Prediction of Screw Loosening After Dynamic Pedicle Screw Fixation With Lumbar Polyetheretherketone Rods Using Magnetic Resonance Imaging-Based Vertebral Bone Quality Score.

OBJECTIVE: To investigate the correlation between magnetic resonance imaging-based vertebral bone quality (VBQ) score and screw loosening after dynamic pedicle screw fixation with polyetheretherketone (PEEK) rods, and evaluate its predictive value. METHODS: A retrospective analysis was conducted on the patients who underwent dynamic pedicle screw fixation with PEEK rods from March 2017 to June 2022. Data on age, sex, body mass index, hypertension, diabetes, hyperlipidemia history, long-term smoking, alcohol consumption, VBQ score, L1-4 average Hounsfield unit (HU) value, surgical fixation length, and the lowest instrumented vertebra were collected. Logistic regression analysis was employed to assess the relationship between VBQ score and pedicle screw loosening (PSL). RESULTS: A total of 24 patients experienced PSL after surgery (20.5%). PSL group and non-PSL group showed statistical differences in age, number of fixed segments, fixation to the sacrum, L1-4 average HU value, and VBQ score (p < 0.05). The VBQ score in the PSL group was higher than that in the non-PSL group (3.56 ± 0.45 vs. 2.77 ± 0.31, p < 0.001). In logistic regression analysis, VBQ score (odds ratio, 3.425; 95% confidence interval, 1.552-8.279) were identified as independent risk factors for screw loosening. The area under the receiver operating characteristic curve for VBQ score predicting PSL was 0.819 (p < 0.05), with the optimal threshold of 3.15 (sensitivity, 83.1%; specificity, 80.5%). CONCLUSION: The VBQ score can independently predict postoperative screw loosening in patients undergoing lumbar dynamic pedicle screw fixation with PEEK rods, and its predictive value is comparable to HU value.

Clinical study on freehand of bicortical sacral screw fixation with the assistance of torque measurement device.

BACKGROUND: Sacral screw loosening is a typical complication after internal fixation surgery through the vertebral arch system. Bicortical fixation can successfully prevent screw loosening, and how improving the rate of bicortical fixation is a challenging clinical investigation. OBJECTIVE: To investigate the feasibility of improving the double corticality of sacral screws and the optimal fixation depth to achieve double cortical fixation by combining the torque measurement method with bare hands. METHODS: Ninety-seven cases of posterior lumbar internal fixation with pedicle root system were included in this study. Based on the tactile feedback of the surgeon indicating the expected penetration of the screw into the contralateral cortex of the sacrum, the screws were further rotated by 180°, 360°, or 720°, categorized into the bicortical 180° group, bicortical 360° group, and bicortical 720° group, respectively. Intraoperatively, the torque during screw insertion was recorded. Postoperatively, the rate of double-cortex engagement was evaluated at 7 days, and screw loosening was assessed at 1 year follow-up. RESULTS: The bicortical rates of the 180° group, 360° group, and 720° group were 66.13%, 91.18% and 93.75%, respectively. There were statistically significant differences between the 180° group and both the 360° and 720° groups (P < 0.05). However, there was no statistically significant difference between the 360° group and the 720° group (P > 0.05).The rates of loosening of sacral screws in the 180° group, 360° group, and 720° group were 20.97%, 7.35% and 7.81%, respectively. There were statistically significant differences between the 180° group and both the 360° and 720° groups (P < 0.05). However, there was no statistically significant difference between the 360° group and the 720° group (P > 0.05). The bicortical 360° group achieved a relatively satisfactory rate of dual cortical purchase while maintaining a lower rate of screw loosening. CONCLUSION: Manual insertion of sacral screws with the assistance of a torque measurement device can achieve a relatively satisfactory dual cortical purchase rate while reducing patient hospitalization costs.

Demethylation of TIMP2 and TIMP3 Inhibits Cell Proliferation, Migration, and Invasion in Pituitary Adenomas.

