Comparison of radiological and clinical outcomes of cervical laminoplasty versus lateral mass screw fixation in patients with ossification of the posterior longitudinal ligament.

PURPOSE: This study aimed to compare cervical sagittal parameters and clinical outcomes between patients undergoing cervical laminoplasty(CL) and those undergoing lateral mass screw fixation(LMS). METHODS: We retrospectively studied 67 patients with multilevel ossification of the posterior longitudinal ligament (OPLL) of the cervical spine who underwent lateral mass screw fixation (LMS = 36) and cervical laminoplasty (CL = 31). We analyzed cervical sagittal parameters (C2-7 sagittal vertical axis (C2-7 SVA), C0-2 Cobb angle, C2-7 Cobb angle, C7 slope (C7s), T1 slope (T1s), and spino-cranial angle (SCA)) and clinical outcomes (visual analog scale [VAS], neck disability index [NDI], Japanese Orthopaedic Association [JOA] scores, recovery rate (RR), and minimum clinically significant difference [MCID]). The cervical sagittal parameters at the last follow-up were analyzed by binary logistic regression. Finally, we analyzed the correlation between the cervical sagittal parameters and each clinical outcome at the last follow-up after surgery in both groups. RESULTS: At the follow-up after posterior decompression in both groups, the mean values of C2-C7 SVA, C7s, and T1s in the LMS group were more significant than those in the CL group (P ≤ 0.05). Compared with the preoperative period, C2-C7 SVA, T1s, and SCA gradually increased, and the C2-C7 Cobb angle gradually decreased after surgery (P < 0.05). The improvement in the JOA score and the recovery rate was similar between the two groups, while the improvement in the VAS-N score and NDI score was more significant in the CL group (P = 0.001; P = 0.043). More patients reached MCID in the CL group than in the LMS group (P = 0.036). Binary logistic regression analysis showed that SCA was independently associated with whether patients reached MCID at NDI postoperatively. SCA was positively correlated with cervical NDI and negatively correlated with cervical JOA score at postoperative follow-up in both groups (P < 0.05); C2-7 Cobb angle was negatively correlated with cervical JOA score at postoperative follow-up (P < 0.05). CONCLUSION: CL may be superior to LMS in treating cervical spondylotic myelopathy caused by OPLL. In addition, smaller cervical SCA after posterior decompression may suggest better postoperative outcomes.

Comparison of full-endoscopic foraminoplasty and lumbar discectomy (FEFLD), unilateral biportal endoscopic (UBE) discectomy, and microdiscectomy (MD) for symptomatic lumbar disc herniation.

PURPOSE: This study aimed to evaluate the clinical outcomes of full-endoscopic foraminoplasty and lumbar discectomy (FEFLD), unilateral biportal endoscopic (UBE) discectomy, and microdiscectomy (MD) in the treatment of symptomatic lumbar disc herniation (LDH). METHODS: From January 2020 and May 2021, 128 patients with single-level LDH at L4-5 or L5-S1 received FEFLD, UBE discectomy or MD. Patients were divided into three groups according to surgical method: the FEFLD group (n = 43), the UBE group (n = 42), and the MD group (n = 43). Operative time, fluoroscopy frequency, in-bed time, length of hospital stays, total expenses, complications, visual analogue scale (VAS, 0-10), and Oswestry Disability Index (ODI, 0-100%) were assessed and compared among three groups. RESULTS: There were no significant differences in VAS or ODI scores at 12 months after surgery among three groups. In comparison with the MD group, the FEFLD and UBE group yield better VAS scores for back pain on the first day following surgery (P < 0.05). The FEFLD group was superior to the UBE group or MD group with less time in bed and shorter hospital stay (P < 0.05). The operation time and total expenses in the UBE group were significantly longer and higher than those in the FEFLD group or MD group (P < 0.05). CONCLUSIONS: FEFLD and UBE discectomy yield comparable results to conventional MD concerning pain relief and functional outcomes. In addition, FEFLD and UBE discectomy enable less back pain in the immediate postoperative period. FEFLD offers advantages in rapid recovery. Conventional MD is still an efficient and cost-effective surgical procedure.

Incidence and risk factors of lumbar plexus injury in patients undergoing oblique lumbar interbody fusion surgery.

