Epidemiology of osteoarthritis

Molecular signaling pathways in osteoarthritis and biomaterials for cartilage regeneration: a review

Osteoarthritis is a prevalent degenerative joint disease characterized by cartilage degradation, synovial inflammation, and subchondral bone alterations, leading to chronic pain and joint dysfunction. Conventional treatments provide symptomatic relief but fail to halt disease progression. Recent advancements in biomaterials, molecular signaling modulation, and gene-editing technologies offer promising therapeutic strategies. This review explores key molecular pathways implicated in osteoarthritis, including fibroblast growth factor, phosphoinositide 3-kinase/Akt, and bone morphogenetic protein signaling, highlighting their roles in chondrocyte survival, extracellular matrix remodeling, and inflammation. Biomaterial-based interventions such as hydrogels, nanoparticles, and chitosan-based scaffolds have demonstrated potential in enhancing cartilage regeneration and targeted drug delivery. Furthermore, CRISPR/Cas9 gene editing holds promise in modifying osteoarthritis-related genes to restore cartilage integrity. The integration of regenerative biomaterials with precision medicine and molecular therapies represents a novel approach for mitigating osteoarthritis progression. Future research should focus on optimizing biomaterial properties, refining gene-editing efficiency, and developing personalized therapeutic strategies. The convergence of bioengineering and molecular science offers new hope for improving joint function and patient quality of life in osteoarthritis management.

Therapeutic potential of SOX family transcription factors in osteoarthritis

BACKGROUND

As the worldwide population ages, osteoarthritis has significantly increased. This musculoskeletal condition has become a pressing global health issue and thus, prevention and treatment of osteoarthritis have become the primary focus of domestic and international research. Scholarly investigations of the molecular mechanisms that are related to the occurrence and development of osteoarthritis have shed light on the pathological causes of this condition to a certain extent, providing a foundation for its prevention and treatment. However, further research is necessary to fully understand the critical role of the transcription factor SOX9 in chondrocyte differentiation and the development of osteoarthritis. As a result, there has been widespread interest in SOX transcription factors. While SOX9 has been utilized as a biomarker to indicate the occurrence and prognosis of osteoarthritis, investigations into other members of the SOX family and the development of targeted treatments around SOX9 are still required.

PURPOSE

This article considers the impact of the SOX protein on the development and inhibition of osteoarthritis and highlights the need for therapeutic approaches targeting SOX9, as supported by existing research.

RESULTS

SOX9 can contribute to the process of osteoarthritis through acetylation and ubiquitination modifications. The regulation of the WNT signalling pathway, Nrf2/ARE signalling pathway, NF-κB signalling pathway and SOX9 is implicated in the emergence of osteoarthritis. Non-coding RNA may play a role in the onset and progression of osteoarthritis by modulating various SOX family members, including SOX2, SOX4, SOX5, SOX6, SOX8, SOX9 and SOX11.

CONCLUSION

SOX9 has the capability of mitigating the onset and progression of osteoarthritis through means such as medication therapy, stem cell therapy, recombinant adeno-associated virus (rAAV) vector therapy, physical therapy and other approaches.

Perfluoroalkyl and polyfluoroalkyl substances crossing the blood-joint barrier: Their occurrence and distribution in synovial fluid

Per- and polyfluoroalkyl substances (PFASs) have garnered considerable research attention due to their potential adverse effects on human health. Epidemiological studies have indicated a possible association between PFASs exposure and the prevalence of osteoarthritis (OA). However, the presence of PFASs in the synovial fluid of OA patients and the distribution of PFASs across the blood-joint barrier remains unreported. This study identified significant differences in PFASs profiles between patients and controls, with a markedly higher PFOS-to-PFOA ratio observed in patients. Additionally, the blood-joint transfer efficiency of PFOS was significantly greater in patients than in controls (0.75 vs. 0.53, p < 0.05). Furthermore, PFOS levels were elevated in patients with advanced OA compared to those in the early stages. Positive correlations were observed between synovial fluid PFOS and inflammatory markers C-reactive protein (CRP) and tumor necrosis factor-α (TNF-α), implying that inflammation may facilitate the distribution of PFOS across the joint barrier. This study represents the first documented evidence of the human joint exposure to PFASs and their blood-joint transfer abilities.

Blocking the LRH-1/LCN2 axis by ML-180, an LRH-1 inverse agonist, ameliorates osteoarthritis via inhibiting the MAPK pathway

Osteoarthritis (OA) is a chronic and degenerative disease marked by inflammation and extracellular matrix (ECM) degeneration, contributing to synovial inflammation and cartilage destruction. Accumulating evidence has demonstrated that Liver receptor homolog-1 (LRH-1), an orphan nuclear receptor, mediates inflammatory response. However, there is a lack of evidence regarding the regulatory role of LRH-1 in OA pathogenesis. In this study, we confirmed that chondrocytes expressed LRH-1, and observed its upregulation in both IL-1β-treated chondrocytes and cartilage of destabilization of the medial meniscus (DMM)-operated mice. Overexpression of LRH-1 promoted inflammation and dysregulation of ECM metabolism in IL-1β-induced chondrocytes, reversed by inhibition of LRH-1 with ML-180 or gene silencing to protect chondrocytes. Moreover, ML-180 treatment in vivo improved the deteriorated OA phenotypes in mouse models, alleviating OA development. Mechanistically, RNA sequencing revealed that Lipocalin-2 (LCN2), a member of the lipocalin family associated with inflammation, is located downstream of LRH-1 and is positively regulated by it. Furthermore, the LRH-1/LCN2 axis mainly relied on activating the mitogen-activated protein kinase (MAPK) signaling pathway to promote inflammation and dysregulation of ECM metabolism, ultimately damaging chondrocytes. Our findings demonstrate that LRH-1 positively modulates LCN2,activating the MAPK pathway, indicating that targeting the LRH-1/LCN2/MAPK axis may represent a potential therapeutic strategy for OA.

Ultrasound-based radiomics and machine learning for enhanced diagnosis of knee osteoarthritis: Evaluation of diagnostic accuracy, sensitivity, specificity, and predictive value

Purpose

To evaluate the usefulness of radiomics features extracted from ultrasonographic images in diagnosing and predicting the severity of knee osteoarthritis (OA).

Methods

In this single-center, prospective, observational study, radiomics features were extracted from standing radiographs and ultrasonographic images of knees of patients aged 40-85 years with primary medial OA and without OA. Analysis was conducted using LIFEx software (version 7.2.n), ANOVA, and LASSO regression. The diagnostic accuracy of three different models, including a statistical model incorporating background factors and machine learning models, was evaluated.

Results

Among 491 limbs analyzed, 318 were OA and 173 were non-OA cases. The mean age was 72.7 (±8.7) and 62.6 (±11.3) years in the OA and non-OA groups, respectively. The OA group included 81 (25.5 %) men and 237 (74.5 %) women, whereas the non-OA group included 73 men (42.2 %) and 100 (57.8 %) women. A statistical model using the cutoff value of MORPHOLOGICAL_SurfaceToVolumeRatio (IBSI:2PR5) achieved a specificity of 0.98 and sensitivity of 0.47. Machine learning diagnostic models (Model 2) demonstrated areas under the curve (AUCs) of 0.88 (discriminant analysis) and 0.87 (logistic regression), with sensitivities of 0.80 and 0.81 and specificities of 0.82 and 0.80, respectively. For severity prediction, the statistical model using MORPHOLOGICAL_SurfaceToVolumeRatio (IBSI:2PR5) showed sensitivity and specificity values of 0.78 and 0.86, respectively, whereas machine learning models achieved an AUC of 0.92, sensitivity of 0.81, and specificity of 0.85 for severity prediction.

Conclusion

The use of radiomics features in diagnosing knee OA shows potential as a supportive tool for enhancing clinicians' decision-making.

The influence of zinc levels on osteoarthritis: A comprehensive review

Osteoarthritis (OA), a disease with a multifactorial aetiology and an enigmatic root cause, affects the quality of life of many elderly patients. Even though there are certain medications utilised to reduce the symptomatic effects, a reliable treatment method to reverse the disease is yet to be discovered. Zinc is a cofactor of over 3000 proteins and is the only metal found in all six classes of enzymes. We explored zinc’s effect on the immune system and the bones as OA affects both. We also discussed zinc-dependent enzymes, highlighting their significant role in the disease’s pathogenesis. It is important to note that both excessive and deficient zinc levels can negatively affect bone health and immune function, thereby exacerbating OA. The purpose of this review is to offer a better understanding of zinc’s impact on OA pathogenesis and to provide clarity regarding its beneficial and detrimental outcomes. We searched thoroughly systematic reviews, meta-analysis, review articles, research articles and randomised controlled trials to ensure a comprehensive review. In brief, using zinc supplementation in the treatment of OA may act as a doubled-edged sword, offering potential benefits but also posing risks.

The Effect of Corticosteroid Doses on Pain in Knee Osteoarthritis: A Systematic Review and Meta-Analysis

OBJECTIVE

To evaluate the effect of various doses of intra articular corticosteroid injection (IACI) on pain reduction in knee osteoarthritis when compared with normal saline and perform a between-dose comparison.

METHODS

A systematic review with meta-analysis was conducted searching four databases until April 2024. RCTs comparing the effect of IACI with normal saline on pain relief in knee osteoarthritis were included. The different doses were pooled into three categories: low (< 40 mg methylprednisolone equivalent), usual (40 mg), or high dose (> 40 mg). Their effect compared to normal saline was evaluated at very short (VST, 1-3 weeks), short (ST, 4-8 weeks) and middle term (MT, 10-16 weeks). A multivariate analysis carried out the influence of dosage on pain relief, at each time point. The Jadad scale was used to assess risks of bias and GRADE for certainty of evidence.

RESULTS

Eleven studies were included in the meta-analyses (n = 1125 patients). Low dose was significantly superior to normal saline in the VST, but not in the ST (low-quality evidence). No data were available for the MT. The usual dose was significantly superior to normal saline in the ST, but not in the VST and MT (moderate-quality evidence). A high dose was significantly superior to normal saline in the ST and MT (low-quality evidence). Multivariate analysis showed that the dose significantly influenced pain reduction at ST and MT, but not in the VST (low-quality evidence).

CONCLUSION

The dose of IACI doesn't influence pain reduction in the peak effect, but a higher dose seems to have a more prolonged effect.

Dual-Contrast Agent with Nanoparticle and Molecular Components in Photon-Counting Computed Tomography: Assessing Articular Cartilage Health

PURPOSE

Photon-counting detectors (PCDs) are cutting-edge technology that enable spectral computed tomography (CT) imaging with a single scan. Spectral imaging is particularly effective in contrast-enhanced CT (CECT) imaging, especially when multiple contrast agents are utilized, as materials are distinguishable based on their unique X-ray absorption. One application of CECT is joint imaging, where it assesses the structure and composition of articular cartilage soft tissue. This evaluates articular cartilage and reveals compositional changes associated with early-stage osteoarthritis (OA) using a photon-counting detector CT (PCD-CT) technique combined with a dual-contrast agent method.

