Au Nanorods Activated the Zn/Ce Composites with Cancer Cell Specific Cytotoxicity for Enhanced Chemodynamic Therapy.

Chemodynamic therapy based on the Fenton reaction has been developed as an extremely promising modality for cancer therapeutics. In this study, a core-shell structure nanoplatform was constructed by a Au nanorod externally encapsulating Ce/Zn-based composites (ACZO). The nanoparticles can catalyze the generation of reactive oxygen species (ROS) under acidic conditions and effectively consume existing glutathione (GSH) to destroy the redox balance within the tumor. Moreover, the decomposition of the nanocomplexes under acidic conditions releases large amounts of zinc ions, leading to zinc overload in cancer cells. The photothermal effect generated by the Au nanorods not only provides photothermal therapy (PTT) but also augments the catalytic reaction and ions action mentioned above. This facile strategy to improve the efficacy of chemodynamic therapy by the photothermal enhancement of catalytic activity and zinc ion release provides a promising perspective for potential tumor treatment.

The enhanced connectivity between the frontoparietal, somatomotor network and thalamus as the most significant network changes of chronic low back pain.

The prolonged duration of chronic low back pain (cLBP) inevitably leads to changes in the cognitive, attentional, sensory and emotional processing brain regions. Currently, it remains unclear how these alterations are manifested in the interplay between brain functional and structural networks. This study aimed to predict the Oswestry Disability Index (ODI) in cLBP patients using multimodal brain magnetic resonance imaging (MRI) data and identified the most significant features within the multimodal networks to aid in distinguishing patients from healthy controls (HCs). We constructed dynamic functional connectivity (dFC) and structural connectivity (SC) networks for all participants (n = 112) and employed the Connectome-based Predictive Modeling (CPM) approach to predict ODI scores, utilizing various feature selection thresholds to identify the most significant network change features in dFC and SC outcomes. Subsequently, we utilized these significant features for optimal classifier selection and the integration of multimodal features. The results revealed enhanced connectivity among the frontoparietal network (FPN), somatomotor network (SMN) and thalamus in cLBP patients compared to HCs. The thalamus transmits pain-related sensations and emotions to the cortical areas through the dorsolateral prefrontal cortex (dlPFC) and primary somatosensory cortex (SI), leading to alterations in whole-brain network functionality and structure. Regarding the model selection for the classifier, we found that Support Vector Machine (SVM) best fit these significant network features. The combined model based on dFC and SC features significantly improved classification performance between cLBP patients and HCs (AUC=0.9772). Finally, the results from an external validation set support our hypotheses and provide insights into the potential applicability of the model in real-world scenarios. Our discovery of enhanced connectivity between the thalamus and both the dlPFC (FPN) and SI (SMN) provides a valuable supplement to prior research on cLBP.

Biomechanical changes of oblique lumbar interbody fusion with different fixation techniques in degenerative spondylolisthesis lumbar spine: a finite element analysis.

OBJECTIVE: There is a dearth of comprehensive research on the stability of the spinal biomechanical structure when combining Oblique Lumbar Interbody Fusion (OLIF) with internal fixation methods. Hence, we have devised this experiment to meticulously examine and analyze the biomechanical changes that arise from combining OLIF surgery with different internal fixation techniques in patients diagnosed with degenerative lumbar spondylolisthesis. METHODS: Seven validated finite element models were reconstructed based on computed tomography scan images of the L3-L5 segment. These models included the intact model, a stand-alone (S-A) OLIF model, a lateral screw rod (LSR) OLIF model, a bilateral pedicle screw (BPS) OLIF model, an unilateral pedicle screw (UPS) OLIF model, a bilateral CBT (BCBT) OLIF model, and an unilateral CBT(UCBT) OLIF model. The range of motion (ROM), as well as stress levels in the cage, L4 lower endplate, L5 upper endplate, and fixation constructs were assessed across these different model configurations. RESULTS: S-A model had the highest average ROM of six motion modes, followed by LSR, UPS, UCBT, BPS and BCBT. The BCBT model had a relatively lower cage stress than the others. The maximum peak von Mises stress of the fixation constructs was found in the LSR model. The maximum peak von Mises stress of L4 lower endplate was found in the S-A model. The peak von Mises stress on the L4 lower endplate of the rest surgical models showed no significant difference. The maximum peak von Mises stress of the L5 upper endplate was found in the S-A model. The minimum peak von Mises stress of the L5 upper endplate was found in the BCBT model. No significant difference was found for the peak von Mises stress of the L5 upper endplate among LSR, BPS, UPS and UCBT models. CONCLUSION: Among the six different fixation techniques, BCBT exhibited superior biomechanical stability and minimal stress on the cage-endplate interface. It was followed by BPS, UCBT, UPS, and LSR in terms of effectiveness. Conversely, S-A OLIF demonstrated the least stability and resulted in increased stress on both the cage and endplates. Combining OLIF with BCBT fixation technique enhanced biomechanical stability compared to BPS and presented as a less invasive alternative treatment for patients with degenerative lumbar spondylolisthesis.

