Cartilage Structure Research Articles

Alcian Blue Staining for Chondrocranium Development in Zebrafish.

Craniofacial abnormalities are one of the most frequent birth malformations in humans, affecting around one in every thousand live births. The zebrafish (Danio rerio), a model organism that has seen increased usage in toxicological research in recent years, is ideal for assessing the effects of various chemicals on bone and cartilage structures. Chondrogenesis developed in zebrafish embryos by embryonic day 2, and supporting cartilage components are apparent at hatching (72h post-fertilization). Individual cartilage may be observed using Alcian Blue staining as early as 2 days post-fertilization (dpf). The preferential binding of Alcian Blue causes the staining of zebrafish cartilage to acidic glycoproteins in an acidic solution (pH2.2). In 72-120 hpf embryos, the cranial skeleton is easily visible after cartilage staining using Alcian Blue. Various cranial lengths and structures can be determined by measuring specific distances and angles to optimize the quantitative analysis of cranial malformations in zebrafish after exposure to various toxic agents. This chapter explains the Alcian Blue staining procedure to identify craniofacial cartilaginous structures in zebrafish embryos.

Curcumin Alleviates Osteoarthritis Through the p38MAPK Pathway: Network Pharmacological Prediction and Experimental Confirmation.

Osteoarthritis (OA) is a common degenerative disease worldwide. While curcumin has shown therapeutic effects on OA, its mechanism remains unknown. This study aimed to investigate the molecular mechanism of curcumin in treating OA through network pharmacology and both in vivo and in vitro experiments. Curcumin-related targets were obtained using the HERB and DrugBank databases. GeneCards and DisGeNET were used to build a target database for OA. The STRING database was employed to construct protein-protein interaction networks and analyze related protein interactions. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and gene ontology enrichment analyses of core targets were performed using Metascape. In addition, Autodock software was utilized for molecular docking validation of curcumin and disease targets. Further validation of the main findings was conducted through in vitro and in vivo experiments. In the in vitro experiments, an inflammation model was constructed through nitric oxide donor (SNP) stimulation of chondrocytes. Subsequently, the regulatory effects of curcumin on core targets and signaling pathways were validated using Western blotting and immunofluorescence staining techniques. In the in vivo experiments, an OA model was established by performing medial meniscectomy on male Sprague-Dawley rats. The therapeutic effects were evaluated using enzyme-linked immunosorbent assays, histologic staining, and micro-computed tomography (micro-CT) techniques. Core targets of curcumin relevant to OA therapy included tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, IL-6, matrix metalloproteinase 9 (MMP-9), B-cell lymphoma 2 (BCL-2), and caspase-3. The major biological processes involved oxidative stress and apoptotic processes, among others. The p38 mitogen-activated protein kinase (p38/MAPK) pathway was identified as the most likely pathway involved. In vitro experiments showed that curcumin significantly reduced oxidative stress levels, inhibited the expression of inflammatory factors IL-6 and Cyclooxygenase-2 (COX-2) and downregulated the expression of MMP-9 and MMP-1. In addition, curcumin was found to regulate the expression of BCL-2 and caspase-3 through the p38/MAPK pathway, inhibiting chondrocyte apoptosis. In vivo animal experiments demonstrated that curcumin significantly reduced the expression of OA-related factors (IL-1, IL-6, and TNF-α). Histological analysis and micro-CT results revealed that curcumin treatment significantly increased cartilage thickness, improved cartilage morphology, structure, and function, inhibited cartilage degradation, and enhanced the resorption of subchondral bone in the knee joints of rats with OA. Curcumin regulates oxidative stress and maintains mitochondrial function, thereby protecting chondrocyte guard. In addition, curcumin attenuates the inflammatory response of chondrocytes by inhibiting the phosphorylation of P38MAPK, slowing down the breakdown of the extrachondral matrix while preventing apoptosis of chondrocytes. Additionally curcumin attenuated cartilage degradation and bone damage while helping to boost bone density.