METHODS

A dual-contrast agent combination was used, consisting of proteoglycan-binding cationic tantalum oxide nanoparticles, developed in our lab, and a commercial non-ionic iodinated iodixanol agent. Ex vivo equine stifle joint cartilage samples (N = 30) were immersed in the contrast agent bath for 96 hours and imaged at multiple timepoints for analysis of proteoglycan, collagen, and water contents as well as collagen orientation, histological scoring, and biomechanical parameters.

RESULTS

By analyzing contrast agent concentrations, the technique provided a simultaneous assessment of the solid constituents and function of cartilage. Contrast agent diffusion depended on contrast agent composition and was significantly different between healthy and early-stage OA groups within 12 hours.

CONCLUSION

The present study shows the promising utility of the dual-contrast PCD-CT technique for articular cartilage assessment and early-stage OA detection.

Macrophages-derived small extracellular vesicles regulate chondrocyte proliferation and affect osteoarthritis progression via upregulating Osteopontin expression

Small extracellular vesicles (sEVs) are considered promising gene-delivery vehicles for the treatment of osteoarthritis (OA). This study aimed to explore the molecular mechanism by which M2 macrophage-derived sEVs (M2-sEVs) modulate chondrocyte proliferation and apoptosis, thereby affecting OA progression. M2 macrophages were successfully induced, and M2-sEVs were successfully isolated. The sEVs were small vesicles with diameters ranging from 50 to 150 nm. The exosomal markers, including CD9, CD63, and CD81, were highly expressed, whereas the negative marker calnexin was absent in M2-sEVs. M2-sEVs effectively alleviated OA tissue and chondrocyte damage in both in vivo and in vitro models, evidenced by reduced rat knee joint injury, increased chondrocyte viability, and decreased chondrocyte apoptosis and extracellular matrix (ECM) degradation. Furthermore, M2-sEVs decreased the levels of pro-inflammatory cytokines IL-6 and TNF-α. Osteopontin (OPN) was upregulated within rats with OA and IL-1β-induced chondrocytes. Silencing of OPN exacerbated IL-1β-induced chondrocyte damage and partially abrogated the therapeutic effects of M2-sEVs. Additionally, M2-sEVs enhanced OPN expression and activated CD44 and the PI3K/AKT signaling pathway. In conclusion, M2-sEVs promoted OPN expression to improve knee joint tissue damage in rats with OA and chondrocyte damage. This protective effect of M2-sEVs might be associated with the activation of CD44 and the PI3K/AKT signaling.

Anti-citrullinated procollagen C-endopeptidase enhancer antibody (anti-PCOLCE): a potential biomarker for seronegative rheumatoid arthritis

OBJECTIVES

Although with great advances, the biomarkers used in the diagnosis of rheumatoid arthritis (RA) are still challenging, especially in seronegative RA. Recently, procollagen C-endopeptidase enhancer (PCOLCE) was revealed as a potential autoantigen of seronegative RA by our group. This study aimed to further analyse the B-cell autoantigenic epitopses of PCOLCE and the diagnostic value of its antibody in seronegative RA.

METHODS

The B-cell epitopes of PCOLCE were elucidated by the Immune Epitope Database and molecular mimicry analyses. The anti-citrullinated PCOLCE271-284 antibody (anti-PCOLCE) was tested in a total of 612 serum samples including RA patients, healthy controls and patients with other rheumatic diseases. The diagnostic value of anti-PCOLCE in RA, especially for seronegative RA, was evaluated by ROC curve, sensitivity and specificity. Anti-PCOLCE in combination with anti-CCP for RA diagnosis was also demonstrated. The correlations of anti-PCOLCE with RA patient features were further analysed.

RESULTS

Anti-PCOLCE was significantly elevated in RA serums with a sensitivity of 51.53% and specificity of 93.60%. More importantly, anti-PCOLCE had a favorable diagnostic value in seronegative RA, revealing a positive rate of 40.00% in anti-CCP negative RA, 38.76% in RF negative RA and 36.46% in anti-CCP and RF negative RA. The combination of anti-PCOLCE with anti-CCP demonstrated a high sensitivity of 82.14% and specificity of 90.21%. Anti-PCOLCE also has good diagnostic value in RA patients with normal inflammatory factors and early RA. Moreover, anti-PCOLCE was positively correlated with CRP, anti-CCP and RF.

CONCLUSION

Anti-PCOLCE could serve as a novel biomarker for RA, especially for seronegative RA.

Does osteoarthritis physiotherapy research in South Korea align with the National Institute for Health and Care Excellence guidelines: a systematic review of English and Korean literature

BACKGROUND

Osteoarthritis (OA) is a leading cause of lower limb disability worldwide, imposing significant socioeconomic and personal burden. Thus, many internationally recognised organisations have developed management guidelines for this condition. Among these, the National Institute for Health and Care Excellence (NICE) recommends four first-line approaches to osteoarthritis management: education, exercise, self-management, and weight management. Despite the development of guidelines, adherence to OA management recommendations appears to be suboptimal internationally, and little is known about guideline adherence in South Korea. This study aimed to explore whether research-based physiotherapy interventions for OA in South Korea align with the NICE guidelines.

METHODS

A comprehensive search was conducted across multiple Korean and English electronic databases, including the Korea Citation Index (KCI), Korean Studies Information Service System (KISS), MEDLINE, EMBASE, CINAHL, SPORTDiscus SCOPUS, and Google Scholar. Twelve randomized controlled trials conducted in South Korea met the inclusion criteria, with sample sizes ranging from 20 to 60 participants. Participants' mean age ranged from 57 to 75 years, and their Body Mass Index (BMI) varied from 23.00 to 25.68 kg/m². The primary outcome measure was the alignment of interventions with NICE OA guidelines, assessed using a scoring system (0-2 points per study) developed specifically for this review. Additionally, the methodological quality of included studies was evaluated using the Physiotherapy Evidence Database (PEDro) scale.

RESULTS

Most studies had poor methodological quality (PEdro scale range: 3-5). Only 42% of the Korean studies aligned with the NICE OA recommendations. Commonly applied interventions were predominantly passive, such as heat therapy, electrotherapy, and kinesiology taping, none of which are recommended by NICE.

CONCLUSIONS

A discrepancy was found between research-based physiotherapy interventions for osteoarthritis in South Korea and the therapeutic approaches recommended by the National Institute for Health and Care Excellence guidelines. Factors such as a lack of evidence-based education, research, healthcare funding in South Korea, and cultural health experiences and expectations of the patients may have contributed to these findings. These results could help develop new strategies for improving osteoarthritis management in South Korea.

Extracorneal connective tissue alterations in keratoconus: ultrasonographic evaluation of tendon, plantar fascia, and cartilage

PURPOSE

Structures such as the cornea, Achilles tendon (AT), plantar fascia (PF), and cartilage share the common feature of containing collagen and being associated with collagenous tissue disorders. However, the relationship between keratoconus and AT and PF thicknesses has not been investigated before. The importance of this study lies in the potential to identify a link between keratoconus and conditions such as Achilles tendinitis, plantar fasciitis, or osteoarthritis.

METHODS

This prospective, comparative study includes 33 keratoconus patients and 33 age- and gender-matched controls. AT, PF, talar cartilage (TC), and distal femoral cartilage (DFC) thicknesses were obtained by ultrasound (US). US parameters of the study and control groups were compared.

RESULTS

The mean AT and PF thicknesses were significantly higher in the study group (p = 0.002 and p < 0.001, respectively). On the other hand, the mean lateral femoral condyle (LFC), medial femoral condyle (MFC), DFC, and TC thicknesses were significantly lower in the study group (p < 0.001, for all). There was a significant correlation between corneal thickness and AT thickness (r = - 0.482, p = 0.005) and between corneal thickness and intercondylar area (IA) thickness (r = 0.367, p = 0.036). No significant relationship was found between maximum keratometry and US parameters, and BCV index and US parameters (p > 0.05, for all).

CONCLUSION

This study clearly demonstrates that patients with keratoconus have significant PF, tendon and cartilage thickness abnormalities. Keratoconus patients may have a tendency to develop conditions such as Achilles tendinitis, plantar fasciitis, or osteoarthritis.

Global, regional, and national burden of osteoarthritis from 1990 to 2021 and projections to 2035: A cross-sectional study for the Global Burden of Disease Study 2021

OBJECTIVE

This study aims to report the trends and cross-national disparities in the burden of osteoarthritis (OA) by region, age, gender, and time from 1990 to 2021, and to further project changes through 2035.

METHODS

In this systematic analysis based on the Global Burden of Disease (GBD) study, population survey data on osteoarthritis from 21 countries/regions and U.S. insurance claims data were used to estimate the prevalence and incidence of OA in 204 countries and regions from 1990 to 2021. The reference case definition for OA was symptomatic and radiographically confirmed osteoarthritis. Studies using definitions other than the reference, such as self-reported OA, were adjusted through a regression model to align with the reference case. The distribution of OA severity was derived from a pooled meta-analysis using the Western Ontario and McMaster Universities Arthritis Index (WOMAC). Final prevalence estimates were multiplied by disability weights to calculate years lived with disability (YLD). An Autoregressive Integrated Moving Average (ARIMA) model was used to forecast the prevalence and incidence of OA through 2035.

RESULTS

In 2021, approximately 607 million (95%UI 538-671) people worldwide were affected by osteoarthritis, accounting for 7.7% of the global population. Compared to 2020, the age-standardized prevalence of OA among males is projected to increase from 5,763 per 100,000-5,922 per 100,000 by 2036, while the age-standardized prevalence among females is expected to decline slightly from 8,034 per 100,000-7,925 per 100,000. In 2021, the global age-standardized YLD rate for osteoarthritis was 244.5 (95%UI 117.06-493.11), the global age-standardized prevalence rate was 6,967.29 (95%UI 6,180.7-7,686.06), and the global age-standardized incidence rate was 535 (95%UI 472.38-591.97). In 2021, the age-standardized prevalence rate exceeded 5.5% across all regions, ranging from 5,675.8 per 100,000 (95%UI 5,001.76-6,320.8) in Southeast Asia to 8,608.63 per 100,000 (95%UI 7,674.07-9,485.19) in high-income Asia Pacific regions. The knee was the most commonly affected joint. High BMI and metabolic risks are the only two GBD risk factors for osteoarthritis. From 1990 to 2021, the age-standardized prevalence, incidence, and YLD attributable to osteoarthritis have been on the rise, with substantial international variations across indicators. Countries with high socio-demographic index (SDI) bear a disproportionately high burden of OA, and inequalities in the burden of disease due to differences in SDI between countries have been increasing over time.

