Aim. Efficacious antibiotic treatment is crucial for managing and preventing orthopedic infections due to their complexity and associated risk of treatment failure. Previous reviews on antibiotic target tissue concentrations have primarily focused on static measurements, which may not accurately reflect the dynamic pharmacokinetic/pharmacodynamic (PK/PD) changes encountered in clinical settings. This review aimed to summarize the current literature on antibiotic distribution in orthopedically relevant tissues and settings using dynamic sampling methods. Method. In accordance with PRISMA guidelines, a literature search was conducted with a scientific librarian's assistance. PubMed and Embase databases were systematically searched using relevant MeSH terms, entries, and keywords. English-published studies between 2004 and 2023 involving systemic antibiotic administration and dynamic measurements were included. 4467 titles were identified. After title and abstract screening, 77 eligible studies remained. Results. The studies covered clinical and pre-clinical studies on both healthy and infected tissue. Dynamic measurements were obtained from various tissues including bone, intervertebral discs, joints, muscles, and subcutaneous tissue. Microdialysis was the predominant sampling method (98.70%, 76/77). Antibiotics like cefuroxime, linezolid, and vancomycin were extensively studied. Fluoroquinolones, tetracyclines, and most beta-lactams typically presented good tissue penetration in relation to relevant PK/PD-targets. In contrast, glycopeptides, macrolides, and flucloxacillin exhibited poorer penetration. Conclusions. This review provides valuable insights of antibiotic distribution in orthopedically relevant target tissues and settings, which may help improve dosing recommendations and treatment outcomes. Our findings are limited to the investigated dosing regimens and administration methods and depend on the chosen PK/PD target. Many antibiotics still require further research to address the significant knowledge gaps, such as the lack of dynamic evaluations for certain antibiotic types and further investigation across various orthopedic settings and tissues

Aim. This study seeks to outline the clinical, laboratory, and imaging features of patients with pyogenic spondylitis. It aims to define a novel imaging sign that could indicate the severity of suppurative spondylitis, aiding in its early diagnosis and treatment. Method. This retrospective study included 137 patients from 2013 to 2023. Through the analysis and summary of imaging characteristics among all patients, we identified a distinct MRI sign known as ‘the Disc Penetration sign’ (DP). This sign is defined as an image finding on sagittal MRI depicting the anterior and posterior penetration of an abscess through the intervertebral disc space, affecting both the anterior margin of the vertebrae and the structures within the spinal canal. Observational parameters included WBC, ESR, CRP, hemoglobin, and albumin levels. Documentation of the study included location and segment of the lesion, presence or absence of spinal cord compression, and paravertebral abscesses. Results. 56 patients presented with the Disc Penetration sign(DP) and 81 did not. In both groups, there were no significant differences in gender ratio or age (P > 0.05). However, significant differences were observed in the presence of comorbid diabetes and chronic kidney disease (p < 0.05). The DP group had a significantly greater ESR level (74.30±33.79 mm/h vs. 51.46±30.46 mm/h, P < 0.001) and CRP level (47.28 mg/L vs. 26.18 mg/L, P = 0.003). Additionally, the DP group had a significantly lower Hb (100.66±19.82 g/L vs. 116.99±19.99g/L,P < 0.001) and the serum albumin level (28.81±6.59 g/L vs. 34.09±6.17 g/L,P < 0.001). Imaging results showed no significant differences in affected spinal segments or parts (p>0.05). Patients in the DP group showed a higher likelihood of developing paravertebral abscesses compared to those in the non-DP group (n = 54 [96.4%] vs. n = 33 [40.7%], P < 0.001), and also exhibited a higher incidence of spinal cord compression(n = 32 [57.1%] vs. n = 17 [21.0%], P < 0.001). Conclusions. The study suggests that the Disc Penetration sign in pyogenic spondylitis patients correlates with more severe inflammation and higher incidence of paraspinal abscess, pointing to worse stability of the spine, longer bone restructuring time, and potentially poorer prognosis. These findings enable clinicians to rapidly assess the severity of the disease and prognosticate outcomes more effectively We emphasize the need for early, pathogen-specific diagnosis and treatment, particularly considering surgical intervention for patients demonstrating substantial paraspinal abscesses or spinal instability

