Osteoarthritis: new insights. Part 1: the disease and its risk factors

The relation of walking forces to structural damage in the knee: The Multicenter Osteoarthritis Study

OBJECTIVE

Mechanical loading is an important, modifiable risk factor for knee osteoarthritis. Identifying walking loads associated with disease worsening presents intervention opportunities. Our purpose was to evaluate the longitudinal relation of the baseline vertical ground reaction force (GRF) during walking to worsening bone marrow lesions (BMLs) and cartilage damage using cohort data from the Multicenter Osteoarthritis Study (MOST).

METHODS

MOST participants with GRF data at baseline and magnetic resonance imaging examinations at baseline and 2-year follow-up were included. Peak impact force (PIF) and average loading rate (ALR) from the vertical GRF were analyzed with respect to four joint regions (i.e., the medial and lateral portions of the tibiofemoral and patellofemoral joints). Analyses used logistic regression with generalized estimating equations and adjusted for relevant covariates.

RESULTS

Higher PIF was associated with increased odds of worsening BMLs in the lateral patellofemoral joint (odds ratio (95% confidence interval [CI]): 1.33 (1.11, 1.60)) and worsening cartilage damage in the lateral patellofemoral joint (1.48 (1.24, 1.77)), lateral tibiofemoral joint (1.24 (1.03, 1.50)), and medial tibiofemoral joint (1.25 (1.06, 1.48)). Higher ALR was associated with reduced odds of BML worsening in the lateral tibiofemoral joint (0.60 (0.41,0.87)).

CONCLUSIONS

Higher peak forces when walking were associated with worsening BMLs in the lateral patellofemoral joint and with worsening cartilage damage in regions of the knee associated with higher contact forces during walking. Higher ALRs were not associated with increased odds of structural worsening (BMLs or cartilage).

Beyond weight: Exploring the nexus between obesity and osteoarthritis

Obesity is a well-established risk factor for osteoarthritis (OA), traditionally attributed to increased mechanical stress on weight-bearing joints. However, recent research suggests a more complex interplay, involving metabolic, biomechanical, and inflammatory pathways. This review delves into these multifaceted connections between obesity and osteoarthritis, extending beyond the conventional understanding of weight-bearing stress. It explores the role of adipokines such as leptin, visfatin, adiponectin, and resistin in OA pathogenesis and progression, highlighting their potential as targets for novel therapeutics. The review also examines how obesity alters the biomechanics of lower extremities, contributing to changes in joint load and movement patterns. Systemic effects, including inflammation and metabolic factors, are discussed to elucidate their roles in exacerbating OA beyond joint loading. Furthermore, the impact of bariatric surgery and weight loss strategies on OA symptoms and progression is evaluated. This comprehensive review aims to provide new insights into obesity-induced OA, paving the way for more targeted and effective treatment strategies.

Therapeutic potential of CHI3L1 in osteoarthritis: Inhibition of cartilage matrix degradation and inflammation through TLR4-MAPK-STAT1 pathway

AIMS

CHI3L1 has been identified as a protein expressed in various tissues and tumor tissues, playing critical roles in diverse physiological and pathological processes such as inflammation, oxidative stress, cell death, and immune regulation. Previous studies have indicated that the elevated CHI3L1 levels in synovial fluid and serum of osteoarthritis patients may serve as a biomarker for osteoarthritis. However, the mechanisms by which CHI3L1 affects chondrocytes and the significance of its upregulated expression remain to be fully elucidated. This study aims to investigate the effects of CHI3L1 on chondrocytes and elucidate its molecular mechanisms.

METHODS

Interleukin-1 beta (IL-1β) was utilized in vitro to induce an inflammatory injury model in chondrocytes. The destabilization of the medial meniscus (DMM) surgery was employed to establish a mouse model of osteoarthritis in vivo. Experimental techniques, including Western blot, RT-qPCR, immunofluorescence, transcriptome sequencing, and co-immunoprecipitation, were applied to investigate the effects and mechanisms of CHI3L1 on chondrocytes. Microcomputed tomography (micro-CT), X-ray imaging, and IHC were used to evaluate the impact of CHI3L1 on knee joint osteoarthritis in mice.