Compare Three Types of Surgery for Meniscal Tears

Meniscus injuries, often associated with sports, have become a growing concern because of their potential to affect patients’ knee joints and, thus, People’s Daily lives. A meniscal tear is a half-moon-shaped fibrous cartilage structure in the knee joint. This article explores the meniscus’s complex anatomical structure and biochemistry, emphasizing its critical importance in maintaining optimal knee function. Our discussion extends to modern diagnostic procedures, particularly emphasizing the direct visualization capabilities of non-invasive magnetic resonance imaging (MRI) and arthroscopy. In addition, this paper lists three major surgical interventions for meniscus injuries: Meniscus repair, which aims to preserve the natural meniscus; Meniscectomy, the removal of the damaged meniscus; and Meniscus replacement using biological grafts or innovative synthetic materials. While meniscectomy can provide quick relief from symptoms, it carries the potential threat of diseases such as osteoarthritis in the long run. In contrast, meniscus repair and replacement strategies are longer-lasting treatment options, although postoperative recovery times and the complexity of the procedure vary.

Osteoarthritis in the Elderly Population: Preclinical Evidence of Nutrigenomic Activities of Flavonoids.

Osteoarthritis (OA) is a degenerative joint disease that is age-related and progressive. It causes the destruction of articular cartilage and underlying bone, often aggravated by inflammatory processes and oxidative stresses. This pathology impairs the quality of life of the elderly, causing pain, reduced mobility, and functional disabilities, especially in obese patients. Phytochemicals with anti-inflammatory and antioxidant activities may be used for long-term treatment of OA, either in combination with current anti-inflammatories and painkillers, or as an alternative to other products such as glucosamine and chondroitin, which improve cartilage structure and elasticity. The current systematic review provides a comprehensive understanding of the use of flavonoids. It highlights chondrocyte, cartilage, and subchondral bone activities, with a particular focus on their nutrigenomic effects. The molecular mechanisms of these molecules demonstrate how they can be used for the prevention and treatment of OA in the elderly population. However, clinical trials are still needed for effective use in clinical practice.

Harpagide inhibits the TNF-α-induced inflammatory response in rat articular chondrocytes by the glycolytic pathways for alleviating osteoarthritis

Osteoarthritis (OA) causes severe and functional dysfunction due to abnormal inflammation. The objective of this study was to evaluate the effect of Harpagide (HPG) on TNF-α-induced inflammation in vitro and in vivo. The effect of HPG on the proliferation of rat chondrocytes was studied. The anti-inflammatory effect of HPG and its molecular mechanisms were elucidated by qPCR, Western blotting, flow cytometry, metabolome analysis in vitro. In addition, the OA rat model was established, and the effect of HPG on OA was verified in vivo. We revealed 10 μM HPG demonstrated biocompatibility. The results demonstrated that HPG restored the upregulation of MMP-13, COX2, IL-1β and IL-6 induced by TNF-α. Moreover, HPG reversed TNF-α induced degradation of the extracellular matrix of chondrocytes. TNF-α treatment induced down-regulation of the mRNA/protein levels of proliferative markers Bcl2, CDK1 and Cyclin D1 were also recovered. HPG can inhibit TNF-α-induced inflammatory response through glycolytic metabolic pathways. HPG can restore TNF-α-induced upregulation of GRP78/IRE1α, and downregulation of AMPK proteins. In vivo experiments demonstrated that after HPG treatment, the appearance and physiological structure of articular cartilage were more integrated with highly organized chondrocytes and rich cartilage matrix compared with OA group. Finally, the molecular docking of HPG and selected key factors in glycolysis results showed that HPG had good binding potential with PFKM, PFKP, PFKFB3, PKM, HK2, and PFKL. In conclusion, the results shown HPG protects and activates chondrocytes, inhibits TNF-α-induced inflammatory response by glycolysis pathway in rat articular chondrocytes, and plays a role in the treatment of OA.