PURPOSE: To investigate the incidence and risk factors of lumbar plexus injury (LPI) after oblique lumbar interbody fusion (OLIF) surgery. METHODS: A total of 110 patients who underwent OLIF surgery between January 2017 and January 2021 were retrospectively reviewed. Patients were divided into two groups: the group with LPI (LPI group) and the group without LPI (non-LPI group). The baseline demographic data, surgical variables and radiographic parameters were compared and analyzed between these two groups. RESULTS: Among all participants, 13 (8.5%) had LPI-related symptoms postoperatively (short-term), and 6 (5.5%) did not fully recover after one year (long-term). Statistically, there were no significant differences in the baseline demographic data, surgery duration, intraoperative blood loss, preoperative diagnosis, surgical procedures used and incision length. Compared with the non-LPI group, patients in the LPI group had a narrower OLIF channel space. In LPI group, the anterior edge of left psoas major muscle overpasses the anterior edge of surgical intervertebral disk (IVD) on axial MRI. Logistic regression analysis revealed that narrow OLIF channel space and the anterior edge of left psoas major muscle overpassing the anterior edge of surgical IVD on axial MRI were independently associated with both short-term and long-term LPI. CONCLUSION: Narrow OLIF channel space and the anterior edge of left psoas major muscle overpassing the anterior edge of surgical IVD are significant risk factors of OLIF surgery-related LPI. Surgeons should use preoperative imaging to adequately assess these risk factors to reduce the occurrence of LPI.

Endoplasmic reticulum stress mediates nickel chloride-induced epithelial­mesenchymal transition and migration of human lung cancer A549 cells through Smad2/3 and p38 MAPK activation.

BACKGROUND: The endoplasmic reticulum (ER) is a cellular membrane-bound organelle whereby proteins are synthesized, folded and glycosylated. Due to intrinsic (e.g., genetic) and extrinsic (e.g., environmental stressors) perturbations, ER proteostasis can be deregulated within cells which triggers unfolded protein response (UPR) as an adaptive stress response that may impact the migration and invasion properties of cancer cells. However, the mechanisms underlying the nickel compounds on lung cancer cell migration and invasion remain uncertain. OBJECTIVE: We aimed to study whether Nickel chloride (NiCl2) induces ER stress in lung cancer cells, and whether ER stress is involved in modulating epithelial-mesenchymal transition (EMT) and migration by Smads and MAPKs pathways activation following NiCl2 treatment. METHODS: A549 cells were treated with NiCl2 to determine the cell viability using MTT assay. The wound healing assay was used to evaluate cell migration ability. ER ultrastructure was observed by transmission electron microscopy. Western blotting assay was performed to evaluate the protein levels of BIP, PERK, IRE-1α, XBP-1 s, and ATF6 for ER stress and UPR, E-cadherin and Vimentin for EMT, p-Smad2/3, p-ERK, p-JNK, and p-P38 for activation of Smads and MAPKs signaling pathways. RESULTS: The expression levels of BIP, PERK, IRE-1α, XBP-1 s, and ATF6 were significantly increased following treatment with NiCl2 in time- and dose-effect relationship. The ER stress inhibitor 4-PBA downregulated the expression levels of the above five proteins, and reversed the decrease in E-cadherin protein level and the increase in vimentin protein expression and cell migration abilities caused by NiCl2. Furthermore, 4-PBA significantly reduced nickel chloride-induced Smad2/3 and p38 MAPK pathway activation, while not affected ERK and JNK MAPK pathways. CONCLUSION: NiCl2 triggers ER stress and UPR in A549 cells. Moreover, 4-PBA alleviates NiCl2-induced EMT and migration ability of A549 cells possibly through the Smad2/3 and p38 MAPK pathways activation, rather than ERK and JNK MAPK pathways.

Vertebral endplate defects are associated with bone mineral density in lumbar degenerative disc disease.

PURPOSE: Evidence has shown that lumbar vertebral endplate defects are clinically relevant and closely related to disc degeneration, but the relationship between endplate defects and bone mineral density (BMD) remains unclear. This study aimed to explore the association between endplate defects and BMD-related values in patients with lumbar degenerative disc disease (LDD). METHODS: Three hundred and twenty-five Chinese adult subjects diagnosed with LDD underwent dual energy X-ray absorptiometry. Endplate defects were classified using lumbar MRI. Groups were subdivided based on the occurrence rates of defect endplates. BMD at the lumbar vertebral and bilateral femur necks was compared between groups, and the association between endplate defects and lumbar BMD-related values was analyzed and adjusted for confounders including age, sex, serum levels of 25-hydroxy vitamin D (25(OH)D), calcium (Ca) and phosphorus (P). RESULTS: Of 325 patients and 3250 endplates, 59.72% had defects, and 188 patients were divided into the higher defect rate group (occurrence rate > 50%). The higher defect rate group was associated with older age, more common postmenopausal females, higher osteoporosis rates and lower serum Ca and P levels. Lumbar BMD was greater than that at bilateral femur necks and was not equal to osteoporosis diagnosis. Endplate defects were more prevalent in lower segments. The occurrence of endplate defects was positively associated with lumbar BMD-related values in the partial correlation analysis. The association between endplate defects and lumbar BMD varies for subtypes and segments, with a trend of positive association in rim and erosive subtypes after adjusting for confounders. CONCLUSIONS: The present study demonstrated that the occurrence of endplate defects was associated with greater lumbar BMD values in patients with LDD. This association varies for different defect subtypes and segments. The results indicated that endplate defects should be taken into consideration in osteoporosis treatment to alleviate disc degeneration.

