Minimally invasive posterior cervical foraminotomy versus anterior cervical discectomy and fusion for cervical radiculopathy: a meta-analysis.

With the recent development of minimally invasive techniques, minimally invasive posterior cervical foraminotomy (MIS-PCF) has become increasingly popular as a minimally invasive method to treat cervical radiculopathy. However, there are still controversies about whether MIS-PCF is superior to anterior cervical discectomy and fusion (ACDF). The purpose of this study is to evaluate the therapeutic effects of MIS-PCF and ACDF on unilateral cervical radiculopathy without myelopathy. We searched PubMed, Embase, the Cochrane Library, and Scopus comprehensively using the terms related to MIS-PCF. Two reviewers independently evaluated the potential studies, and extracted and analyzed the data of operation time, hospital stay, neck disability index (NDI) score, visual analog scale for neck pain (VAS-neck) and arm pain (VAS-arm) scores, reoperation rate, and complications. Seven studies with 1175 patients were included. The study population was 53.5% male, with a mean age of 48.9. MIS-PCF presented a significantly shorter postoperative hospitalization time compared to ACDF, while the operation time, complication/reoperation rate, and VAS-arm, VAS-neck, and NDI scores were comparable between the two cohorts. In North America, the average cost of MIS-PCF is lower than ACDF. Thus, we suggest that MIS-PCF is an alternative to ACDF for selected patients.

Predictive factors for residual leg numbness after decompression surgery for lumbar degenerative diseases.

BACKGROUND: The purpose of this study is to evaluate the change patterns of leg numbness (LN) after lumbar decompression surgery (LDS), and to find the predictive factors that affect the recovery of numbness. METHODS: Patients who underwent LDS in our institution between August 2020 and July 2021 were prospectively enrolled in this study, and were followed by a 12-month follow-up. The degree of LN, leg pain (LP) and the disability were assessed using the visual analog scale (VAS) and oswestry disability index (ODI). RESULTS: A total of 314 patients finished the 12-month follow-up. The preoperative mean VAS-LN score was 3.49 ± 2.44, which decreased to 1.91 ± 1.30 at 3 months, to 1.29 ± 0.97 at 6 months and to 1.26 ± 0.96 at 12 months after surgery. The preoperative mean VAS-LP score was 6.05 ± 1.30, which decreased to 2.00 ± 0.86 at 3 months, to 1.02 ± 0.80 at 6 months, and to 0.49 ± 0.71 at 12 months after surgery. The preoperative mean ODI score was 27.90 ± 7.08, which decreased to 9.73 ± 3.09 at 3 months, to 6.72 ± 2.98 at 6 months, and to 4.57 ± 2.76 at 12 months after surgery. Via multivariate logistic regression analysis, only preoperative VAS-LN score (p < 0.001*) was identified as a significantly independent predictive factor for residual LN after operation. CONCLUSION: Clinically significant improvement in LN was observed in the majority of patients within 6 months after LDS, and the improvement of VAS-LN was slower than the VAS-LP. High pre-operative VAS-LN score can independently predict the presence of residual LN after surgery at 12-month follow up.

Allicin can suppress the activity of vascular endothelial cells probably by regulating JAK2/STAT3 pathway.

Whether allicin can suppress the angiogenesis via inhibiting the activity of vascular endothelial cells (VECs) in preventing epidural hypertrophic scars remains unknown. VECs were treated by allicin at a gradient of concentrations. Cell activity was measured by CCK-8 assay, scratch assay and flow cytometry. Reverse-transcription PCR and Western Blot were used to measure the expression levels of relevant genes and proteins. After treated with allicin at concentrations of 0, 25, 50 and 100 mg/L, the viability of VECs significantly decreased at 24 h (p < 0.001*) and 48 h (p < 0.001*), and migration rate significantly decreased in scratch assay (p = 0.017*) and in Transwell assay (p = 0.021*). As the concentrations of allicin increased, the apoptosis rate of VECs rose up (p = 0.018*). There was no significant difference on cell numbers at S phase (p = 0.25), but cell numbers at G1 phase decreased (p = 0.039*) and at G2 phase increased (p = 0.047*). With the increase of allicin concentrations, the ability of tube formation for VECs significantly decreased (p < 0.001*). Comparing with control group, the expression of PCNA and BCL-2 decreased (p < 0.001*), while the expression of BAX increased significantly (p < 0.001*). Regarding to JAK2/STAT3 pathway, the expression levels of JAK3 and STAT3 decreased significantly with the increase of allicin concentrations (p < 0.001*). Allicin can suppress the activity of VECs probably by regulating JAK2/STAT3 pathway.