Morphohistological study of regeneration of knee joint cartilage defects in an experimental model under the influence of nuclear magnetic resonance therapy

Despite the variety of modern methods of treatment, the problem of hyaline cartilage regeneration is still relevant. Purpose of the study: to determine the effect of nuclear magnetic resonance therapy on the regenerative ability of simulated defects in the cartilage tissue of the knee joint in rats, to assess the dynamics of microscopic changes in articular cartilage in the main and control groups. The study was performed on 60 sex-mature rats. The defects were created in the area of the articular surfaces of the left knee joint – 30 defects in the main group and 30 defects in the control group. The right knee joint of both study groups was used as the norm. Medical (antibiotics, anti-inflammatory, analgesic) therapy was carried out for 3 days after the surgery. On the 4th day after surgery, rats of the main group were given nuclear magnetic resonance therapy for 60 minutes, for 7 days. After 7, 14, 21, 28 days after therapy, histological analysis of cartilage regenerate was performed. 28 days after the use of nuclear magnetic resonance therapy, the height of cartilage regenerate in rats was 82.12±8.89 μm in the intervention group and 56.34±7.82 μm in the control group. Cartilage regenerate in rats after nuclear magnetic resonance therapy was close to the structure of intact hyaline cartilage. However, complete regeneration did not occur, as evidenced by the smaller thickness of the articular cartilage compared to that in the right knee joint. In the control group, the formation of the regeneration had pronounced signs of dysregeneration. The cartilage tissue in the area of the defect, was predominantly fibrous in the nature with areas of necrosis. Nuclear magnetic resonance therapy contributes to the formation of articular cartilage in the defect – cartilage regenerate, which in its histological structure approaches hyaline cartilage.

Long-term tralopyril exposure results in endocrinological and transgenerational toxicity: A two-generation study of marine medaka (Oryzias melastigma)

This study aims to investigate the impact of tralopyril, a newly developed marine antifouling agent, on the reproductive endocrine system and developmental toxicity of offspring in marine medaka. The results revealed that exposure to tralopyril (0, 1, 20 μg/L) for 42 days resulted in decreased reproductive capacity in marine medaka. Moreover, it disrupted the levels of sex hormones E2 and T, as well as the transcription levels of genes related to the HPG axis, such as cyp19b and star. Sex-dependent differences were observed, with females experiencing more pronounced effects. Furthermore, intergenerational toxicity was observed in F1 offspring, including increased heart rate, changes in retinal morphology and cartilage structure, decreased swimming activity, and downregulation of transcription levels of relevant genes (HPT axis, GH/IGF axis, cox, bmp4, bmp2, runx2, etc.). Notably, the disruption of the F1 endocrine system by tralopyril persisted into adulthood, indicating a transgenerational effect. Molecular docking analysis suggested that tralopyril's RA receptor activity might be one of the key factors contributing to the developmental toxicity observed in offspring. Overall, our study highlights the potential threat posed by tralopyril to the sustainability of fish populations, as it can disrupt the endocrine system and negatively impact aquatic organisms for multiple generations.

Integrated omics analysis of coronary artery calcifications and myocardial infarction: the Framingham Heart Study

Gene function can be described using various measures. We integrated association studies of three types of omics data to provide insights into the pathophysiology of subclinical coronary disease and myocardial infarction (MI). Using multivariable regression models, we associated: (1) single nucleotide polymorphism, (2) DNA methylation, and (3) gene expression with coronary artery calcification (CAC) scores and MI. Among 3106 participants of the Framingham Heart Study, 65 (2.1%) had prevalent MI and 60 (1.9%) had incident MI, median CAC value was 67.8 [IQR 10.8, 274.9], and 1403 (45.2%) had CAC scores > 0 (prevalent CAC). Prevalent CAC was associated with AHRR (linked to smoking) and EXOC3 (affecting platelet function and promoting hemostasis). CAC score was associated with VWA1 (extracellular matrix protein associated with cartilage structure in endomysium). For prevalent MI we identified FYTTD1 (down-regulated in familial hypercholesterolemia) and PINK1 (linked to cardiac tissue homeostasis and ischemia–reperfusion injury). Incident MI was associated with IRX3 (enhancing browning of white adipose tissue) and STXBP3 (controlling trafficking of glucose transporter type 4 to plasma). Using an integrative trans-omics approach, we identified both putatively novel and known candidate genes associated with CAC and MI. Replication of findings is warranted.

Chronic Iodine Intake Excess Damages the Structure of Articular Cartilage and Epiphyseal Growth Plate.

