Effect of two-level decompressive procedures on the biomechanics of the lumbo-sacral spine: an ex vivo study.

Hemilaminectomy and laminectomy are decompressive procedures commonly used in case of lumbar spinal stenosis, which involve the removal of the posterior elements of the spine. These procedures may compromise the stability of the spine segment and create critical strains in the intervertebral discs. Thus, this study aimed to investigate if decompressive procedures could alter the biomechanics of the lumbar spine. The focus was on the changes in the range of motion and strain distribution of the discs after two-level hemilaminectomy and laminectomy. Twelve L2-S1 cadaver specimens were prepared and mechanically tested in flexion, extension and both left and right lateral bending, in the intact condition, after a two-level hemilaminectomy on L4 and L5 vertebrae, and a full laminectomy. The range of motion (ROM) of the entire segment was assessed in all the conditions and loading configurations. In addition, Digital Image Correlation was used to measure the strain distribution on the surface of each specimen during the mechanical tests, focusing on the disc between the two decompressed vertebrae and in the two adjacent discs. Hemilaminectomy did not significantly affect the ROM, nor the strain on the discs. Laminectomy significantly increased the ROM in flexion, compared to the intact state. Laminectomy significantly increased the tensile strains on both L3-L4 and L4-L5 disc (p = 0.028 and p = 0.014) in ipsilateral bending, and the compressive strains on L4-L5 intervertebral disc, in both ipsilateral and contralateral bending (p = 0.014 and p = 0.0066), with respect to the intact condition. In conclusion, this study found out that hemilaminectomy did not significantly impact the biomechanics of the lumbar spine. Conversely, after the full laminectomy, flexion significantly increased the range of motion and lateral bending was the most critical configuration for largest principal strain.

Enhanced multistage deep learning for diagnosing anterior disc displacement in temporomandibular joint using magnetic resonance imaging.

OBJECTIVES: This study aimed to propose a new method for the automatic diagnosis of anterior disc displacement of the temporomandibular joint (TMJ) using magnetic resonance imaging (MRI) and deep learning. By employing a multistage approach, the factors affecting the final result can be easily identified and improved. METHODS: This study introduces a multistage automatic diagnostic technique using deep learning. This process involves segmenting the target from MR images, extracting distance parameters, and classifying the diagnosis into three classes. MRI exams of 368 TMJs from 204 patients were evaluated for anterior disc displacement. In the first stage, five algorithms were used for the semantic segmentation of the disc and condyle. In the second stage, 54 distance parameters were extracted from the segments. In the third stage, a rule-based decision model was developed to link the parameters with the expert diagnosis results. RESULTS: In the first stage, DeepLabV3+ showed the best result (95% Hausdorff distance, Dice coefficient, and sensitivity of 6.47 ± 7.22, 0.84 ± 0.07, and 0.84 ± 0.09, respectively). This study used the original MRI exams as input without preprocessing and showed high segmentation performance compared with that of previous studies. In the third stage, the combination of SegNet and a random forest model yielded an accuracy of 0.89 ± 0.06. CONCLUSIONS: An algorithm was developed to automatically diagnose TMJ-anterior disc displacement using MRI. Through a multistage approach, this algorithm facilitated the improvement of results and demonstrated high accuracy from more complex inputs. Furthermore, existing radiological knowledge was applied and validated.

Risk factors of bone loss after Prestige-LP cervical disc arthroplasty.