RESULTS

In vitro experiments demonstrated that CHI3L1 enhanced matrix synthesis markers, suppressed matrix degradation indicators, and reduced inflammatory factors levels in chondrocytes. In vivo studies showed that intra-articular overexpression of CHI3L1 via rAAV-Chi3l1 alleviated cartilage degeneration and synovial inflammation in a murine osteoarthritis model. Mechanistically, integrated transcriptomic profiling and functional assays revealed that CHI3L1 interacts with TLR4 to attenuate MAPK phosphorylation, thereby inhibiting STAT1 phosphorylation and nuclear translocation.

CONCLUSION

The expression of CHI3L1 is upregulated in osteoarthritis. CHI3L1 alleviates osteoarthritis inflammation and cartilage matrix degradation through the TLR4-MAPK-STAT1 pathway, thereby inhibiting the progression of osteoarthritis. These findings indicate that CHI3L1 is a cytokine with protective effects in osteoarthritis and may represent a promising therapeutic target for alleviating osteoarthritis.

ARTICLE FOCUS

The objective of this study is to investigate the effects of CHI3L1 on chondrocytes and to further elucidate the underlying mechanisms by which CHI3L1 exerts its influence on chondrocytes.

KEY MESSAGES

In this study, it is proposed that CHI3L1 maintains the homeostasis of the cartilage matrix and alleviates inflammation by inhibiting the activation of the TLR4-MAPK-STAT1 signaling pathway.

STRENGTHS AND LIMITATIONS

We have established the protective role of CHI3L1 in maintaining cartilage matrix homeostasis, identified potential receptors and pathways associated with CHI3L1, and elucidated its mechanisms of action. The role of CHI3L1 in osteoarthritic synovial tissue has not yet been investigated. Further research is needed to elucidate the effects of CHI3L1 secreted by synovial tissue on chondrocytes.

Patients with Higher Pulse Wave Velocity Are More Likely to Develop a More Severe Form of Knee Osteoarthritis: Implications for Cardiovascular Risk

Background/Objectives: Knee osteoarthritis (KOA) is a progressive degenerative joint disease characterised by low-grade inflammation and is associated with increased cardiovascular (CV) risk and arterial stiffness. Pulse wave velocity (PWV) is a quantitative measure of arterial stiffness and an important tool for detecting subclinical arterial calcification and CV risk. This study aimed to determine whether PWV can distinguish radiographically mild KOA (Kellgren-Lawrence grades 1-2) from severe KAO (Kellgren-Lawrence grades 3-4) in terms of CV risk factors. Methods: A total of 223 postmenopausal women with KOA participated in this cross-sectional study. Assessments included anthropometry, laboratory analyses, blood pressure and PWV measurements, a 6 min walk test, pain evaluation using a visual analogue scale (VAS), and completion of the International Physical Activity Questionnaire (IPAQ). Results: PWV was significantly higher in the severe KOA group (10.53 m/s vs. 8.78 m/s, p < 0.001). A cut-off value of 8.4 m/s effectively distinguished between severe and mild forms of KOA (AUC = 0.798, p = 0.001). OA grade, pain, age, waist circumference, WHR, SCORE 2/SCORE 2OP, systolic blood pressure, serum glucose, HbA1c, uric acid, creatinine, and erythrocyte sedimentation rate were increased in the group with PWV > 8.4 m/s, compared to the group with PWV ≤ 8.4 m/s. Conversely, eGFR, the 6 min walk test and physical activity of patients were reduced in the group with PWV > 8.4 m/s. A patient with a PWV > 8.4 m/s has a 1.77 times higher chance of developing a more severe form of the disease than a patient with a lower PWV. Conclusions: Patients with a higher PWV are more likely to develop a more severe form of KOA, which is associated with increased cardiovascular risk.