CONCLUSIONS

As a major public health problem, the overall global burden of OA has shown an upward trend from 1990 to 2019, including an increase in the number of cases and inequalities in distribution across the globe, which has resulted in significant health losses and economic burdens. In addition, SDI-related inequalities between countries are increasing. In this regard, national public health authorities and the World Health Organization (WHO) should work together to improve diagnosis and early treatment rates by strengthening disease awareness and education, as well as strengthening international cooperation, providing necessary medical assistance to less developed regions, and actively exploring new strategies for the prevention and treatment of OA.

Identification of a RANKL/TNF-α Dual-Inhibitor as a Potential Disease-Modifying Agent for the Treatment of Knee Osteoarthritis

Osteoarthritis (OA) is a multifactorial degenerative disease involved subchondral bone remodeling, cartilage destruction and synovium inflammation. While receptor activator of nuclear factor-κB ligand (RANKL), a tumor necrosis factor (TNF) superfamily protein, is the critical regulator in bone metabolism associated with subchondral bone resorption, TNF-α is also an important inflammatory factor involved in the OA inflammation and cartilage destruction. Based on previous compound Y1599, we identified a novel tetrahydro-β-carboline derivative Y2641 with both RANKL and TNF-α inhibition in this study. Y2641 exhibited potent RANKL-induced osteoclastogenic inhibition (IC50 = 109.1 nM), and had anti-inflammatory and cartilage destruction inhibiting effects at 10 μM with low cytotoxicity. SPR assays demonstrated the binding affinity of Y2641 to RANKL (Kd = 3.984 μM) and TNF-α (Kd = 18.59 μM). In vivo assay further revealed the disease-modifying effects of Y2641 in OA rats, establishing Y2641 as a promising lead compound for the development of disease-modifying osteoarthritis drugs.

Initial learning curve of lateral unicompartmental knee arthroplasty

This study obtained the learning curve of a chief surgeon's lateral unicompartmental knee arthroplasty surgery using the cumulative summation analysis (CUSUM) method and divided the curve into two stages: the learning stage and the proficient stage. The inflection point of the learning curve is around the 11th case. The surgical time and team anxiety were relieved in the proficient stage. The study also summarized some possible methods for shortening the learning curve.

PURPOSE

To describe the initial learning curve of lateral unicompartmental knee arthroplasty (LUKA), compare its effectiveness at different stages, optimize its learning curve, reduce surgical risks, and provide experience and theoretical guidance for clinical practice.

METHODS

A retrospective analysis was conducted on the relevant data of the initial 30 patients who underwent LUKA performed by a single primary surgeon from August 2018 to September 2022. Cumulative summation analysis (CUSUM) was utilized to analyse the surgical time of 30 consecutive surgeries and plot the learning curve. The learning curve was divided into two stages: the learning stage and the proficient stage. The perioperative parameters, including the state-trait anxiety inventory (STAI), surgical time, pre- and postoperative haemoglobin levels, length of hospital stay, and surgical incision length, were recorded. Postoperative imaging indicators, which reflect the placement position of the prosthesis, and functional follow-up results between these two stages were explored and analysed.

RESULTS

The CUSUM showed that the learning curve reached a maximum at the 11th case and then decreased gradually; hence, patients 1-11 represented the learning stage, and patients 12-30 represented the proficient stage. All patients were followed up at 6-month, 1-year and 2-year after surgery. During the follow-up period, none of the patients experienced complications such as implant loosening, periprosthetic fracture, dislocation of the bearing insert, or periprosthetic infection. There were no statistically significant differences (P > 0.05) observed between the learning stage and proficient stage for any of the observed parameters, except for surgical time.

CONCLUSIONS

The operation time-related learning curve for LUKA patients was 11, but surgery did not affect postoperative imaging or functional outcomes at early follow-up.

DNA Origami-Based CD44-Targeted Therapy Silences Stat3 Enhances Cartilage Regeneration and Alleviates Osteoarthritis Progression

Osteoarthritis (OA) is a widespread musculoskeletal disorder affecting ≈600 million people globally, and small interfering RNA (siRNA) therapy shows potential in targeting OA progression. However, the efficient and targeted delivery of siRNA remains a major challenge due to issues with tissue specificity and degradation in vivo. In this study, A DNA origami-based chondrocyte-targeted delivery system (OCS) is designed for siRNA delivery to OA-affected cartilage. The DNA origami is engineered to load with siRNA targeting signal transducer and activator of transcription 3 (Stat3), a key regulator of inflammation and cartilage degradation, and is functionalized with anti-CD44 aptamers for selective targeting of OA chondrocytes. In vitro, the DNA origami system effectively delivers siRNA to diseased chondrocytes, silencing matrix metalloproteinases expression and reducing inflammation. In OA rat models, it preserves cartilage integrity, promotes regeneration, and mitigates ECM degradation without evident side effects. These findings highlight DNA origami as a promising platform for siRNA-based OA therapy, offering a promising solution to the challenges of targeted and efficient siRNA delivery.

Associations Between Total and Regional Fat-To-Muscle Mass Ratio and Osteoarthritis Incidence: A Prospective Cohort Study

OBJECTIVE

To investigate the associations between total and regional fat-to-muscle mass ratio (FMR) and incident osteoarthritis among adults.

DESIGN

This prospective cohort study included 328,549 participants from the UK Biobank. FMR was calculated as the ratio of fat mass to muscle mass for the whole body, trunk, arms, and legs using a body composition analyzer. Incident osteoarthritis was identified via ICD-10 codes. Cox proportional-hazard regression models were used to identify the association between each type of FMR separately and incident osteoarthritis. Subgroup analyses by age,sex and specific joint sites were conducted.

RESULTS

During a median follow-up of 14.4 years, 48,997 incident osteoarthritis cases were identified. We found an increasing trend in incident osteoarthritis with higher FMRs, particularly among females. In the fully adjusted models, each one standard deviation increase in arm FMR was associated with a 6% higher hazard in males and 11% in females. For leg FMR, the corresponding increases were 5% in males and 14% in females, respectively. Whole-body and trunk FMR were significantly associated with osteoarthritis risk only in women.

CONCLUSIONS

FMR was generally positively associated with osteoarthritis risk, with significant associations for arm and leg FMR remaining independent of body mass index across sex and age subgroups. These findings highlight FMR as a valuable marker for identifying those at risk of incident osteoarthritis.

Evaluation of the healing effect of kappa-carrageenan combined with dental pulp stem cell-derived exosomes on induced knee osteoarthritis in male rats

BACKGROUND

Osteoarthritis (OA) is a degenerative joint disease that causes pain and reduces quality of life. Exosomes, dental pulp stem cells, and kappa carrageenan are arising as potential therapies for enhancing cartilage regeneration.

OBJECTIVE

The aim of this study is to evaluate the combined therapeutic effects of exosomes, dental pulp stem cells, and kappa carrageenan in reducing osteoarthritis severity.

MATERIALS AND METHODS

Fifty-four male Sprague Dawley rats (10-wk-old, 200 ± 20 gr) were divided into nine groups. Human dental pulp stem cells (HDPSCs) were isolated from healthy third Molars of human teeth and cultured. Osteoarthritis was induced by anterior cruciate ligament transection. Treatments included intra-articular injections of kappa carrageenan, exosomes, HDPSCs, or their combinations. Ten weeks after treatment, knee joints were obtained and prepared for histopathological evaluation. Radiological evaluations were performed with CBCT imaging. A p-value of less than 0.05 is considered statistically significant.

RESULTS

The group treated with Exosomes, Carrageenan, HDPSCs (ECD group) showed the most substantial reduction in Total Radiology and Osteophyte scores (p < 0.0001 and p = 0.0003, respectively). The exosome with HDPSCs group also showed significant improvements (p = 0.0002 and p = 0.0005). Histopathological analysis showed that the ECD group had significantly better cartilage integrity, matrix structure, and cell viability (p = 0.0225, p = 0.0002, and p = 0.0009). In Masson's Trichrome and Safranin O staining, the ECD, ED, and EC-treated groups demonstrated improved matrix quality with better collagen alignment.

CONCLUSIONS

The intraarticular injection of the combination of exosomes, carrageenan, and HDPSCs significantly improved both the radiological and histopathological results in an osteoarthritis model.

Chilean Cross-Cultural Adaptation and Validation of the Hip Disability and Osteoarthritis Outcome Score

BACKGROUND

The Hip disability and Osteoarthritis Outcome Score (HOOS) has been used for the evaluation of patients who have hip osteoarthritis. It is one of the most frequently used instruments for the follow-up of patients operated on for total hip arthroplasty (THA) in different national registries. The purpose of this study was to carry out the transcultural adaptation and validation of the Chilean version of the HOOS questionnaire in patients who have hip osteoarthritis.

METHODS

The translation and cross-cultural adaptation process were based on international guidelines to obtain a Chilean version of the HOOS questionnaire. The Chilean version was evaluated in the pretest phase and then in the validation phase with patients in the outpatient setting, from patients who had initial osteoarthritis to patients who had end-stage disease waiting for surgery. We assessed the psychometric properties as convergent validity, evaluating correlations with the Short Form 12 Health Survey (SF12) questionnaire and the World Health Organization Disability Assessment Schedule 2.0 (WHODAS2.0) tool; structural validity by conducting a confirmatory factor analysis; and internal consistency using Cronbach's alpha.

RESULTS

There were 30 outpatients who participated in the pre-test phase and 111 in the validation phase. There was a positive correlation between the HOOS score in the dimensions of activities of daily living, pain, and symptoms with the physical dimension of the SF12 (r > 0.7; P < 0.001). In the same way, the HOOS quality of life item was correlated with the mental dimension of the SF12 (r = 0.51; P < 0.001). The WHODAS2.0 tool had a moderate negative correlation with all the HOOS dimensions (P < 0.001). Confirmatory factor analysis confirmed good construct validity. Cronbach's alpha was 0.97 for the global questionnaire.

CONCLUSIONS

The Chilean version of the HOOS questionnaire showed adequate validity and reliability, with adequate psychometric properties. This could have relevance in the evaluation and treatment of patients who have hip osteoarthritis and in the evaluation of the results of patients undergoing THA.

Effect of gait retraining strategies on clinical and biomechanical outcomes in subjects with knee osteoarthritis: a systematic review with meta-analysis and GRADE recommendations

PURPOSE

To assess the effects of gait retraining strategies on clinical and/or biomechanical variables in knee osteoarthritis.