Naringin alleviates H2O2-induced apoptosis via the PI3K/Akt pathway in rat nucleus pulposus-derived mesenchymal stem cells.

Purpose: To investigate the protective effect of naringin (Nar) on H2O2-induced apoptosis of nucleus pulposus-derived mesenchymal stem cells (NPMSC) and the potential mechanism in this process. Methods: Rat NPMSC were cultured in MSC culture medium or culture medium with different concentrations of H2O2. Nar or the combination of Nar and LY294002 was added into the culture medium to investigate the effects of Nar. Cell viability was evaluated by cell counting kit-8 (CCK-8) assay. The apoptosis rate was determined using Annexin V/PI dual staining and terminal deoxynucleotide transferase-mediated dUTP nick end labeling (TUNEL) assays. Additionally, the levels of reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) were analyzed by flow cytometry. ATP level in NPMSC was analyzed via ATP detection kit. Mitochondrial ultrastructure change was observed through transmission electron microscope (TEM). Levels of apoptosis-associated molecules (cleaved caspase-3, Bax and Bcl-2) were evaluated via RT-PCR and western blot, respectively. Results: The cells isolated from NP met the criteria for MSC. H2O2 significantly promoted NPMSC apoptosis in a dose and time-dependent manner. Nar showed no cytotoxicity effect on NPMSC up to a concentration of 100 µM for 24 h. Nar exhibited protective effects against H2O2-induced NPMSC apoptosis including apoptosis rate, expressions of proapoptosis and antiapoptosis related genes and protein. Nar could also alleviate H2O2-induced mitochondrial dysfunction of increased mitochondrial ROS production, reduced MMP, decreased intracellular ATP and mitochondrial ultrastructure change. However, these protected effects were inhibited after LY294002 treatment. Conclusions: Our results demonstrated that Nar efficiently attenuated H2O2-induced NPMSC apoptosis and mitochondrial dysfunction. The activation of ROS-mediated PI3K/Akt pathway may be the potential mechanism in this process.

The effect of high glucose on the biological characteristics of nucleus pulposus-derived mesenchymal stem cells.

Diabetes mellitus (DM) is a dependent risk factor in the progression of intervertebral disc degeneration (IVDD). High glucose supply has negative effects on nucleus pulpous (NP) cell and mesenchymal stem cell (MSC) biology. However, the effect of hyperglycaemia on the biological characterization of nucleus pulpous-derived mesenchymal stem cell (NPMSC) has not been investigated previously. Therefore, further exploration of the effects of DM-associated hyperglycaemia on NPMSC biology is important to better understand and develop endogenous repair strategies of DM patient-associated IVDD. Therefore, the cell biological characteristics were compared between NPMSC cultured in media with low glucose concentration (LG-NPMSC) and high glucose concentration (HG-NPMSC). The results demonstrated that HG-NPMSC showed significantly decreased cell proliferation, colony formation ability, migration and wound-healing capability compared with those of LG-NPMSC. HG-NPMSC also showed significantly decreased expressions of stemness genes and mRNA and protein expressions of silent information regulator protein 1 (SIRT1), SIRT6, hypoxia inducible factor-1α (HIF-1α) and glucose transporter 1 (GLUT-1), whereas increased cell apoptosis, cell senescence and caspase-3 expression. These results suggest that high glucose may decrease proliferation and stemness maintenance ability and increase apoptosis and senescence of NPMSC. SIGNIFICANCE OF THE STUDY: We found that high glucose concentration significantly decreased cell proliferation, colony formation ability, migration and wound-healing capability of nucleus pulposus-derived mesenchymal stem cells. Moreover, high glucose cultured nucleus pulposus-derived mesenchymal stem cells showed significantly decreased expression of stemness genes, related mRNA and protein, whereas increased cell apoptosis, cell senescence and expression of caspase-3. The present study indicated that better control of high concentration glucose in the early stage of diabetes mellitus should be recommended to prevent or limit intervertebral disc degeneration.