Elevated Contact Stresses Compromise Activity-Mediated Cartilage Rehydration but not Lubrication

PURPOSE

Understanding how obesity-a key risk factor for osteoarthritis-effects articular cartilage function is critical to understand OA pathoetiology. Cartilage, a biphasic material, supports vanishingly low friction coefficients in vivo, but is tribomechanically compromised by load-induced interstitial pressure/lubrication loss. To maintain tribomechanical function, cartilage must recover fluid lost to habitual/average contact stresses, a problem obesity likely exacerbates. Recently, we have shown that articulation/sliding drives robust interstitial fluid recovery and indefinite maintenance of biofidelic tissue strains and frictions through generation of hydrodynamic pressures within cartilage contact interfaces, i.e., via 'tribological rehydration.' However, the impact of elevated contact stresses on tribological rehydration and cartilage's function/lubrication remains unknown.

METHODS

Using our convergent stationary contact area (cSCA) testing approach on ovine stifle cartilage explants bathed in PBS, we aimed to elucidate several points: (1) the effect of elevated contact stress on tribological rehydration during high-speed articulation, and how (2) cartilage material properties and (3) sliding speed influence contact stress-dependent fluid exudation, rehydration, and lubrication.

RESULTS

Overall, we identified that (i) contact stress, across a narrow range, and (ii) static loading time are key controllers of tribological rehydration magnitude, compression accumulation, and equilibrium/total compression under biofidelic cSCA loading and sliding conditions. However, over the range tested (i.e., 0.2-0.8 MPa), (iii) contact stresses had no appreciable effect on cartilage's remarkable lubricity in the cSCA.

CONCLUSIONS

These results show that obesity is likely to directly physically impair articular cartilage function, and that obesity-driven tissue compression/strain, and not friction per se, may be the primary mechanical driver of cartilage dysfunction and OA risk.

Burden of Osteoarthritis in Iran: A National and Subnational Perspective, 1990-2019 Global Burden of Disease Study

Background and Aims

Osteoarthritis (OA) is a chronic degenerative joint disease caused by pro-inflammatory factors and protease activity, leading to progressive joint destruction. The data on a global scale indicate a substantial rise in OA. This study evaluates the burden of OA in Iran, given its high impact and the limited number of epidemiological studies on the condition.

Methods

The data pertaining to the prevalence, years lived with disability (YLD), and incidence and age-standardized rates of OA in Iran and its subnational regions were retrieved using the Global Burden of Disease Study (GBD) Results Tool.

Results

Age-standardized prevalence rate (ASPR) of OA in Iran was 5224.14 (4699.54-5821.43) and 5588.22 (5041.17-6228.61) in 1990 and 2019, which was lower than the global level. The knee was the most prevalent OA in both 1990 and 2019 in Iran, 3326.63 (2862.19-3841.62) and 3660.61 (3151.81-4228.27) respectively, followed by hand OA (1432.43 (1078.03-1922.21) in 1990 and 1476.24 (1107.91-1979.80) in 2019) and hip OA (239.08 (184.05-300.68) in 1990 and 277.65 (213.24-351.43) in 2019). The age-standardized YLD rate of OA in Iran was 180.96 (91.76-355.00) in 1990 and 195.27 (98.67-381.01) in 2019. The age-standardized YLD rate of site-specific OA followed the same trend as ASPR. Tehran province, followed by Alborz and Yazd provinces, had the highest ASPR of OA in 1990. In 2019, Tehran province (6144.94 (5526.53-6862.14)) remained at the first rank, followed by Mazandaran (5536.591 (4974.13-6165.62)) and Alborz (5512.88 (4946.79-6138.54)) provinces. Our findings show that the OA incidence rate peaked in the 55-59 age group in both males and females in 1990 and 2019.

Conclusion

Despite being lower than global averages, the prevalence, incidence, and YLD due to OA in Iran have significantly increased over the past three decades. This highlights the need for healthcare policymakers to implement comprehensive strategies to manage OA burden and costs.

Does Advanced Osteoarthritis Mimic Neuropathic Joint?

Introduction

Osteoarthritis (OA) is a prevalent condition among the elderly and leads to pain and functional limitations. Radiographic imaging often fails to correlate with symptom severity, and advanced OA may exhibit features reminiscent of neuropathic joints. This study explored the clinicopathological and histopathological correlations between advanced OA and neuropathic joints, hypothesizing clinical similarities.

