Neurospine最新文献

Lumbar disc herniation (LDH) is one of the most common causes of low back and leg pain. While mechanical and degenerative factors have long been considered the main contributors, persistent or recurrent symptoms in many patients suggest additional biological mechanisms. Recent research has highlighted the microbiome as a potential modulator of inflammation, immune response, and pain sensitization, introducing the "gut-spine axis" concept. This scoping review summarizes the current evidence on the role of both gut and local disc microbiota in LDH. A systematic search of PubMed/MEDLINE and Scopus was conducted up to June 2025, following PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews) guidelines. Twenty-six studies were included, encompassing preclinical and clinical investigations. Animal models showed that LDH may alter gut microbial composition and that microbiome-targeted interventions can reduce inflammation, neuroinflammatory signaling, and pain sensitivity. In human studies, low-virulence bacteria, particularly Cutibacterium acnes, were frequently detected in surgically excised intervertebral discs, although results were inconsistent due to methodological heterogeneity and potential contamination. Some studies reported associations between bacterial colonization and Modic changes, disc height loss, or chronic pain. Additionally, genetic and metabolomic data suggest that gut dysbiosis and related microbial metabolites may influence systemic immune and metabolic pathways implicated in disc degeneration and pain perception. Overall, the current evidence suggests the biological plausibility of microbiome involvement in LDH pathophysiology, acting through both systemic and local mechanisms. However, the available data remain preliminary, and no mechanistic study has confirmed the observed correlations to date. Further standardized, contamination-aware studies are required to clarify causality and explore microbiome-targeted therapeutic strategies.

Objective: This study aimed to characterize international practice patterns in the surgical management of primary lumbar disc herniation (LDH) among AO Spine surgeons.

Methods: A cross-sectional online survey was distributed in September 2024 to AO Spine members. The questionnaire collected detailed information on demographic characteristics, surgical indications, preferred techniques, and approaches for primary LDH treatment. Data on specialty, practice setting, fellowship training, and surgical case volume were analyzed using univariate and multivariate logistic regression to identify significant associations between surgeon characteristics and treatment preferences.

Results: A total of 714 surgeons participated, representing diverse regions: North America (9.0%), Latin America (18.7%), Europe & Southern Africa (34.7%), Middle East & Northern Africa (12.8%), and Asia Pacific (24.8%). Neurological status was the most critical factor influencing early operative treatment in nonurgent cases, while bladder/bowel dysfunction and severe motor deficits were the primary indications in urgent scenarios. The majority of respondents (54.2%) preferred a mini-open technique-using either a surgical microscope or loupes-with partial laminotomy (58.1%) and partial discectomy (63.2%) being the most frequently performed procedures. Regional variations and differences in surgeon training were significantly associated with the choice of surgical approach and overall case volume.

Conclusion: The findings reveal substantial variability in the surgical management of primary LDH across regions and specialties. This comprehensive dataset underscores the need for standardized, evidence-based guidelines to harmonize treatment strategies and optimize patient outcomes.

Objective: To biomechanically compare the stress distribution of established posterior cervical fixation techniques-conventional pedicle screw (PS), Abumi technique, unicortical lateral mass screw (LMS), and bicortical LMS-with a novel PS method, the Lee point technique, using finite element modeling (FEM).

Methods: A patient-specific FEM of C5-6 was developed using high-resolution computed tomography scan data of a degenerative cervical spine. Five fixation models were constructed: Lee point, Abumi, conventional PS, unicortical LMS, and bicortical LMS. Screw dimensions were ø3.5×28 mm for PS and ø3.5×14/18 mm for LMS. A pure moment of 1.0 N·m was applied in flexion, extension, axial rotation, and lateral bending, and the peak von Mises stress (PVMS) of both the vertebrae and implants was recorded for each loading condition.

Results: Abumi technique showed the highest PVMS at C5-6 (23.09-43.22 MPa and 24.96-39.91 MPa), with stress concentrated at the pedicle entry and medial wall. Lee point and conventional PS demonstrated more evenly distributed stress across the pedicle and near cortex of the lateral mass. Unicortical and bicortical LMS showed stress mainly at the entry point, with overall lower and more uniform magnitudes. Implant stress was greatest in Abumi construct (up to 295 MPa), moderate in Lee and conventional PS, and lowest in LMS models.

Conclusion: Abumi technique showed higher localized stress concentrations that may warrant careful patient selection, particularly in those with compromised bone quality. Lee point technique achieved a balanced stress profile comparable to conventional PS, suggesting a favorable biomechanical profile for posterior cervical fixation.