OBJECTIVE: Tissue inhibitors of matrix metalloproteinases (TIMPs) are prognostic markers in cancers. However, the role of TIMPs in DNA methylation during invasive pituitary adenoma (PA) remains unclear. The purpose of this study was to assess the effects of TIMP2 and TIMP3 promoter demethylation on the proliferation, migration, and invasion of invasive PA cells. METHODS: Methylation-specific polymerase chain reaction (PCR), quantitative PCR, and western blots were used to analyze the promoter methylation and expression of TIMP1-3. Cell counting kit-8 (CCK-8), wound healing, and transwell assays were carried out to determine the effects of TIMP2 and TIMP3 demethylation. RESULTS: TIMP1-3 showed downregulated expression in invasive PA tissues and cell lines (p < 0.05). The low expression of TIMP1-3 was due to promoter methylation of these genes (p < 0.05). The results showed that downregulation of TIMP2 and TIMP3 can promote cell proliferation, migration, and invasion (p < 0.05), whereas overexpression of TIMP2 and TIMP3 can inhibit cell proliferation, migration, and invasion (p < 0.05). After treatment with 5-azacytidine (5-AzaC), the cell activity decreased, the proliferation rate decreased, and the invasion ability weakened (p < 0.05). Treatment with 5-AzaC increased TIMP2 and TIMP3 expression and decreased DNA (cytosine-5-)-methyltransferase 1 (DNMT1), DNMT3a, and DNMT3b expression (p < 0.05). CONCLUSIONS: We showed that DNA methylation causes the silencing of TIMP2 and TIMP3 in invasive PA, it can also lead to malignant cell proliferation and cause pathological changes, whereas the use of 5-AzaC can inhibit the methylation process and can inhibit cell proliferation. Our results provide a novel method for clinical diagnosis and prevention of invasive PA.

New evidence on the controversy over the correlation between vertebral osteoporosis and intervertebral disc degeneration: a systematic review of relevant animal studies.

OBJECTIVE: The effect of vertebral osteoporosis on disc degeneration remains controversial. The aim of this study was to conduct a systematic review and meta-analysis of relevant animal studies to shed more light on the effects and mechanisms of vertebral osteoporosis on disc degeneration and to promote the resolution of the controversy. METHODS: The PubMed, Cochrane Library, and Embase databases were searched for studies that met the inclusion criteria. Basic information and data were extracted from the included studies and data were analyzed using STATA 15.1 software. This study was registered on INPLASY with the registration number INPLASY202370099 and https://doi.org/10.37766/inplasy2023.7.0099 . RESULTS: A total of 13 studies were included in our study. Both animals, rats and mice, were covered. Meta-analysis results showed in disc height index (DHI) (P < 0.001), histological score (P < 0.001), number of osteoblasts in the endplate (P = 0.043), number of osteoclasts in the endplate (P < 0.001), type I collagen (P < 0.001), type II collagen (P < 0.001), aggrecan (P < 0.001), recombinant a disintegrin and metalloproteinase with thrombospondin-4 (ADAMTS-4) (P < 0.001), matrix metalloproteinase-1 (MMP-1) (P < 0.001), MMP-3 (P < 0.001), MMP-13 (P < 0.001), the difference between the osteoporosis group and the control group was statistically significant. In terms of disc volume, the difference between the osteoporosis group and the control group was not statistically significant (P = 0.459). CONCLUSION: Our study shows that vertebral osteoporosis may exacerbate disc degeneration. Abnormal bone remodeling caused by vertebral osteoporosis disrupts the structural integrity of the endplate, leading to impaired nutrient supply to the disc, increased expression of catabolic factors, and decreased levels of type II collagen and aggrecan may be one of the potential mechanisms.

Timing of decompression in central cord syndrome: a systematic review and meta-analysis.

PURPOSE: This study compared the recovery of motor function and the safety of early and delayed surgical intervention in patients with central cord syndrome (CCS). METHODS: PubMed, Embase, Cochrane Library, and Web of Science were employed to retrieve the targeted studies published from inception to February 19, 2023. Comparative studies of early versus delayed surgical decompression in CCS based on American Spinal Injury Association motor score (AMS) recovery, complication rates, and mortality were selected. The statistical analyses were performed using STATA 16.0 and RevMan 5.4. RESULTS: Our meta-analysis included 13 studies comprising 8424 patients. Results revealed that early surgery improved AMS scores significantly compared with delayed surgery, with an increase in MDs by 7.22 points (95% CI 1.98-12.45; P = 0.007). Additionally, early surgery reduced the complication rates than delayed surgery (OR 0.53, 95% CI 0.42-0.67, P < 0.00001). However, no significant difference was observed in mortality between the two groups (OR 0.97; 95% CI 0.75-1.26; P = 0.84). CONCLUSIONS: Early surgical decompression for CCS can improve motor function and reduce the incidence of complications without affecting the mortality rate in patients. Future research should focus on investigating and analyzing the optimal window period for early CCS surgery. Additionally, the timing of surgery should be determined based on the patient's condition and available medical resources.

[Metabolomics of quality formation of different cultivars of Peucedanum praeruptorum].