Clinical application of the C2 pars screw technique in the treatment of ossification of the posterior longitudinal ligament.

BACKGROUND: Our research was designed to decide whether the application of C2 pars screws is an alternative choice for patients with OPLL involving the C2 segment. METHODS: A total of 40 patients who underwent cervical laminectomy with fusion (LF) from C2 to C6 for OPLL were reviewed. Among them, C2 pedicle screws were placed in 23 patients, who were the pedicle group, and C2 pars screws were placed in 17 patients, who were the pars group. The screw placement and vertebral artery (VA) anatomy presented by standard CT. General clinical characteristics and health-related outcomes were evaluated and compared preoperatively and during the follow-up period. RESULTS: The Pars group tended to have a shorter operation duration and less blood loss than the pedicle group (operation time: 115.29 ± 28.75 vs 133.48 ± 26.22, p = 0.044; blood loss: 383.53 ± 116.19 vs 457.83 ± 145.45, p = 0.039). Operation time and blood loss were both independently related to the pars group (operation time: OR = 0.966, p = 0.021; blood loss: OR = 0.993, p = 0.046). The idealization and acceptability of C2 screws in the pars group exceeded those in the pedicle group (100% vs 91.3%). However, no statistically obvious variation in the included complications or health-related outcomes between the pedicle and pars groups was observed. CONCLUSION: In the treatment of patients with OPLL involving the C2 segment, the application of C2 pars screws is an alternative choice, which is not only safer but also reduces the amount of blood loss, shortens the operation time and obtains a more ideal screw placement.

Risk factors of postoperative deep vein thrombosis (DVT) under low molecular weight heparin (LMWH) prophylaxis in patients with thoracolumbar fractures caused by high-energy injuries.

To determine the incidence of DVT and to evaluate the risk factors of DVT under LMWH prophylaxis in patients with thoracolumbar fractures caused by high­energy injuries postoperatively. A total of 534 patients from January 2016 to November 2019 were included in this retrospective study. Medical record data, including demographic data, perioperative variables, and laboratory results, were collected. LMWH prophylaxis was used for DVT in all the patients. The incidence and risk factors of DVT after surgery were identified by logistic regression analysis and receiver operating characteristic (ROC) curve analysis. The overall incidence of postoperative DVT was 18.91% (101/534). Three patients (0.56%) had proximal DVT and ninety-eight (18.35%) patients had distal DVT. The incidence of postoperative DVT in patients with thoracic fractures was 26.80% and 15.50% with lumbar fractures. The multivariate analysis showed that six risk factors increased the incidence of postoperative DVT, including advanced age, decreased lower extremity motor, blood transfusion, duration of bed rests, fibrinogen (FIB), and D-dimer. The ROC analysis indicated that the diagnostic value of D-dimer was highest whose area under the ROC curves (AUC) value was 0.754. Despite LMWH prophylaxis, the risk of postoperative DVT is still very high, especially in thoracic fracture. Advanced age, decreased lower extremity motor, blood transfusion, duration of bed rests, FIB, and D-dimer are risk factors for DVT. Moreover, the diagnostic value of D-dimer is the highest among these factors.

Clinical effect analysis of laminectomy alone and laminectomy with instrumentation in the treatment of TOLF.