Introduction. Intervertebral disc degeneration has been associated with low back pain (LBP) which is a major cause of long-term disability worldwide. Observed mechanical and biological modifications have been related to decreased water content. Clinical traction protocols as part of LBP management have shown positive outcomes. However, the underlying mechanical and biological processes are still unknown. The study purpose was to evaluate the impact of unloading through traction on the mechanobiology of healthy bovine tail discs in culture. Method. We loaded bovine tail discs (n=3/group) 2h/day at 0.2Hz for 3 days, either in dynamic compression (-0.01MPa to -0.2MPa) or in dynamic traction (-0.01MPa to 0.024MPa). In between the dynamic loading sessions, we subjected the discs to static compression loading (-0.048MPa). We assessed biomechanical and biological parameters. Result. Over the 3 days of loading, disc height decreased upon dynamic compression loading but increased upon unloading. The neutral zone was restored for all samples at the end of the dynamic unloading. Upon dynamic compression, the stiffness increased over time while the hysteresis decreased. Upon dynamic unloading, sulfated glycosaminoglycan (sGAG) release in the medium was lower at the endpoint. In the outer annulus fibrosus (AFo), we saw a higher water/sGAG of at least 30%. In the nucleus pulposus, COL2 mRNA was expressed more highly upon dynamic unloading while MMP3, iNOS and TRPV4 expression levels were lower. In the AFo of the unloading group, COL2 expression was higher but COL1 was lower. Conclusion. The biomechanical and biological results consistently indicate that dynamic unloading of healthy bovine discs in culture facilitates water uptake and promotes an anti-catabolic response which reflects a function optimization of the disc. This work combines biomechanical and biological results and opens the door to evidence-based improvement of regenerative protocols for degenerated discs and conservative LBP management. This study is funded by AO Foundation and AO Spine

Introduction. Low back pain (LBP) is a worldwide leading cause of disability. This preclinical study evaluated the safety of a combined advanced therapy medicinal product developed during the European iPSpine project (#825925) consisting of mesendoderm progenitor cells (MEPC), derived from human induced pluripotent stem cells, in combination with a synthetic poly(N-isopropylacrylamide) hydrogel (NPgel) in an ovine intervertebral disc degeneration (IDD) model. Method. IDD was induced through nucleotomy in 4 adult sheep, 5 lumbar discs each (n=20). After 5 weeks, 3 alternating discs were treated with NPgel (n=6) or NPgel+MEPC (n=6). Before sacrifice, animals were subjected to: MRI of lumbar spines (disc height and Pfirmann grading); blood sampling (hematological, biochemical, metabolic and lymphocyte/monocytes immunological). After 3 months the sheep were sacrificed. The spines were processed for: macroscopic morphology (Thompson grading), microscopic morphology (Histological grading), and glycosaminoglycan content (GAG, DMMB Assay). Furthermore, at sacrifice biodistribution of human MEPC was assessed by Alu-sequences quantification (qPCR) from three tissue samples of heart, liver, spleen, brain, lungs, and kidneys, and PBMCs collected to assess activation of systemic immune cells. To each evaluation, appropriate statistical analysis was applied. Result. Flow cytometry showed no induction of systemic activation of T cells or monocytes. Alu quantification did not give detection of any cells in any organ. Disc height index was slightly increased in discs treated with NPgel+MEPC. Pfirmann's and Thompson's classification showed that treatment with NPgel or NPgel+MEPC gave no adverse reactions. Histological grading showed similar degeneration in vertebrae treated with NPgel+MEPC or with NPgel alone. The amount of GAG was significantly increased in the nucleus pulposus following treatment with NPgel+MEPC compared to NPgel alone, in which a decrease was observed compared to untreated discs in both nucleus pulposus and annulus fibrosus. Conclusion. This study showed the safety of both NPgel+MEPC and NPgel treatments