This study aims to reveal the quality formation of different cultivars of Peucedanum praeruptorum based on the metabolic differences and provide a theoretical basis for the development and utilization of this medicinal herb. The non-target metabonomics analysis based on ultra-high performance liquid chromatography tandem mass spectrometry(UHPLC-MS/MS) was conducted for six cultivars(YS, H, LZ, LY, LX, and Z) of P. praeruptorum of the same origin and at the same development stage. The principal component analysis, orthogonal partial least squares discriminant analysis, and univariate statistical analysis were carried out to screen the differential metabolites of different cultivars. The potential biomarkers associated with quality formation were predicted based on the mass-to-charge ratio, Kyoto Encyclopedia of Genes and Genomes pathway enrichment, information of relevant literature, and correlation analysis. The results showed that metabolites differed significantly among the six cultivars, and 571 and 465 differential metabolites were obtained in the positive and negative ion modes, respectively. From the differential metabolites, 22 potential biomarkers related to quality formation were predicted, which involved 9 metabolic pathways, including phenylalanine, tyrosine and tryptophan biosynthesis, biosynthesis of phenylpropanoids, and biosynthesis of plant hormones. Compared with the YS cultivar, other cultivars showed decreased concentrations of psoralen, imperatorin, and luvangetin and increased concentrations of 7-hydroxycoumarine, esculetin, columbianetin, and jasmonic acid, which were involved in the biosynthesis of phenylpropanoids. The concentrations of 2-succinylbenzoate, heraclenol, and L-tyrosine involved in other metabolic pathways decreased, especially in the Z and H cultivars. Therefore, regulating the biosynthesis of phenylpropanoids is one of the key mechanisms for improving the cultivar quality of P. praeruptorum. The Z and H cultivars have better quality and metabolic processes than other cultivars and thus can be used for the screening and breeding of high-quality germplasm.

Axon-like aligned conductive CNT/GelMA hydrogel fibers combined with electrical stimulation for spinal cord injury recovery.

Rehabilitation and regenerative medicine are two promising approaches for spinal cord injury (SCI) recovery, but their combination has been limited. Conductive biomaterials could bridge regenerative scaffolds with electrical stimulation by inducing axon regeneration and supporting physiological electrical signal transmission. Here, we developed aligned conductive hydrogel fibers by incorporating carbon nanotubes (CNTs) into methacrylate acylated gelatin (GelMA) hydrogel via rotating liquid bath electrospinning. The electrospun CNT/GelMA hydrogel fibers mimicked the micro-scale aligned structure, conductivity, and soft mechanical properties of neural axons. For in vitro studies, CNT/GelMA hydrogel fibers supported PC12 cell proliferation and aligned adhesion, which was enhanced by electrical stimulation (ES). Similarly, the combination of aligned CNT/GelMA hydrogel fibers and ES promoted neuronal differentiation and axon-like neurite sprouting in neural stem cells (NSCs). Furthermore, CNT/GelMA hydrogel fibers were transplanted into a T9 transection rat spinal cord injury model for in vivo studies. The results showed that the incorporating CNTs could remain at the injury site with the GelMA fibers biodegraded and improve the conductivity of regenerative tissue. The aligned structure of the hydrogel could induce the neural fibers regeneration, and the ES enhanced the remyelination and axonal regeneration. Behavioral assessments and electrophysiological results suggest that the combination of aligned CNT/GelMA hydrogel fibers and ES could significantly restore motor function in rats. This study demonstrates that conductive aligned CNT/GelMA hydrogel fibers can not only induce neural regeneration as a scaffold but also support ESto promote spinal cord injury recovery. The conductive hydrogel fibers enable merging regenerative medicine and rehabilitation, showing great potential for satisfactory locomotor recovery after SCI.

Changes in the centre of rotation and the anterior bone loss of the vertebral body in Mobi-C artificial disc replacement segments after cervical hybrid surgery: a retrospective study.