Methods

A retrospective study involving 43 patients who underwent total knee arthroplasty for advanced knee OA was conducted from 2016 to 2020. Clinical, radiological, and histopathological evaluations were performed. Advanced OA was defined as an Ahlbach grade IV or above. The functional Knee Society Score (KSS) was used to assess clinical severity, and histopathology was considered "significant" if the results were consistent with the neuropathic joint findings. The statistical analyses included univariate and binary logistic regression analyses.

Results

The mean age was 57.63 ± 17.13 years, and most patients were females (69.77%). A total of 53.49% of the grading systems yielded histopathological findings resembling those of neuropathic joints. Univariate analysis revealed significant correlations between histopathology and the functional KSS, Ahlbach grade, and NRS score (p < 0.01). Binary logistic regression confirmed that KSS (< 40) and NRS score (< 7) were significant predictors (p < 0.001, Nagelkarke R 2  = 0.576).

Conclusion

Patients with advanced knee OA may exhibit characteristics resembling those of neuropathic joints, particularly individuals with a poorer functional knee. Thorough assessments are crucial for distinguishing between primary OA and neuropathic joint pathology and for carrying out more precise management strategies. This study provides valuable insights into the complex presentation of advanced knee OA and highlights the importance of using more constrained prosthesis and long stem components for potentially better outcomes.

Nanosurgery and Bioengineered Regenerative Protocols for the Treatment of Hip Osteoarthritis: A Double-Blind Randomized Controlled Trial as an Alternative to Surgical Hip Replacement

Introduction: Hip osteoarthritis (HOA) significantly affects mobility and quality of life, with total hip arthroplasty (THA) being a common treatment. However, complications and increasing revision rates highlight the need for alternative approaches. This study evaluates the efficacy of ultrasound-guided nanosurgery and bioengineering treatment (NSBT) compared to non-standardized platelet-rich plasma (PRP) treatment for patients with symptomatic HOA. Methods: A double-blind, randomized trial included 38 patients referred for THA, divided into two groups. The study group received NSBT with modified PRP enriched with somatotropin and Strophanthus kombe, while the control group received PRP and hyaluronic acid injections without a standardized protocol. Treatments were guided by ultrasound, and outcomes were assessed using the Visual Analog Scale (VAS), Western Ontario and McMaster Universities Arthritis Index (WOMAC), Harris Hip Score (HHS), and range of motion (RoM) evaluations over 12 months. Results: The study group showed significant improvements in all clinical outcomes, including reductions in VAS scores from 7.8 to 0.2 (p < 0.0001) and WOMAC scores from 76.2 to 10.5 (p < 0.0001). The HHS improved from 56.4 to 93.0, and RoM showed substantial gains in flexion, external rotation, and internal rotation (all p < 0.001). The control group demonstrated less pronounced improvements. Conclusions: NSBT offers a safe and effective alternative for managing HOA, significantly reducing pain and improving joint function while potentially delaying or avoiding the need for THA. Further long-term studies are warranted to confirm these findings.

MRI-based radiomics to determine the role of thigh muscle quality in the development of knee osteoarthritis: A discovery and validation study

INTRODUCTION

Although the reduced muscle quality is common in elderly people, its role in the development of knee osteoarthritis (OA) remains unclear. Magnetic Resonance Imaging (MRI) is considered the gold standard imaging modality to assess muscle quality, which might holistically capture the underlying pathology.

OBJECTIVES

This study aimed to apply MRI-based radiomics to assess the quality of thigh muscles comprehensively, and examine its prediction performance for incident knee OA.

METHODS

The participants at risk of knee OA during the 48-month visit were selected from a multicenter cohort and analyzed using a nested case-control design. Cases were matched 1:1 to controls according to age, sex, and contralateral knee status. A multitask framework was developed to comprehensively evaluate thigh muscle quality by calculating conventional quantitative markers and radiomic features. Baseline collected thigh and knee MRI scans were respectively used for discovery and validation procedures. In each procedure, three (cross-sectional area [CSA], intramuscular adipose tissue [intra-MAT] CSA, and radiomic signature score [Rad-score]) imaging models of each muscle group (extensors, flexors, and auxiliaries) were trained and tested. The prediction performance of each muscle Rad-score was compared with conventional markers respectively. Furthermore, the incremental predictive value of clinical characteristics for Rad-score model was investigated.