INTRODUCTION. Intervertebral disc (IVD) degeneration is not completely understood because of the lack of relevant models. In vivo models are inappropriate because animals are quadrupeds. IVD is composed of the Nucleus Pulposus (NP) and the Annulus Fibrosus (AF), an elastic tissue that surrounds NP. AF consists of concentric lamellae made of collagen I and glycosaminoglycans with fibroblast-like cells located between layers. In this study, we aimed to develop a novel 3D in vitro model of Annulus Fibrosus to study its degeneration. For this purpose, we reproduced the microenvironment of AF cells using 3D printing. METHOD. An ink consisting of dense collagen (30 mg.mL. -1. ) and tyramine-functionalized hyaluronic acid (THA) at 7.5 mg.mL. -1. was first designed by modulating pH and [NaCl] in order to inhibit the formation of polyionic complexes between collagen and THA. Then, composite inks were printed in different gelling baths to form collagen hydrogels. Last, THA photocrosslinking using eosin and green light was performed to strengthen hydrogels. Selected 3D printed constructs were then cellularized with fibroblasts. RESULTS. The physicochemical study revealed that collagen/THA solutions (4:1 ratio) used at pH 5 with 200 mM NaCl were homogenous. In addition, collagen fibrils were observed in these solutions. The dense composite collagen/THA inks printed in a 2X PBS bath rapidly gelled and the photo-crosslinking increased the mechanical properties by 2 to reach 25 kPa (Young's modulus). Then, 3D printing parameters were optimized (85 kPa, extrusion, 4.5 mm/s speed and 80% fill-in percentage) to generate flat and anisotropic lamellae observed by polarized light microscopy. For the in vitro study, several anisotropic layers were printed and fibroblasts seeded between them. Cells adhered to layers, spread, proliferate and aligned along the axis of printed layers. CONCLUSION. Taken together, these results show it is possible to reproduce in vitro the main AF's biochemical and physical properties

Introduction. Analogous to articular cartilage, changes in spatial chondrocyte organisation have been proposed to be a strong indicator for local tissue degeneration and destruction in the intervertebral disc (IVD). While a progressive structural and functional degradation of the extracellular (ECM) and pericellular (PCM) matrix occurs in osteoarthritic cartilage, these processes have not yet been biomechanically elucidated in the IVD. We aimed to evaluate the local stiffness of the ECM and PCM in the anulus fibrosus of the IVD on the basis of local cellular spatial organisation. Method. Using atomic force microscopy, we measured the elastic modulus of the local ECM and PCM in human disc samples using the spatial chondrocyte patterns as an image-based biomarker. Result. By measuring tissue from 30 patients, we found a significant difference in the elastic moduli of the PCM in clusters when compared to the healthy patterns single cells (p=0.029), pairs (p=0.016), and string formations (p=0.010) whereas the values of the elastic moduli of the ECM only reached statistical significance when clusters were compared with string formations. The ECM/PCM ratio ranged from 0.62 to 0.89. Overall, the reduced elastic moduli in clusters demonstrates that cluster formation is not only a morphological phenomenon describing disc degeneration, but it marks a compromised biomechanical functioning. Conclusion. This study is the first to describe and quantify the differences in the elastic moduli of the ECM in relation to the PCM in the anulus fibrosus of the IVD by means of atomic force microscopy on the basis of spatial chondrocyte organisation. Advanced disc degeneration is accompanied by a biomechanically compromised tissue functioning

Introduction. Functional Spine Units (FSUs) play a vital role in understanding biomechanical characteristics of the spine, particularly bone fracture risk assessment. While established models focus on simulating axial compression of individual bones to assess fracture load, recent models underscore the importance of understanding fracture load within FSUs, offering a better representation of physiological conditions. Despite the limited number of FSU fracture studies, they predominantly rely on a linear material model with an annulus fibrosus Young's modulus set at 500 MPa, significantly higher than stiffness values (ca. 4 MPa) utilized in other FSU and spine section biomechanical models. Thus, this study aims to study the effect of varying annulus fibrosus stiffness on FSU fracture load, aiming to identify physiologically relevant biomechanical parameters. Method. Subject-specific geometry and material properties of bones were derived from computed tomography (CT) image data of five human cadaveric FSU specimens. The annulus fibrosus and nucleus pulposus were manually recreated and assigned linear elastic material properties. By subjecting the model to axial compression, the fracture load of the FSU was deduced from the peak of the force-displacement graph. To explore the effect of stiffness of the annulus fibrosus on simulated fracture load, we conducted a parameter study, varying stiffness values from the high 500 MPa to a more physiologically relevant 25 MPa, aiming to approximate values applied in FSU kinematic models while achieving bone fracture. Result. Significant reductions in fracture load were observed, ranging from 23% to 46%, as annulus stiffness decreased from 500MPa to 25MPa. Additionally, a discernible, gradual decline in fracture load was observed with a decrease in stiffness values. Conclusion. The stiffness of the annulus fibrosus significantly influences the simulated fracture load of an FSU. Future investigations should prioritize biomechanically accurate modeling of the intervertebral disc, ensuring alignment with experimental findings regarding FSU fracture load while maintaining biomechanical fidelity