The effect of intervertebral disc degenerative change on biological characteristics of nucleus pulposus mesenchymal stem cell: an in vitro study in rats.

Purpose: To evaluate the change on biological characteristics of mesenchymal stem cell (MSC) derived from normal and degenerative intervertebral disc (IVD). Methods: MSC was isolated from normal and degenerative IVD rat model. Immunophenotype detected by flow cytometric analysis, expression of stemness genes determined by reverse-transcription polymerase chain reaction (RT-PCR) and osteogenic, adipogenic and chondrogenic differentiation were compared between MSC derived from normal IVD (N-NPMSC) and degenerative IVD (D-NPMSC). The biological characteristics including cell proliferation, colony formation, apoptosis, caspase-3 activity and mRNA and protein expressions of hypoxia inducible factor-1α (HIF-1α), glucose transporter 1 (GLUT-1), vascular endothelial growth factor (VEGF), silent information regulator protein 1 (SIRT1) and silent information regulator protein 6 (SIRT6) were compared between N-NPMSC and D-NPMSC. Results: Both of N-NPMSC and D-NPMSC highly expressed CD105, CD90 and CD73, and lower expressed CD34 and CD45. There was no significant difference in cell morphology and multipotent differentiation ability between N-NPMSC and D-NPMSC. D-NPMSC showed significantly lower expressions of stemness genes, cell proliferation and colony formation ability. D-NPMSC also exhibited increased cell apoptosis rate and caspase-3 expression, and significantly lower expressions of HIF-1α, GLUT-1, VEGF, SIRT1 and SIRT6 in mRNA and protein levels compared with N-NPMSC. Conclusions: N-NPMSC showed significantly higher proliferation rate, better colony forming and stemness maintenance ability, whereas reduced cell apoptosis rate compared with D-NPMSC. HIF-1α-mediated signal pathway may be involved in the regulation of NPMSC proliferation. These findings indicated that degenerative change of IVD should be taken into account when selecting a source of NPMSC for clinical application.

Time-Course Investigation of Intervertebral Disc Degeneration Induced by Different Sizes of Needle Punctures in Rat Tail Disc.

BACKGROUND This study aimed to determine the best size needle to use in inducing IVDD and to find the proper time point of disc degeneration suitable for further biologic treatment study. MATERIAL AND METHODS First, rat tail level 5/6, 7/8, and 9/10 discs were punctured by 18G, 21G, or 25G needles. Then, degeneration was assessed by radiography, MRI, and histological evaluation at 2, 4, and 6 weeks after puncture. Later, real-time reverse transcriptase (RT-PCR) was used to examine mRNA expressions of aggrecan, collagen type II, hypoxia-inducible factor-1a (HIF-1a), glucose transporter1 (GLUT-1), and vascular endothelial growth factor (VEGF). RESULTS Significant differences were identified in almost all parameters compared with the control group in the 18G and 21G group at almost all time points. To assess the effect of different needle sizes on DHI, we used magnetic resonance imaging (MRI), grade, and mRNA expression. We found significant differences between different groups, except for DHI between the 21G group and 25G group and MRI grade between the 18G and 21G group at the 2-week time point. In assessing the effect of different needle sizes on HE staining score and toluidine blue staining grade, statistical differences were observed at some time points. The effects of time on all parameters were significant at almost all time points in all groups. CONCLUSIONS The middle-size needle (21G) performed better in inducing disc degeneration. The 2-week time point may be better for use in further experimental studies.