PURPOSE: Cervical disc arthroplasty (CDA) is widely employed for patients diagnosed with cervical degenerative disc disease (CDDD). Postoperative bone loss (BL) represents a radiological alteration that is a relatively novel consideration in the realm of CDA. This study endeavors to examine the risk factors associated with BL following CDA, aiming to elucidate the underlying mechanisms and the impact of BL on surgical outcomes. METHODS: A retrospective study was undertaken, encompassing consecutive patients subjected to one-level CDA, two-level CDA, or two-level hybrid surgery (HS) for the treatment of CDDD at our institution. Patient demographic and perioperative data were systematically recorded. Radiological images obtained preoperatively, at 1-week post-operation, and during the last follow-up were collected and evaluated, following with statistical analyses. RESULTS: A total of 295 patients and 351 arthroplasty segments were involved in this study. Univariate logistic regressions indicated that age ≥ 45 years and two-level HS was associated with lower risk of BL; and a greater ΔDA (change of disc angle before and after surgery) was correlated with an increased risk of BL. Multivariate logistic regression determined that two-level HS and greater ΔDA were independent preventative and risk factors for BL, respectively. Further analysis revealed that severe BL significantly elevated the risk of implant subsidence compared to non-BL and mild BL. CONCLUSIONS: This study posited bone remodeling and micromotion as potential underlying mechanisms of BL. Subsequent research endeavors should delve into the divergent mechanisms and progression observed between lower- and higher-grade BL, aiming to prevent potential adverse outcomes associated with severe BL.

Treatment of failed cervical total disc replacements in a series of 53 cases and description of a management strategy.

PURPOSE: To describe modes of failure of cervical TDR, their related treatment strategies, and to describe a management strategy for the treatment of failed cervical TDR. METHODS: This retrospective study was based on a consecutive series of 53 cervical TDR patients who underwent removal or revision surgery. Chart review was conducted to collect general descriptive data, reasons for TDR removal/revision, duration from index implantation to re-operation, and the subsequent procedure performed. RESULTS: Among 53 patients, 36 underwent TDR removal and fusion, 16 underwent TDR removal and replacement with another TDR, and one patient's TDR was revised by repositioning. The mean duration from index surgery to removal/revision was 40.1 months (range: 3 days-222 months). In all cases, removal/revision surgery was completed without complication. The most common reason for removal was severe osteolysis, often involving C. acnes infection, and was primarily associated with one implant type. TDR removal and fusion were performed for subsidence, device migration, treatment of symptoms arising from posterior anatomy (facet joints, etc.), approach-related complications and pain. TDR replacement was feasible for hypermobility, metal allergy, implant locked in kyphosis, and oversized implant use. In one case of TDR malpositioning, the device was successfully revised into appropriate position. CONCLUSION: After cervical TDR failure, replacing a TDR with another implant can be feasible. Reasons for revision or removal after cervical TDR surgery include biomechanical failure, implant migration, surgeon or technical error, or biological reasons. The type of failure can help the surgeon create a strategy to address these complications.

The mechanics of tissue-engineered temporomandibular joint discs: Current status and prospects for enhancement.

The temporomandibular joint (TMJ) disc is an essential protective but vulnerable fibrocartilage. Their high mechanical strength is vital in absorbing loads, reducing friction, and protecting the condylar surface. Many diseases can lead to the destruction or degeneration of the mechanical function of the TMJ disc. Unfortunately, conservative treatment is ineffective in restoring the defective mechanical properties of the discs. Tissue engineering has been investigated as a promising alternative treatment approach to approximate the properties of native tissue. However, it is difficult for tissue-engineered discs to obtain sufficient mechanical properties. Several approaches have been proposed to improve the mechanical properties of tissue-engineered constructs. In this review, we summarized the mechanical properties of native TMJ discs and discussed the current mechanical testing methods. We then summarized the current advances in improving the mechanical properties of TMJ disc tissue-engineered constructs. Moreover, existing challenges and outbreak directions are discussed. This review assists future research in better understanding the mechanical properties of both native and tissue-engineered TMJ discs. It provides new insights into future mechanical property enhancement for TMJ disc tissue engineering.

The emerging role of Piezo1 in the musculoskeletal system and disease.

Piezo1, a mechanosensitive ion channel, has emerged as a key player in translating mechanical stimuli into biological signaling. Its involvement extends beyond physiological and pathological processes such as lymphatic vessel development, axon growth, vascular development, immunoregulation, and blood pressure regulation. The musculoskeletal system, responsible for structural support, movement, and homeostasis, has recently attracted attention regarding the significance of Piezo1. This review aims to provide a comprehensive summary of the current research on Piezo1 in the musculoskeletal system, highlighting its impact on bone formation, myogenesis, chondrogenesis, intervertebral disc homeostasis, tendon matrix cross-linking, and physical activity. Additionally, we explore the potential of targeting Piezo1 as a therapeutic approach for musculoskeletal disorders, including osteoporosis, muscle atrophy, intervertebral disc degeneration, and osteoarthritis.