Introduction. Intervertebral disc degeneration (IDD) is a progressive process affecting all disc tissues, namely the nucleus pulposus (NP), annulus fibrosus (AF), and cartilaginous endplates (CEPs). Several cell-based therapies have been proposed to replenish the disc cell population and promote tissue regeneration. However, cell-free therapeutics have been increasingly explored due to potentially higher advantages and cost-effectiveness compared to cell transplantation. Recently, extracellular vesicles (EVs) isolated from healthy Tie2. +. -NP cells (NPCs) have shown promising regenerative outcomes on degenerative NPCs (dNPCs). The aim of this study was to assess the effect of such EVs on all disc cell types, including AF cells (AFCs) and CEP cells (CEPCs), compared to EVs isolated from bone-marrow derived mesenchymal stromal cells (BM-MSCs). Method. NPCs harvested from young donors underwent an optimized culture protocol to maximize Tie2 expression (NPCs. Tie2+. ). BM-MSCs were retrieved from a commercial cell line or harvested during spine surgery procedures. EV characterization was performed via particle size analysis (qNano), expression of EV markers (Western blot), and transmission electron microscopy. dNPCs, AFCs, and CEPCs were isolated from surgical specimens of patients affected by IDD, culture-expanded, and treated with NPCs. Tie2+. -EVs or BM-MSC-EVs ± 10 ng/mL IL-1b. EV uptake was assessed with PKH26 staining of EVs under confocal microscopy. Cell proliferation and viability were assessed with the CCK-8 assay. Result. Upon characterization, isolated EVs exhibited the typical exosomal characteristics. NPCs. Tie2+. -EVs and BM-MSC-EVs uptake was successfully observed in all dNPCs, AFCs, and CEPCs. Both EV products significantly increased dNPC, AFC, and CEPC viability, especially in samples treated with NPCs. Tie2+. -EVs. Conclusion. NPCs. Tie2+. -EVs demonstrated to significantly stimulate the proliferation and viability of degenerative cells isolated from all disc tissues. Rather than the sole NP, EVs isolated by committed progenitors physiologically residing within the disc may exert their regenerative effects on the whole organ, thus possibly constituting the basis for a new therapy for IDD

Aims

Developmental cervical spinal stenosis (DcSS) is a well-known predisposing factor for degenerative cervical myelopathy (DCM) but there is a lack of consensus on its definition. This study aims to define DcSS based on MRI, and its multilevel characteristics, to assess the prevalence of DcSS in the general population, and to evaluate the presence of DcSS in the prediction of developing DCM.

Aims

This study aimed to define the histopathology of degenerated humeral head cartilage and synovial inflammation of the glenohumeral joint in patients with omarthrosis (OmA) and cuff tear arthropathy (CTA). Additionally, the potential of immunohistochemical tissue biomarkers in reflecting the degeneration status of humeral head cartilage was evaluated.

Aims

A variety of surgical methods and strategies have been demonstrated for Andersson lesion (AL) therapy. In 2011, we proposed and identified the feasibility of stabilizing the spine without curettaging the vertebral or discovertebral lesion to cure non-kyphotic AL. Additionally, due to the excellent reunion ability of ankylosing spondylitis, we further came up with minimally invasive spinal surgery (MIS) to avoid the need for both bone graft and lesion curettage in AL surgery. However, there is a paucity of research into the comparison between open spinal fusion (OSF) and early MIS in the treatment of AL. The purpose of this study was to investigate and compare the clinical outcomes and radiological evaluation of our early MIS approach and OSF for AL.