Hoffmann's sign in cervical spondylotic myelopathy patients: pathological insights from neuroimaging.

OBJECTIVE: Hoffmann's sign testing is a commonly used physical examination in clinical practice for patients with cervical spondylotic myelopathy (CSM). However, the pathophysiological mechanisms underlying its occurrence and development have not been thoroughly investigated. Therefore, the present study aimed to explore whether a positive Hoffmann's sign (PHS) in CSM patients is associated with spinal cord and brain remodeling and to identify potential neuroimaging biomarkers with diagnostic value. METHODS: Seventy-six patients with CSM and 40 sex- and age-matched healthy controls (HCs) underwent multimodal MRI. Based on the results of the Hoffmann's sign examination, patients were divided into two groups: those with a PHS (n = 38) and those with a negative Hoffmann's sign (NHS; n = 38). Quantification of spinal cord and brain structural and functional parameters of the participants was performed using various methods, including functional connectivity analysis, voxel-based morphometry, and atlas-based analysis based on functional MRI and structural MRI data. Furthermore, this study conducted a correlation analysis between neuroimaging metrics and neurological function and utilized a support vector machine (SVM) algorithm for the classification of PHS and NHS. RESULTS: In comparison with the NHS and HC groups, PHS patients exhibited significant reductions in the cross-sectional area and fractional anisotropy (FA) of the lateral corticospinal tract (CST), reticulospinal tract (RST), and fasciculus cuneatus, concomitant with bilateral reductions in the volume of the lateral pallidum. The functional connectivity analysis indicated a reduction in functional connectivity between the left lateral pallidum and the right angular gyrus in the PHS group. The correlation analysis indicated a significant positive association between the CST and RST FA and the volume of the left lateral pallidum in PHS patients. Furthermore, all three variables exhibited a positive correlation with the patients' motor function. Finally, using multimodal neuroimaging metrics in conjunction with the SVM algorithm, PHS and NHS were classified with an accuracy rate of 85.53%. CONCLUSIONS: This research revealed a correlation between structural damage to the pallidum and RST and the presence of Hoffmann's sign as well as the motor function in patients with CSM. Features based on neuroimaging indicators have the potential to serve as biomarkers for assessing the extent of neuronal damage in CSM patients.

Clinical application of spinal robot in cervical spine surgery: safety and accuracy of posterior pedicle screw placement in comparison with conventional freehand methods.

The novel robot-assisted (RA) technique has been utilized increasingly to improve the accuracy of cervical pedicle screw placement. Although the clinical application of the RA technique has been investigated in several case series and comparative studies, the superiority and safety of RA over conventional freehand (FH) methods remain controversial. Meanwhile, the intra-pedicular accuracy of the two methods has not been compared for patients with cervical traumatic conditions. This study aimed to compare the rate and risk factors of intra-pedicular accuracy of RA versus the conventional FH approach for posterior pedicle screw placement in cervical traumatic diseases. A total of 52 patients with cervical traumatic diseases who received cervical screw placement using RA (26 patients) and FH (26 patients) techniques were retrospectively included. The primary outcome was the intra-pedicular accuracy of cervical pedicle screw placement according to the Gertzbin-Robbins scale. Secondary outcome parameters included surgical time, intraoperative blood loss, postoperative drainage, postoperative hospital stay, and complications. Moreover, the risk factors that possibly affected intra-pedicular accuracy were assessed using univariate analyses. Out of 52 screws inserted using the RA method, 43 screws (82.7%) were classified as grade A, with the remaining 7 (13.5%) and 2 (3.8%) screws classified as grades B and C. In the FH cohort, 60.8% of the 79 screws were graded A, with the remaining screws graded B (21, 26.6%), C (8, 10.1%), and D (2, 2.5%). The RA technique showed a significantly higher rate of optimal intra-pedicular accuracy than the FH method (P = 0.008), but there was no significant difference between the two groups in terms of clinically acceptable accuracy (P = 0.161). Besides, the RA technique showed remarkably longer surgery time, less postoperative drainage, shorter postoperative hospital stay, and equivalent intraoperative blood loss and complications than the FH technique. Furthermore, the univariate analyses showed that severe obliquity of the lateral atlantoaxial joint in the coronal plane (P = 0.003) and shorter width of the lateral mass at the inferior margin of the posterior arch (P = 0.014) were risk factors related to the inaccuracy of C1 screw placement. The diagnosis of HRVA (P < 0.001), severe obliquity of the lateral atlantoaxial joint in the coronal plane (P < 0.001), short pedicle width (P < 0.001), and short pedicle height (P < 0.001) were risk factors related to the inaccuracy of C2 screw placement. RA cervical pedicle screw placement was associated with a higher rate of optimal intra-pedicular accuracy to the FH technique for patients with cervical traumatic conditions. The severe obliquity of the lateral atlantoaxial joint in the coronal plane independently contributed to high rates of the inaccuracy of C1 and C2 screw placements. RA pedicle screw placement is safe and useful for cervical traumatic surgery.