METHODS

This study was registered in PROSPERO-CRD42023402778. Studies were searched up to June/2024. PEDro scale and GRADE approach were used to assess methodological quality and certainty of evidence. A meta-analysis was conducted using R-software.

RESULTS

The included studies employed backward walking (5), toe-out (1), and freely strategies (2). The meta-analysis revealed a significant difference with low quality of evidence favoring gait retraining for pain (MD = -1.12; 95% CI: [-1.61; -0.62]; I2 = 78%; p < 0.01) and with high quality for function (SMD = -0.80; 95% CI: [-1.12; -0.48]; I2 = 0%; p = 0.42). A significant difference also favoring gait retraining was observed for first knee adduction moment (KAM) (MD = -0.20; 95% CI: [-0.38; -0.02]; I2 = 84%; p < 0.01). The comparisons indicated similarity between groups for second KAM (MD = -0.16; 95% CI: [-0.47; 0.16]; I2 = 79%; p = 0.03) and for knee flexion moment (MD = 0.07; 95% CI: [-0.07; 0.20]; I2 = 76%; p = 0.02).

CONCLUSION

Gait retraining improved pain, function and first KAM. Second KAM and knee flexion moment did not modify.

The role of adipose-derived stem cells in knee osteoarthritis treatment: insights from a triple-blind clinical study

BACKGROUND

Osteoarthritis (OA) is a degenerative joint disease that primarily affects older adults, characterized by cartilage degradation, synovitis, and osteophyte formation. Despite its prevalence, no medical treatment can reverse the joint cartilage degradation, leading many patients to undergo invasive procedures such as arthroplasty. Mesenchymal stem cells (MSCs), particularly those derived from adipose tissue, have emerged as a promising therapeutic approach due to their ability to differentiate into chondrocytes and potentially regenerate cartilage. While MSCs from bone marrow and umbilical cord have shown efficacy in treating OA, adipose-derived MSCs (ADMSC) are more accessible and cost-effective. This study aims to evaluate the safety and efficacy of allogeneic ADMSC in treating knee OA.

METHODS

This triple-blind, interventional clinical trial included 20 patients with idiopathic knee OA, meeting the American College of Rheumatology (ACR) criteria. Patients were randomly assigned to receive an intra-articular injection of either 0.5 × 108 allogeneic ADMSC or saline (control group). Participants were evaluated for clinical signs of inflammation at baseline, and then at 2 weeks, 2 months, and 6 months post-injection using clinical assessments, the Visual Analogue Scale (VAS), Knee injury and Osteoarthritis Outcome Score (KOOS), range of motion (ROM), and Magnetic Resonance Arthrography (MRA).

RESULTS

The ADMSC group exhibited significant improvement in pain reduction as measured by VAS scores compared to the control group (P < 0.05). However, no significant differences were observed between the groups in ROM, and based on KOOS; quality of life, activity of daily living (ADL), recreation and sports activities, symptom and pain. Although there were no significant changes in ADL, recreation, and sports activities between groups, the ADMSC group showed significant improvements between several follow-up periods. Similar improvements were reported in the ADMSC group between several follow-ups' periods on other scales. Radiological outcomes showed a significant increase in cartilage thickness at specific locations (e.g., middle-lateral patella (P = 0.017), Tibial compartment lateral (P < 0.000)) in the ADMSC group after 6 months, demonstrating the regenerative potential of ADMSC in certain MRA sites. Multivariable analysis underlines the complexity of the interactions among treatment, time, and baseline level of variables. Although ADMSC treatment shows potential for some measures, its effects are not consistently significant for all measures.

CONCLUSION

Allogeneic ADMSC are safe and effective in reducing pain (based on VAS scale) and increasing cartilage thickness in knee OA patients. However, they do not significantly enhance quality of life or daily activity compared to placebo. Further research with larger sample sizes and longer follow-up periods is needed to confirm these findings and determine optimal dosing strategies.

TRIAL REGISTRATION

Trial Registry Code: IRCT2016021123298N3, 20 February 2016. https://irct.behdasht.gov.ir/trial/19909.

Association between visceral adiposity index and osteoarthritis in U.S. adults aged 50 and older: a cross-sectional study

Background

Existing evidence linking visceral adiposity index (VAI) to osteoarthritis (OA) remains limited and requires further investigation. This study aimed to evaluate the potential relationship between higher VAI scores and an increased risk of OA.

Methods

A retrospective cross-sectional analysis was conducted using data from 9,464 participants aged 50 and older, sourced from the 2011 to 2018 National Health and Nutrition Examination Survey (NHANES). The VAI was categorized into three tertiles, with the first tertile (T1) representing the lowest VAI and third tertile (T3) the highest. Weighted logistic regression was employed to examine the association between VAI and OA. To explore potential non-linear relationships, smoothed curve fitting and threshold effect analyses were performed. Subgroup analyses were performed to validate these findings.

Results

The average age of the study population was 63.16 ± 9.05 years, and 47.22% were male. After adjusting for confounding factors, a statistically significant positive correlation was observed between VAI and OA risk (OR = 1.03, 95% CI: 1.01-1.06, P < 0.01). Participants in the highest VAI tertile exhibited a 35% greater likelihood of developing OA compared to those in the lowest tertile (OR = 1.35, 95% CI: 1.06-1.70, P = 0.015). Furthermore, multivariate restricted cubic spline (RCS) regression analysis revealed a non-linear relationship (non-linear P < 0.05) with a threshold effect at a VAI value of 3.9. Subgroup analyses showed no significant interaction effects (all P-values for interaction > 0.05).

Conclusion

This study highlights a significant association between elevated VAI and an increased risk of developing OA in individuals aged 50 and older. These results emphasize the potential of the VAI as a risk factor for OA and warrant further research to explore its role in prevention and management strategies in older populations.

The efficacy of home-based remote rehabilitation versus usual rehabilitation for patients with knee osteoarthritis: A systematic review and meta-analysis

PURPOSE

To compare home-based remote rehabilitation with usual rehabilitation care for knee osteoarthritis (OA).

METHODS

PubMed, Cochrane, and Embase databases were searched for randomized controlled trials (RCTs) comparing home-based remote rehabilitation (telephone calls, video calls, apps, or websites) with usual in-person rehabilitation in patients with knee OA. Mean differences (MDs) or standardized mean differences (SMDs) were calculated for continuous outcomes and risk ratios (RRs) for binary outcomes, with 95 % confidence intervals (CIs). Statistical analyses were performed using R Software, version 4.4.1.

RESULTS

A total of 9 RCTs were included, comprising 974 patients with knee OA, of whom 483 (49.6 %) were randomized to home-based remote rehabilitation. Compared with usual rehabilitation, home-based remote rehabilitation significantly reduced pain severity (SMD -0.34; 95 % CI -0.67 to -0.02) and significantly improved physical activity levels (SMD -0.45; 95 % CI -0.85 to -0.05). Furthermore, the home-based remote rehabilitation group showed a significant reduction in pain assessed with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) (MD -0.95 points; 95 % CI -1.84 to -0.06), an improvement in functionality assessed with the Timed Up and Go test (MD -0.83 s; 95 % CI -1.64 to -0.02), and a greater patient satisfaction (RR 2.01; 95 % CI 1.46 to 2.76).

CONCLUSION

The results demonstrated that home-based remote rehabilitation reduced pain and increased patient satisfaction, however, there is insufficient evidence to state that remote rehabilitation significantly improved physical activity and functionality. Home-based remote rehabilitation appears to be a viable and effective alternative for patients with knee OA.

Curcumin-PLGA NPs coated with targeting biomimetic personalized stem cell membranes for osteoarthritis therapy

Traditional drug delivery systems for OA treatments face limitations due to rapid clearance within the joint and low biocompatibility. Moreover, the inflammation associated with OA exacerbates tissue damage and delays the regenerative capacity of therapeutics. To overcome these limitations, an OA-specific drug delivery system designated dCOL2-CM-Cur-PNPs is developed herein to target OA cartilage for anti-inflammatory and cartilage regeneration purposes. This system is constructed using cell membranes obtained from induced pluripotent stem cell -derived mesenchymal stem cells (iMSC-CMs), poly(D,l-lactide-co-glycolide) (PLGA) nanoparticles loaded with the well-known anti-inflammatory and cartilage-regenerating agent curcumin (Cur-PNPs), and damaged type II collagen (dCOL2)-targeting phospholipids. Coating the Cur-PNPs with iMSC-CMs enhances the sustained release of curcumin and improves its cellular uptake by OA-induced chondrocytes. The dCOL2-CM-Cur-PNPs restores the chondrogenic properties of the OA-induced chondrocytes, inhibit the pro-inflammatory function of M1 macrophages, and promote the anti-inflammatory function of M2 macrophages. The dCOL2-targeting phospholipids integrated on the surface of the iMSC-CMs facilitate specific binding to OA cartilage, as validated by in-vitro and in-vivo experiments. Additionally, the dCOL2-CM-Cur-PNPs alleviate OA progression in a DMM rat model. This drug delivery system based on iMSC-CMs modified with dCOL2-targeting phospholipids demonstrates significant potential as a next-generation platform for promoting cartilage regeneration through OA-specific therapy.

Physical therapy vs. glucocorticoid injection in patients with meniscal tears and knee osteoarthritis: a multi-center, randomized, controlled trial

BACKGROUND

Physical therapy is commonly recommended for treating meniscus tears and knee osteoarthritis (KOA). However, data from randomized trials that compare the effectiveness of this treatment with that of glucocorticoid injections are lacking.

METHODS

This randomized, single-blind, multicenter trial included 273 patients with KOA who were divided into either the physical therapy group (n = 133) or the glucocorticoid injection group (n = 140). The physical therapy included kinesiology tape, exercise protocols, and exercise training programs to increase core stability and periprosthetic muscle strength. The primary endpoint was the overall Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score at 1 year. Additionally, proprioception and safety were assessed. All analyses were performed with the use of the intention-to-treat approach. The data are reported as percentages (%) (n), and the threshold for statistical significance was p < 0.05.

RESULTS

There was no significant difference in the baseline characteristics between the two groups (p > 0.05). The average (± SD) WOMAC score at 1-year was 76.85 ± 2.50 in the physiotherapy group. And 99.55 ± 2.09 in the glucocorticoid injection group (mean difference = - 22.70; 95% confidence interval [95% CI] - 23.43 to - 21.96; p < 0.001). Compared with the glucocorticoid injection group, the physical therapy group exhibited superior performance in terms of proprioception, especially in the eyes-closed in situ stepping test (14.27 ± 0.75 versus 5.98 ± 0.74; mean difference = 8.29; 95% CI 8.09-8.50; p < 0.001). The incidence of serious adverse events at the 1-year follow-up was comparable between the two groups. Most of these events were determined to be complications arising from physical therapy and glucocorticoid injection.