Incidence and risk factors for postoperative shoulder imbalance in scoliosis: a systematic review and meta-analysis.

PURPOSE: This is the first systematic review and meta-analysis to detect the incidence and risk factors for postoperative shoulder imbalance (PSI) in scoliosis. METHODS: A systematic online search was conducted to identify eligible studies. ES, OR and WMD with 95% CI were used to assess the incidence and risk factors associated with PSI. RESULTS: Twenty-six studies were recruited. The pooled incidence of PSI was 25% (95% CI 20-31%). The incidence in Lenke 1 AIS, Lenke 2 AIS, Lenke 5 AIS and mixed AIS was 20% (9-31%), 26% (15-37%), 31% (17-45%) and 27% (19-35%), respectively. Using RSH ≥10 mm as the criterion of PSI, we found that preoperative LC, postoperative RSH, correction rate of MTC at follow-up were primary risk factors for PSI at follow-up. In the analysis of using RSH ≥20 mm as the criterion of PSI, our results showed that Risser sign, postoperative RSH, correction rate of PTC at follow-up, and LC at follow-up were contributing to PSI. Besides, scoliosis patients with PSI were more likely to suffer from adding-on. CONCLUSIONS: The pooled incidence of PSI in scoliosis was 25%. Risser sign, preoperative LC, postoperative RSH, correction rate of PTC at follow-up, correction rate of MTC at follow-up, and LC at follow-up were risk factors for PSI in patients with scoliosis. Adding-on might be a compensatory mechanism for PSI. It is recommended that (1) sufficient correction of PTC and moderate correction of MTC and LC in the operation should be performed; (2) PSI should be prevented not only for the patients' postoperative appearance, but also for preventing the adding-on phenomenon.

Unipedicular versus bipedicular percutaneous vertebroplasty for osteoporotic vertebral compression fractures: a prospective randomized study.

BACKGROUND: Percutaneous vertebroplasty (PVP) typically involves conventional lower-viscosity cement injection via bipedicular approach. Limited evidence is available comparing the clinical outcomes and complications in treating osteoporotic vertebral compression fractures (OVCFs) with PVP using high-viscosity cement through unipedicular or bipedicular approach. METHODS AND DESIGN: Fifty patients with OVCFs were randomly allocated into two groups adopting unipedicular or bipedicular PVP. The efficacy of unipedicular and bipedicular PVP was assessed by comparing operation time, X-ray exposure time, incidence of complications, vertebral height restoration, and improvement of the visual analogue scale (VAS), Oswestry disability index (ODI) and Short Form-36 (SF-36) General Health Survey scores. RESULTS: The mean operative and exposure time to X-rays in the unipedicular PVP group was less than that of the bipedicular group (p < 0.05). No statistically significant differences were observed in the VAS score, ODI score, SF-36 score, cement leakage rate or vertebral height restoration between the two groups (p > 0.05). CONCLUSION: Unipedicular and bipedicular PVP are safe and effective treatments for OVCF. Compared with bipedicular PVP, unipedicular PVP entails a shorter surgical time and lower X-ray irradiation.

Antibiotic penetration into rabbit nucleus pulposus with discitis.