Characteristics and evaluation of C1 posterior arch variation for transpedicular screw placement between patients with and without basilar invagination.

BACKGROUND: C1 transpedicular screw (C1TS) placement provided satisfactory pullout resistance and 3D stability, but its application might be limited in patients with basilar invagination (BI) due to the high incidences of the atlas anomaly and vertebral artery (VA) variation. However, no study has explored the classifications of C1 posterior arch variations and investigated their indications and ideal insertion trajectories for C1TS in BI. PURPOSE: To investigate the bony and surrounding arterial characteristics of the atlas, classify posterior arch variations, identify indications for C1TS, evaluate ideal insertion trajectories for C1TS in BI patients without atlas occipitalization (AO), and compare them with those without BI and AO as control. METHODS: A total of 130 non-AO patients with and without BI (52 patients and 78 patients, respectively) from two medical centers were included at a 1:1.5 ratio. The posterior arch variations were assessed using a modified C1 morphological classification. Comparisons regarding the bony and surrounding arterial characteristics, morphological classification distributions, and ideal insertion trajectories between BI and control groups were performed. The subgroup analyses based on different morphological classifications were also conducted. In addition, the factors possibly affecting the insertion parameters were investigated using multiple linear regression analyses. RESULTS: The BI group was associated with significantly smaller lateral mass height and width, sagittal length of posterior arch, pedicle height, vertical height of posterior arch, and distance between VA and VA groove (VAG) than control group. Four types of posterior arch variations with indications for different screw placement techniques were classified; Classifications I and II were suitable for C1TS. The BI cohort showed a significantly lower rate of Classification I than the control cohort. In the BI group, the subgroup of Classification I had significantly larger distance between the insertion point (IP) and inferior aspect of the posterior arch. In addition, it had the narrowest width along ideal screw trajectory, but a significantly more lateral ideal mediolateral angle than the subgroup of Classification II. Multiple linear regression indicated that the cephalad angle was significantly associated with the diagnosis of BI (B = 3.708, P < 0.001) and sagittal diameter of C1 (B = 3.417, P = 0.027); the ideal mediolateral angle was significantly associated with BMI (B = 0.264, P = 0.031), sagittal diameter of C1 (B = - 4.559, P = 0.002), and pedicle height (B = - 2.317, P < 0.001); the distance between the IP and inferior aspects of posterior arch was significantly associated with age (B = - 0.002, P = 0.035), BMI (B = - 0.007, P = 0.028), sagittal length of posterior arch (B = - 0.187, P = 0.032), pedicle height (B = - 0.392, P < 0.001), and middle and lower parts of posterior arch (B = 0.862, P < 0.001). CONCLUSION: The incidence of posterior arch variation in BI patients without AO was remarkably higher than that in control patients. The insertion parameters of posterior screws were different between the morphological classification types in BI and control groups. The distance between VA V3 segments and VAG in BI cohort was substantially smaller than that in control cohort. Preoperative individual 3D computed tomography (CT), CT angiography and intraoperative navigation are recommended for BI patients receiving posterior screw placement.

Posterior osteosynthesis with a new self-designed lateral mass screw-plate system for unstable atlas burst fractures.