Aims

To report the development of the technique for minimally invasive lumbar decompression using robotic-assisted navigation.

Aims. The presence of facet tropism has been correlated with an elevated susceptibility to lumbar disc pathology. Our objective was to evaluate the impact of facet tropism on chronic lumbosacral discogenic pain through the analysis of clinical data and finite element modelling (FEM). Methods. Retrospective analysis was conducted on clinical data, with a specific focus on the spinal units displaying facet tropism, utilizing FEM analysis for motion simulation. We studied 318 intervertebral levels in 156 patients who had undergone provocation discography. Significant predictors of clinical findings were identified by univariate and multivariate analyses. Loading conditions were applied in FEM simulations to mimic biomechanical effects on intervertebral discs, focusing on maximal displacement and intradiscal pressures, gauged through alterations in disc morphology and physical stress. Results. A total of 144 discs were categorized as ‘positive’ and 174 discs as ‘negative’ by the results of provocation discography. The presence of defined facet tropism (OR 3.451, 95% CI 1.944 to 6.126) and higher Adams classification (OR 2.172, 95% CI 1.523 to 3.097) were important predictive parameters for discography-‘positive’ discs. FEM simulations showcased uneven stress distribution and significant disc displacement in tropism-affected discs, where loading exacerbated stress on facets with greater angles. During varied positions, notably increased stress and displacement were observed in discs with tropism compared to those with normal facet structure. Conclusion. Our findings indicate that facet tropism can contribute to disc herniation and changes in intradiscal pressure, potentially exacerbating disc degeneration due to altered force distribution and increased mechanical stress. Cite this article: Bone Joint Res 2024;13(9):452–461

Background. The association between lumbar intervertebral disc degeneration (LDD) and low back pain (LBP) is modest. We have recently shown that genetic propensity to pain is an effect modifier of the LDD-LBP relationship when LDD is defined as a summary score of LDD (LSUM), suggesting the association may be driven by individuals with the greatest genetic predisposition to pain. This study examined the association between individual spine magnetic resonance imaging (MRI)-determined LDD features and LBP in subgroups defined by genetic predisposition to pain. Method. We developed a polygenic risk score (PRS) for “genetic propensity to pain” defined as the number of non-back pain locations (head, face, neck/shoulder, stomach/abdomen, hip, and knee) with duration ≥3 months in 377,538 UK Biobank participants of European ancestry. This PRS was used to stratify TwinsUK MRI samples (n=645) into four strata of genetic propensity to pain. We examined the association between LBP and MRI features of lumbar disc height, disc signal intensity, disc bulge, and osteophytes with adjustments for age, sex, PRS strata, interaction terms for each MRI feature x PRS strata, and twin status. Results. We found significant effect modification of the LDD-LBP relationship by genetic propensity to pain for the lumbar MRI features of disc height (p=0.03 for the interaction term with highest quartile of genetically-predicted propensity to pain) and disc signal intensity (p=0.001), but not for disc bulge and osteophytes. Conclusion. Genetic propensity to pain modifies the association between individual LDD features and LBP and should be considered in LBP clinical studies. Conflicts of interest. No conflicts of interest. Sources of funding. No funding obtained. Acknowledgement. UKBB data were obtained under the project #18219. This paper is submitted to the Spine journal and is under review