OBJECTIVE: To examine the short-term efficacy and imaging results of using the Mobi-C in cervical hybrid surgery on 2-level cervical spondylolisthesis. To observe post-operative changes in the flexion-extension centre of rotation (FE-COR) and anterior bone loss (ABL) of the anterior cervical disc replacement (ACDR) segment. METHODS: Forty-two patients (20 males and 22 females, aged 42‒67 years) who underwent cervical hybrid surgery were retrospectively analysed. Their ACDR segment used Mobi-C, and the fusion segment used ROI-C, with a follow-up of 25‒42 months (31.1 ± 4.8 months). The modified Japanese Orthopaedic Association (mJOA) score, Neck Disability Index (NDI), and visual analogue scale (VAS) were used to assess clinical outcomes. Pre-operative, 6-month post-operative, and final follow-up radiographs were collected to compare total cervical spine curvature (C2-C7), curvature of the operated segments, range of motion (ROM) in the total cervical spine, operated segmental ROM, ACDR segmental ROM, and operated adjacent segmental ROM. The height of the superior articular process (HSAP), the orientation of zygapophyseal joint spaces (OZJS), and the length of the superior articular surface (LSAS) were measured. The FE-COR of the ACDR segment was measured using the mid-plumb line method. The translation distance of the Mobi-C was measured. The degree of disc degeneration in the adjacent segment, bony fusion of the ACDF segment, and ABL of the upper and lower vertebra of the ACDR segment were observed. RESULTS: In our group, all patients have shown improvements in their postoperative mJOA, NDI, and VAS scores. Overall cervical ROM and surgical segmental ROM decreased (P < 0.05). However, there was no significant decrease in ACDR segmental ROM and upper or lower adjacent segmental ROM compared with pre-operatively (P > 0.05). For FE-COR-X, only the last follow-up compared with pre-surgery showed statistical significance (46.74 ± 7.71% vs. 50.74 ± 6.92%, P < 0.05). For FE-COR-Y, the change was statistically significant at both 6 months post-operation and the final follow-up compared to pre-operation (45.37% ± 21.11% vs. 33.82% ± 10.87%, 45. 37% ± 21.11% vs. 27.48% ± 13.58%, P < 0.05). No significant difference in the Mobi-C translation distance was observed (P > 0.05). Moreover, the difference in HSAP was not statistically significant at each node (P > 0.05). The OZJS and LSAS were significantly different at the final follow-up compared to the pre-operative period (P < 0.05). All the ACDF segments were observed in a stable condition at the final follow-up. Furthermore, 9 of the adjacent segments showed imaging ASD (9/82, 10.98%), and all were present at the last follow-up, of which 6 were mild, and 3 were moderate. Twenty of the 42 Mobi-C segments had no significant ABL (grade 0) 6 months post-operatively (47.62%). Sixteen cases (38.10%) showed mild ABL (grade 1), and 6 cases (14.28%) showed moderate ABL (grade 2). No severe ABL occurred. CONCLUSION: The cervical hybrid surgery using Mobi-C artificial cervical discs can achieve satisfactory results. The Mobi-C segmental FE-COR-X shows a slow forward shift trend, and FE-COR-Y drops noticeably within 6 months post-surgery before stabilizing. It's common to see mild to moderate ABL after cervical hybrid surgery using Mobi-C, and significant progression is unlikely in the short term. Furthermore, changes in the FE-COR after hybrid surgery in the Mobi-C segment might not affect clinical outcomes.

The application of stem cell sheets for neuronal regeneration after spinal cord injury: a systematic review of pre-clinical studies.

BACKGROUND: Stem cell sheet implantation offers a promising avenue for spinal cord injury (SCI) and is currently under investigation in pre-clinical in vivo studies. Nevertheless, a systematic review of the relevant literature is yet to be performed. Thus, this systematic review aims to explore the efficacy of stem cell sheet technology in treating SCI, as indicated by experimental animal model studies. METHODS: We searched PubMed, EMBASE, and Web of Science. Manuscripts that did not pertain to in vivo pre-clinical studies and those published in non-English languages were excluded. A risk assessment for bias was performed using the SYRCLE tool. Extracted data were synthesized only qualitatively because the data were not suitable for conducting the meta-analysis. RESULTS: Among the 847 studies retrieved from electronic database searches, seven met the inclusion criteria. Six of these studies employed a complete transection model, while one utilized a compression model. Stem cell sources included bone marrow mesenchymal stem cells, stem cells from human exfoliated deciduous teeth, and adipose-derived mesenchymal stem cells. In all included studies, stem cell sheet application significantly improved motor and sensory functional scores compared to intreated SCI rats. This functional recovery correlated with histological improvements at the injury site. All studies are at low risk of bias but certain domains were not reported by some or all of the studies. CONCLUSION: The results of our systematic review suggest that stem cell sheets may be a feasible therapeutic approach for the treatment of SCI. Future research should be conducted on stem cell sheets in various animal models and types of SCI, and careful validation is necessary before translating stem cell sheets into clinical studies.

The correlation between the lumbar disc MRI high-intensity zone and discogenic low back pain: a systematic review and meta-analysis.