Targeting type I DED interactions at the DED filament serves as a sensitive switch for cell fate decisions.

Activation of procaspase-8 in the death effector domain (DED) filaments of the death-inducing signaling complex (DISC) is a key step in apoptosis. In this study, a rationally designed cell-penetrating peptide, DEDid, was engineered to mimic the h2b helical region of procaspase-8-DED2 containing a highly conservative FL motif. Furthermore, mutations were introduced into the DEDid binding site of the procaspase-8 type I interface. Additionally, our data suggest that DEDid targets other type I DED interactions such as those of FADD. Both approaches of blocking type I DED interactions inhibited CD95L-induced DISC assembly, caspase activation and apoptosis. We showed that inhibition of procaspase-8 type I interactions by mutations not only diminished procaspase-8 recruitment to the DISC but also destabilized the FADD core of DED filaments. Taken together, this study offers insights to develop strategies to target DED proteins, which may be considered in diseases associated with cell death and inflammation.

Risk factors for reoperation after discectomy of lumbar herniated intervertebral disc disease.

Objectives: Discectomy is the most common surgery for lumbar herniated intervertebral disc (HIVD) disease. However, 5%-24% of patients undergo a second surgery due to recurrent disc herniation. Materials and Methods: This study was aimed to identify the risk factors for reoperation after discectomy of lumbar HIVD and recommend treatment for patients with a high risk of reoperation. We recruited patients diagnosed as having single-level lumbar HIVD who underwent open discectomy from January 1, 2000, to December 31, 2012 in our hospital. We used a survival curve to inspect the survival time and reoperation rate after surgery. We discussed the correlation of reoperation rate with discectomy level, body mass index, heavy lifting after surgery, sex, and age. Furthermore, we investigated the correlation between the experience of a surgeon and the reoperation rate. Results: A total of 619 patients were enrolled in our study. Most patients were 40-60 years old (48.8%), and most of them had herniation at L4/5 level (48.9%). The 8-year survival rate was 92%. Weight lifting after surgery may increase the reoperation rate by 115 and 18 times for those >60 years and <40 years, respectively. In addition, less experience of the surgeon and female sex had a high reoperation rate. Conclusion: Postoperative working modification may be very important for preventing patients from recurrent HIVD. For elderly people with HIVD, a more conservative therapy could be selected. If patients with lumbar spine hypermobility or severe degeneration require wide laminectomy, primary fusion should be considered.

Clinical management of bone loss in cervical total disc arthroplasty: literature review and treatment recommendations.

PURPOSE: Cervical total disc replacement (cTDR) has been established as an alternative treatment for degenerative cervical radiculopathy and myelopathy. While the rate of complications for cTDR is reasonably low, recent studies have focused on bone loss after cTDR. The purpose of this work is to develop a clinical management plan for cTDR patients with evidence of bone loss. To guide our recommendations, we undertook a review of the literature and aimed to determine: (1) how bone loss was identified/imaged, (2) whether pre- or intraoperative assessments of infection or histology were performed, and (3) what decision-making and revision strategies were employed. METHODS: We performed a search of the literature according to PRISMA guidelines. Included studies reported the clinical performance of cTDR and identified instances of cervical bone loss. RESULTS: Eleven case studies and 20 cohort studies were reviewed, representing 2073 patients with 821 reported cases of bone loss. Bone loss was typically identified on radiographs during routine follow-up or by computed tomography (CT) for patients presenting with symptoms. Assessments of infection as well as histological and/or explant assessment were sporadically reported. Across all reviewed studies, multiple mechanisms of bone loss were suspected, and severity and progression varied greatly. Many patients were reportedly asymptomatic, but others experienced symptoms like progressive pain and paresthesia. CONCLUSION: Our findings demonstrate a critical gap in the literature regarding the optimal management of patients with bone loss following cTDR, and treatment recommendations based on our review are impractical given the limited amount and quality evidence available. However, based on the authors' extensive clinical experience, close follow-up of specific radiographic observations and serial radiographs to assess the progression/severity of bone loss and implant changes are recommended. CT findings can be used for clinical decision-making and further follow-up care. The pattern and rate of progression of bone loss, in concert with patient symptomatology, should determine whether non-operative or surgical intervention is indicated. Future studies involving implant retrieval, histopathological, and microbiological analysis for patients undergoing cTDR revision for bone loss are needed.