Background. Magnetic resonance imaging (MRI) algorithm identifies end stage severely degenerated disc as ‘black’, and a moderately degenerate to non-degenerated disc as ‘white’. MRI is based on signal intensity changes that identifies loss of proteoglycans, water, and general radial bulging but lacks association with microscopic features such as fissure, endplate damage, persistent inflammatory catabolism that facilitates proteoglycan loss leading to ultimate collapse of annulus with neo-innervation and vascularization, as an indicator of pain. Thus, we propose a novel machine learning based imaging tool that combines quantifiable microscopic histopathological features with macroscopic signal intensities changes for hybrid assessment of disc degeneration. Methods. 100-disc tissue were collected from patients undergoing surgeries and cadaveric controls, age range of 35–75 years. MRI Pfirrmann grades were collected in each case, and each disc specimen were processed to identify the 1) region of interest 2) analytical imaging vector 3) data assimilation, grading and scoring pattern 4) identification of machine learning algorithm 5) predictive learning parameters to form an interface between hardware and software operating system. Results. Kernel algorithm defines non-linear data in xy histogram. X,Y values are scored histological spatial variables that signifies loss of proteoglycans, blood vessels ingrowth, and occurrence of tears or fissures in the inner and outer annulus regions mapped with the dampening and graded series of signal intensity changes. Conclusion. To our knowledge this study is the first to propose a machine learning method between microscopic spatial tissue changes and macroscopic signal intensity grades in the intervertebral disc. No conflict of interest declared.  . Sources of Funding. ICMR/5/4-5/3/42/Neuro/2022-NCD-1, Dr TMA PAI SMU/ 131/ REG/ TMA PURK/ 164/2020. A part of the above study was presented as an oral paper at the International Society for the Study of Lumbar Spine (ISSLS) meeting held on 1–5. th. May 2023, Melbourne, Australia

Background. Chronic low back pain is strongly linked to degeneration of the intervertebral disc (IVD), which currently lacks any targeted treatments. This study explores NPgel, a biomaterial combined with notochordal cells (NC), developmental precursor cells, as a potential solution. NCs, known for anti-catabolic effects on IVD cells, present a promising avenue for regenerating damaged IVD tissue. Methods. Bovine IVDs underwent enzymatic degeneration before NPgel (+/- NC) injection. Degenerated bovine IVDs were cultured under biomechanical loading for 21 days. Histology and immunohistochemistry assessed NC survival, phenotype, and matrix production. Within an in vivo sheep pilot study, NPgel (+/- NC) was injected into degenerated IVDs, blood was taken, and immune cell activation was monitored via flow cytometry over three months post-injection. Results. Within the ex vivo model, IVDs injected with NPgel (+/- NC) exhibited increased matrix expression and deposition. Viable NCs were detected post-culture, indicating survival and matrix production. In the in vivo model, NPgel injection into sheep IVDs did not significantly increase activation of immune cells compared to controls, suggesting no systemic inflammatory effects. Conclusion. NPgel, combined with NCs, shows promise for IVD regeneration. Ex vivo findings indicate NPgel supports NC survival and matrix production. Moreover, in vivo results demonstrate the absence of systemic immunogenic responses post-NPgel injection. This suggests NPgel's potential as a carrier for NCs in IVD regeneration therapy. These findings underscore NPgel's candidacy for further investigation in addressing chronic low back pain associated with IVD degeneration. Subsequent research, including long-term efficacy and safety evaluations, is imperative for clinical translation. Conflicts of interest. There are no conflicts of interest. Sources of funding. iPSpine, grant # 825925, Horizon 2020

Introduction. Vertebral compression fractures are the most common type of osteoporotic fracture. Though 89% of clinical fractures occur anteriorly, it is challenging to replicate these ex vivo with the underlying intervertebral discs (IVDs) present. Furthermore, the role of disc degeneration in this mechanism is poorly understood. Understanding how disc morphology alters vertebral strain distributions may lead to the utilisation of IVD metrics in fracture prediction, or inform surgical decision-making regarding instrumentation type and placement. Aim. To determine the effect of disc degeneration on the vertebral trabecular bone strain distributions in axial compression and flexion loading. Methods. Eight cadaveric thoracolumbar segments (T11-L3) were prepared (N=4 axial compression, N=4 flexion). µCT-based digital volume correlation was used to quantify trabecular strains. A bespoke loading device fixed specimens at the resultant displacement when loaded to 50N and 800N. Flexion was achieved by adding 6° wedges. Disc degeneration was quantified with Pfirrmann grading and T2 relaxation times. Results. Anterior axial strains were 80.9±39% higher than the posterior region in flexion (p<0.01), the ratio of which was correlated with T2 relaxation time (R. 2. =0.80, p<0.05). In flexion, the central-to-peripheral axial strain ratio in the endplate region was significantly higher when the underlying IVDs were non-degenerated relative to degenerated (+38.1±12%, p<0.05). No significant differences were observed in axial compression. Conclusion. Disc degeneration is a stronger determinant of the trabecular strain distribution when flexion is applied. Load transfer through non-degenerate IVDs under flexion appears to be more centralised, suggesting that disc degeneration predisposes flexion-type compression fractures by shifting high strains anteriorly. Conflicts of interest. The authors declare none. Sources of funding. This work was funded by the Engineering & Physical Sciences Research Council (EP/V029452/1), and Back-to-Back