This study aimed to explore the influence of excess iodine on the articular cartilage and epiphyseal growth plate in rats. Wistar rats (n = 200) were randomly divided into five groups with 40 rats in each: normal iodine (NI), 5-fold high iodine group (5HI), 10-fold high iodine group (10HI), 50-fold high iodine group (50HI), and 100-fold high iodine group (100HI). The rats were executed in 6 and 12months. 24-h urinary iodine concentration (UIC) was monitored by arsenic-cerium catalytic spectrophotometry. The chemiluminescence method was used to determine the thyroid function. The pathological changes in the epiphyseal plate, articular cartilage, and thickness of the epiphyseal plate were observed. The mRNA expression of collagen II (ColII), collagen X, matrix metalloproteinase-13 (MMP-13), and fibroblast growth factor receptor 1 in articular chondrocytes was detected by RT-PCR. 24-h UIC increased as iodine intake increased. In the 12th month, there was a significant increase in serum sTSH and a decrease in serum FT4 in HI groups, compared to the NI group. There was a decrease in the number of proliferating cells in the epiphyseal plate and an increase in the number of mast cell layers. The chondrocytes appeared disorganized, and the tidal lines were disturbed or even broken. Growth plate thickness decreased with increasing iodine intake. Compared with the NI group, ColII and MMP-13 mRNA expression in chondrocytes in all HI groups significantly increased. Chronic iodine overdose increases the risk of hypothyroidism. Chronic iodine overdose leads to abnormal morphology of epiphyseal growth plates and articular cartilage, increasing the risk of osteoarthritis.

Role of pathogenic and mentally pathogenic microflora, which are localized in the orotopharynx in the ethiopathogenesis of secondary osteoarthrosis

ABSTRACT. Much attention is paid to the problem of secondary osteoarthritis caused by various microorganisms and fungi of the genus S. albicans, associated with their significant growth and prevalence throughout the world among the population of various age groups, high temporary and permanent disability. At the same time, the problem of immunopathology in the pathogenesis of secondary osteoarthritis is being actively studied. The developed immunopathological process induced by pathogenic and opportunistic microflora in articular cartilage and synovial membrane is the main factor in the degenerative destruction of articular cartilage. Goal. to determine the role of pathogenic and opportunistic microflora localized in the oropharynx in the etiopathogenesis of secondary osteoarthritis. Research materials and methods. 65 patients aged from 19 to 45 years, who were undergoing inpatient treatment at Artz Klinic, Kharkiv, were examined for secondary osteoarthritis of the knee joint. The diagnosis was established according to the International Classification of Diseases of the 10th revision (ICD-10) - M18.1. Patients with a history of a high frequency of accompanying pathologies of the oropharynx were selected for the study: chronic tonsillitis - 48 (73.8%), tonsillitis - 32 (49.2%), pharyngitis - 34 (52.3%), sinusitis - 13 (20) %), otitis – 9 (13.8%) the etiology of which is determined by gram-positive and gram-negative microorganisms. All patients underwent microbiological examination of throat swabs, and 24 patients underwent microbiological examination of synovial fluid, which was taken for examination before intra-articular therapy. The obtained data were statistically processed by calculating the arithmetic mean and its error. The results. Presented modern ideas about secondary osteoarthritis caused by etiologically significant macroflora persisting in the oropharynx and as a result of organotropy due to the inclusion in its structure of mimicking antigens of articular cartilage play a leading role in the degradation of articular cartilage and articular bag, transferring the pathological process to an autoimmune basis. This approach makes it possible to develop early immunodiagnostics, prognosis of the disease, and immunocorrective therapy. Conclusions. Pathogenic and conditionally pathogenic microflora persisting in the oropharynx is characterized by organotropy (community of lipopolysaccharides and glycoproids), is identical to the cell-tissue structures of articular cartilage and synovial membrane in the causative agent and modulates the immune response through mimicking antigens.

Double-edged role of mechanical stimuli and underlying mechanisms in cartilage tissue engineering.