BACKGROUND: To explore the clinical effect of laminectomy alone and laminectomy with instrumentation in the treatment of TOLF. METHODS: A retrospective study was conducted on the clinical data of 142 patients with TOLF and laminectomy who underwent spine surgery at XXX Medical University from January 2003 to January 2018. According to whether the laminectomy was combined with instrumentation, the patients were divided into two groups: group A (laminectomy alone (LA), n = 77) and group B (laminectomy with instrumentation (LI), n = 65). Comparisons of possible influencing factors of demographic variables and operation-related variables were carried out between the two groups. In this study, the clinical effects of LA and LI in the treatment of TOLF were discussed. Thus, we explored the clinical effect of LA and LI in the treatment of TOLF. RESULTS: In terms of demographics, there was a statistically significant difference in BMI between group A and group B (P < 0.05). The differences in age, sex, smoking, drinking, heart disease, hypertension and diabetes were not statistically significant (P > 0.05). In terms of preoperative symptoms, there was a significant difference in gait disturbance, pain in the LE, and urination disorder between group A and group B (P < 0.05), but there was no significant difference in other variables between the two groups (P > 0.05). In terms of operation-related variables, there was a significant difference in the preoperative duration of symptoms, intramedullary signal change on MRI, dural ossification, residual rate of cross-sectional spinal canal area on CT, shape on the sagittal MRI, operation time, pre-mJOA, post-mJOA at 1 year, and leakage of cerebrospinal fluid between group A and group B (P < 0.05), but there was no significant difference in other variables between the two groups (P > 0.05). The preoperative average JOA score of group A was 6.37 and that of group B was 5.19. In group A, the average JOA score at 6 months, 1 year and 2 years after surgery was 7.87, 8.23 and 8.26, respectively, and the average JOA score improvement rate was 32.79 %, 38.32 and 38.53 %, respectively. In group B, the average JOA score at 6 months, 1 year and 2 years after surgery was 7.74, 8.15 and 8.29, respectively, and the average JOA score improvement rate was 39.15 %, 46.86 and 47.12 %, respectively. CONCLUSIONS: Currently, there is no consensus on whether instrumentation is needed after laminectomy for TOLF. We found that for patients with a long duration of gait disturbance, urination disorder, preoperative duration of symptoms, intramedullary signal change on MRI, dural ossification, residual rate of cross-sectional spinal canal area on CT less than 60 %, and shape on the sagittal MRI being beak and low, pre-mJOA had better clinical effects after LI as compared to those after LA, and the incidence of perioperative complications was lower.

Does cervical facet degeneration impact surgical outcomes and sagittal balance in patients with radiculopathy?

PURPOSE: In our present study, we aimed to investigate (1) whether cervical facet degeneration (FD) affects the clinical functional scores of patients with cervical radiculopathy after single-segment anterior cervical discectomy fusion (ACDF) and (2) whether FD affects the sagittal parameters of the cervical spine. METHODS: A total of 120 enrolled patients who underwent single-segment ACDF for radiculopathy with more than 2 years of follow-up were classified into two groups based on whether the preoperative mean FD was greater than or less than the mean FD grading score: mild FD group (mean score ≤ 2, n = 102) or severe FD group (mean score > 2, n = 48). Sagittal alignment changes and clinical functional scores were compared between the 2 groups. The relevant factors for FD were identified using multivariate logistic regression. RESULTS: Age, duration of symptoms, disc height and interfacet distance were independently associated with preoperative FD (age: P < 0.001; duration of symptoms: P = 0.020; disc height: P < 0.001; interfacet distance: P = 0.045). Compared with the mild FD group, the preoperative VAS (neck pain) score and NDI of the severe FD group were also higher, and the improvement of neck symptoms was better during the follow-up period. However, all clinical scores and radiographic parameters showed no significant differences during the 2-year follow-up. Additionally, no significant differences in the sagittal parameter changes were presented. CONCLUSION: Patients with severe FD tended to experience more severe neck pain before surgery and greater improvement of neck symptoms at the follow-up visit. However, 2-year clinical efficacy and sagittal alignment after ACDF may not be markedly affected by preoperative FD severity. ACDF is considered to be a good choice for patients with radiculopathy, especially for patients with severe FD.

Spino cranial angle as a predictor of loss of cervical lordosis after laminoplasty in patients with cervical myelopathy.

BACKGROUND: To explore the relationship between spino cranial angle (SCA) and loss of cervical lordosis (LOCL), and to determine whether SCA has the ability to predict LOCL for patients with cervical myelopathy. METHODS: A total of 68 consecutive patients with cervical myelopathy who received laminoplasty (LAMP) were selected to the current study. C2-C7 lordosis was defined as a representation of the cervical alignment. Alignment change > 0° was considered LOCL. Multiple linear regression analysis was applied to evaluate the association between LOCL and various sagittal parameters at preoperative, such as SCA, CL, T1s and cSVA. Linear regression analysis was applied to evaluate the relationships between LOCL and preoperative SCA in each subgroup. RESULTS: Patients were assigned to three groups depending on the quartile of preoperative SCA. The first quarter of patients were defined as the low SCA group, the last quarter were defined as the high SCA group and the middle half were defined as the middle SCA group. There was no statistically significant difference in age, sex and the type of OPLL among the three groups. Patients in the low SCA group showed more cervical lordosis before surgery and more LOCL after LAMP (p < 0.001). After linear regression analysis for SCA and LOCL, preoperative SCA was negatively correlated with LOCL in the low SCA group (r = - 0.857, p < 0.001) and high SCA group (r = - 0.515, p = 0.034). However, there was no significant correlation between preoperative SCA and LOCL in the middle SCA group (r = 0.027, p = 0.881). CONCLUSIONS: Patients with lower SCA had more lordosis preoperatively and performed more LOCL after LAMP at 2 years of follow-up. Both too high or low preoperative SCA were negatively correlated with the degree of LOCL, while when the SCA fluctuates in a suitable range, it is easier to compensate for the changes of cervical sagittal alignment.