RESULTS

448 participants (mean age 61 years, 63 % female) were identified and split into training (314 [70.1 %]) and testing (134 [29.9 %]) cohorts. In the discovery procedure, the extensors Rad-score provided superior prediction performance than extensors CSA and intra-MAT CSA (area under the curve [AUC] 0.832 [95 % CI 0.765-0.899] vs 0.595 [0.498-0.692] and 0.600 [0.503-0.697] in testing cohort; all p < 0.001). Contrarily, the performances of the Rad-score and conventional markers of flexors were relatively poor, as were those of the auxiliaries. Extensors Rad-score also outperformed auxiliaries Rad-score, flexors Rad-score, and the clinical model (AUC 0.832 [0.765-0.899] vs 0.687 [0.597-0.777], 0.634 [0.541-0.728], and 0.577 [0.483-0.671] in testing cohort; all p < 0.001). Unexpectedly, the integration of other radiomic signatures and clinical characteristics showed comparable net benefit in decision curve analysis when compared with extensors Rad-score alone. Similar findings were obtained in the validation procedure.

CONCLUSION

MRI-based radiomics could enable comprehensive assessment of muscle quality and allow exact prediction of incident knee OA, which helps uncover the precursory role of reduced extensors quality in developing knee OA. The radiomic signature from extensors would be an alternative indicator for future diagnosis and treatment in knee OA.

Whole-Organ Magnetic Resonance Imaging Score (WORMS) of the Knee in Professional Soccer Players

ObjectiveThe goal of our study was to assess the prevalence of osteoarthritis in the knee joint of active male professional soccer players by means of the semi-quantitative Whole-Organ Magnetic Resonance Imaging Score (WORMS).DesignMagnetic resonance imagings (MRIs) of both knees were performed on 85 male professional soccer players during their "medicals" (age = 24 ± 4 years). All baseline data (age, playing position) were obtained. Based on the WORMS, the status of the cartilage and bone in the medial and lateral femoro-tibial joint (MFTJ and LFTJ), as well as the patellofemoral joint was assessed. Menisci and ligaments were evaluated separately. The final score was the sum of all regional scores.ResultsThe mean WORMS of the 170 knee joints was 13.3 ± 13.5 points (range = 0-111, achievable scores: 0-290). Cartilage changes were the most common pathologies, observed in 141 of the 170 knee joints. Structural cartilage lesions (WORMS ≥ 2) were observed in 54% of the studied knees. Pathologies of the medial meniscus were associated with cartilage damage of the corresponding MFTJ (r = 0.424, P < 0.0001). The same effect was observed for the lateral meniscus and the corresponding LFTJ (r = 0.553, P < 0.0001). However, lateral meniscal lesions could be correlated with more other joint pathologies compared to medial meniscal lesions. Total WORMS correlated significantly with increasing age (r = 0.386, P = 0.001).ConclusionThe provided data show the high incidence of knee joint damage in professional football players. In particular, the lateral meniscus appears to play a critical role.

Quantifying knee-adjacent subcutaneous fat in the entire OAI baseline dataset - Associations with cartilage MRI T2, thickness and pain, independent of BMI

OBJECTIVE

Knee-adjacent subcutaneous fat (kaSCF) has emerged as a potential biomarker and risk factor for osteoarthritis (OA) progression. This study aims to develop an artificial intelligence-based tool for the automatic segmentation of kaSCF thickness and evaluate the cross-sectional associations between kaSCF, cartilage thickness, magnetic resonance imaging-based cartilage T2 relaxation time, knee pain, and muscle strength independent of body mass index (BMI).

DESIGN

Baseline 3.0T MR images of the right knee from the entire Osteoarthritis Initiative cohort (n=4796) were used to quantify average values of kaSCF, cartilage thickness, and T2 using deep learning algorithms. Regression models (adjusted for age, gender, BMI, and race) were used to evaluate the associations between standardized kaSCF and outcomes of cartilage thickness, T2, pain, and knee extension strength.