OBJECTIVE: To assess the penetration into nucleus pulposus (NP) of cephazolin and clindamycin in a discitis model. MATERIALS AND METHODS: Twenty New Zealand white rabbits were inoculated with 103 Staphylococcus aureus at lumbar disc space. The rabbits with discitis confirmed by MRI 10 days after inoculation were divided into two groups. One was given cephazolin by intravenous (IV) at 80 mg/kg/day at 1.5 h interval for 5 half-lives; the other was given clindamycin by IV at 30 mg/kg/day at 2.5-h interval for 5 half-lives. Thirty minutes after completion of the last dose, NP and serum were sent to measure antibiotic concentration. RESULTS: Two rabbits died during inoculation. After 10 days, 18 rabbits were confirmed discitis in the inoculated levels. The cephazolin and clindamycin can diffuse throughout the infected, sham-infected and normal NP. The serum concentration of cephazolin and clindamycin was 251.3 ± 40.5 and 21.6 ± 4.71 mg/l, respectively. The cephazolin concentration in infected NP (1.93 ± 0.84 mg/l) was higher than that in sham-infected (1.73 ± 0.61 mg/l) and normal NP (1.68 ± 0.65 mg/l), but the difference showed no statistically significant (P > 0.05). The cephazolin penetration into NP averaged 0.68-0.77 % of serum level. The clindamycin concentration in infected NP (4.32 ± 1.54 mg/l) was higher than that in sham-infected NP (2.63 ± 1.26 mg/l) and normal NP (2.59 ± 1.01 mg/l) (P < 0.05). The penetration into NP averaged 11.9-20 % of serum level. There was no significance difference between sham-infected and normal NP in clindamycin and cephazolin concentration (P > 0.05). CONCLUSIONS: This study demonstrates cephazolin and clindamycin can penetrate the infected and normal NP. The antibiotics charge influences the delivery. Furthermore, infection condition selectively promotes antibiotic distribution within NP.

The Influence of Spray Cooling Parameters on Workpiece Residual Stress of Turning GH4169.

To effectively reduce residual stresses in GH4169 workpieces, thus enhancing fatigue strength and operational lifespan, this study investigates the influence of spray cooling parameters on surface residual stresses during GH4169 turning in spray cooling conditions, utilizing both simulation and experimental approaches. A simulation model of residual stresses was established using finite element analysis when GH4169 was cut in spray cooling. The effects of spray pressure and flow rate on residual tensile stresses were analyzed. The analysis reveals that with increasing spray pressure, residual tensile stresses show a decreasing trend, gradually stabilizing. Conversely, with an increasing spray flow rate, residual tensile stresses initially decrease and then increase. The turning experiments of GH4169 were conducted under different spray parameters. After the experiment, the workpiece was sectioned and analyzed for residual stresses using X-ray diffraction instrumentation. The value residual stress measured closely matched those of simulation, with a relative error within 6%, validating the accuracy of the simulation model and confirming the appropriateness of parameter settings. These results contribute to the further promotion of spray cooling technology and facilitate the rational selection of spray parameters.

A Bibliometric Analysis of Artificial Intelligence Applications in Spine Care.

BACKGROUND: With the rapid development of science and technology, artificial intelligence (AI) has been widely used in the diagnosis and prognosis of various spine diseases. It has been proved that AI has a broad prospect in accurate diagnosis and treatment of spine disorders. METHODS: On May 7, 2022, the Web of Science (WOS) Core Collection database was used to identify the documents on the application of AI in the field of spine care. HistCite and VOSviewer were used for citation analysis and visualization mapping. RESULTS: A total of 693 documents were included in the final analysis. The most prolific authors were Karhade A.V. and Schwab J.H. United States was the most productive country. The leading journal was Spine. The most frequently used keyword was spinal. The most prolific institution was Northwestern University in Illinois, USA. Network visualization map showed that United States was the largest network of international cooperation. The keyword "machine learning" had the strongest total link strengths (TLS) and largest number of occurrences. The latest trends suggest that AI for the diagnosis of spine diseases may receive widespread attention in the future. CONCLUSIONS: AI has a wide range of application in the field of spine care, and an increasing number of scholars are committed to research on the use of AI in the field of spine care. Bibliometric analysis in the field of AI and spine provides an overall perspective, and the appreciation and research of these influential publications are useful for future research.

The Efficacy and Safety of Topical Saline Irrigation with Tranexamic Acid on Perioperative Blood Loss in Patients Treated with Percutaneous Endoscopic Interlaminar Diskectomy: A Retrospective Study.