Exosomes Derived from Bone Marrow Mesenchymal Stem Cells Prevent Acidic pH-Induced Damage in Human Nucleus Pulposus Cells.

BACKGROUND The exosomes (Exo) derived from mesenchymal stem cells (MSCs) are capable of attenuating the apoptosis of nucleus pulposus cells (NPCs) elicited by proinflammatory cytokines. However, it remains unknown whether MSC-derived Exo also exert a protective effect on NPCs in the pathological acid environment. MATERIAL AND METHODS NPCs were divided into 3 groups: Group A, pH 7.1-7.3; Group B, pH 6.5-6.7 and Group C, pH 5.9-6.1. The NPCs were cultured in the above-defined acidic medium, and 3 different amounts of Exo were added into the media. Finally, the expression of the caspase-3, aggrecan, collagen II, and MMP-13 was analyzed and compared among the different groups. RESULTS Compared with cells cultured at pH 7.1-7.3 (Group A), proliferation activity of NPCs cultured at pH 5.9-6.7 (Group B and C) decreased significantly. Collagen II and aggrecan expression was also obviously reduced with the decrease of cell proliferation. Conversely, the expression of caspase-3 and MMP-13 significantly increased. Further experiments showed that proliferation activity was significantly attenuated in NPCs cultured at pH 5.9-6.1 without Exo treatment (Group E) compared with those cultured at pH 7.1-7.3 without Exo treatment (Group D). CONCLUSIONS In the pathological acid environment, MSC-derived Exo promotes the expression of chondrocyte extracellular matrix, collagen II, and aggrecan, and reduces matrix degradation by downregulating matrix-degrading enzymes, protecting NPCs from acidic pH-induced apoptosis. This study reveals a promising strategy for treatment of IVD degeneration.

Clinical Efficacy of Laminectomy with Instrumented Fixation in Treating Thoracolumbar Intradural Extramedullary Schwannomas: A Comparative Study.

BACKGROUND This study investigated the clinical effect of laminectomy plus pedicle screw fixation in treating thoracolumbar intradural extramedullary schwannomas. MATERIAL AND METHODS Between October 2011 and May 2017, 57 patients undergoing resection of thoracolumbar schwannomas were retrospectively identified and included in the study. Based on the surgical procedures used, all participants were assigned to either the laminectomy-only group (n=33) or the combination group (laminectomy plus pedicle screw fixation, n=24). All participants were followed up for over 2 years. In the laminectomy, the spinal process, vertebral laminae, and bilateral upper articular processes of the surgical segments were completely resected and the lower articular processes were reserved. For further analysis, we evaluated the pain levels using visual analogue scale (VAS) score. The assessment of neurological function was performed with Japanese Orthopaedic Association (JOA) score and Oswestry disability index (ODI). The comparisons of Cobb angle changes were carried out pre-surgery and post-surgery. RESULTS The demographic data were well matched between the laminectomy-only group and combination group, without significant differences (P>0.05). After surgery, both surgical procedures achieved significant improvement in VAS score, ODI, and JOA score (P<0.001), but no significant differences were found between these 2 surgical procedures (P>0.05). The postoperative change in Cobb angle indicated a significant difference in the laminectomy-only group, but not in the combination group (P<0.05). In addition, postoperative spinal instability/deformity was found in the laminectomy-only group (P<0.05). CONCLUSIONS In conclusion, the combination of laminectomy and pedicle screw fixation is a safe and effective surgical procedure when used to treat thoracolumbar schwannoma, and appears to be superior to the laminectomy-only procedure.

Locking stand-alone cage versus anterior plate construct in anterior cervical discectomy and fusion: a systematic review and meta-analysis based on randomized controlled trials.