BACKGROUND: In the treatment of unstable atlas fractures using the combined anterior-posterior approach or the posterior monoaxial screw-rod system, factors such as severe trauma or complex surgical procedures still need to be improved despite the favourable reduction effect. This research described and evaluated a new technique for the treatment of unstable atlas fracture using a self-designed lateral mass screw-plate system. METHODS: A total of 10 patients with unstable atlas fractures using this new screw-plate system from January 2019 to December 2021 were retrospectively reviewed. All patients underwent posterior open reduction and internal fixation (ORIF) with a self-designed screw-plate system. The medical records and radiographs before and after surgery were noted. Preoperative and postoperative CT scans were used to determine the type of fracture and evaluate the reduction of fracture. RESULTS: All 10 patients were successfully operated with this new system, with an average follow-up of 16.7 ± 9.6 months. A total of 10 plates were placed, and all 20 screws were inserted into the atlas lateral masses. The mean operating time was 108.7 ± 20.1 min and the average estimated blood loss was 98.0 ± 41.3 ml. The lateral mass displacement (LMD) averaged 7.1 ± 1.9 mm before surgery and almost achieved satisfactory reduction after surgery. All the fractures achieved bony healing without reduction loss or implant failure. No complications (vertebral artery injury, neurologic deficit, or wound infection) occurred in these 10 patients. At the final follow-up, the anterior atlantodens interval (AADI) was 2.3 ± 0.8 mm and the visual analog scale (VAS) was 0.6 ± 0.7 on average. All patients preserved almost full range of motion of the upper cervical spine and achieved a good clinical outcome at the last follow-up. CONCLUSIONS: Posterior osteosynthesis with this new screw-plate system can provide a new therapeutic strategy for unstable atlas fractures with simple and almost satisfactory reduction.

Medium and long-term radiographic and clinical outcomes of Dynesys dynamic stabilization versus instrumented fusion for degenerative lumbar spine diseases.

BACKGROUND: Dynesys stabilization (DS) is utilized to preserve mobility at the instrumental segments and prevent adjacent segment pathology in clinical practice. However, the advantages of DS method in medium and long-term follow-up remain controversial. OBJECTIVE: To compare the radiographic and clinical outcomes between DS and instrumented fusion in the treatment of degenerative lumbar spine disease with or without grade I spondylolisthesis with a minimum follow-up period of 2 years. METHODS: We conducted a comprehensive search of PubMed, EMBASE, Cochrane, and Web of Science databases, Chinese National Knowledge Databases, and Wanfang Database for potentially eligible articles. Clinical outcomes were assessed in terms of VAS and ODI scores, screw loosening and breakage, and surgical revision. Radiographic outcomes were assessed in terms of postoperative range of movement (ROM) and disc heigh. Moreover, adjacent segment degeneration (ASDeg) and adjacent segment disease (ASDis) were evaluated. RESULTS: Seventeen studies with 1296 patients were included in the meta-analysis. The DS group was associated with significantly lower postoperative VAS scores for low-back and leg pain, and lower rate of surgical revision than the fusion group. Moreover, the Dynesys group showed significantly less ASDeg than the fusion group but showed no significant advantage over the fusion group in terms of preventing ASDis. Additionally, the ROM at the stabilized segments of the fusion group decreased significantly and that at the adjacent segments increased significantly compared with those of the DS group. CONCLUSION: DS showed comparable clinical outcomes and provided benefits in preserving the motion at the stabilized segments, thus limiting the hypermobility at the adjacent segments and preventing ASDeg compared with the fusion method in degenerative disease with or without grade I spondylolisthesis.

High levels of TDO2 in relation to pro-inflammatory cytokines in synovium and synovial fluid of patients with osteoarthritis.

BACKGROUND: Tryptophan 2,3-dioxygenase (TDO2) is the primary enzyme that catabolizes tryptophan to kynurenine. Numerous studies have suggested that TDO2 is involved in inflammation-related diseases. However, its role in osteoarthritis (OA) has not yet been investigated. The aim of the present study was to explore the levels of TDO2 in the synovium and synovial fluid (SF) of patients with OA and its correlation with clinical manifestations and levels of pro-inflammatory cytokines.  METHODS : Synovium and SF samples were collected from patients with OA and patients with joint trauma (controls) during surgery. An enzyme-linked immunosorbent assay (ELISA) was used to measure TDO2, interleukin-1ß (IL-1ß), and tumor necrosis factor-α (TNF-α) levels in the synovium and SF. Diagnostic performance of TDO2 in the synovium to discriminate between controls and OA patients was assessed using receiver operating characteristic (ROC) curve analysis. Correlations between TDO2 levels, OA clinical features, and pro-inflammatory cytokines were evaluated using Pearson correlation analysis. Effects of IL-1ß or TNF-α stimulation on TDO2 expression in OA-fibroblast-like synoviocytes (OA-FLS) were also examined. RESULTS: The levels of TDO2, IL-1ß, and TNF-α in the synovium of patients with OA were found to be significantly higher than those in controls. ROC curve analysis revealed an area under the curve (AUC) of 0.800 with 64.3% sensitivity and 85.0% specificity of TOD2 in the synovium, which enabled discriminating patients with OA from controls. Moreover, protein expression of TDO2 was upregulated to a greater extent in OA-FLS than in normal synovial fibroblasts (NSF). Furthermore, the levels of TDO2 showed significantly positive correlation with IL-1ß and TNF-α levels in the synovium and SF. TDO2 levels in the synovium were also positively correlated with the Kellgren-Lawrence score. Additionally, TDO2 protein expression was significantly increased in IL-1ß‒ or TNF-α‒stimulated OA-FLS than in control FLS. CONCLUSION: These data indicate that highTDO2 levels in the synovium can be correlated with pro-inflammatory cytokines and severity of OA.