OBJECTIVE: This study aimed to investigate the correlation between the MRI high-intensity zone (HIZ) and the pathogenesis of discogenic low back pain. METHODS: Literature from PubMed, EMBASE, Cochrane Library, Science Direct, China Knowledge Network, Wanfang Database, and China Biomedical Literature Database was searched until August 2023. Cohort studies including patients with low back pain who underwent lumbar spine MRI and discography, as well as the results evaluating the correlation between HIZ and discography for morphological changes in the disc and pain replication phenomena, were included in the analysis. The literature that met the inclusion criteria was screened, and the methodological quality of the included studies was evaluated. Meta-analysis of the extracted data was performed by using RevMan 5.1.1. RESULTS: In total, 28 reports were included in this meta-analysis. There was a statistically significant correlation between a positive HIZ and abnormal disc morphology in discography (OR 28.15, 95% CI [7.38, 107.46], p < 0.00001). Patients with HIZ-positive discs had a significantly higher incidence of consistent pain (71.0%, 969/1365) than those with HIZ-negative imaging (29.0%, 1314/4524) (OR 7.71, 95% CI [5.29, 11.23], p < 0.00001).Segments that were HIZ-positive and had abnormal disc morphology had a higher incidence of consistent pain (86.1%, 230/267) than HIZ-negative subjects (32.2%, 75/233) (OR 14.09, 95% CI [2.12, 93.48], p = 0.006). CONCLUSION: A positive MRI T2-weighted image of the lumbar disc with HIZ indicates disc degeneration. In addition, HIZ may be a specific indicator for the physical diagnosis of discogenic low back pain. A more advanced degree of disc degeneration on the basis of HIZ positivity corresponded to a greater probability of discography-induced consistent pain, whereas the degree of disc degeneration on the basis of HIZ negativity was less correlated with contrast-induced consistent pain.

Biomechanical and clinical research of Isobar semi-rigid stabilization devices for lumbar degenerative diseases: a systematic review.

While lumbar spinal fusion using rigid rods is a prevalent surgical technique, it can lead to complications such as adjacent segment disease (ASDis). Dynamic stabilization devices serve to maintain physiological spinal motion and alleviate painful stress, yet they are accompanied by a substantial incidence of construct failure and subsequent reoperation. Compared to traditional rigid devices, Isobar TTL semi-rigid stabilization devices demonstrate equivalent stiffness and effective stabilization capabilities. Furthermore, when contrasted with dynamic stabilization techniques, semi-rigid stabilization offers improved load distribution, a broader range of motion within the fixed segment, and reduced mechanical failure rates. This paper will review and evaluate the clinical and biomechanical performance of Isobar TTL semi-rigid stabilization devices. A literature search using the PubMed, EMBASE, CNKI, Wanfang, VIP, and Cochrane Library databases identified studies that met the eligibility criteria. Twenty-eight clinical studies and nine biomechanical studies were included in this systematic review. The VAS, the ODI, and Japanese Orthopedic Association scoring improved significantly in most studies. UCLA grading scale, Pfirrmann grading, and modified Pfirrmann grading of the upper adjacent segments improved significantly in most studies. The occurrence rate of ASD was low. In biomechanical studies, Isobar TTL demonstrated a superior load sharing distribution, a larger fixed segment range of motion, and reduced stress at the rod-screw/screw-bone interfaces compared with titanium rods. While findings from mechanical studies provided promising results, the clinical studies exhibited low methodological quality. As a result, the available evidence does not possess sufficient strength to substantiate superior outcomes with Isobar semi-rigid system in comparison to titanium rods. To establish more conclusive conclusions, further investigations incorporating improved protocols, larger sample sizes, and extended follow-up durations are warranted.

Does vertebral osteoporosis delay or accelerate lumbar disc degeneration? A systematic review.

The effect of vertebral osteoporosis on disc degeneration is still debated. The purpose of this study was to provide a systematic review of studies in this area to further reveal the relationship between the two. Relevant studies were searched in electronic databases, and studies were screened according to inclusion and exclusion criteria, and finally, basic information of the included studies was extracted and summarized. This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A total of 34 publications spanning 24 years were included in our study. There were 19 clinical studies, including 12 prospective studies and 7 retrospective studies. Of these, 7 considered vertebral osteoporosis to be positively correlated with disc degeneration, 8 considered them to be negatively correlated, and 4 considered them to be uncorrelated. Two cadaveric studies were included, one considered the two to be negatively correlated and one considered them not to be correlated. Seven animal studies were included, of which five considered a positive correlation between vertebral osteoporosis and disc degeneration and two considered a negative correlation between the two. There were also 6 studies that used anti-osteoporosis drugs for intervention, all of them were animal studies. Five of them concluded that vertebral osteoporosis was positively associated with disc degeneration, and the remaining one concluded that there was no correlation between the two. Our systematic review shows that the majority of studies currently consider an association between vertebral osteoporosis and disc degeneration, but there is still a huge disagreement whether this association is positive or negative. Differences in observation time and follow-up time may be one of the reasons for the disagreement. A large number of clinical and basic studies are still needed in the future to further explore the relationship between the two.

Comparative efficacy of five most common traditional Chinese medicine monomers for promoting recovery of motor function in rats with blunt spinal cord injury: a network meta-analysis.