PURPOSE: To evaluate the efficacy of locking stand-alone cage (LSC) compared with anterior plate construct (APC) in anterior cervical discectomy and fusion (ACDF). METHODS: A comprehensive literature search was carried out in PubMed, Embase, Web of Science, and Cochrane Library to screen randomized controlled trials (RCTs) that directly compared LSC with APC in ACDF. The Cochrane Collaboration's tool was used for assessment of study quality. Data were analyzed with the Review Manager 5.3 software. RESULTS: A total of seven RCTs were included. The results revealed no significant differences between LSC and APC in ACDF regarding the fusion rate, Japanese Orthopaedic Association score, visual analogue scale score, neck disability index score, hospital stay, subsidence rate, cervical lordosis, segmental Cobb angle, and disc height. However, LSC was associated with a significantly shorter operation time, less blood loss, lower overall incidence of dysphagia, and lower adjacent-level ossification (ALO) rate compared with APC. CONCLUSION: In summary, LSC is not only a safe and effective device for ACDF but also has the advantages of significantly reduced operation time, blood loss, overall incidence of dysphagia, and ALO rate over APC. Therefore, LSC is a better alternative than APC for the patients undergoing ACDF procedures.

Exogenous hydrogen sulfide donor NaHS alleviates nickel-induced epithelial-mesenchymal transition and the migration of A549 cells by regulating TGF-ß1/Smad2/Smad3 signaling.

Nickel compounds are known to be common environmental and occupational carcinogens which also promote the migration of lung cancer cells. However, the molecular mechanism yet remains to be clarified. Hydrogen sulfide (H2S) is involved in cancer biological processes. However, the exact effect and functionality of H2S on nickel, towards the promotion of the migration ability of lung cancer cells, remains to be unknown. In this study, we have found that the nickel chloride (NiCl2) treatment significantly downregulates the protein levels of endogenous H2S enzyme cystathionine ß-synthase (CBS), cystathionine γ-lyase (CSE) and 3-Mercaptopyruvate sulfurtransferase (3-MST). A correlation between NiCl2-induced epithelial-mesenchymal transition (EMT) and the migration ability of lung cancer A549 cells has been observed. Exogenous H2S donor, sodium hydrogen sulfide (NaHS) (100 µmol/L), can reverse NiCl2-induced EMT as well as the migration ability of A549 cells. NiCl2 treatment is able to upregulate the protein level of transforming growth factor-ß1 (TGF-ß1), p-Smad2, p-Smad3, p-JNK, p-ERK and p-P38 in a time-dependent fashion, indicating that both TGF-ß1/Smad2/Smad3 and mitogen-activated protein kinase (MAPK) signaling cascades (a non-Smad pathway) may play essential roles in NiCl2-dependent EMT as well as cell migration of human lung cancer cells. Furthermore, exogenous NaHS alleviates the NiCl2-induced EMT and the migration ability of A549 cells only by regulating TGF-ß1/Smad2/Smad3, rather than the MAPK, signaling pathway. These results indicate that the exogenous administration of NaHS might be a potential therapeutic strategy against nickel-induced lung cancer progression.

Hydrogen sulfide attenuates paraquat-induced epithelial-mesenchymal transition of human alveolar epithelial cells through regulating transforming growth factor-ß1/Smad2/3 signaling pathway.

Exogenous H2 S donor, sodium hydrosulfide (NaHS), can influence the bleomycin-induced pulmonary fibrosis by attenuating the epithelial-mesenchymal transition (EMT) of alveolar epithelial cells, but whether NaHS affects paraquat (PQ)-induced EMT and the molecular mechanisms remain unclarified. The aim of the present study is to examine the effect of exogenous NaHS on PQ-induced EMT in human alveolar epithelial cells (A549 cells) and assess if this effect occurs through regulating transforming growth factor (TGF)-ß1/Smad2/3 signaling pathway. The expressions of endogenous H2 S producing enzymes, namely cystathionine ß-synthase, cystathionine γ-lyase and 3-mercaptopyruvate sulfur transferase, were detected by reverse transcription-polymerase chain reaction and western blotting. The induced EMT was assessed by morphological and phenotypic characterizations, and the protein level of E-cadherin and vimentin were detected by western blotting. To investigate the effect of NaHS on PQ-induced EMT and potential mechanism, A549 cells were pretreated with NaHS before incubating with PQ and then evaluated by morphological changes, cell migration ability, the expression of EMT markers and TGF-ß1/Smad2/3 signaling pathway related proteins. PQ significantly downregulated the expression levels of cystathionine ß-synthase and cystathionine γ-lyase, but not 3-mercaptopyruvate sulfur transferase, in a time-dependent manner in A549 cells. Exogenous NaHS could significantly retard PQ-induced morphological changes and cell migration ability. Furthermore, exogenous NaHS significantly upregulated the expression of E-cadherin, whereas it downregulated the expression of vimentin. In addition, exogenous NaHS could also significantly attenuates PQ-induced TGF-ß1, phosphorylated Smad2/3 proteins expression, which induced by PQ in a time-dependent manner. This study provides the first evidence that exogenous NaHS attenuates PQ-induced EMT and migration of human alveolar epithelial cells through regulating the TGF-ß1/Smad2/3 signaling pathway.