BACKGROUND: Tranexamic acid (TXA) is safe and effective in preventing bleeding during spinal surgery. However, there is currently no relevant research on the efficacy and safety of adding TXA to the saline irrigation fluid in percutaneous endoscopic interlaminar diskectomy (PEID). This study aimed to evaluate the efficacy and safety of topical saline irrigation with TXA for PEID in the treatment of lumbar disk herniation. METHODS: In this single-center, retrospective cohort study, patients who underwent PEID for L5-S1 lumbar disk herniation were included and allocated to two groups according to whether they had been administered TXA. PEID was performed with saline irrigation fluid containing 0.33 g of TXA per 1 L of saline in the TXA group (n = 38). In the control group (n = 51), the saline irrigation fluid was injected with the same volume of normal saline. All PEIDs were performed by the same spine surgery team. The hidden blood loss (HBL), intraoperative blood loss (IBL), total blood loss (TBL), amount of fluid used, operation time, visual clarity, hospital stay, blood transfusion rate, coagulation index, and complication rate were compared between the two groups. RESULTS: The TBL, HBL, and IBL in the TXA group were significantly lower than those of the control group. The postoperative hemoglobin in the TXA group was significantly higher than that of the control group. Visual clarity was significantly better and the operation time was significantly shorter in the TXA group. However, there was no significant difference in postoperative hematocrit, blood coagulation function, amount of fluid used, blood transfusion rate, and perioperative complications between the two groups. CONCLUSION: In PEID, the addition of TXA to topical saline irrigating fluid can significantly reduce the HBL, IBL, and TBL. The addition of TXA to topical saline irrigating fluid can improve visual clarity in the surgery and reduce operation time, but it does not change the coagulation function or the complication rate.

[Effect of electroacupuncture combined epidural anesthesia on plasma concentration of IL-1beta in patients undergoing gynecological surgery].

OBJECTIVE: To study the effect of electroacupuncture (EA) combined epidural anesthesia on plasma concentration of IL-1beta in patients undergoing gynecological surgery. METHODS: Forty patients who were scheduled to receive gynecological operation under epidural anesthesia were randomly assigned to the epidural anesthesia group (Group A, 20 cases) and the epidural combined EA group (Group B, 20 cases). All patients in the two groups received epidural anesthesia. Continuous EA at Zusanli (ST36) and Sanyinjiao (SP6) with the frequency of 30 -100 Hz was applied in those in Group B. The peri-operative hemodynamic changes, visual analog scale (VAS), and the plasma concentration of IL-1 3 were observed. RESULTS: There was no statistical difference in peri-operative hemodynamic changes between the two groups (P >0.05). Compared with Group A, the VAS was lower in Group B at post-operative 8, 24, and 48 h, respectively (P <0.05), and the plasma concentration of IL-1beta was also lower in Group B at post-operative 4 h, 24 h, and 3 days (P <0. 05). CONCLUSION: Acupuncture could ease postoperative pain and reduce the plasma concentration of IL-1beta.

Update on the roles of macrophages in the degeneration and repair process of intervertebral discs.

Intervertebral disc (IVD) degeneration is the common cause of lumbar degenerative diseases, causing severe social and economic burden. The process of IVD degeneration involves a complex of pathologic changes on both extracellular matrix degradation and resident cell apoptosis. In recent years, there is increasing evidence that macrophages play vital roles during the damage and repair process of IVD degeneration. Nevertheless, the interactions between macrophages and IVD are not well understood, even if the IVD has long been regarded as the immune privileged site. Therefore, this review mainly focuses on the progress and obstacles of studies investigating the blood supply, immune response and especially macrophages during the IVD degeneration process.

Role of regulatory T cells in spinal cord injury.