Deep Learning Assisted Classification of T1ρ-MR Based Intervertebral Disc Degeneration Phases.

BACKGROUND: According to the T1ρ value of nucleus pulposus, our previous study has found that intervertebral disc degeneration (IDD) can be divided into three phases based on T1ρ-MR, which is helpful for the selection of biomaterial treatment timing. However, the routine MR sequences for patients with IDD are T1- and T2-MR, T1ρ-MR is not commonly used due to long scanning time and extra expenses, which limits the application of T1ρ-MR based IDD phases. PURPOSE: To build a deep learning model to achieve the classification of T1ρ-MR based IDD phases from routine T1-MR images. STUDY TYPE: Retrospective. POPULATION: Sixty (M/F: 35/25) patients with low back pain or lower limb radiculopathy are randomly divided into training (N = 50) and test (N = 10) sets. FIELD STRENGTH/SEQUENCES: 1.5 T MR scanner; T1-, T2-, and T1ρ-MR sequence (spin echo). ASSESSMENT: The T1ρ values of the nucleus pulposus in intervertebral discs (IVDs) were measured. IVDs were divided into three phases based on the mean T1ρ value: pre-degeneration phase (mean T1ρ value >110 msec), rapid degeneration phase (mean T1ρ value: 80-110 msec), and late degeneration phase (mean T1ρ value <80 msec). After measurement, the T1ρ values, phases, and levels of IVDs were input into the model as labels. STATISTICAL TESTS: Intraclass correlation coefficient, area under the receiver operating characteristic curve (AUC), F1-score, accuracy, precision, and recall (P < 0.05 was considered significant). RESULTS: In the test dataset, the model achieved a mean average precision of 0.996 for detecting IVD levels. The diagnostic accuracy of the T1ρ-MR based IDD phases was 0.840 and the AUC was 0.871, the average AUC of 5-folds cross validation was 0.843. DATA CONCLUSION: The proposed deep learning model achieved the classification of T1ρ-MR based IDD phases from routine T1-MR images, which may provide a method to facilitate the application of T1ρ-MR in IDD. EVIDENCE LEVEL: 4 TECHNICAL EFFICACY: Stage 2.

Clinical characteristics of peripapillary hyperreflective ovoid mass-like structures in myopic children.

AIM: To describe the characteristics of peripapillary hyperreflective ovoid mass-like structure (PHOMS) in myopic children and to investigate factors associated with PHOMS. METHODS: This retrospective observational study included 101 eyes of 101 children (age ≤17y) with myopia. All included patients underwent comprehensive clinical examination. Optic nerve canal parameters, including disc diameter, optic nerve head (ONH) tilt angle, and border tissue angle were measured using serial enhanced-depth imaging spectral-domain optical coherence tomography (EDI-OCT). Based on the optic disc drusen consortium's definition of PHOMS, eyes were classified as PHOMS group and non-PHOMS group. PHOMS was categorized according to height. RESULTS: Sixty-seven (66.3%) eyes were found with PHOMS. Small PHOMS could only be detected by optical coherence tomography (OCT). Medium PHOMS could be seen with blurred optic disc borders corresponding to OCT. The most frequent location of PHOMS was at the nasosuperior (91%, 61 of 67 eyes) to ONH disc. The axial length and spherical equivalent were more myopic in the PHOMS group than in the non-PHOMS group (both P<0.001). ONH tilt angle was also significantly greater in PHOMS group than in non-PHOMS group [8.90 (7.16-10.54) vs 3.93 (3.09-5.25), P<0.001]. Border tissue angle was significantly smaller in PHOMS group than in non-PHOMS group [29.70 (20.90-43.81) vs 45.62 (35.18-60.45), P<0.001]. In the multivariable analysis, spherical equivalent (OR=3.246, 95%CI=1.209-8.718, P=0.019) and ONH tilt angle (OR=3.275, 95%CI=1.422-7.542, P=0.005) were significantly correlated with PHOMS. There was no disc diameter associated with PHOMS. In the linear regression analysis, border tissue angle was negatively associated with PHOMS height (ß=-2.227, P<0.001). CONCLUSION: PHOMS is associated with optic disc tilt and optic disc nasal shift in myopia. Disc diameter is not a risk factor for PHOMS. The changes in ONH caused by axial elongation facilitated an understanding of the mechanism of PHOMS.