Abnormal change of paravertebral muscle in adult degenerative scoliosis and its association with bony structural parameters.

PURPOSE: While many studies have explored the association between paravertebral muscle (PVM) change and low back pain/lumbar spinal stenosis, little is known about PVM change in adult degenerative scoliosis (ADS). The present study explored the PVM change in ADS and investigated its association with bony structural parameters. METHODS: We evaluated 78 patients in ADS without radiculopathy (ADS group) and 65 healthy persons without degenerative lumbar diseases (control group). Percentage of fat infiltration area (%FIA) of multifidus muscle at L1 to S1 disk level was measured by MRI, using ImageJ software. Lumbar scoliosis Cobb's angle, lumbar lordotic angle, lateral vertebral translation, and apical vertebral rotation were recorded in ADS group, and relationship between PVM change and these factors was analyzed. RESULTS: In the control group, the mean %FIA of multifidus muscle was not significantly different between the bilateral sides at all levels (P > 0.05). In the ADS group, the mean %FIA was significantly higher on the concave side than the convex side at all levels (P < 0.05). Asymmetric degree of multifidus muscle change was 8.55% ± 4.91%, which was positively correlated with lumbar scoliosis Cobb's angle, lateral vertebral translation, and apical vertebral rotation (0 < r < 1, P < 0.05), but negatively weak-correlated with lumbar lordotic angle (- 1 < r < 0, P < 0.05). CONCLUSIONS: Asymmetric PVM change in ADS is more often seen on the concave side, which is positive to evaluate the progression of scoliosis. Its asymmetric degree increases with progression of lumbar scoliosis Cobb's angle and decreased lumbar lordotic angle. Apical vertebral rotation and lateral vertebral translation can aggravate the asymmetric degree.

The Treatment Evaluation for Osteoporotic Kummell Disease by Modified Posterior Vertebral Column Resection: Minimum of One-Year Follow-Up.

BACKGROUND The aim of this study was to evaluate the clinical efficacy of modified posterior vertebral column resection (MPVCR) in treating osteoporotic Kummell disease. MATERIAL AND METHODS Between January 2013 and January 2015, 10 patients who were diagnosed with Kummell disease underwent MPVCR treatment, and their medical records were retrospectively collected. Every patient had follow-up for at least one year, with an average of 15 months. Clinical efficacy of MPVCR treatment was evaluated by kyphotic Cobb's angle, Oswestry disability index (ODI) and visual analogue scale (VAS) score. RESULTS Data analyses showed that operation time was 188.39±30.8 minutes, and blood loss was 860±130 mL with 600±200 mL of blood transfusions. VAS score decreased significantly after MPVCR surgery (p<0.001, Mann-Whitney U test). In addition, data analyses showed that postoperative ODI was less than preoperative ODI, which was a statistically significant difference (p<0.001, Mann-Whitney U test). X-ray radiograph showed that kyphotic Cobb's angle was 45°±12° preoperatively, 10°±4° two weeks after surgery, and 15°±6° at last follow-up, indicating that Cobb's angle after MPVCR surgery was significantly improved, compared to the preoperative scores (p<0.05, SNK-q test). CONCLUSIONS MPVCR surgery was an effective and safe surgical method to treat Kummell disease, especially for patients with kyphotic deformity and obvious nerve-oppressed symptoms. However, the long-term clinical effect still needs further studies.

Risk Factors Associated with Adjacent Vertebral Compression Fracture Following Percutaneous Vertebroplasty After Menopause: A Retrospective Study.

BACKGROUND Clinically, percutaneous vertebroplasty (PVP) is frequently applied to treat osteoporotic vertebral compression fracture (OVCF). It is believed that new compression fractures are more likely to occur adjacent to the PVP-treated segment, typically within 1 month after PVP. The purpose of this study was to investigate risk factors for adjacent vertebral compression fractures (AVCF) after PVP in patients with OVCF after menopause. MATERIAL AND METHODS Between Jun 2012 and Dec 2016, 412 patients were initially identified. We enrolled 390 patients in this study, and 22 were lost to follow-up. The medical records of the patients were retrospectively collected. Patients were followed up for at least 6 months, with an average follow-up period of 18 months. The potential risk factors investigated in this study included age, duration of menopause (DoM), preoperative vertebral compression, number of preoperative vertebral fractures (NPVF), bone mineral density (BMD), surgical approach (unilateral or bilateral), anesthesia methods, bone cement dose, complications (including COPD), and anti-osteoporosis treatment. Logistic regression analysis was used to determine the risk factors. RESULTS Sixty-eight patients were observed to have suffered from AVCF after PVP at the last follow-up. Univariate analysis showed that age, DoM, NPVF, BMD, COPD, and anti-osteoporosis treatment were the potential variables associated with the onset of AVCF (all P<0.05). Binary logistic regression analysis showed that the logistic regression equation was as follows: logit P=-3.10-1.07×X2+0.99×X3+2.15×X4 (where X2=BMD; X3=DoM; X4=NPVF), and "logit P" stands for the likelihood of developing an AVCF following PVP. CONCLUSIONS A long duration of menopause and preoperative multi-level vertebral fractures were the risk factors for AVCF in patients following PVP after menopause, while a high-level BMD acted in a protective role for AVCF development.