Spinal cord injury is an intricate process involving a series of multi-temporal and multi-component pathological events, among which inflammatory response is the core. Thus, it is crucial to find a way to prevent the damaging effects of the inflammatory response. The research has found that Treg cells can suppress the activation, proliferation, and effector functions of many parenchymal cells by multiple mechanisms. This review discusses how Treg cells regulate the inflammatory cells to promote spinal cord recovery. These parenchymal cells include macrophages/microglia, oligodendrocytes, astrocytes, and others. In addition, we discuss the adverse role of Treg cells, the status of treatment, and the prospects of cell-based therapies after spinal cord injury. In conclusion, this review provides an overview of the regulatory role of Treg cells in spinal cord injury. We hope to offer new insights into the treatment of spinal cord injury.

Safety and Efficacy of Local Steroid Application on Dysphagia Following Anterior Cervical Discectomy and Fusion: A Systematic Review and Meta-analysis.

STUDY DESIGN: A systematic review and meta-analysis. OBJECTIVE: To evaluate the safety and efficacy of local steroid application (LSA) on dysphagia after anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA: Dysphagia is one of the most common adverse events in the early postoperative period of ACDF. LSA is reported as an effective method to reduce the swelling of soft tissues, thereby decreasing the incidence of dysphagia. However, the safety and efficacy of LSA on dysphagia after ACDF need to be systematically reviewed and analyzed. METHODS: A comprehensive literature search was carried out in the database PubMed, Web of Science, EMBASE, Clinical key, Cochrane library, and Wiley Online Library to screen papers that report LSA in ACDF surgery. The Cochrane Collaboration tool and a methodological index for nonrandomized studies were used for the assessment of study quality. Data were analyzed with the Review Manager 5.3 software. RESULTS: A total of 10 studies were included. The results revealed no significant differences between the steroid group and the control group in ACDF regarding postoperative drainage, estimated blood loss, and neck disability index score ( P > 0.05). LSA significantly alleviates visual analog scale score for neck pain (or odynophagia) ( P < 0.05), reduces the length of hospital stay (weighted mean difference, -1.00 (-1.05 to -0.95); P < 0.001), and mitigates dysphagia rate and prevertebral soft-tissue swelling in the early postoperative period ( P < 0.05). There seemed to be no significant increase in the complication rate and steroid-related adverse events in the steroid group compared with the control group ( P < 0.05). CONCLUSIONS: LSA shows advantages in reducing the length of hospital stay, decreasing dysphagia rate, and mitigating prevertebral soft-tissue swelling in the early postoperative period of ACDF. Further large-scale studies are urgently required for the development of a standard protocol for LSA and further analysis of potential delay complications.

Incidence of Spontaneous Resorption of Lumbar Disc Herniation: A Meta-analysis.

STUDY DESIGN: A meta-analysis. OBJECTIVE: This study aimed to analyze the incidence of spontaneous resorption of lumbar disk herniation (LDH) after conservative treatment. SUMMARY OF BACKGROUND DATA: The resorption of intervertebral disks has been more frequently reported, but there is a lack of reference to the probability of resorption. METHODS: We strictly refer to the standard established in the PRISMA (Preferred Reporting Items for a Systematic Review and Meta-analysis) statement, comprehensively searched electronic databases using the terms related to the spontaneous resorption of LDH. Two reviewers independently evaluated the potential studies, extracted, and analyzed the enrolled data. RESULTS: Thirty-one studies with 2233 patients who received conservative treatment were included for this analysis. We found that the pooled overall incidence of disk resorption was 70.39%, 87.77% for disk sequestration, 66.91% for disk extrusion, 37.53% for disk protrusion, and 13.33% for disk bugle, respectively. The resorption incidence in of 25%≤ reduction of disk herniation (RDH) 50%, RDH≥50%, and RDH=100% were 40.19%, 43.62, and 36.89%. The resorption incidence was 66.98% in Japan, 61.66% in the United States, 83.52% in Korea, 60.68% in China, 78.30% in the UK, 56.70% in Italy, and 83.68% in Turkey, respectively. Subgroup analysis showed that there was no significant difference in resorption incidence among prospective, retrospective studies and randomized controlled trials (P=0.77), and there was no significant difference in evaluation method among qualitative and quantitative studies (P=0.05). CONCLUSIONS: The existing evidence shows that the overall resorption incidence of LDH was 70.39%, the resorption incidence of ruptured LDH is higher than that of contained LDH. There are significant differences in the resorption incidence among countries. The resorption process mainly occurred within 6 months of conservative treatment.