CONCLUSIONS

The results revealed that pain, quality of life, and balance were greater in the physiotherapy group than in the glucocorticoid injection group within the 1-year study period. However, the long-term effects beyond this timeframe remain unknown, and future studies with extended follow-up times are needed to confirm the sustainability of these benefits.

TRIAL REGISTRATION

The protocol was approved by the local ethics committee of the ethical commission of the Hebei Sports Science Research Institute (SEC20200213019) and Ethics Committee of Sichuan Taikang Hospital (SCTK-IRB-032). The study was registered at the Chinese Clinical Trial Registry (ChiCTR2000032508).

Hand Osteoarthritis: Molecular Mechanisms, Randomized Controlled Trials, and the Future of Targeted Treatment

Hand osteoarthritis (OA) is a prevalent and disabling condition, yet its pathogenesis remains less studied than OA in large weight-bearing joints. Emerging genetic, epigenetic, and microbiome research suggests that hand OA might be biologically distinct, involving joint-specific pathways not shared by knee or hip OA. This review integrates genome-wide association studies specific to hand OA, highlighting key molecular contributors such as inflammatory cytokines. These genetic insights, together with emerging data on epigenetic alterations and gut microbial dysbiosis, point to broader systemic and regulatory influences on hand OA onset and progression. We also assess pharmacologic interventions tested in randomized controlled trials that have attempted to target these pathways. While agents such as TNF and IL-6 inhibitors, hydroxychloroquine, and corticosteroids have shown limited success, emerging evidence supports the potential of methotrexate in synovitis-positive general hand OA, platelet-rich plasma in thumb carpometacarpal (CMC) OA, and prolotherapy in interphalangeal (IP) OA. These findings illustrate the persistent gap between mechanistic understanding and therapeutic success. Future work must prioritize multifactorial strategies for addressing pain and translational frameworks that link molecular mechanisms to treatment response. In summary, this review offers an update on hand OA and identifies key opportunities for more targeted and effective therapy.

Association between geriatric nutritional risk index and osteoarthritis in aged person over 60: data from NHANES 2005-2018

Background

Osteoarthritis (OA), a prevalent age-related degenerative joint disorder, demonstrates significant associations with nutritional status. This study examines the prognostic value of the Geriatric Nutritional Risk Index (GNRI) in OA risk stratification among elderly individuals.

Methods

This retrospective analysis utilized seven NHANES cycles (2005-2018) encompassing geriatric participants (≥ 60 years) possessing complete GNRI measurements and baseline covariates. For comparative cohort balancing, propensity score matching was executed using inverse probability weighting a matched-pairs design, adjusting for age, alcohol consumption, and the Poverty Income Ratio. Multivariable-adjusted weighted logistic regression quantified GNRI-OA associations, with restricted cubic splines (RCS) characterizing nonlinear dynamics. Subgroup analyses were also performed.

Results

This cross-sectional analysis identified 656 OA cases among 3,120 rigorously screened geriatric participants. Elevated GNRI levels demonstrated a significant association with increased OA risk among geriatric populations, with the correlation remaining robust in sensitivity analyses adjusted for metabolic confounders. Specifically, a GNRI ≥ 123.63 was associated with a higher probability of OA in this population. RCS analysis revealed a significant non-linear relationship (p_non-linear < 0.001) between GNRI and OA risk, particularly among men and non-smokers. Subgroup analyses indicated that males, Hispanic Americans, Non-Hispanic Black people, non-smokers, and those with a low PIR were more sensitive to changes in GNRI.

Conclusion

Elevated GNRI was independently associated with OA prevalence in geriatric populations, demonstrating nutritional status's pivotal role in degenerative joint pathophysiology. The impact of GNRI on OA risk may differ across demographic subgroups, highlighting the need for personalized approaches in managing OA risk based on nutritional status.

The role of triglycerides in predicting new-onset arthritis in the general population over 45 years old: evidence from the China health and retirement longitudinal study

Background

Arthritis is a common degenerative joint disease with a high prevalence especially in the elderly population. Due to its strong association with chronic pain and dysfunction, arthritis has become an important challenge in public health. Recent studies have shown that triglyceride (TG) levels, as key metabolic markers, may play an important role in the pathogenesis of arthritis, and its associated inflammatory response may accelerate joint degeneration and inflammatory process.

Objective

Based on the above findings, the aim of this study was to investigate the association between baseline TG levels and the incidence of arthritis in adults aged 45 years and older, utilizing data from the China Health and Retirement Longitudinal Study(CHARLS).

Methods

This study utilized the CHARLS from 2011 to 2018, which included 7,551 participants aged 45 years and older. The association between TG levels and new-onset arthritis was assessed by logistic regression modeling, adjusting for demographic and health-related variables. The potential role of HDL-C, LDL-C, and BMI in the TG-arthritis association was further assessed by mediation analysis, which decomposed the association into direct and indirect effects.

Results

During the study period, 3,363 participants (44.5%) developed arthritis. Higher TG levels were significantly associated with arthritis risk, with an 8% increase in arthritis risk for each interquartile range (IQR) increase in TG (OR=1.08; 95% CI, 1.039-1.137.) Interquartile analyses of TG levels showed a significant dose-response trend (P trend <0.05), suggesting that the risk of arthritis tended to rise progressively with higher TG levels. Mediation analysis further revealed that HDL-C mediated approximately 43.5% of the TG-arthritis association, suggesting an important role of HDL-C in the metabolic pathway of arthritis development.

Conclusion

Elevated TG levels were significantly associated with an increased risk of arthritis, and this association was partially mediated by HDL-C. The findings suggest that interventions targeting reduced TG levels and enhanced HDL function may have potential value in arthritis prevention. Future studies should focus on lipid metabolism intervention strategies to reduce arthritis risk and delay disease progression, providing a new scientific basis for arthritis management.

Unraveling the Molecular Mechanisms of Osteoarthritis: The Potential of Polyphenols as Therapeutic Agents

The complex nature of osteoarthritis (OA), driven by the intricate interplay of genetic, environmental, and lifestyle factors, necessitates the development of a single treatment method, which is highly challenging. The long-term use of non-steroidal anti-inflammatory drugs (NSAIDs) and corticosteroids often leads to adverse side effects like kidney damage and stomach ulcers. Major health threats like obesity and aging create a milieu of chronic low-grade inflammation and increased mechanical stress on the joints resulting in cartilage deterioration. Additionally, postmenopausal women with lower circulating 17β-estradiol levels experience accelerated joint deterioration due to increased immune activity resulting in the increased production of pro-inflammatory cytokines, with elevated MMP expression and decreased type II collagen synthesis. Polyphenols are nature's gifted magic molecules, which possess diverse biological properties like anti-oxidant, anti-bacterial, anti-inflammatory, estrogenic, and insulin-sensitizing effects, which can manage and treat all the multi-factorial contributing factors of OA effectively. Certain polyphenols can act as phytoestrogens and mimic the effects of natural estrogen by binding to ERα and ERβ and can act as SERMs and prevent degradation of the articular cartilage thereby alleviating osteoarthritic conditions. These molecules downregulate the expression of various pro-inflammatory cytokines, apoptotic genes, and matrix-degrading proteases (MMPs) while upregulating major ECM proteins like type II collagen, aggrecan, and proteoglycans in various osteoarthritic animal models. This review provides a comprehensive overview of the molecular mechanisms involved in OA development and also explores the therapeutic potential of different polyphenols in mitigating joint inflammation and their protective effect in inhibiting the degradation of cartilage extracellular matrix (ECM) and enhancing joint homeostasis.

Development of a bovine gelatin-kappa carrageenan-based dual network biomimetic hydrogel for chondrogenic differentiation of mesenchymal stem cells

Direct stem cell delivery for cartilage tissue engineering faces significant drawbacks, including loss of cells via circulation and poor viability in a hostile microenvironment. Hence, scaffold-based approaches for stem cell delivery are gaining significant momentum. In this study, composite hydrogel films composed of gelatin and κ-carrageenan dually crosslinked with glutaraldehyde and potassium chloride have been developed through the solvent casting method. The protein-polysaccharide composite mimics the natural extracellular matrix of native cartilage and the synergistic effects of covalent and ionic crosslinking provide mechanical strength, stability, and satisfactory biological performance. The physicochemical properties of the composite were analyzed using SEM-EDS, AFM, FTIR, XPS, and XRD. Rheological analysis revealed self-healing properties of the film and mechanical analysis demonstrated the ultimate tensile strength to be 13.49 ± 2.89 MPa, which mechanically mimics the native cartilage. The composite film remained stable for approximately 4 weeks in PBS, validating its stability. Biological assessments of the film after 7 days of culture demonstrated its long-term cytocompatibility, showing cell viability of 97.56 ± 0.21 %, cell adhesion was observed using FESEM micrographs, and cell proliferation through Live/Dead assay. The dually crosslinked biomimetic composite films aided in chondrogenic differentiation, as confirmed using collagen II staining and TGF-β expression studies, and hence demonstrate promising potential for cartilage tissue regeneration.

The Effects of Structured Prehabilitation on Postoperative Outcomes Following Total Hip and Total Knee Arthroplasty: An Overview of Systematic Reviews and Meta-analyses of Randomized Controlled Trials

OBJECTIVE: To evaluate the effects of prehabilitation on postoperative outcomes following total hip arthroplasty (THA) and total knee arthroplasty (TKA). DESIGN: Overview of systematic reviews and meta-analyses of randomized controlled trials. LITERATURE SEARCH: Guided by the PRIOR (Preferred Reporting Items for Overviews of Reviews) statement, a systematic search of MEDLINE, Embase, Web of Science, and Cochrane CENTRAL (Cochrane Register of Controlled Trials) was conducted using the following overarching topics: hip, knee, arthroplasty, and prehabilitation. STUDY SELECTION CRITERIA: Systematic reviews, meta-analyses, or meta-regressions of randomized controlled trials that investigated how postoperative outcomes differed between patients who underwent primary THA or TKA and engaged in a structured prehabilitation program (exclusively resistance training [RT]-focused or multimodal with RT) or non-RT exercising controls. DATA SYNTHESIS: THA and TKA data were analyzed separately, with results delineated based on RT components (ie, weekly sets, frequency, and load) and the follow-up period (ie, short term: 1-3 years; midterm: 5-7 years; and long term: ≥10 years). RESULTS: Three systematic reviews and 21 meta-analyses (19 THA randomized controlled trials, 1110 THA patients; 46 TKA randomized controlled trials, 3362 TKA patients) ranging from critically low- to moderate-quality evidence were included. Prehabilitation was favorable for reducing the rate of complications, improving strength, objective function, quality of life, and self-reported function in patients undergoing THA and TKA. Effects were attenuated over time and were generally confined to the first 6 months. RT volume did not affect postoperative outcomes in 2 meta-regressions. No analyses evaluated how the manipulation of RT components affected postoperative outcomes. CONCLUSION: Prehabilitation reduced complication rates and improved objective and subjective postoperative outcomes following THA and TKA, with effects generally confined to the first 6 months. J Orthop Sports Phys Ther 2025;55(5):1-22. Epub 3 April 2025. doi:10.2519/jospt.2025.13075.