Introduction. Multiple studies have identified Cutibacterium acnes (C.acnes) and other microbes in intervertebral disc tissue using 16S DNA Sequencing and microbial cultures. However, it remains unclear whether these bacteria are native to the discs or result from perioperative contamination. Our study aimed to detect Gram-positive bacteria in non-herniated human disc samples and explore correlations with Toll-like receptors (TLR) 2, TLR4, NLRP3, and Gasdermin D. Methods. Immunohistochemical staining was conducted on 75 human IVD samples for Gram-positive bacteria, S. aureus, C.acnes, TLR2, TLR4, NLRP3, and Gasdermin D. Cell detection and classification were performed using QuPath. NP cells were treated with Lipopolysaccharide (LPS) and Peptidoglycan (PGN) in monolayer and alginate beads for up to 72 hours, followed by secretome analysis using Luminex. Statistical analysis included Kruskal-Wallis, Dunn's multiple comparison test, and Pearson correlation. Results. Immunohistochemical staining revealed Gram-positive bacteria exclusively within cells, with C. acnes positivity ranging from 5–99% and correlating with patient age (r=0.41, p= 0.007). TLR2 positivity ranged from 5–99% and TLR4 from 3–72%, showing a strong correlation (r= 0.62, p= 1.5e-006). Females with mid-degenerative grades exhibited significantly decreased TLR2 expression compared to those without degeneration signs. Treatment with LPS and PGN increased catabolic cyto- and chemokines associated with IVD degeneration. Conclusion. In conclusion, this study confirms Gram-positive bacteria presence in non-herniated human disc samples and highlights their role in triggering a catabolic response in disc cells. No conflicts of interest.  . Sources of funding. This project is part of the Disc4All Training network to advance integrated computational simulations in translational medicine, applies to intervertebral disc degeneration and funded by Horizon 2020 (H2020-MSCA-ITN-ETN-2020 GA: 955735)

Background. It has become increasingly important to conduct studies assessing clinical outcomes, reoperation rates, and revision rates to better define the indications and efficacy of lumbar spinal procedures and its association with symptomatic adjacent segment degeneration (sASD). Adjacent segment degeneration (ASD) is defined as the radiographic change in the intervertebral discs adjacent to the surgically treated spinal level. SASD represents adjacent segment degeneration which causes pain or numbness due to post-operative spinal instability or nerve compression at the same level. The most common reason for early reoperation and late operation is sASD, therefore is in our best interest to understand the causes of ASD and make steps to limit the occurrence. Method. A comprehensive literature search was performed selecting Randomized controlled trials (RCTs) and retrospective or prospective studies published up to December 2023. Meta-analysis was performed on 38 studies that met the inclusion criteria and included data of clinical outcomes of patients who had degenerative disc disease, disc herniation, radiculopathy, and spondylolisthesis and underwent lumbar fusion or motion-preservation device surgery; and reported on the prevalence of ASD, sASD, reoperation rate, visual analogue score (VAS), and Oswestry disability index (ODI) improvement. Results. When compared to fusion surgery, a significant reduction of ASD, sASD and reoperation was observed in the cohort of patients that underwent motion-preserving surgery. Conclusion. Dynamic fusion constructs are treatment options that may help to prevent sASD. Conflicts of interest. This research was funded by Paradigm Spine. Sources of funding. Paradigm Spine

Aims

People with severe, persistent low back pain (LBP) may be offered lumbar spine fusion surgery if they have had insufficient benefit from recommended non-surgical treatments. However, National Institute for Health and Care Excellence (NICE) 2016 guidelines recommended not offering spinal fusion surgery for adults with LBP, except as part of a randomized clinical trial. This survey aims to describe UK clinicians’ views about the suitability of patients for such a future trial, along with their views regarding equipoise for randomizing patients in a future clinical trial comparing lumbar spine fusion surgery to best conservative care (BCC; the FORENSIC-UK trial).