Influence of the facet joint angle on facet joint degeneration following pedicle screw fixation without fusion in thoracolumbar fractures.

BACKGROUND: Posterior approach pedicle screw fixation without fusion is widely used in the treatment of neurologically intact type A3 thoracolumbar fractures. OBJECTIVE: To analyze the influence of the facet joint (FJ) angle on FJ degeneration following posterior approach pedicle screw fixation without fusion in neurologically intact type A3 thoracolumbar fractures. METHODS: Fifty-eight patients who underwent pedicle screw fixation via the traditional posterior approach (n= 28) or the Wiltse approach (n= 30) were enrolled. A CT scan was performed before fixation and before fixation removal (Within 1.5 to 2 years after fixation) to evaluate the FJs parameters, including FJ inclination (FJI), FJ tropism (FJT), FJ violation, and FJ degeneration grade (FJDG), of three fixed segments and the adjacent segment below the fixed segments. RESULTS: There was no significant difference in FJ violation rate, FJDG deterioration, or FJ angle between the two groups (P> 0.05). FJDG deterioration showed a weak positive correlation with FJI and FJT before fixation, and the angular change in FJI (P< 0.05); and FJT before fixation and the angular change in FJI were risk factors for FJDG deterioration (P< 0.01). CONCLUSION: The Wiltse approach did not increase the rate of FJDG deterioration and FJs angle changes. However, the FJT before fixation and the angular change in FJI were risk factors for FJDG deterioration.

Nucleus Pulposus Cells Induce M2 Polarization of RAW264.7 via CX3CL1/CX3CR1 Pathway and M2 Macrophages Promote Proliferation and Anabolism of Nucleus Pulposus Cells.

Background: The mechanisms underlying M2 macrophage polarization induced by nucleus pulposus (NP) cells are unclear. The effects that M2-polarized macrophages have on NP cells are also controversial. Methods: Transcriptome sequencing was performed to detect the gene change profiles between NP cells from ruptured intervertebral disc (IVD) and normal IVD. The main difference on biological activities between the two cell groups were analyzed by GO analysis and KEGG analysis. Virus transduction, flow cytometry, immunofluorescence, RT-PCR, western blot, CCK-8, TUNEL staining, and AO/EB staining were performed to explore the interactions between NP cells and RAW264.7 macrophages. Statistics were performed using SPSS26. Results: 801 upregulated and 276 downregulated genes were identified in NP cells from ruptured IVD in mouse models. According to GO and KEGG analysis, we found that the differentially expressed genes (DEG) were dominantly enriched in inflammatory response, extracellular matrix degradation, blood vessel morphogenesis, immune effector process, ossification, chemokine signaling pathway, macrophage activation, etc. CX3CL1 was one of the top 20% DEG, and we confirmed that both NP tissue and cells expressed remarkably higher level of CX3CL1 in mouse models (p < 0.001∗). Besides, we further revealed that both the recombinant CX3CL1 and NP cells remarkably induced M2 polarization of RAW264.7 (p < 0.001∗), respectively, while this effect was significantly reversed by si-CX3CL1 or JMS-17-2 (p < 0.001∗). Furthermore, we found that M2 macrophages significantly decreased the apoptosis rate (p < 0.001∗) and the catabolic gene levels (p < 0.001∗) of NP cells, while increased the viability, proliferation as well as the anabolic gene levels of NP cells (p < 0.01∗). Conclusions: Via regulating CX3CL1/CX3CR1 pathway, NP cells can induce the M2 macrophage polarization. M2 polarized macrophages can further promote NP cell viability, proliferation, and anabolism, while inhibit NP cell apoptosis and catabolism.