Mechanical stimuli regulate the chondrogenic differentiation of mesenchymal stem cells and the homeostasis of chondrocytes, thus affecting implant success in cartilage tissue engineering. The mechanical microenvironment plays fundamental roles in the maturation and maintenance of natural articular cartilage, and the progression of osteoarthritis Hence, cartilage tissue engineering attempts to mimic this environment in vivo to obtain implants that enable a superior regeneration process. However, the specific type of mechanical loading, its optimal regime, and the underlying molecular mechanisms are still under investigation. First, this review delineates the composition and structure of articular cartilage, indicating that the morphology of chondrocytes and components of the extracellular matrix differ from each other to resist forces in three top-to-bottom overlapping zones. Moreover, results from research experiments and clinical trials focusing on the effect of compression, fluid shear stress, hydrostatic pressure, and osmotic pressure are presented and critically evaluated. As a key direction, the latest advances in mechanisms involved in the transduction of external mechanical signals into biological signals are discussed. These mechanical signals are sensed by receptors in the cell membrane, such as primary cilia, integrins, and ion channels, which next activate downstream pathways. Finally, biomaterials with various modifications to mimic the mechanical properties of natural cartilage and the self-designed bioreactors for experiment in vitro are outlined. An improved understanding of biomechanically driven cartilage tissue engineering and the underlying mechanisms is expected to lead to efficient articular cartilage repair for cartilage degeneration and disease.

Collagen-Based Hydrogels for Cartilage Regeneration.

Cartilage regeneration remains difficult due to a lack of blood vessels. Degradation of the extracellular matrix (ECM) causes cartilage defects, and the ECM provides the natural environment and nutrition for cartilage regeneration. Until now, collagen hydrogels are considered to be excellent material for cartilage regeneration due to the similar structure to ECM and good biocompatibility. However, collagen hydrogels also have several drawbacks, such as low mechanical strength, limited ability to induce stem cell differentiation, and rapid degradation. Thus, there is a demanding need to optimize collagen hydrogels for cartilage regeneration. In this review, we will first briefly introduce the structure of articular cartilage and cartilage defect classification and collagen, then provide an overview of the progress made in research on collagen hydrogels with chondrocytes or stem cells, comprehensively expound the research progress and clinical applications of collagen-based hydrogels that integrate inorganic or organic materials, and finally present challenges for further clinical translation.

Construction and Properties of High-Toughness Soft-Soft Interfaces Based on the Adhesion of Natural Polyphenols.

Artificial joint replacement is the most effective way to treat osteoarthritis. However, these artificial joints are too stiff with high interfacial contact stress and poor surface lubrication, resulting in stress shielding and severe wear and tear lead to an extremely high failure rate. At present, hydrogels are considered the most promising substitute for artificial joint prostheses owing to their good biocompatibility, adjustable mechanical properties, and excellent flexibility. Nevertheless, a traditional single-layer hydrogel has poor bearing capacity and lubrication, which are far from the properties of natural articular cartilage. The high strength and low friction properties of natural articular cartilage are based on its own multilayer fibrous structure. Therefore, by simulating the multilayer structure of natural cartilage, a bilayer bionic cartilage hydrogel was prepared; that is, the upper hydrogel realized excellent lubrication and the lower hydrogel realized high load-bearing capacity. However, the interface binding of bilayer hydrogels is a challenge at present. Therefore, the interfacial adhesion of the bilayer hydrogel is improved by adding tannic acid (TA) based on the adhesion of the natural polyphenol structure. The average interfacial toughness reaches 3650 J/m2, and the average interfacial shear force reaches 800 kPa. In the preparation of the bilayer hydrogel, taking advantage of the coordination reaction between TA and metal cations, Fe3+ is further added to endow the bilayer hydrogel with excellent mechanical properties and good sliding friction performance. Therefore, this work opens up a new way to construct cartilage-like materials with high toughness and a soft-soft interface.

Cartilage‐Inspired Multidirectional Strain Sensor with High Elasticity and Anisotropy Based on Segmented Embedded Strategy

AbstractFlexible, stretchable, and sensitive multidirectional sensing systems that can decouple different mechanical inputs and identify multidirectional signals are crucial for dynamic human signal perception and intelligent human–computer interaction. Most reported multidirectional sensors are suitable for discriminating in‐plane deformation directions, and the sensing materials are difficult to balance between stretchability and mechanical strength. Here, a segmented embedded structure strategy inspired by the interlaced structure of cartilage is proposed. This strategy combines soft and hard materials in a topological and zipper‐shear chain manner and balances the performance of reinforced composites with flexibility and high toughness. In the case of segmented embedded hydrogels (SEHs), a wearable multidirectional sensing system that can decouple and identify planar strain/pressure is constructed. The multidirectional sensing system exploits the inherent anisotropy and layered structure design of composites to decouple the sensing functions. Supported by machine learning algorithms, the high accuracy demonstration of the multidirectional sensors in typical multidirectional motion joint posture monitoring and recognition confirms their potential in practical applications such as personal health sensing and human–computer interaction.