Objective: To quantify the effect of different hip positions on lumbar lordosis (LL) and spinopelvic parameters in the right lateral decubitus position (RLDP) and identify the configuration that most closely replicates physiologic standing alignment during lateral lumbar interbody fusion in minimally invasive spinal surgery.

Methods: Thirty healthy volunteers (15 males, 15 females; mean age, 27.8±8.6 years) underwent lateral lumbar radiographs in standing position and 5 RLDP configurations: neutral hips (NN), 30° flexion of both hips (30FF), 30° flexion of the right hip with left hip neutral (30FN), 60° flexion of both hips (60FF), and 60° flexion of the right hip with left hip neutral (60FN). LL, pelvic tilt (PT), sacral slope (SS), and pelvic incidence (PI) were measured. Each position was compared to standing using paired t-tests. Intra- and interobserver reliability were evaluated using intraclass correlation coefficients (ICCs).

Results: LL decreased significantly in all RLDP positions compared with standing (51.1°±3.8°). The 30FN position showed the smallest change (ΔLL=-4.9°, p<0.001), whereas 60FF showed the greatest (ΔLL=-15.0°, p<0.001). In 30FN, PT decreased (p=0.013) and SS increased (p=0.003), indicating mild anterior pelvic rotation. PI showed minimal variation across positions. Intra- and interobserver ICCs ranged from 0.92 to 0.99, confirming high measurement reliability.

Conclusion: Hip position significantly influences lumbar and pelvic alignment in RLDP. Among tested configurations, the 30FN position (right hip flexed 30°, left neutral) showed the smallest numerical deviation from standing alignment and spinopelvic harmony relative to standing in RLDP.

To address disc reherniation, several annular repair strategies have been developed, including implantable devices, suture-based techniques, and biomaterials. This review evaluates the clinical evidence supporting these strategies. A systematic search of PubMed, Cochrane, and Embase and MEDLINE via Ovid was performed from database inception to July 2025. A combination of keywords was used in the search string. Publications were included if they were clinical studies and described closing the annulus or blocking the annulus defect with biologics, sutures, or physical devices. Exclusion criteria were animal studies, in vitro studies, non-English articles, and abstracts. A single-arm proportional meta-analysis was performed for studies reporting extractable reherniation, reoperation, or complication data. The initial search identified 1,349 records. After removal of 315 duplicates, 1,034 studies underwent screening, with 84 full texts reviewed and 62 meeting inclusion criteria. Forty-one studies (66%) assessed implantable physical devices, of which 40 (98%) evaluated the Barricaid annular closure device (ACD) (Intrinsic Therapeutics, Inc., USA). Eighteen studies (29%) evaluated suture-based closure of the annulus fibrosus, using preloaded devices, bone-anchored systems, or manual suturing techniques. Three studies (5%) examined the use of biomaterials as either an adjunct or standalone method in the form of autologous conditioned plasma, bone marrow stromal cells, and fibrin sealant. For physical devices, the pooled reherniation, reoperation, and complication rates were 4.71%, 4.84%, and 1.76% respectively. Suture-based techniques had reherniation, reoperation, and complication rates of 1.37%, 0.35%, and 0.28%, respectively. For biomaterial-based approaches, only a pooled reherniation rate was calculated (2.11%), as insufficient data were available to pool reoperation and complication rates. Annular repair following discectomy is associated with low rates of reherniation, reoperation, and complications across physical devices, suture-based techniques, and biomaterial approaches. Physical devices and suturing techniques have robust clinical evidence and show generally favorable outcomes, but results remain mixed and heterogenous across techniques. Biomaterials demonstrate early promise but are limited by small study size and short follow-up. While pooled proportional meta-analysis supports the overall safety and effectiveness of annular repair, heterogeneity and limited comparative evidence prevent determination of relative superiority.

Objective: Lumbar disc herniation is among the most common and disabling spinal disorders, driven by the interplay of mechanical overload, structural failure, and cellular dysfunction. Despite advances in surgical interventions, achieving true biological repair of herniated discs remains a major clinical challenge. This review aims to critically examine the biomechanical landscape of disc herniation, focusing on how altered load transmission, tissue stiffness, and structural disruption influence cellular behavior and tissue regeneration. It further explores mechanobiological mechanisms governing repair and highlights emerging biomimetic models and technologies that integrate mechanical and biological insights to promote functional disc restoration.