Molecular characteristics and evaluation of the phenotypic detection of carbapenemases among Enterobacterales and Pseudomonas via whole genome sequencing.

Background/purposes: The continuously increasing carbapenem resistance within Enterobacterales and Pseudomonas poses a threat to public health, nevertheless, the molecular characteristics of which in southern China still remain limited. And carbapenemase identification is a key factor in effective early therapy of carbapenem-resistant bacteria infections. We aimed to determine the molecular characteristics of these pathogens and compare commercial combined disc tests (CDTs) with the modified carbapenem inactivation method (mCIM) and EDTA-CIM (eCIM) in detecting and distinguishing carbapenemases using whole genome sequencing (WGS). Methods: A total of 78 Enterobacterales, 30 Pseudomonas were obtained from two tertiary hospitals in southern China. Susceptibility tests were conducted using an automated VITEK2 compact system with confirmation via the Kirby-Bauer method. The WGS was conducted on all clinical isolates and the molecular characteristics were analyzed by screening the whole genome sequences. CDTs with or without cloxacillin, mCIM, and eCIM, were performed and compared by taking WGS results as the benchmark. Results: A total of 103 carbapenem non-susceptible and 5 carbapenem susceptible bacteria were determined, with Klebsiella pneumoniae (42.7%), Pseudomonas aeruginosa (23.3%) and Escherichia coli (18.4%) being most prevalent. Carbapenemase genes were detected in 58 (56.3%) of the 103 carbapenem-non-susceptible clinical isolates, including 46 NDM, 6 KPC, 3 IMP, 1 IPM+VIM,1NDM+KPC, and 1 OXA-181. Carbapenemase-producing isolates were detected more frequently in Enterobacterales (76.3%). Among K. pneumoniae, the major sequence types were st307 and st11, while among E. coli and P. aeruginosa, the most prevalent ones were st410 and st242 respectively. For carbapenemase detection in Enterobacterales, the mCIM method achieved 100.00% (95% CI, 92.13-100.00%) sensitivity and 94.44% (70.63-99.71%) specificity (kappa, 0.96); for Pseudomonas, detection sensitivity was 100% (5.46-100.00%), and 100% (84.50-100.00%) specificity (kappa, 0.65). Commercial CDT carbapenemase detection sensitivity for Enterobacterales was 96.49% (86.84-99.39%), and 95.24% (74.13-99.75%) specificity (kappa, 0.90); for Pseudomonas, carbapenemase detection sensitivity was 100.00% (5.46-100.00%) and 37.93% (21.30-57.64%) specificity (kappa, 0.04). When cloxacillin testing was added, CDT specificity reached 84.61% (64.27-94.95%). Conclusion: The molecular epidemiology of carbapenem-non-susceptible isolates from pediatric patients in Southern China exhibited distinctive characteristics. Both the mCIM-eCIM combination and CDT methods effectively detected and differentiated carbapenemases among Enterobacterales isolates, and the former performed better than CDT among Pseudomonas.

Research progress on long non­coding RNAs in non­infectious spinal diseases (Review).

Spinal diseases, including intervertebral disc degeneration (IDD), ankylosing spondylitis, spinal cord injury and other non­infectious spinal diseases, severely affect the quality of life of patients. Current treatments for IDD and other spinal diseases can only relieve symptoms and do not completely cure the disease. Therefore, there is an urgent need to explore the causes of these diseases and develop new treatment approaches. Long non­coding RNA (lncRNA), a form of non­coding RNA, is abundant in diverse sources, has numerous functions, and plays an important role in the occurrence and development of spinal diseases such as IDD. However, the mechanism of action of lncRNAs has not been fully elucidated, and significant challenges remain in the use of lncRNAs as new therapeutic targets. The present article reviews the sources, classification and functions of lncRNAs, and introduces the role of lncRNAs in spinal diseases, such as IDD, and their therapeutic potential.