Objective: This research employed a network meta-analysis (NMA) to examine the effectiveness of five traditional Chinese medicine (TCM) monomers for promoting motor function recovery in rats with blunt spinal cord injury (SCI). Methods: Wangfang, China National Knowledge Infrastructure, Web of Science, Embase, Chinese Scientific Journal Database, PubMed, and the Chinese Biomedical Literature Databases were searched for retrieving relevant articles published from their inception to December 2022. Two reviewers performed screening of search results, data extraction, and literature quality assessment independently. Results: For this meta-analysis, 59 publications were included. Based on the recovery of motor function at weeks 1, 2, 3, and 4 in NMA, almost all TCM groups had significantly increased positive effects than the negative control animals. In terms of cumulative probability, the tanshinone IIA (TIIA) group ranked first in restoring motor function in the first week after blunt SCI, and the resveratrol (RSV) group ranked first during the last 3 weeks. Conclusion: The NMA revealed that TCM monomers could effectively restore motor function in the rat model of blunt SCI. In rats with blunt SCI, TIIA may be the most effective TCM monomer during the first week, whereas RSV may be the most effective TCM monomer during the last 3 weeks in promoting motor function recovery. For better evidence reliability in preclinical investigations and safer extrapolation of those findings into clinical settings, further research standardizing the implementation and reporting of animal experiments is required. Systematic Review Registration: https://inplasy.com/, identifier INPLASY202310070.

Polyetheretherketone (PEEK) rods versus titanium rods for posterior lumbar fusion surgery: a systematic review and meta-analysis.

BACKGROUND: Rigid fixation, represented by titanium rods, is a widely used fixation technique for lumbar fusion. However, this technique carries the risk of degeneration of adjacent segments. In recent years, the semi-rigid fixation technique represented by PEEK rods has gradually matured, and its effectiveness has been verified by numerous studies. The aim of this study was to systematically evaluate the effectiveness of these two fixation modalities in posterior lumbar fusion surgery. METHODS: Studies meeting the inclusion criteria were searched in PubMed, Cochrane Library, ScienceDirect, Embase, CNKI, and Wanfang databases. After data extraction and quality assessment of included studies, meta-analysis was performed using STATA 15.1 software. The protocol for this systematic review was registered on INPLASY (2021110049) and is available in full on the inplasy.com ( https://inplasy.com/inplasy-2021-11-0049/ ). RESULTS: Fifteen relevant studies were finally included, including eight prospective studies and seven retrospective studies. The results of meta-analysis showed that in ODI (P = 0.000), JOA score (P = 0.017), VAS score for lower limb pain (P = 0.027), fusion rate of bone graft at week 12 (P = 0.001), fusion rate of bone graft at last follow-up (P = 0.028), there was a statistical difference between the two groups. The PEEK rod group was superior to the titanium rod group in the above aspects. While in VAS score for LBP (P = 0.396), there was no statistical difference between the two groups. CONCLUSION: Both PEEK rods and titanium rods are effective fixation materials in lumbar fusion surgery. PEEK rods may be superior to titanium rods in improving postoperative function and improving bone graft fusion rates. However, given the limitations of this study, whether these conclusions are applicable needs further research.

Isobar hybrid dynamic stabilization with posterolateral fusion in mild and moderate lumbar degenerative disease.

OBJECTIVE: The aim of this study was to investigate the feasibility of using the Isobar TTL system and posterolateral fusion in a two-segment hybrid fixation approach, combined with spinal decompression, for treating mild and moderate lumbar degenerative disease. Specifically, we sought to evaluate the effectiveness of this approach for managing two-segment mild and moderate lumbar degenerative disease, and to determine whether it could provide a safe and reliable alternative to traditional surgical methods. METHODS: This retrospective study included 45 consecutive patients with two-level lumbar disc herniation or spinal stenosis, 24 of whom underwent the TTL system and posterolateral fusion combined (TTL group), and 21 of whom underwent posterolateral fusion alone (Rigid group). The surgical segment, admission diagnosis, operation time, and intraoperative bleeding were recorded separately for the two groups of patients. Imaging studies included pre- and postoperative radiography, magnetic resonance imaging, and computed tomography. The clinical outcomes were measured by Oswestry Disability Index (ODI) scores, and a visual analogue scale (VAS) for back and leg pain. RESULTS: All patients completed the surgery successfully with a mean follow-up of 56.09 months. The operative time and intraoperative bleeding were lower in the TTL group than in the Rigid group (p < 0.05). All patients showed significant improvements in clinical outcomes, including VAS for back and leg pain, and ODI scores (p < 0.05). ODI scores, the TTL group was better than the Rigid group at 1 year after surgery and at the final follow-up (p < 0.05). Postoperative surgical segment range of motion (ROM) decreased in both groups (p < 0.05). The postoperative ROM of the upper adjacent segment increased in both groups and was significantly higher in both groups at the last follow-up compared with the preoperative period (p < 0.05), and the superior adjacent segment rom of the TTL group was lower than the Rigid group (p < 0.05). The modified Pfrrmann classification of the superior adjacent segment was significantly increased in both groups at the last follow-up (p < 0.05). And in the TTL group, ROM, DH, and modified Pfrrmann grading of dynamic segment outperformed fusion segments. According to the UCLA classification, the incidence of adjacent segment degeneration (ASD) was 4.2% in the TTL group and 23.8% in the Rigid group, and the incidence of ASD was lower in the TTL group than in the Rigid group (P < 0.05). CONCLUSION: The Isobar TTL System was utilized in two-level lumbar hybrid surgery, resulting in no evident indications of lumbar instability being detected on X-rays captured at a minimum of 4 years after the operation, while retaining partial range of motion of the surgical segment. The general clinical efficacy is equivalent to titanium rod fusion surgery, presenting an alternative treatment for individuals with mild and moderate lumbar degenerative disease.