Unilateral Pedicle Screw Fixation with Bone Graft vs. Bilateral Pedicle Screw Fixation with Bone Graft or Cage: A Comparative Study.

BACKGROUND: The aim of this study was to explore the clinical efficacy of unilateral pedicle screw fixation with bone graft (UPSFB) in treating single-segment lumbar degenerative diseases (LDD), as compared to bilateral pedicle screw fixation with bone graft (BPSFB) or with cage (BPSFC). MATERIAL/METHODS: Medical records were retrospectively collected between 01/2010 and 02/2015 in Longyao County Hospital. According to surgical methods used, all patients were divided into 3 groups: UPSFB group, BPSFB group, and BPSFC group. Clinical outcomes were evaluated by blood loss, blood transfusion, duration of operation, hospital stay, postoperative complications, interbody fusion rate, reoperation rate, medical expenses, patient satisfaction survey, and JOA score. RESULTS: Ninety-five patients were included and underwent 2.5-year follow-up, with 7 patients lost to regular follow-up. As compared to the BPSFB group and BPSFC group, the UPSFB group had less blood loss and less blood transfusion, as well as shorter hospital stay (p<0.05). Medical expenses were far lower in the UPSFB group (p<0.001). There were no significant differences among the 3 groups in postoperative complications, interbody fusion rate, reoperation rate, JOA score, and patient satisfaction (all p>0.05). CONCLUSIONS: As compared to BPSFB and BPSFC, UPSFB has the same reliability and effectiveness in treating single-segment LDD with unilateral radicular symptoms in a single lower extremity, with the additional advantage being less expensive.

Incidence and risk factors for proximal junctional kyphosis: a meta-analysis.

PURPOSE: To analyse the incidence and risk factors associated with proximal junctional kyphosis (PJK) following spinal fusion, we collect relative statistics from the articles on PJK and perform a meta-analysis. METHODS: An extensive search of literature was performed in PubMed, Embase, and The Cochrane Library (up to April 2015). The following risk factors were extracted: age at surgery, gender, combined anterior-posterior surgery, use of pedicle screw at top of construct, hybrid instrumentation, thoracoplasty, fusion to sacrum (S1), preoperative thoracic kyphosis angle (T5-T12) >40°, bone mineral density (BMD) and preoperative to postoperative sagittal vertical axis (SVA difference) >5 cm. Data analysis was conducted with RevMan 5.3 and STATA 12.0. RESULTS: A total of 14 unique studies including 2215 patients were included in the final analyses. The pooled analysis showed that there were significant difference in age at surgery >55 years old (OR 2.19, 95 % CI 1.36-3.53, p = 0.001), fusion to S1 (OR 2.12, 95 % CI 1.57-2.87, p < 0.001), T5-T12 >40° (OR 2.68, 95 % CI 1.73-4.13, p < 0.001), low BMD (OR 2.37, 95 % CI 1.45-3.87, p < 0.001) and SVA difference >5 cm (OR 2.53, 95 % CI 1.24-5.18, p = 0.01). However, there was no significant difference in gender (OR 0.98, 95 % CI 0.74-1.30, p = 0.87), combined anterior-posterior surgery (OR 1.55, 95 % CI 0.98-2.46, p = 0.06), use of pedicle screw at top of construct (OR 1.55, 95 % CI 0.67-3.59, p = 0.30), hybrid instrumentation (OR 1.31, 95 % CI 0.92-1.87, p = 0.13) and thoracoplasty (OR 1.55, 95 % CI 0.89-2.72, p = 0.13). The incidence of PJK following spinal fusion was 30 % (ranged from 17 to 62 %) based on the 14 studies. CONCLUSIONS: The results of our meta-analysis suggest that age at surgery >55 years, fusion to S1, T5-T12 >40°, low BMD and SVA difference >5 cm are risk factors for PJK. However, gender, combined anterior-posterior surgery, use of pedicle screw at top of construct, hybrid instrumentation and thoracoplasty are not associated with PJK.