MAGI1 attenuates osteoarthritis by regulating osteoclast fusion in subchondral bone through the RhoA-ROCK1 signaling pathway

Background

Osteoarthritis (OA) is a chronic joint disorder that predominantly affects middle-aged or elderly individuals. Subchondral bone remodeling due to osteoclast hyperactivation is regarded as a major feature of early OA. During osteoclast fusion and multinucleation, the cytoskeleton reorganization leads to the formation of actin belts and ultimately bone resorption. Membrane-associated guanylate kinase with an inverted repeat member 1 (MAGI1) is a scaffolding protein that is crucial for linking the extracellular environment to intracellular signaling pathways and cytoskeleton. However, the role of MAGI1 in subchondral bone osteoclast fusion remains unclear.

Methods

In this study, we collected knee joint samples from OA patients and established the OA mouse model to examine the expression of MAGI1. Furthermore, we established the OA rat model and locally injected rAAV9-mediated shMagi1 into the subchondral bone to knock down MAGI1 expression. Micro-CT, histological staining, and immunofluorescence were employed to assess the effects of MAGI1 knockdown on subchondral bone homeostasis and OA process. We isolated and cultured osteoclasts from femoral and tibial bone marrow. Receptor activator of nuclear factor-κB ligand (RANKL)-stimulated osteoclasts served as an in vitro model for OA and underwent RNA sequencing. We employed gain- and loss-of-function experiments using MAGI1-overexpression plasmids and small interfering RNA to explore the role of MAGI1 in osteoclast differentiation. Further molecular experiments, including RT-qPCR, western blotting, immunofluorescence staining, and LC-MS/MS were performed to investigate underlying mechanisms.

Results

MAGI1 expression was significantly downregulated during RANKL-induced osteoclastogenesis in vitro. Additionally, a progressive decrease in MAGI1 expression was consistently observed in both knee joint samples from OA patients and mouse OA models, correlating with OA progression. Knockdown of MAGI1 in subchondral bone increased osteoclast numbers and worsened subchondral bone microarchitecture and cartilage degeneration; MAGI1 knockdown rats exhibited elevated PDGF-BB, Netrin-1, and CGRP+ sensory innervation. Overexpression and knockdown of MAGI1 suppressed and promoted osteoclast differentiation, respectively. Mechanistically, MAGI1 overexpression decreased the levels of RhoA, ROCK1, and p-p65 in RANKL-treated osteoclasts, which was rescued by the addition of RhoA activator narciclasine.

Conclusion

Our results demonstrate that MAGI1 suppresses osteoclast fusion through the RhoA/ROCK1 signaling pathway, targeting MAGI1 in subchondral bone osteoclasts may be a promising therapeutic strategy mitigate the advancement of OA.

The translational potential of this article

This study reveals that the scaffold protein MAGI1 participates in osteoarthritis progression by regulating osteoclast fusion, providing novel theoretical foundations and potential therapeutic targets for osteoarthritis treatment.

Common Pain Disorders in Women: Diagnosis, Treatment, and Rehabilitation Management

There is well-established epidemiologic evidence demonstrating variance in the pain disorders affecting women compared with men, although limited conclusive evidence exists regarding the pathophysiologic mechanisms to account for this difference. Six of the most common pain disorders affecting women include migraine headache, fibromyalgia, endometriosis, interstitial cystitis, temporomandibular disorders, and osteoarthritis. The sex-specific prevalence, risk factors, triggers, presentations, and treatments of these disorders are critical for physicians to appreciate and understand to provide the highest standard of care when treating these common pain conditions.

SHP2-mediated ROS activation induces chondrocyte paraptosis in osteoarthritis and is attenuated by low-intensity pulsed ultrasound

Background

Paraptosis is a novel form of programmed cell death, generally caused by disrupted proteostasis or alterations of redox homeostasis. However, its impact and underlying mechanisms on the pathology of osteoarthritis (OA) are still unclear. This study aimed to investigate the role and regulatory mechanism of SHP2 in chondrocyte paraptosis and the effects influenced by low-intensity pulsed ultrasound (LIPUS).

Methods

SHP2, a MAPK upstream intermediary, has been identified as one of the critical targets of IL-1β-induced paraptosis in the GEO and GeneCard databases. The expression of SHP2 in chondrocytes was regulated by either siRNA knockdown or plasmid overexpression. Additionally, adeno-associated viruses were injected into the knee joints of rats to explore whether SHP2 plays a role in the development of OA. The impact of LIPUS on paraptosis and OA was examined in IL-1β-induced chondrocytes and a post-traumatic OA model, with SHP2 regulation assessed at both cellular and animal levels.

Results

An increase in cellular reactive oxygen species (ROS) caused by IL-1β halts the growth of chondrocytes and induces paraptosis in the chondrocytes. IL-1β-induced paraptosis, manifested as endoplasmic reticulum (ER)-derived vacuolization, was mediated by ROS-mediated ER stress and MAPK activation. SHP2 facilitates ROS production, thereby exacerbating the chondrocytes paraptosis. SHP2 knockdown and ROS inhibition effectively reduced this process and significantly mitigated inflammation and cartilage degeneration. Furthermore, we discovered that LIPUS delayed OA progression by inhibiting the activation of the MAPK pathway, ER stress, and ER-derived vacuoles in chondrocytes, all of which play critical roles in paraptosis, through the downregulation of SHP2 expression. Results on animals showed that LIPUS inhibited cartilage degeneration and alleviated OA progression.

Conclusion

SHP2 exacerbates IL-1β-induced oxidative stress and the subsequent paraptosis in chondrocytes, promoting OA progression. LIPUS mitigates paraptosis by modulating SHP2, which in turn slows OA progression.

The translational potential of this article

This study indicates that a novel SHP2-mediated cell death mechanism, paraptosis, plays a role in post-traumatic OA progression. LIPUS helps maintain cartilage-subchondral bone unit integrity by targeting SHP2 inhibition. SHP2 emerges as a potential therapeutic target, while LIPUS provides a promising non-invasive approach for treating trauma-related OA.

Creating Perforations in the Sclerotic Region of the Proximal Tibia During Total Knee Arthroplasty to Enhance Prosthesis Stability

OBJECTIVE

In patients with varus deformity of the knee, the redistribution of the subchondral bone mineral density (BMD) of the tibia leads to sclerotic zones that may cause osteoarthritis. Drilling the sclerotic area of the tibia prior to cementing during total knee arthroplasty is advisable practice. However, the extent of the sclerotic area and the effect of drilling on the tibial component are not well defined. We aimed to quantify the BMD and sclerotic bone distribution of the knee to clarify the effect of drilling on the stability of the prosthesis.

METHODS

Our retrospective cohort study enrolled a total of 97 patients from December 2018 to December 2019, categorized into drilled and nondrilled groups, with their computed tomography (CT) knee joint images documented. The proximal tibia image was divided into nine regions, the BMD of each region calculated, and CT values compared between the affected and normal sides. We established finite element models to analyze the drilling and stress distribution. The differences in CT values were assessed using the paired t test and Wilcoxon signed-rank test.

RESULTS

The mean thickness of sclerotic bone was 7.7 ± 1.4 mm, and the surface area was 441.9 ± 89.4 mm2. The CT values of the affected anteromedial, anterolateral, mediomedial, mediolateral, posteromedial, posteromedian, and posterolateral tibial areas were significantly higher than their normal counterparts. Stress concentration around the boreholes in all finite element models is minimal, with stress values ranging from 0.01 to 3.73 MPa, markedly lower than the 13.93 MPa observed in the undrilled model.

CONCLUSION

Abnormal stress in the proximal tibia alters the distribution pattern of BMD, and drilling in the sclerotic area is associated with improved prosthesis stability.

AI-Assisted Plasmonic Diagnostics Platform for Osteoarthritis and Rheumatoid Arthritis With Biomarker Quantification Using Mathematical Models

Osteoarthritis (OA) and rheumatoid arthritis (RA) are major causes of functional impairment, disability, and chronic pain, leading to a substantial rise in healthcare costs. Despite differences in pathophysiology, these diseases share overlapping features that complicate diagnosis, necessitating early, more accurate, and cost-effective diagnostic tools. This study introduces an innovative plasmonic diagnostics platform for rapid and accurate label-free diagnosis of OA and RA. The sensing platform utilizes a highly dense urchin-like gold nanoarchitecture (UGN), which enhances the surface plasmonic area to significantly amplify the Raman signal. The feasibility of the developed platform for arthritis diagnosis is demonstrated by analyzing the synovial fluid (SVF) of patients. Assisted by a machine learning model, Raman signals of OA and RA groups are successfully classified with high clinical sensitivity and specificity. Metabolic biomarkers are further investigated using mathematical models of combined Pearson correlation coefficient (PCC) and non-negative matrix factorization (NMF), suggesting valuable insights for arthritis biomarker quantification. In addition, RA severity is studied using the sensing platform by classifying results from the hematology test, achieving successful stage discrimination. This platform offers a versatile, affordable, and scalable in-clinic arthritis diagnostic solution with potential applications in diagnosing and monitoring other diseases through biofluid analysis.

Butyrate (short-chain fatty acid) alleviates lipopolysaccharide-binding proteins and improves physical function in knee osteoarthritis patients

Knee-osteoarthritis (OA) is often associated with increased intestinal permeability, potentially causing sarcopenia, and mobility issues. Current treatments are ineffective. The objective of this study was to investigate if butyrate improves sarcopenia and physical function in knee-OA patients, and if improvements correlate with changes in gut health, specifically intestinal permeability, and bacterial load. In this double-blind study, 60 OA patients received placebo, 52 received 300 mg butyrate daily for 12-weeks. Gut health (zonulin), and systemic bacterial load (lipopolysaccharide-binding proteins (LBP)) were assessed. Handgrip strength (HGS), Oxford knee scores (OKS), and short physical performance battery (SPPB) were measured at the beginning and end of the study to assess physical functionality. Patients taking butyrate showed improvement in HGS, walking speed, OKS scores, and maintained a better balance, walking ability and no decline in rising from chair, according to SPPB-scores. Butyrate lowered blood levels of zonulin, LBP, and CRP as markers of intestinal permeability, bacterial load, and inflammation, respectively (all p < 0.05). Regression analysis exhibited marked correlations of zonulin with HGS, OKS, walking speed, and SPPB scores in the butyrate-treated group. These observations suggest that butyrate could serve as a therapeutic option for sarcopenia and physical decline in OA, potentially by improving intestinal barrier function.