Correlation between surgical segment mobility and paravertebral muscle fatty infiltration of upper adjacent segment in single-segment LDD patients: retrospective study at a minimum 2 years' follow-up.

OBJECTIVE: The purpose of this study was to investigate the relationship between surgical segment mobility and fatty infiltration of the adjacent segment paravertebral muscles in patients with single-segment lumbar degenerative disease (LDD) who underwent decompression with fusion or dynamic stabilization. METHODS: Retrospective analysis of patients who underwent lumbar decompression combined with titanium rod fixation intertransverse fusion (PITF group), Isobar TTL dynamic stabilization (TTL group) or Isobar EVO dynamic stabilization (EVO group) for single-segment lumbar degenerative disease, from March 2012 to July 2018. The preoperative and final follow-up clinical indexes C-LDSI and the measured imaging indexes (range of motion of the surgical segment and the upper adjacent segment, and Goutallier grade of the upper adjacent segment) were counted, and the differences between the preoperative and final follow-up indexes were compared. RESULTS: According to the inclusion and exclusion criteria, 68 patients were included in this study, 21 in the PITF group, 24 in the TTL group, and 23 in the EVO group. At the final follow-up, the C-LSDI score had significantly higher in the PITF group than the TTL and EVO groups, and the C-LSDI score was a very strongly negatively correlated with ROM of surgical segment (r=-0.7968, p < 0.001). There was a strong negative correlation between surgical segment and upper adjacent segment mobility (r = -0.6959, p < 0.001). And there was a very strong negative correlation between ROM of surgical segment and upper adjacent segment paravertebral muscle Goutallier classification (r = -0.8092, p < 0.001), whereas the ROM of the upper adjacent segment was strong positive correlated with the Goutallier classification (r = 0.6703, P < 0.001). CONCLUSION: Compared with decompression combined with rigid fusion, decompression combined with dynamic fixation for single-segment lumbar degenerative disease can significantly reduce postoperative low back stiffness. And a certain range of increased mobility of the dynamic stabilization device can effectively reduce the compensatory mobility of the upper adjacent segment and slow down the fatty infiltration of the paravertebral muscle in the adjacent segment.

Comparison between single-segment Isobar EVO dynamic stabilization and Isobar TTL dynamic stabilization in the treatment of lumbar degenerative diseases: a single center retrospective study over 4 years.

OBJECTIVE: Posterior instrumented fusion is the most widely accepted surgical treatment for spinal stenosis and disc herniation. However, fusion can affect daily activities due to lumbar stiffness. In recent years, dynamic stabilization has been introduced to overcome the drawbacks of fusion, however, it is inconclusive whether dynamic stabilization requires the maintenance of a level of activity that is closer to the physiological state of activity for better clinical efficacy. The purpose of this study was to compare the effectiveness of dynamic stabilization with different levels of activity (Isobar EVO and TTL) in the treatment of spinal stenosis and disc herniation. METHODS: This study retrospectively reviewed 80 consecutive patients with lumbar degenerative diseases who were undergoing surgical treatment between March 2014 and July 2018. 41 patients (EVO group) and 39 patients (TTL group) underwent fenestrated decompression with Isobar EVO stabilization and Isobar TTL stabilization, respectively. Clinical outcomes, radiographic data, and postoperative complications were compared between the two groups. RESULTS: At an average follow-up of 52.23 ± 2.97 months, there were no significant differences in the oswestry disability index (ODI) (P > 0.05). The visual analog scale for back pain (VASback) and visual analog scale for the leg pain (VASleg) of the EVO group were lower compared with the TTL group (P < 0.05). The range of motion (ROM) of operated segments were significantly higher in the EVO group as compared to the TTL group (P < 0.05). The intervertebral space height (ISH) of upper adjacent segments were significantly higher in the EVO group as compared to the TTL group (P < 0.05). The overall complications were less in the EVO group, but the difference was not statistically significant (P > 0.05). CONCLUSION: Both Isobar EVO dynamic stabilization and TTL dynamic stabilization can improve clinical outcomes of patients with spinal stenosis and disc herniation. Isobar EVO has advantages over Isobar TTL in terms of improving low back and leg pain, maintaining mobility of the operated segment, and preventing further degeneration of the upper adjacent segment.