Rates and risk factors of intrapedicular accuracy and cranial facet joint violation among robot-assisted, fluoroscopy-guided percutaneous, and freehand techniques in pedicle screw fixation of thoracolumbar fractures: a comparative cohort study.

BACKGROUND: Robot-assisted (RA) technique has been increasingly applied in clinical practice, providing promising outcomes of inserting accuracy and cranial facet joint protection. However, studies comparing this novel method with other assisted methods are rare, and the controversy of the superiority between the insertion techniques remains. Thus, we compare the rates and risk factors of intrapedicular accuracy and cranial facet joint violation (FJV) of RA, fluoroscopy-guided percutaneous (FP), and freehand (FH) techniques in the treatment of thoracolumbar fractures. METHODS: A total of 74 patients with thoracolumbar fractures requiring pedicle screw instruments were retrospectively included and divided into RA, FP, and FH groups from June 2016 to May 2020. The primary outcomes were the intrapedicular accuracy and cranial FJV. The factors that affected the intrapedicular accuracy and cranial FJV were assessed using multivariate analyses. RESULTS: The optimal intrapedicular accuracy of pedicle screw placement (Grade A) in the RA, FP, and FH groups was 94.3%, 78.2%, and 88.7%, respectively. This finding indicates no significant differences of RA over FH technique (P = 0.062) and FP technique (P = 0.025), but significantly higher accuracies of RA over FP (P < 0.001). In addition, the rates of proximal FJV in RA, FP, and FH groups were 13.9%, 30.8%, and 22.7%, respectively. RA had a significantly greater proportion of intact facet joints than the FP (P = 0.002). However, FP and FH (P = 0.157), as well as RA and FH (P = 0.035) showed significantly similar outcomes with respect to the proximal FJV. The logistic regression analysis showed that FP technique (OR = 3.056) was independently associated with insertion accuracy. Meanwhile, the age (OR = 0.974), pedicle angle (OR = 0.921), moderate facet joint osteoarthritis (OR = 5.584), and severe facet joint osteoarthritis (OR = 11.956) were independently associated with cranial FJV. CONCLUSION: RA technique showed a higher rate of intrapedicular accuracy and a lower rate of cranial FJV than FP technique, and similar outcomes to FH technique in terms of intrapedicular accuracy and cranial FJV. RA technique might be a safe method for pedicle screw placement in thoracolumbar surgery. LEVEL OF EVIDENCE: 3.

Predictors of accurate intrapedicular screw placement in single-level lumbar (L4-5) fusion: robot-assisted pedicle screw, traditional pedicle screw, and cortical bone trajectory screw insertion.

BACKGROUND: The superiorities in proximal facet joint protection of robot-assisted (RA) pedicle screw placement and screw implantation via the cortical bone trajectory (CBT) have rarely been compared. Moreover, findings on the screw accuracy of both techniques are inconsistent. Therefore, we analyzed the screw accuracy and incidence of facet joint violation (FJV) of RA and CBT screw insertion in the same study and compared them with those of conventional pedicle screw (PS) insertion. The possible factors affecting screw accuracy and FJV were also analyzed. METHODS: A total of 166 patients with lumbar degenerative diseases requiring posterior L4-5 fusion were retrospectively included and divided into the RA, PS, and CBT groups from March 2019 to December 2021. The grades of intrapedicular accuracy and superior FJV were evaluated according to the Gertzbin-Robbins scale and the Babu scale based on postoperative CT. Univariable and multivariable analyses were conducted to assess the possible risk factors associated with intrapedicular accuracy and superior FJV. RESULTS: The rates of optimal screw insertion in the RA, PS, and CBT groups were 87.3%, 81.3%, and 76.5%, respectively. The difference between the RA and CBT groups was statistically significant (P = 0.004). Superior FJVs occurred in 28.2% of screws in RA, 45.0% in PS, and 21.6% in CBT. The RA and CBT groups had fewer superior FJVs than the PS group (P = 0.008 and P < 0.001, respectively), and no significant difference was observed between the RA and CBT groups (P = 0.267). Multivariable analysis revealed that the CBT technique was an independent risk factor for intrapedicular accuracy. Furthermore, older age, the conventional PS technique and a smaller facet angle were independently associated with the incidence of superior FJVs. CONCLUSIONS: The RA and CBT techniques were associated with fewer proximal FJVs than the PS technique. The RA technique showed a higher rate of intrapedicular accuracy than the CBT technique. The CBT technique was independently associated with screw inaccuracy. Older age, conventional PS technique and coronal orientation of the facet join were independent risk factors for superior FJV.