Exploring causal correlations between inflammatory cytokines and intervertebral disc degeneration: A Mendelian randomization.

Background: Inflammatory cytokines have been reported to be related to intervertebral disc degeneration (IVDD) in several previous studies. However, it remains unclear about the causal relationship between inflammatory cytokines and IVDD. This study employs Mendelian randomization (MR) to analyze the causal link between inflammatory cytokines and the risk of IVDD. Method: We used genetic variants associated with inflammatory cytokines from a meta-analysis of genome-wide association study (GWAS) in 8293 Finns as instrumental variables and IVDD data were sourced from the FinnGen consortium. The main analytical approach utilized Inverse-Variance Weighting (IVW) with random effects to assess the causal relationship. Additionally, complementary methods such as MR-Egger, weighted median, simple mode, weighted mode, and MR pleiotropy residual sum and outlier were employed to enhance the robustness of the final results. Result: We found interferon-gamma (IFN-γ, p = 2.14 × 10-6, OR = 0.870, 95% CI = 0.821-0.921), interleukin-1 beta (IL-1b, p = 0.012, OR = 0.951, 95% CI = 0.914-0.989), interleukin-4 (IL-4, p = 0.034, OR = 0.946, 95% CI = 0.899-0.996), interleukin-18 (IL-18, p = 0.028, OR = 0.964, 95% CI = 0.934-0.996), granulocyte colony-stimulating factor (GCSF, p = 0.010, OR = 0.919, 95% CI = 0.861-0.980), and Stromal cell-derived factor 1a (SDF1a, p = 0.014, OR = 1.072, 95% CI = 1.014-1.134) were causally associated with risk of IVDD. Conclusion: Our MR analyses found a potential causal relationship between six inflammation cytokines (IFN-γ, IL-1b, IL-4, IL-18, SDF1a, and GCSF) and altered IVDD risk.

Progress in the Application of Hydrogels in Intervertebral Disc Repair: A Comprehensive Review.

PURPOSE OF REVIEW: Intervertebral disc degeneration (IVDD) is a common orthopaedic disease and an important cause of lower back pain, which seriously affects the work and life of patients and causes a large economic burden to society. The traditional treatment of IVDD mainly involves early pain relief and late surgical intervention, but it cannot reverse the pathological course of IVDD. Current studies suggest that IVDD is related to the imbalance between the anabolic and catabolic functions of the extracellular matrix (ECM). Anti-inflammatory drugs, bioactive substances, and stem cells have all been shown to improve ECM, but traditional injection methods face short half-life and leakage problems. RECENT FINDINGS: The good biocompatibility and slow-release function of polymer hydrogels are being noticed and explored to combine with drugs or bioactive substances to treat IVDD. This paper introduces the pathophysiological mechanism of IVDD, and discusses the advantages, disadvantages and development prospects of hydrogels for the treatment of IVDD, so as to provide guidance for future breakthroughs in the treatment of IVDD.

Causal relationship between bone mineral density and intervertebral disc degeneration: a univariate and multivariable mendelian randomization study.