Evaluation of the Efficacy of Stem Cell Therapy in Animal Models of Intervertebral Disc Degeneration Based on Imaging Indicators: A Systematic Review and Meta-Analysis.

Objective: The purpose of this study is to make a systematic review of the therapeutic effect of stem cells in animal models of disc degeneration from an imaging point of view. Methods: Data were extracted by searching electronic databases for RCTs that met the inclusion criteria. Data analysis was performed using RevMan 5.3 and STATA 15.1 software. This meta-analysis was registered with INPLASY, registration number INPLASY202240148. Results: A total of 34 studies were included, covering four species of animals, rabbits, sheep, rats, and mice, with a total of 1163 intervertebral discs. In terms of DHI, the efficacy of stem cell group in rabbits (P < 0.001), mice (P < 0.001), sheep (P < 0.001), and rats (P = 0.001) was better than that in control group. In terms of disc height, the efficacy of stem cell group in rats (P < 0.001) was better than that in control group, while in sheep (P = 0.355), there was no statistical difference between two groups. In terms of MRI index, the efficacy of stem cell group in rats (P < 0.001), mice (P < 0.001), and rabbits (P = 0.016) was better than that in control group. In terms of MRI signal score, the efficacy of stem cell group in rabbits (P < 0.001) was better than that of control group. In terms of T2 signal intensity, stem cell group was more effective than control group in rabbits (P < 0.001), mice (P < 0.001), and rats (P = 0.003). Conclusion: Stem cell therapy can improve intervertebral disc-related imaging parameters in animal models of disc degeneration, indicating that stem cell therapy has a repairing effect on intervertebral discs. However, given the heterogeneity and limitations of this study, this conclusion still needs to be tested by a large number of studies.

White matter regeneration induced by aligned fibrin nanofiber hydrogel contributes to motor functional recovery in canine T12 spinal cord injury.

A hierarchically aligned fibrin hydrogel (AFG) that possesses soft stiffness and aligned nanofiber structure has been successfully proven to facilitate neuroregeneration in vitro and in vivo. However, its potential in promoting nerve regeneration in large animal models that is critical for clinical translation has not been sufficiently specified. Here, the effects of AFG on directing neuroregeneration in canine hemisected T12 spinal cord injuries were explored. Histologically obvious white matter regeneration consisting of a large area of consecutive, compact and aligned nerve fibers is induced by AFG, leading to a significant motor functional restoration. The canines with AFG implantation start to stand well with their defective legs from 3 to 4 weeks postoperatively and even effortlessly climb the steps from 7 to 8 weeks. Moreover, high-resolution multi-shot diffusion tensor imaging illustrates the spatiotemporal dynamics of nerve regeneration rapidly crossing the lesion within 4 weeks in the AFG group. Our findings indicate that AFG could be a potential therapeutic vehicle for spinal cord injury by inducing rapid white matter regeneration and restoring locomotion, pointing out its promising prospect in clinic practice.

Biphasic mineralized collagen-based composite scaffold for cranial bone regeneration in developing sheep.

Appropriate mechanical support and excellent osteogenic capability are two essential prerequisites of customized implants for regenerating large-sized cranial bone defect. Although porous bone scaffolds have been widely proven to promote bone regeneration, their weak mechanical properties limit the clinical applications in cranioplasty. Herein, we applied two previously developed mineralized collagen-based bone scaffolds (MC), porous MC (pMC) and compact MC (cMC) to construct a biphasic MC composite bone scaffold (bMC) to repair the large-sized cranial bone defect in developing sheep. A supporting frame composed of cMC phase in the shape of tic-tac-toe structure was fabricated first and then embedded in pMC phase. The two phases had good interfacial bond, attributing to the formation of an interfacial zone. The in vivo performance of the bMC scaffold was evaluated by using a cranial bone defect model in 1-month-old sheep. The computed tomography imaging, X-ray scanning and histological evaluation showed that the pMC phase in the bMC scaffold, similar to the pMC scaffold, was gradually replaced by the regenerative bone tissues with comprehensively increased bone mineral density and complete connection of bone bridge in the whole region. The cMC frame promoted new bone formation beneath the frame without obvious degradation, thus providing appropriate mechanical protection and ensuring the structural integrity of the implant. In general, the sheep with bMC implantation exhibited the best status of survival, growth and the repair effect. The biphasic structural design may be a prospective strategy for developing new generation of cranioplasty materials to regenerate cranial bone defect in clinic.