Molecular mechanisms and potential applications of chondroitin sulphate in managing post-traumatic osteoarthritis.

Post-traumatic osteoarthritis (PTOA), a disorder of the synovium, subchondral bone, and cartilage that affects the entire joint, constitutes approximately 12% of all cases of symptomatic osteoarthritis. This review summarizes the pathogenetic mechanisms that underlie the positive influence of chondroitin sulphates (CSs) on PTOA as means of preventive and therapeutic treatment. Mechanisms of PTOA development involve chondrocytes undergoing various forms of cell death (apoptosis, pyroptosis, necroptosis, ferroptosis and/or necrosis). Chondroitin sulphates are a class of glycosaminoglycans that improve the structure and function of cartilage and subchondral bone, which is associated with their ability to decrease the activation of NF-κB and p38 MAPK, and up-regulate Nrf2. Standardized small fish extract (SSFE) is an example of the drugs that can attenuate NF-κB-mediated systemic inflammation, potentially helping to reduce joint inflammation and cartilage degradation, improve joint function, and alleviate pain and disability in patients with these conditions.

Tetracalcium Phosphate Biocement Hardened with a Mixture of Phytic Acid–Phytase in the Healing Process of Osteochondral Defects in Sheep

Hyaline articular cartilage has unique physiological, biological, and biomechanical properties with very limited self-healing ability, which makes the process of cartilage regeneration extremely difficult. Therefore, research is currently focused on finding new and potentially better treatment options. The main objective of this in vivo study was to evaluate a novel biocement CX consisting of tetracalcium phosphate–monetit biocement hardened with a phytic acid–phytase mixture for the regeneration of osteochondral defects in sheep. The results were compared with tetracalcium phosphate–monetit biocement with classic fast-setting cement systems and untreated defects. After 6 months, the animals were sacrificed, and the samples were evaluated using macroscopic and histologic methods as well as X-ray, CT, and MR-imaging techniques. In contrast to the formation of fibrous or fibrocartilaginous tissue on the untreated side, treatment with biocements resulted in the formation of tissue with a dominant hyaline cartilage structure, although fine fibres were present (p < 0.001). There were no signs of pathomorphological changes or inflammation. Continuous formation of subchondral bone and hyaline cartilage layers was present even though residual biocement was observed in the trabecular bone. We consider biocement CX to be highly biocompatible and suitable for the treatment of osteochondral defects.

The healing effects of L-carnitine and spongostan on cartilage defect in rat model

PurposeWe aimed to determine the effect of L-carnitine and spongostan on cartilage healing in an experimental animal model with a full-thickness cartilage defect. MethodsIn the study 32 Sprague–Dawley rats were divided into four groups in equal numbers. A cartilage defect with a diameter of 1 mm and a depth of 3 mm was created in the femoral intercondylar region of rats in groups A, B, and C. Group A received no treatment in the defective area. Group B received treatment with spongostan. Group C received treatment with spongostan soaked in L-carnitine. Group D served as the healthy control group. The rats were euthanized 6 weeks after the treatment. Histological evaluation of the condyles was done with the modified Mankin scoring. ResultsIn the histopathological imaging of the cartilage structure, it was observed that in group A, there was complete disorganization and cellular structure was completely absent up to the subchondral bone. In group B, moderate structural improvement, partially intact appearance in border integrity and mostly diffuse hypercellularity were observed. In group C, a near-normal healing, a completely intact appearance in boundary integrities and normal or hypercellularity in cellular structure were observed. The total score of the modified Mankin decreases numerically from A to D. There was no statistically significant difference observed between the A-B (p = 0.176), C-D (p = 0.145), and C-B (p = 0.580) groups, while significant differences were detected between the A–C (p = 0.004), B–D (p = 0.007), and A–D (p = 0.000) groups. ConclusionIt has been known that mitochondrial activity is reduced in the osteoarthritis, and as a result, decrease in cellular activity occurs with ATP synthesis. For this reason, we found that L-carnitine, which we expect to stimulate cell proliferation by stimulating ATP synthesis, makes a positive contribution to cartilage healing, as expected. It has been found that combining spongostan with L-carnitine for the treatment of cartilage healing, instead of applying spongostan alone, provides near-normal healing.