Vitamin D receptor gene polymorphisms and osteoarthritis: a meta-analysis.

OBJECTIVE: To investigate the association of vitamin D receptor (VDR) gene polymorphisms with OA susceptibility. METHODS: Meta-analyses were performed using allelic contrast, contrast of homozygotes, and recessive and dominant models to clarify the association between OA and VDR ApaI, BsmI, TaqI and FokI polymorphisms. Odds ratio (OR) and the corresponding 95% CI were obtained, and subgroup analyses were performed based on the ethnicity and OA sites. RESULTS: A total of 18 studies with 2983 OA patients and 4177 controls were included in this meta-analysis. There were statistically significant associations in the spine between OA susceptibility and the VDR BsmI (B vs b: OR = 1.25, 95% CI: 1.03, 1.53, P = 0.026; BB vs bb: OR = 1.56, 95% CI: 1.02, 2.37, P = 0.038) and TaqI (T vs t: OR = 0.73, 95% CI: 0.54, 0.99, P = 0.044; TT vs Tt + tt: OR = 0.63, 95% CI: 0.42, 0.95, P = 0.028) polymorphisms, but not for the other polymorphisms. A statistically significant association was found between the VDR FokI polymorphism and OA susceptibility in the knee in the recessive model contrast (FF vs Ff + ff: OR = 0.63, 95% CI: 0.42, 0.95, P = 0.028), but this result was only pooled from one study. However, no significant associations were found between the VDR ApaI polymorphism and OA. Besides, ethnic stratification also indicated that there was no significant association between VDR gene polymorphism and OA in Caucasians or Asians. CONCLUSION: Our meta-analysis suggests that the VDR BsmI and TaqI polymorphisms are associated with OA susceptibility in the spine. However, the VDR ApaI polymorphism is not a significant genetic risk factor for OA.

An innovative adjustable prone positioning frame for treatment of severe kyphosis secondary to ankylosing spondylitis with two-level osteotomy.

PURPOSE: This study aims to introduce an innovative adjustable prone positioning frame (APPF) and explore its feasibility and safety for treatment of severe kyphosis secondary to ankylosing spondylitis (AS) with two-level osteotomy. METHODS: A retrospective, non-controlled study was conducted to illustrate the process where 13 patients diagnosed with severe kyphosis secondary to AS received operations on the APPF. Parameters of chin brow vertical angle (CBVA), global kyphosis (GK), thoracolumbar kyphosis (TLK), lumbar lordosis (LL) and sagittal vertical axis (SVA) were measured. Positioning time, operation time, intraoperative blood loss ahd complications were also determined. The Scoliosis Research Society outcomes instrument (SRS-22) was applied for clinical assessment. RESULTS: All patients were placed on the APPF successfully with the positioning time of 2.92 ± 0.76 min, received operation with 457.00 ± 88.04 min and had blood loss of 2330.77 ± 1423.25 ml. Four cases experienced pain due to tensional skin of the abdomen and one case suffered cerebrospinal fluid leakage postoperatively, but these patients were all cured conservatively. No neurological complications were observed, although sagittal translation occurred in four patients. Significant improvements were detected in CBVA, GK, TLK, LL and SVA postoperatively (P < 0.05), but no significant difference was observed between postoperation and the final follow-up (P > 0.05). The SRS-22 scores at 2 years after operation were significantly higher than those before operation (P < 0.05). CONCLUSION: The innovative APPF provided great convenience to place patients with severe kyphosis secondary to AS in a prone position. Performing two-level osteotomy with the aid of APPF is safe, feasible and effective.

Bone mesenchymal stem cell-conditioned medium attenuates the effect of oxidative stress injury on NSCs by inhibiting the Notch1 signaling pathway.