BACKGROUND: Although previous studies have suggested a possible association between bone mineral density (BMD) and intervertebral disc degeneration (IDD), the causal relationship between them remains unclear. Evidence from accumulating studies indicates that they might mutually influence one another. However, observational studies may be affected by potential confounders. Meanwhile, Mendelian randomization (MR) study can overcome these confounders to assess causality. OBJECTIVES: This Mendelian randomization (MR) study aimed to explore the causal effect of bone mineral density (BMD) on intervertebral disc degeneration (IDD). METHODS: Summary data from genome-wide association studies of bone mineral density (BMD) and IDD (the FinnGen biobank) have been acquired. The inverse variance weighted (IVW) method was utilized as the primary MR analysis approach. Weighted median, MR-Egger regression, weighted mode, and simple mode were used as supplements. The Mendelian randomization pleiotropy residual sum and outlier (MR-PRESSO) and MR-Egger regression were performed to assess horizontal pleiotropy. Cochran's Q test evaluated heterogeneity. Leave-one-out sensitivity analysis was further conducted to determine the reliability of the causal relationship. Multivariate MR (MVMR) analyses used multivariable inverse variance-weighted methods to individually and jointly adjust for four potential confounders, body mass index (BMI), Type2 diabetes, hyperthyroidism and smoking. A reverse MR analysis was conducted to assess potential reverse causation. RESULTS: In the univariate MR analysis, femoral neck bone mineral density (FNBMD), heel bone mineral density (eBMD), lumbar spine bone mineral density (LSBMD), and total body bone mineral density (TB BMD) had a direct causal effect on intervertebral disc degeneration (IDD) [FNBMD-related analysis: OR(95%CI) = 1.17 (1.04 to 1.31), p = 0.008, eBMD-related analysis: OR(95%CI) = 1.06 (1.01 to 1.12), p = 0.028, LSBMD-related analysis: OR(95%CI) = 1.20 (1.10 to 1.31), p = 3.38E-7,TB BMD-related analysis: OR(95%CI) = 1.20 (1.12 to 1.29), p = 1.0E-8]. In the MVMR analysis, it was revealed that, even after controlling for confounding factors, heel bone mineral density (eBMD), lumbar spine bone mineral density (LSBMD), and total body bone mineral density (TB BMD) still maintained an independent and significant causal association with IDD(Adjusting for heel bone mineral density: beta = 0.073, OR95% CI = 1.08(1.02 to 1.14), P = 0.013; Adjusting for lumbar spine bone mineral density: beta = 0.11, OR(95%CI) = 1.12(1.02 to 1.23), P = 0.03; Adjusting for total body bone mineral density: beta = 0.139, OR95% CI = 1.15(1.06 to 1.24), P = 5.53E - 5). In the reverse analysis, no evidence was found to suggest that IDD has an impact on BMD. CONCLUSIONS: The findings from our univariate and multivariable Mendelian randomization analysis establish a substantial positive causal association between BMD and IDD, indicating that higher bone mineral density may be a significant risk factor for intervertebral disc degeneration. Notably, no causal effect of IDD on these four measures of bone mineral density was observed. Further research is required to elucidate the underlying mechanisms governing this causal relationship.

Hypoxia-Preconditioned BMSC-Derived Exosomes Induce Mitophagy via the BNIP3-ANAX2 Axis to Alleviate Intervertebral Disc Degeneration.

Intervertebral disc degeneration (IVDD) is a chronic degenerative disease involving the aging and loss of proliferative capacity of nucleus pulposus cells (NPCs), processes heavily dependent on mitochondrial dynamics and autophagic flux. This study finds that the absence of BCL2/adenovirus E1B 19 kDa interacting protein 3 (BNIP3) is associated with senescence-related NPC degeneration, disrupting mitochondrial quality control. Bone marrow mesenchymal stem cells (BMSCs) have multidirectional differentiation potential and produce extracellular vesicles containing cellular activators. Therefore, in this study, BMSCs are induced under hypoxic stimulation to deliver BNIP3-rich extracellular vesicles to NPCs, thereby alleviating aging-associated mitochondrial autophagic flux, promoting damaged mitochondrial clearance, and restoring mitochondrial quality control. Mechanistically, BNIP3 is shown to interact with the membrane-bound protein annexin A2 (ANXA2), enabling the liberation of the transcription factor EB (TFEB) from the ANXA2-TFEB complex, promoting TFEB nuclear translocation, and regulating autophagy and lysosomal gene activation. Furthermore, a rat model of IVDD is established and verified the in vivo efficacy of the exosomes in repairing disc injuries, delaying NPC aging, and promoting extracellular matrix (ECM) synthesis. In summary, hypoxia-induced BMSC exosomes deliver BNIP3-rich vesicles to alleviate disc degeneration by activating the mitochondrial BNIP3/ANXA2/TFEB axis, providing a new target for IVDD treatment.

MRI study on the influence of lumbosacral vertebral body and disc factors on lumbar lordosis in children.