Methods: A comprehensive literature review was conducted using the Web of Science Core Collection, PubMed (National Library of Medicine), and ScienceDirect databases. The search was limited to peer-reviewed journal articles published in English and focused on studies related to lumbar disc herniation.

Results: While decades of research have elucidated the biomechanical factors contributing to disc herniation, recent advances in mechanobiology have uncovered how mechanical cues influence cellular behavior, tissue repair, and degeneration. Evidence suggests that true disc regeneration cannot be achieved through biological replacement or mechanical stabilization alone; rather, it requires restoring functional biomechanics, specifically, the disc's ability to sense, adapt to, and sustain physiological loading.

Conclusion: Viewing disc herniation through a mechanobiological lens offers new opportunities to develop targeted therapies aimed at restoring both tissue integrity and load-bearing functionality, paving the way for more effective regenerative interventions.

Objective: This systematic review and meta-analysis aimed to compare endoscopic discectomy (ED) with microdiscectomy (MD) for lumbar disc herniation, evaluating patient-reported outcomes, perioperative parameters, and complications to determine if ED could replace MD as the gold standard.

Methods: Following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines, we searched PubMed, Embase, Scopus, and Web of Science (January 2000-June 2025) for randomized controlled trials (RCTs) and prospective cohort studies comparing MD with ED subtypes (transforaminal endoscopic lumbar discectomy [TELD], interlaminar endoscopic lumbar discectomy [IELD], and unilateral biportal endoscopy [UBE]). Outcomes included Oswestry Disability Index (ODI), visual analogue scale (VAS) for pain, operative time, hospital stay, complications, and recurrence. Pooled mean differences and odds ratios (ORs) were calculated using random-effects models, with subgroup analyses by ED subtype. Risk of bias was assessed using RoB 2.0 and ROBINS-I tools.

Results: Seventeen studies (9 RCTs, 8 cohorts; n=3,115) were included. ED significantly reduced hospital stay (mean difference, -2.43 days; 95% CI, -3.62 to -1.23; p<0.05) and showed greater short-term ODI improvement (mean difference, 2.13; 95% CI, 0.58-3.67). No differences were observed in operative time, long-term ODI, or VAS scores. ED had lower wound complications but a higher recurrence risk with TELD (OR, ~2.0). High heterogeneity (I²>95%) and limited long-term data (>2 years) were noted.

Conclusion: ED offers perioperative advantages and comparable efficacy but does not surpass MD due to TELD's increased recurrence risk. IELD and UBE are promising alternatives, but MD remains the benchmark. Long-term RCTs are needed.

Objective: Intervertebral disc degeneration (IVDD) is a complex pathological process involving inflammation, oxidative stress, and immune dysregulation. Emerging evidence suggests that neuroimmune interactions contribute to IVDD progression, but the role of neuropeptide-like factors remains poorly understood.

Methods: We investigated whether Gαi-interacting protein (GINIP+) sensory neurons infiltrate degenerative discs and secrete TAFA chemokine like family member 4 (TAFA4), a neuron-derived cytokine known to influence macrophage activity. In vivo and in vitro models were used to assess TAFA4 expression, its regulatory effects on macrophage polarization, reactive oxygen species (ROS) production, inflammasome activation, and disc cell phenotype. Knockdown of TAFA4 was achieved via lentiviral transduction in rabbit discs and cell coculture models.

Results: TAFA4 was upregulated in IVDD tissues and colocalized with GINIP+ neurons. Knockdown of TAFA4 in vivo exacerbated disc degeneration, increased M1 macrophage presence, elevated ROS levels, and activated the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome. In vitro, GINIP+ neurons promoted macrophage M2 polarization and interleukin (IL)-10 production while suppressing tumor necrosis factor-α and IL-1β. These effects were reversed by TAFA4 knockdown. Moreover, TAFA4 attenuated ROS-dependent NLRP3 activation and preserved anabolic marker expression (ACAN [aggrecan], COL II [type II collagen], SOX9 [SRY-box transcription factor 9]), while reducing catabolic and hypertrophic-related markers (MMP13 [matrix metalloproteinase 13], ADAMTS5 [a disintegrin and metalloproteinase with thrombospondin motifs 5], COL X [collagen type X alpha 1 chain], RUNX2 [Runt-related transcription factor 2]) in nucleus pulposus cells.

Conclusion: TAFA4 acts as a neuron-derived mediator of neuroimmune crosstalk in IVDD that modulates macrophage polarization and oxidative stress, thereby delaying disc degeneration. This neuron-immune axis represents a potential therapeutic target.