Numerous studies have demonstrated the therapeutic effect of bone mesenchymal stem cells on spinal cord injury (SCI), especially on neural stem cells (NSCs). However, the predominant mechanisms of bone mesenchymal stem cells (BMSCs) are unclear. Recently, some researchers have found that paracrine signaling plays a key role in the therapeutic capacity of BMSCs and emphasized that the protective effect of BMSCs may be due to paracrine factors. In this study, we aimed to investigate the potential mechanisms of BMSCs to protect NSCs. NSCs were identified by immunocytochemistry. The oxidative stress environment was simulated by H2 O2 (50, 100, 200 µM) for 2 h. The apoptotic rate of the NSCs was detected via flow cytometry. Lactate dehydrogenase (LDH), malondialdehyde (MDA), and superoxide dismutase (SOD) activity were evaluated via corresponding assay kits. Western blot was used to detect the expressions of Notch1, HES1, caspase-3, cleave caspase-3, Bax, and Bcl-2. We found that H2 O2 could significantly induce the apoptosis of NSCs, increase LDH, MDA levels, and decrease SOD activity by activating the Notch1 signaling pathway. DAPT (the specific blocker of Notch1) and BMSC-conditioned medium (BMSC-CM) could significantly prevent the apoptotic effect and oxidative stress injury on NSCs that were treated with H2 O2 . We also revealed that BMSC-CM could decrease the expression of Notch1, Hes1, cleave caspase-3, Bax, and increases the expression of Bcl-2 in NSCs, which was induced by H2 O2 . These results have revealed that BMSC-CM can neutralize the effect against oxidative stress injury on the apoptosis of NSCs by inhibiting the Notch1 signaling pathway.

Differences in radiographic and clinical outcomes of oblique lateral interbody fusion and lateral lumbar interbody fusion for degenerative lumbar disease: a meta-analysis.

BACKGROUND: In the current surgical therapeutic regimen for the degenerative lumbar disease, both oblique lateral interbody fusion (OLIF) and lateral lumbar interbody fusion (LLIF) are gradually accepted. Thus, the objective of this study is to compare the radiographic and clinical outcomes of OLIF and LLIF for the degenerative lumbar disease. METHODS: We conducted an exhaustive literature search of MEDLINE, EMBASE, and the Cochrane Library to find the relevant studies about OLIF and LLIF for the degenerative lumbar disease. Random-effects model was performed to pool the outcomes about disc height (DH), fusion, operative blood loss, operative time, length of hospital stays, complications, visual analog scale (VAS), and Oswestry disability index (ODI). RESULTS: 56 studies were included in this study. The two groups of patients had similar changes in terms of DH, operative blood loss, operative time, hospital stay and the fusion rate (over 90%). The OLIF group showed slightly better VAS and ODI scores improvement. The incidence of perioperative complications of OLIF and LLIF was 26.7 and 27.8% respectively. Higher rates of nerve injury and psoas weakness (21.2%) were reported for LLIF, while higher rates of cage subsidence (5.1%), endplate damage (5.2%) and vascular injury (1.7%) were reported for OLIF. CONCLUSIONS: The two groups are similar in terms of radiographic outcomes, operative blood loss, operative time and the length of hospital stay. The OLIF group shows advantages in VAS and ODI scores improvement. Though the incidence of perioperative complications of OLIF and LLIF is similar, the incidence of main complications is significantly different.

A preliminary study of 3.0-T magnetic resonance diffusion tensor imaging in cervical spondylotic myelopathy.

PURPOSE: To compare diffusion tensor imaging (DTI) parameters of the spinal cord between patients with cervical spondylotic myelopathy (CSM) and normal subjects, and investigate their significance in the clinical diagnosis, surgical planning and post-operative evaluation of CSM. METHODS: Routine sequence magnetic resonance imaging (MRI) and DTI scans were performed in 50 normal subjects and 60 cases of CSM with 3.0-T MR. DTI images, apparent diffusion coefficient (ADC) and fractional anisotropy (FA) colormaps corresponding to spinal cord cross-sections were obtained. The spinal cord function of CSM patients was measured using modified Japanese Orthopaedic Association (mJOA) scoring and Nurick grade at different times. The changes in DTI parameters and their correlation with spinal cord function scores were analysed by SPSS 19. RESULTS: There were significant differences in DTI parameters of the spinal cord between normal subjects and patients with CSM (ADC: 1.119 ± 0.087 vs. 1.395 ± 0.091, P < 0.01; FA: 0.661 ± 0.057 vs. 0.420 ± 0.080, P < 0.01). The FA values at the maximal compression level of the spinal cord in the patients with CSM were significantly associated with the mJOA score pre-operatively, 1 week, and 1, 3 and 6 months post-operatively, with Pearson's correlation coefficients of 0.58 (P < 0.01), 0.53 (P < 0.05), and 0.51 (P < 0.05), 0.54 (P < 0.05) and 0.55 (P < 0.05), respectively. However, the FA values were significantly negatively associated with the Nurick grade, with Pearson's correlation coefficients of - 0.40 (P < 0.05), - 0.39 (P < 0.05), and -0.41 (P < 0.05), - 0.45 (P < 0.05) and - 0.44 (P < 0.05), respectively. CONCLUSIONS: DTI may play a significant role in diagnosing and predicting the development of CSM. These slides can be retrieved under Electronic Supplementary Material.

