a potential candidate of promoting revascularization of tissue engineering bone and repairing large bone defects.

[Influence of minor back trauma on surgical outcomes in patients with thoracic ossification of ligamentum flavum].

OBJECTIVE: To retrospectively explore the influences of minor back trauma on surgical outcomes in patients with thoracic ossification of ligamentum flavum (TOLF) and preliminarily detect its possible causes. METHODS: A total of 94 TOLF patients were divided into two groups according to the absence or presence of minor back trauma: MT (minor trauma, n = 16) and NT (no trauma, n = 78). They were compared in terms of gender, age, duration of symptoms, levels of involvement, numbers of involved segments, ratio of intramedullary signal changes (IMSC), pre- & post-operative JOA (Japanese Orthopedic Association) score, recovery rate (RR) at the final follow-up. Multiple regression analysis was employed to elucidate the causes related with the surgical outcomes. The MT group was further divided into two subgroups according to the intervals between trauma and surgery to clarify the influences of surgical timing on the efficacies. RESULTS: The JOA scores were 4.0 ± 1.4 and 8.4 ± 1.7 respectively in MT and NT groups at the final follow-up. The neurological status of patients improved in both groups (MT: P = 0.009, NT: P = 0.000). The patients were younger in MT groups (50 ± 11 years) than those in NT groups (58 ± 8 years) (P = 0.046). The ratio of IMSC was higher in MT groups (75.0%) than that in NT groups (25.6%) (P = 0.000). The pre- & post-operative JOA scores were lower in MT groups than those in NT groups (both P = 0.000). Multiple regression analysis revealed that the postoperative JOA score at the final follow-up was positively related with the preoperative JOA score (r = 0.60, P = 0.000) and negatively with trauma and IMSC (r = -1.82 and r = -1.87, P = 0.000) while the final postoperative RR were negatively related with trauma and IMSC (r = -26.26 and r = -33.70, P = 0.000). The surgical timing after trauma did not influence the efficacies (P = 0.147). CONCLUSION: The TOLF patients with minor back trauma have a worse post-operative recovery. A minor trauma might be a risk factor of adverse surgical outcomes.

Siatic nerve regeneration in rats stimulated by fibrin glue containing nerve growth factor: an experimental study.

OBJECTIVE: To study the effects of fibrin sealant containing nerve growth factor on the peripheral nerve regeneration. STUDY DESIGN: A four-group experimental design with repeated measures on one factor was used. METHODS: Fibrin glue (FG) containing NGF was injected into the site of end-and-end sutured peripheral nerve (sciatic nerve) (group I: NGF+FG), meanwhile three control groups were set-up: group II (NGF), group III (FG), and group IV (normal saline). Observation to the function and morphology of the sciatic nerve was carried out at the end of 4, 8, 12 weeks postoperation. Data were analyzed using ANOVA, with the appropriate post hoc between-groups comparison test. RESULTS: Electrophysiological testing. The NAP and NCV of group I (NGF+FG) were greater than those of group II (NGF), group III (FG), or group IV (normal saline) (p<0.05). Sciatic functional index (SFI). It began to ameliorate at 4 weeks postoperation and SFI increased as time went on. And the SFI in group I (NGF+FG) was better than those in group II (NGF), group III (FG), or group IV (normal saline) (p<0.05). Morphology. In the MGF-stained sections, dissociated myelin debris was less and regenerated nerve fibres were in larger quantities in group I (NGF+FG) than in other groups. In the HE-stained sections, regenerated nerve fibres distal to anastomosis significantly increased, and axon and myelin had a clearer outline in group I (NGF+FG) than in other groups. Electron microscopy indicated that the regenerated nerve fibres were more mature and the development of the axons was greater in group I than in other control groups. CONCLUSIONS: FG can be used as carrier of exogenous NGF, and they can provide synergistic effects for the peripheral nerve regeneration after the integration of the two.

Posterior lumbar interbody fusion using one diagonal fusion cage with transpedicular screw/rod fixation.

Posterior lumbar interbody fusion (PLIF) using threaded cages has gained wide popularity for lumbosacral spinal disease. Our biomechanical tests showed that PLIF using a single diagonal cage with unilateral facetectomy does add a little to spinal stability and provides equal or even higher postoperative stability than PLIF using two posterior cages with bilateral facetectomy. Studies also demonstrated that cages placed using a posterior approach did not cause the same increase in spinal stiffness seen with pedicle screw instrumentation, and we concluded that cages should not be used posteriorly without other forms of fixation. On the other hand, placement of two cages using a posterior approach does have the disadvantage of risk to the bilateral nerve roots. We therefore performed a prospective study to determine whether PLIF can be accomplished by utilizing a single diagonal fusion cage with the application of supplemental transpedicular screw/rod instrumentation. Twenty-seven patients underwent a PLIF using one single fusion cage (BAK, Sulzer Spine-Tech, Minneapolis, MN, USA) inserted posterolaterally and oriented anteromedially on the symptomatic side with unilateral facetectomy and at the same level supplemental fixation with a transpedicular screw/rod system. The internal fixation systems included 12 SOCON spinal systems (Aesculap AG, Germany) and 15 TSRH spinal systems (Medtronic Sofamor Danek, USA). The inclusion criteria were grade 1 to 2 lumbar isthmic spondylolisthesis, lumbar degenerative spondylolisthesis, and recurrent lumbar disc herniations with instability. Patients had at least 1 year of low back pain and/or unilateral sciatica and a severely restricted functional ability in individuals aged 28-55 years. Patients with more than grade 2 spondylolisthesis or adjacent-level degeneration were excluded from the study. Patients were clinically assessed prior to surgery by an independent assessor; they were then reassessed at 1, 3, 6, 12, 18, and 24 months postoperatively by the same assessor and put into four categories: excellent, good, fair, and poor. Operative time, blood loss, hospital expense, and complications were also recorded. All patients achieved successful radiographic fusion at 2 years, and this was achieved at 1 year in 25 out of 27 patients. At 2 years, clinical results were excellent in 15 patients, good in 10, fair in 1, and poor in 1. Regarding complications, one patient had a postoperative motor and sensory deficit of the nerve root. Reoperation was required in one patient due to migration of pedicle screws. No implant fractures or deformities occurred in any of the patients. PLIF using diagonal insertion of a single threaded cage with supplemental transpedicular screw/rod instrumentation enables sufficient decompression and solid interbody fusion to be achieved with minimal invasion of the posterior spinal elements. It is a clinically safer, easier, and more economical means of accomplishing PLIF.