Circulating Fetuin-A concentrations in rheumatic diseases: a systematic review and meta-analysis

BACKGROUND

Rheumatic diseases (RDs) include a broad group of disabling conditions with different phenotypes, from autoimmune to autoinflammatory, degenerative, metabolic or mixed manifestations. With the continuous efforts to identify therapeutic targets for new biologic drugs to treat overt clinical manifestations, research is also focusing on the discovery of new biomarkers to diagnose and manage early disease stages. In this context, we conducted a systematic review and meta-analysis of Fetuin-A (FtA), a glycoprotein synthesized by the liver that participates in several biological processes and has been proposed as a biomarker for several disorders, including rheumatoid arthritis.

METHODS

A systematic search in PubMed, Scopus and Web of Science, from inception to the 24th of August 2024, led to the identification of 13 manuscripts from 219 records; six additional studies were identified through reference hand-search, for a total of 19 studies.

RESULTS

There was a significant decrease in FtA concentrations in RD patients (standardized mean difference, SMD = -.91; 95% CI -1.43 to -.39, p = .001), with no substantial contribution from any individual study nor publication bias. The effect size was significantly associated with erythrocyte sedimentation rate, various lipid fractions, geographical area of study conduction, study design and specific type of RD.

CONCLUSION

In conclusion, our study identified significant reductions in FtA concentrations in RD patients versus healthy controls. These alterations were significantly associated with specific study and patient characteristics. Further research is required to identify the exact pathophysiological mechanisms underlying these alterations and the possible utility of measuring FtA for the diagnosis and management of RDs.

The relationship between bariatric surgery and risk of hip or knee replacement in severe osteoarthritis is obesity class-specific

BACKGROUND

In patients with osteoarthritis, bariatric surgery is associated with diminished joint pain and improved functionality.

OBJECTIVES

To evaluate the relationship between the risk of total joint replacement (TJR) and the fact of having undergone bariatric surgery (yes or no) in people living with obesity.

SETTINGS

Data from the French National Hospitals Database.

METHODS

This case-control study was conducted to identify hospitalizations for TJR. The main exposure of interest was having undergone (or not) a bariatric surgery procedure between January 2017 and December 2021. After a 6-month run-in phase, data on hospitalizations for the first TJR (i.e., hip or knee) from July 2017 to December 2023 were classified by obesity class and surgical type.

RESULTS

One hundred sixty thousand seven hundred seventy-three patients who had undergone bariatric surgery (mean age: 40.8 years, 79.5% females) and 160,773 matched controls were identified. The most frequent surgical technique was sleeve gastrectomy (72.2%), followed by gastric bypass (27.8%). The average follow-up was 4.7 years. An increase in the overall risk of TJR, with a hazard ratio (HR) of 1.09 (95% confidence interval [CI], 1.03-1.15), was observed. Depending on obesity class, patients with body mass index (BMI) < 40 kg/m2 had a lower risk of TJR (HR: 5.85; 95% CI: .78-.93), whereas a higher risk was observed in patients with BMI ≥40 kg/m2 (HR: 5 1.25; 95% CI: 1.16-1.34).

CONCLUSIONS

In France, hospitalizations for TJR following bariatric surgery were associated with an increase of 25% in patients with BMI ≥ 40 kg/m2, whereas it was associated with a decrease of 15% in patients with BMI < 40 kg/m2.

The effectiveness of dietary intervention in osteoarthritis management: a systematic review and meta-analysis of randomized clinical trials

This study aimed to evaluate the impact of various dietary interventions on managing osteoarthritis (OA), a condition significantly affecting global health due to joint alterations driven by inflammatory mediators. A systematic review and meta-analysis, adhering to PRISMA guidelines, examined Randomized Controlled Trials (RCTs) investigating dietary interventions in OA. Two reviewers independently conducted study selection, data extraction, and quality assessment. Random effects models calculated standardized mean differences (SMD) and mean differences (MD). Risk of bias was evaluated with the Cochrane Risk of Bias tool (RoB2), and heterogeneity was assessed using I² values. Nine RCTs (898 participants) were identified, assessing various diets: reduced energy (n = 4), Mediterranean (n = 2), low-fat (n = 2), anti-inflammatory (n = 1), low-carbohydrate (n = 1), and plant-based (n = 1). Dietary interventions significantly improved pain (SMD: -0.67; 95% CI: [-1.01, -0.34]; p < 0.0001), and physical function (SMD: -0.62; 95% CI: [-0.94, -0.30]; p = 0.0001) and body weight (MD: -3.18; 95% CI: [-3.52, -2.83], p < 0.0001). Subgroup analyses revealed reduced energy diets improved pain (SMD: -0.85; 95% CI: [-1.15, -0.55], p < 0.0001), physical function (SMD: -0.95; 95% CI: [-1.33, -0.58], p < 0.0001) and body weight (MD: -3.13; 95% CI: [-3.77, -2.49], p < 0.0001). The Mediterranean diet did not significantly impact pain (SMD: -0.27; 95% CI: [-1.14, 0.60], P = 0.54), or physical function (SMD = -0.28; 95% CI: [-0.79, 0.24], p = 0.29). This study emphasizes the significant impact of dietary interventions on pain, physical function, and weight management in people with OA, with reduced energy diets showing the most effectiveness. Specific dietary patterns show promise but require further investigation.

Global shifts in osteoarthritis subtype trends among older adults due to elevated BMI: an age-period-cohort analysis based on the global burden of disease database

Purpose

It remains unclear whether elevated Body Mass Index(BMI)has a similar impact on the disease burden of osteoarthritis subtypes in older adults. This study aims to compare the long-term trends of osteoarthritis subtypes caused by high BMI across different gender groups globally from 1990 to 2021.

Methods

We obtained cross-sectional data from the Global Burden of Disease, Injuries, and Risk Factors Study (GBD) 2021 (https://vizhub.healthdata.org/gbd-results/). The disease burden of osteoarthritis subtypes in older adults attributable to high BMI was quantified using Years Lived with Disability (YLDs). Linear regression and the Age-Period-Cohort (APC) method were employed to calculate the trends in Age-standardized Years lived with disability rate (ASYR), adjusting for age, period, and cohort effects.

Results

The ASYR of osteoarthritis attributable to high BMI in older adults globally has shown a continuous upward trend over the past 32 years, with an Estimated Average Percentage Change (EAPC) of 0.96 (95% CI: 0.94 to 0.99). Specifically, the EAPC for hip osteoarthritis was 0.73 (95% CI: 0.70 to 0.76), while for knee osteoarthritis, it was 0.99 (95% CI: 0.96 to 1.02). China recorded the highest number of osteoarthritis YLDs globally, reaching 0.59 million (95% UI: -0.05 to 1.71). The United States had one of the highest ASYR rates for osteoarthritis at 410.85 per 100,000 (95% UI: -44.47 to 1,083.52), while India exhibited the highest EAPC for osteoarthritis worldwide at 2.74 (95% CI: 2.70 to 2.79), with hip osteoarthritis at 3.36 (95% CI: 3.25 to 3.48) and knee osteoarthritis at 2.70 (95% CI: 2.65 to 2.75). The local drift curves indicated a slow upward trend in the annual percentage change of YLDs for both hip and knee osteoarthritis attributable to high BMI across all age groups. In terms of gender, males exhibited a higher rate and risk of YLDs associated with high BMI.

Conclusion

Our findings provide strong evidence that the ASYR associated with high BMI globally have continuously increased over the past 32 years, with consistent patterns of change observed across different osteoarthritis subtypes. This highlights the critical role of BMI control in effectively alleviating the burden of osteoarthritis in older adults.

Association between lean body mass and osteoarthritis: a cross-sectional study from the NHANES 2007-2018

The prevention of osteoarthritis through controlling body measurements has received increasing attention in recent years, but the relationship between lean body mass (LBM) and osteoarthritis remains unclear. Hence, we explored this association through the data from the National Health and Nutrition Examination Survey (2007-2018). The present study enrolled 31,172 participants. To explore the correlation between LBM and osteoarthritis, we utilized logistic regression equations to explore associations between covariates, exposures, and outcomes. We used multivariate regression models to further control confounding factors. Restricted cubic splines were employed to investigate non-linear relationships. And the inflection point was identified by recursive algorithm. Furthermore, stratified analyses of gender and age were conducted. Osteoarthritis was negatively correlated with LBM [0.74 (0.67, 0.80)] in the model adjusting for all confounders. Based on the restricted cubic spline curve, an inflection point of 52.26 kg was found to confirm the non-linear relationship. LBM was negatively correlated with osteoarthritis at 0.56 (0.48, 0.64) before the inflection point, and the association was not statistically significant afterward. This large-scale study revealed that LBM was non-linearly correlated with osteoarthritis in the general American population. Differences in age and gender were further identified.

Effectiveness of Exergames on Functional Physical Performance in Older Adults with Knee/Hip Osteoarthritis: A Randomized Controlled Trial

Background/Objectives: Osteoarthritis (OA) is a leading cause of mobility impairment in older adults, yet few studies have explored exergames (EXGs) as a complementary therapy for knee and/or hip OA (KOA/HOA). This study evaluated the effects of integrating EXGs into conventional therapy (CT) on functional mobility. Methods: Sixty participants were randomized into an EXG/CT group or a CT-only group. The interventions lasted 10 weeks (3 sessions/week), and the EXGs were selected from the interactive game Ring Fit Adventure (Nintendo Switch®, Kyoto, Japan). Results: Functional mobility (Timed Up and Go test) significantly improved in the EXG/CT group but not in the CT group. Additionally, lower-limb strength and aerobic endurance increased in the EXG/CT group. No adverse events were reported, and the adherence was high. Conclusions: These findings support EXG-based interventions as a viable complement to CT. Future studies should design OA-specific EXGs and include patient subgroups to expand the impact of interventions using virtual systems.

LncRNA EMBP1 sponges miR-454-3p to upregulate IRF1 and activate NLRP3-mediated chondrocyte pyroptosis to drive osteoarthritis progression

BACKGROUND

Osteoarthritis (OA) is the most common degenerative joint disease worldwide. Studies have confirmed that pyroptosis is closely associated with the OA onset and progression, particularly via the classical pathway mediated by the NLRP3 inflammasome. However, the intrinsic regulatory mechanisms underlying pyroptosis in OA remain unclear.