Associations between vitamin D receptor gene polymorphisms and osteoarthritis: an updated meta-analysis.

OBJECTIVE: Vitamin D receptor (VDR) gene polymorphisms may be associated with the risk of OA, however, evidence for this is controversial. This meta-analysis aims to confirm whether VDR gene polymorphisms are associated with OA. METHODS: Meta-analyses on the association between OA and VDR ApaI, BsmI, TaqI and FokI polymorphisms were conducted using allele and homozygote contrast and contrasts in the recessive and dominant models. Stratification analyses by different demographic regions (Europe vs Asian) were also performed and pooled odds ratios (ORs) were obtained using the random effects model if the results were heterogeneous. RESULTS: A total of 13 relevant studies involving OA patients (n = 2104) and controls (n = 2939) were included in the analysis. There were significant associations between VDR ApaI polymorphisms and OA in the Asian population (A vs a: OR= 1.16, 95% CI 1.02, 1.32, P = 0.025; AA vs Aa/aa: OR= 1.36, 95% CI 1.04, 1.77, P = 0.025; AA vs aa: OR= 1.35, 95% CI 1.00, 1.80, P = 0.047), but not in the whole population. There was also a statistically significant association between FokI polymorphism and OA (FF vs Ff/ff: OR= 0.65, 95% CI 0.44, 0.95, P = 0.024); however, this result was derived from only two studies. No significant associations were found between VDR TaqI and BsmI polymorphisms and OA. CONCLUSION: There are modest but statistically significant associations between VDR ApaI polymorphisms and the susceptibility of OA in the Asian population.

Surgical management of the fractures of axis body: indications and surgical strategy.

PURPOSE: The axis body fractures are relatively uncommon and have a variety of presentations. Surgical management to them has been only reported as case reports or included as a minor part of clinical management. The objective of this study is to summarize the indications for surgery and report the clinical outcome of surgical treatment based on different fracture patterns. METHODS: A retrospective analysis of 28 consecutive patients presenting with the axis body fractures was undertaken. The indications for surgical treatment were defined as: (1) fractures associated with instability of adjacent joints; (2) irreducible displaced superior articular facet fracture; (3) fractures resulting in spinal cord compression. The fractures were classified as sagittal, coronal, transverse and lateral mass fracture. One of the following surgical procedures was applied according to the fracture pattern: posterior C1-C2 pedicle screws fixation and fusion (I); posterior C1-C3 screws fixation and fusion (II); posterior osteosynthesis with C2 transpedicular half-thread lag screws (III). RESULTS: 13 patients were successfully managed operatively. Two transverse and two unilateral lateral mass fractures were treated with surgical procedure I, five sagittal fractures with II, four coronal fractures with III. Complications of malposition of screws and neurologic deficit did not occur during operation. Satisfactory reduction and bony union were demonstrated on postoperative radiographics. CONCLUSIONS: Conservative treatment is still advocated as primary management for most axis body fractures. But for patients with obvious adjacent joints instability or irreducible displaced superior articular facet fracture, surgical intervention based on the different fracture pattern is necessary.

Guanylate cyclase promotes osseointegration by inhibiting oxidative stress and inflammation in aged rats with iron overload.

Aims: This study intended to investigate the effect of vericiguat (VIT) on titanium rod osseointegration in aged rats with iron overload, and also explore the role of VIT in osteoblast and osteoclast differentiation. Methods: In this study, 60 rats were included in a titanium rod implantation model and underwent subsequent guanylate cyclase treatment. Imaging, histology, and biomechanics were used to evaluate the osseointegration of rats in each group. First, the impact of VIT on bone integration in aged rats with iron overload was investigated. Subsequently, VIT was employed to modulate the differentiation of MC3T3-E1 cells and RAW264.7 cells under conditions of iron overload. Results: Utilizing an OVX rat model, we observed significant alterations in bone mass and osseointegration due to VIT administration in aged rats with iron overload. The observed effects were concomitant with reductions in bone metabolism, oxidative stress, and inflammation. To elucidate whether these effects are associated with osteoclast and osteoblast activity, we conducted in vitro experiments using MC3T3-E1 cells and RAW264.7 cells. Our findings indicate that iron accumulation suppressed the activity of MC3T3-E1 while enhancing RAW264.7 function. Furthermore, iron overload significantly decreased oxidative stress levels; however, these detrimental effects can be mitigated by VIT treatment. Conclusion: Collectively, our data provide compelling evidence that VIT has the potential to reverse the deleterious consequences of iron overload on osseointegration and bone mass during ageing.