Treatment of Lumbar Degenerative Disease with a Novel Interlaminar Screw Elastic Spacer Technique: A Finite Element Analysis.

A novel interlaminar elastic screw spacer technique was designed to maintain lumbar mobility in treating lumbar degenerative diseases. A validated finite element model of L4/5 was used to establish an ISES-1/2 model and an ISES-1/3 model based on different insertion points, a unilateral fixation model and a bilateral fixed model based on different fixation methods, and a Coflex-F model based on different implants. The elastic rods were used to fix screws. Under the same mechanical conditions, we compared the biomechanical characteristics to investigate the optimal entry point for ISES technology, demonstrate the effectiveness of unilateral fixation, and validate the feasibility of the ISES technique. Compared to ISES-1/3, the ISES-1/2 model had lower intradiscal pressure, facet cartilage stress, and posterior structural stress. Compared to the ISES-BF model, the ISES-UF model had lower intervertebral pressure, larger mobility, and smaller stress on the posterior structures. The ISES model had a similar intervertebral pressure and limitation of extension as the Coflex-F model. The ISES model retained greater mobility and reduced the stress on the facet cartilage and posterior structure compared with the Coflex-F model. Our study suggests that the ISES technique is a promising treatment of lumbar degenerative diseases, especially those with osteoporosis.

Articular Cartilage-From Basic Science Structural Imaging to Non-Invasive Clinical Quantitative Molecular Functional Information for AI Classification and Prediction.

This review presents the changes that the imaging of articular cartilage has undergone throughout the last decades. It highlights that the expectation is no longer to image the structure and associated functions of articular cartilage but, instead, to devise methods for generating non-invasive, function-depicting images with quantitative information that is useful for detecting the early, pre-clinical stage of diseases such as primary or post-traumatic osteoarthritis (OA/PTOA). In this context, this review summarizes (a) the structure and function of articular cartilage as a molecular imaging target, (b) quantitative MRI for non-invasive assessment of articular cartilage composition, microstructure, and function with the current state of medical diagnostic imaging, (c), non-destructive imaging methods, (c) non-destructive quantitative articular cartilage live-imaging methods, (d) artificial intelligence (AI) classification of degeneration and prediction of OA progression, and (e) our contribution to this field, which is an AI-supported, non-destructive quantitative optical biopsy for early disease detection that operates on a digital tissue architectural fingerprint. Collectively, this review shows that articular cartilage imaging has undergone profound changes in the purpose and expectations for which cartilage imaging is used; the image is becoming an AI-usable biomarker with non-invasive quantitative functional information. This may aid in the development of translational diagnostic applications and preventive or early therapeutic interventions that are yet beyond our reach.

Single-cell RNA sequencing reveals differences between force application and bearing in ankle cartilage.

Chondrocytes are the major functional elements of articular cartilage. Force has been demonstrated to influence the structure and function of articular cartilage and chondrocytes. Therefore, it is necessary to evaluate chondrocytes under different force conditions to gain deep insight into chondrocyte function. Six cartilage tissues from the distal tibia (referred to as the AT group) and five cartilage tissues from the trochlear surface of the talus (referred to as the ATa group) were obtained from 6 donors who had experienced fatal accidents. Single-cell RNA sequencing was used on these samples. A total of 149,816 cells were analyzed. Nine chondrocyte subsets were ultimately identified. Pseudotime analyses, enrichment analyses, cell-cell interaction studies, and single-cell regulatory network inference and clustering were performed for each cell type, and the differences between the AT and ATa groups were analyzed. Immunohistochemical staining was used to verify the existence of each chondrocyte subset and its distribution. The results suggested that reactive oxygen species related processes were active in the force-applied region, while tissue repair processes were common in the force-bearing region. Although the number of prehypertrophic chondrocytes was small, these chondrocytes seemed to play an important role in the ankle.