METHODS

We conducted RNA sequencing (RNA-seq) analysis on clinical cartilage samples and identified hub genes connecting OA and pyroptosis. We validated NLRP3-mediated pyroptosis activation, evaluated the diagnostic potential of the hub gene, and explored its regulatory role using a papain-induced rabbit OA model and IL-1β-induced chondrocytes. Subsequently, we constructed a competitive endogenous RNA (ceRNA) network based on the hub gene and validated its competitive binding interactions and regulatory function in NLRP3-mediated pyroptosis. Additionally, hub gene interferon regulatory factor 1 (IRF1) serves as a recognized upstream regulator of the novel cell death paradigm PANoptosis, which integrates apoptosis, necrosis, and pyroptosis. We preliminarily explored the potential molecular mechanisms of PANoptosis in OA through clinical sample analysis and in vitro experiments.

RESULTS

RNA-seq revealed that IRF1, a hub gene linking OA and pyroptosis, is upregulated in OA cartilage and is associated with NLRP3, consistent with the in vivo and in vitro results. Dual-luciferase assays, clinical sample analysis, and in vitro experiments confirmed the competitive binding of the embigin pseudogene 1 (EMBP1)/miR-454-3p/IRF1 ceRNA network. Silencing EMBP1 increased miR-454-3p, inhibiting IRF1 and NLRP3-mediated pyroptosis in vitro; however, miR-454-3p inhibitor rescue experiments abolished the beneficial effects of si-EMBP1. Furthermore, we preliminarily characterized the occurrence of PANoptosis in OA and provided initial evidence suggesting a potential regulatory role for the EMBP1/miR-454-3p/IRF1 axis in this process.

CONCLUSIONS

In OA, EMBP1 acts as a sponge for miR-454-3p, inhibiting its negative regulatory effect on IRF1 and exacerbating NLRP3-mediated chondrocyte pyroptosis. Furthermore, EMBP1/miR-454-3p/IRF1-mediated pyroptosis may be integrated into the broader PANoptosis process, interacting with apoptosis and necrosis to influence OA progression.

Dietary acid load and the odds of knee osteoarthritis: a case-control study

Knee osteoarthritis (KOA) is a common form of arthritis that leads to joint pain and reduced mobility, especially among older adults. Recent studies indicate that dietary acid load (DAL) may play a role in the development of KOA by promoting systemic inflammation. This case-control study aims to investigate the relationship between DAL and KOA in adults aged 40 and older. A total of 150 newly diagnosed cases of KOA and 300 age-, sex-, and BMI-matched controls were recruited from Zabol County, Iran. Dietary intake was assessed using a validated food frequency questionnaire, and DAL was calculated based on nutrient content. Logistic regression was used to estimate the odds of KOA across DAL quartiles, adjusting for confounding factors such as physical activity, smoking, and supplement use. Individuals in the highest quartile of DAL had significantly higher odds of developing KOA compared to those in the lowest quartile (OR: 2.48, 95% CI: 1.36-4.51, p = 0.003), after adjusting for potential confounders. Additionally, the odds of developing KOA was found to increase with increasing quartiles of DAL in both male (OR: 2.52, 95%CI: 1.13 to 5.65, p = 0.024) and female (OR: 2.55, 95%CI: 1.06 to 6.31, p = 0.031) participants, after adjusting for potential confounding variables. This study demonstrates a significant association between high DAL and increased odds of KOA. Reducing DAL through dietary interventions may be a promising strategy for managing KOA, especially in aging populations. Further longitudinal studies are required to confirm these findings and explore causal relationships.

Astragalus polysaccharide alleviates oxidative stress and senescence in chondrocytes in osteoarthritis via GCN2/ATF4/TXN axis

The treatment of osteoarthritis (OA) remains challenging, with oxidative stress in the cartilage emerging as a key therapeutic target. This study investigates how Astragalus polysaccharide (APS) exerts antioxidant effects in OA using in vivo and in vitro models. In mice, APS mitigates OA progression following surgical destabilization of the medial meniscus (DMM) and protects against oxidative damage. Immunofluorescence analysis revealed decreased thioredoxin (TXN) expression in DMM cartilage, which was restored by APS. APS preserved mitochondrial function, redox balance, and matrix synthesis in chondrocytes in vitro while suppressing metalloproteinase expression. APS also reduced senescence markers (p53, p21INK4a, and p16), DNA damage, and β-galactosidase activity in tert-butyl hydroperoxide (tBHP)-treated chondrocytes. TXN knockdown significantly diminishes the protective effects of APS Further analysis showed that ATF4 overexpression supports the GCN2-ATF4 pathway's involvement in APS. GCN2 inhibition using GCN2iB reduced the regulatory impact of APS on TXN, indicating the crucial role GCN2 in APS-mediated protection. These findings demonstrated that APS protects chondrocytes from oxidative stress and senescence in OA via the GCN2/TXN pathway, suggesting its potential as a therapeutic agent for OA.

Association between conicity index (C-index), relative fat mass (RFM), and osteoarthritis (OA): evidence from NHANES 2003-2018

BACKGROUND

Obesity is considered an important risk factor for osteoarthritis (OA), with conicity index (C-index), relative fat mass (RFM) are two novel anthropometric measures of obesity. To investigate the association between OA and these two indicators, we conducted this study.

METHODS

We used data from the National Health and Nutrition Examination Survey (NHANES) to investigate the association between C-index, RFM, and OA. First, the participants were divided into two groups according to whether they had OA, and we compared the baseline characteristics of the two groups. Then, C-index and RFM were divided into quartiles (Q1, Q2, Q3, Q4) for multivariate regression analysis. Additionally, we applied restricted cubic spline (RCS) to assess whether the relationship is non-linear. Finally, we conducted a subgroup interaction analysis to investigate whether this relationship varies across different subgroups.

RESULTS

The study included 34,707 participants, with a weighted OA prevalence of 7.7%. Significant differences in C-index and RFM were observed between OA and non-OA groups. Treating C-index and RFM as categorical variables, logistic regression showed significantly higher OA risk in Q4 compared to Q1: for C-index, Q4 (OR = 1.60; 95% CI: 1.33-1.93; P < 0.001); for RFM, Q4 (OR = 2.07; 95% CI: 1.57-2.73; P < 0.001). The RCS results show that the relationship between C-index and OA is non-linear, while the relationship between RFM and OA is linear. Subgroup interaction analysis showed some interaction effects.

CONCLUSIONS

This study reveals detailed relationships between C-index, RFM, and OA, which may be better indicators of obesity in assessing OA risk.

Unilateral Single Joint Arthritis Changes Joint Power in Unaffected Joints

Pain and disability associated with arthritis of the hip, knee, or ankle is well-documented. However, data on joint power and how arthritis in one joint affects power in that joint and in unaffected joints are limited. This study asks if arthritis in any one joint leads to (1) loss of power in that affected joint compared to the contralateral, unaffected joint; (2) loss of total power in the affected limb as compared to the contralateral, unaffected limb; and (3) increased power production in the joints of the ipsilateral limb. Ground reaction forces and joint angles during self-selected speed walking were collected from participants with symptomatic, unilateral ankle (N = 183), hip (N = 63), and knee arthritis (N = 20). Bilateral joint power from the hip, knee, and ankle joints as well as total limb power was calculated for the last third of the stance phase. Arthritis in the hip (p < 0.001), knee (p = 0.008), or ankle (p < 0.001) lead to a loss of power at the affected joint and in the affected limb, though the knee on the affected side does offset some of that loss in participants with hip and ankle arthritis (p < 0.001). The contralateral, unaffected limb (p < 0.001), especially the ankle, produces greater power. Clinical Significance: Isolated lower limb joint arthritis leads to a loss of power on the affected side and compensation by contralateral, unaffected joints. Those joints may be subsequently impacted through repetitive loading and could lead to further degeneration without intervention.

Serum and synovial fluid levels of CSF-1 and in knee osteoarthritis and its clinical significance

OBJECTIVE

To investigate the serum and synovial fluid levels of CSF-1 in patients with knee osteoarthritis (KOA) and evaluate its clinical significance.

METHODS

We selected 143 patients with KOA who received treatment at our hospital from June 2021 to August 2024. Enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of CSF-1, IL-6, IL-1β, CRP, and HIF-1α in the serum of all study subjects, as well as the levels of these markers in the synovial fluid of all KOA patients. The Kellgren and Lawrence (KL) grading system was used to assess the radiographic severity of all KOA patients. Additionally, we also collected the Visual Analog Scale (VAS) scores and the Western Ontario McMaster University Osteoarthritis Index (WOMAC). Western blot (WB) was used to detect the expression levels of inflammatory factors in macrophages after CSF-1 stimulation.

RESULTS

Compared to healthy volunteers, KOA patients exhibited significantly elevated levels of serum CSF-1, IL-6, IL-1β, CRP, and HIF-1α (p < 0.05). The advanced group of KOA patients had significantly higher levels of serum and synovial fluid CSF-1 compared to the early group. Synovial fluid CSF-1 levels were associated with inflammation and disease severity in KOA patients. CSF-1 stimulation significantly increased the expression of CSF-1R, IL-6, TNF-α, IL-1β, HIF-1α, and MMP-3 in macrophages. Moreover, synovial fluid and serum CSF-1, synovial fluid HIF-1α, and synovial fluid IL-6 were identified as risk factors for advanced KOA.

CONCLUSION

Our findings indicated that the serum and synovial fluid levels of CSF-1 were significantly increased in KOA patients, even higher in patients with KL grade 3-4. Moreover, CSF-1 was identified as a risk factor associated with advanced stage KOA.

Novel insights into the role of ferroptosis in temporomandibular joint osteoarthritis and knee osteoarthritis

Osteoarthritis (OA) is a prevalent degenerative joint disease characterized by pain, limited movement, and joint stiffness, significantly impacting the quality of life and imposing substantial economic burdens. This review paper delves into the novel insights of ferroptosis, an iron-dependent form of cell death associated with lipid peroxidation, in the context of temporomandibular joint osteoarthritis (TMJ OA) and knee osteoarthritis (KOA). We explore the pathogenic characteristics of OA, including synovitis, chondrocyte death, and extracellular matrix (ECM) degradation, and discuss the limitations of current therapeutic interventions. Emerging evidence suggests a significant relationship between ferroptosis and OA, with iron accumulation and lipid peroxidation observed in osteoarthritic cartilage. This review highlights the role of ferroptosis in chondrocyte malfunction and apoptosis, inflammation, and extracellular matrix breakdown, which are central to OA pathogenesis. We also discuss potential therapeutic targets, such as Transient Receptor Potential Vanilloid 1 (TRPV1), Glutathione Peroxidase 4 (GPX4), and Nuclear Factor Erythroid 2-Related Factor 2 (NRF2), which modulate ferroptosis and OA progression. The paper consolidates studies on ferroptosis in OA, offering a comprehensive understanding of its role and the development of innovative therapies targeting this cell death mechanism to improve treatment outcomes for OA patients.