PURPOSE: To evaluate the influence of vertebral and disc wedging on the contribution of lumbar lordosis and the change of disc thickness before and after walking based on MRI. METHODS: Cross-sectional study. A total of 96 normally developing children, aged 5.7 ± 3.0 years old, 55 boys and 41 girls. They were divided into 3 groups: Pre-walking group, Walking group, and Post-walking group. PARAMETERS: lumbar lordosis Angle (LLA), the sum of the lumbar disc wedge Angle (∑D), the sum of the lumbar vertebral body wedge Angle (∑B), disc height (DH). RESULTS: (1) LLA, ∑D, ∑B, and DHL1-S1 were 33.2 ± 8.7°, 14.1 ± 8.6°, 11.9 ± 8.6°, and 6.9 ± 1.2 mm, 7.6 ± 1.4 mm, 8.2 ± 1.6 mm, 8.9 ± 1.7 mm, 8.5 ± 1.8 mm. (2) The difference in LLA values between the Pre-walking and the Post-walking group was statistically significant. DH were significantly different among the three groups. (3) In the Post-walking group, LLA value of girls was significantly higher than that of boys, and DHL3 - 4 and DHL4 - 5 values of girls were significantly lower than that of boys. (4) Age had a low positive correlation with LLA and ∑D and a moderate to strong positive correlation with DH; LLA showed a moderate positive correlation with ∑D, and a low positive correlation with ∑B and DH. CONCLUSION: Age and walking activity are the influencing factors of lumbar lordosis and disc thickening. Walking activity can significantly increase lumbar lordosis, and age is the main factor promoting lumbar disc thickening. DHL4-5 was the thickest lumbar intervertebral disc with the fastest intergroup thickening. Disc wedging contributes more to lumbar lordosis than vertebral wedging.

Bupivacaine pleural effusion mimicking a hemothorax after a thoracoscopic microdiscectomy with epidural anesthesia.

PURPOSE: Post-operative pain after video-assisted thoracoscopic surgery is often treated using thoracic epidural analgesics or thoracic paravertebral analgesics. This article describes a case where a thoracic disc herniation is treated with a thoracoscopic microdiscectomy with post-operative thoracic epidural analgesics. The patient developed a bupivacaine pleural effusion which mimicked a hemothorax on computed tomography (CT). METHODS: The presence of bupivacaine in the pleural effusion was confirmed using a high performance liquid chromatography method. RESULTS: The patient underwent a re-exploration to relieve the pleural effusion. The patient showed a long-term recovery similar to what can be expected from an uncomplicated thoracoscopic microdiscectomy. CONCLUSION: A pleural effusion may occur when thoracic epidural analgesics are used in patents with a corridor between the pleural cavity and epidural space.

An intensity-based self-supervised domain adaptation method for intervertebral disc segmentation in magnetic resonance imaging.

BACKGROUND AND OBJECTIVE: Accurate IVD segmentation is crucial for diagnosing and treating spinal conditions. Traditional deep learning methods depend on extensive, annotated datasets, which are hard to acquire. This research proposes an intensity-based self-supervised domain adaptation, using unlabeled multi-domain data to reduce reliance on large annotated datasets. METHODS: The study introduces an innovative method using intensity-based self-supervised learning for IVD segmentation in MRI scans. This approach is particularly suited for IVD segmentations due to its ability to effectively capture the subtle intensity variations that are characteristic of spinal structures. The model, a dual-task system, simultaneously segments IVDs and predicts intensity transformations. This intensity-focused method has the advantages of being easy to train and computationally light, making it highly practical in diverse clinical settings. Trained on unlabeled data from multiple domains, the model learns domain-invariant features, adeptly handling intensity variations across different MRI devices and protocols. RESULTS: Testing on three public datasets showed that this model outperforms baseline models trained on single-domain data. It handles domain shifts and achieves higher accuracy in IVD segmentation. CONCLUSIONS: This study demonstrates the potential of intensity-based self-supervised domain adaptation for IVD segmentation. It suggests new directions for research in enhancing generalizability across datasets with domain shifts, which can be applied to other medical imaging fields.