RESULTS

Model prediction CVs for kaSCF thickness ranged from 3.57% to 9.87% across femoral and tibial regions. Greater average kaSCF was associated with thinner cartilage in men (std. β= -0.029, 95% CI: -0.050 to -0.007, p=0.010) and higher T2 in women (std. β=0.169, 95% CI: 0.072 to 0.265, p=0.001). Greater kaSCF was also associated with lower knee extension force (std. β= -15.36, 95% CI: -20.39 to -10.33, p<0.001) and higher odds of frequent knee pain (std. odds ratio=1.156, 95% CI: 1.046 to 1.278, p=0.005) across all participants.

CONCLUSIONS

Greater kaSCF was associated with thinner cartilage in men, higher T2 in women, reduced knee strength, and greater knee pain, independent of BMI. These findings suggest a potential role of kaSCF as a predictor for knee osteoarthrits-related structural, functional, and clinical outcomes independent of the effects of BMI.

Degenerative Hip Osteoarthritis in Unilateral Knee Osteoarthritis Patients: A Correlation Analysis

OBJECTIVE

Hip and knee OA often occur successively. However, little is known about the relationship between hip and knee OA in unilateral knee OA patients. The aim of the study was to explore the correlation between unilateral knee OA and bilateral hip degeneration to determine the impact unilateral knee OA has on the severity of hip degeneration.

METHODS

This retrospective case-control study enrolled 162 patients who were presented with unilateral knee osteoarthritis and hospitalized in Zhongshan hospital, Fudan University, from January 2016 to December 2018. The severity of affected knee joint and bilateral hip joint was evaluated by using the Kellgren-Lawrence (KL) score. Variates, such as gender, age, body mass index (BMI) and Knee Society Score (KSS) at admission, were also recorded. Differences in the severity of OA between ipsilateral, contralateral hip joints and affected knee joints were accessed with chi-square tests. Single-factor and multi-factor logistic regression were applied to determine the risk factors for hip OA in patients with unilateral knee OA.

RESULTS

Gender have no impact on KSS, the length of disease, and BMI of patients. In contralateral hip joints, there was significant difference in the proportion of patients with severe hip degeneration (KL score ≥ 2) compared to those with mild hip degeneration (KL score < 2) when considering length of disease (p < 0.001), KSS symptom score < 70 (p = 0.001) or KSS function score (p < 0.001). The risk factors for contralateral hip degeneration of patients with unilateral knee OA include that long disease course (> 5 years) (OR 3.030 [95% CI 1.476 to 6.220]; p < 0.001), and high KSS function score (≥ 70 year) (OR 0.921 [95% CI 0.878 to 0.967]; p < 0.001), increased risk of contralateral hip degeneration of patients with unilateral knee OA.

CONCLUSIONS

The correlation between unilateral knee OA and contralateral hip degeneration was stronger than that between unilateral knee OA and ipsilateral hip degeneration. For knee OA patients with longer course and lower KSS functional score, more attention should be paid to the degeneration process of the contralateral hip joint.

Efficacy of Amniotic Suspension Allografts in the Treatment of Knee Osteoarthritis: A Systematic Review

Knee osteoarthritis significantly impacts mobility and quality of life. This condition is a leading cause of disability in aging populations, with total knee replacement commonly sought in advanced cases. Traditional nonoperative management strategies, including anti-inflammatories, corticosteroid injections, and hyaluronic acid, often provide limited relief, especially in severe cases. Recently, regenerative therapies such as amniotic suspension allografts (ASA) have emerged as promising alternatives due to their anti-inflammatory and regenerative properties, which may counteract the catabolic effects of osteoarthritis. This systematic review evaluated the efficacy and safety of ASA in reducing pain and improving function among knee osteoarthritis patients. Following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines, a comprehensive search of PubMed and Embase databases initially identified 1,733 studies pertaining to ASA, of which 1,575 were screened, and 9 studies ultimately met the inclusion criteria for detailed analysis of ASA in the treatment of knee osteoarthritis. Data extraction and narrative synthesis focused on outcomes such as pain reduction and functional improvement using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), as well as safety profiles. The results demonstrated notable improvements in pain scores following ASA treatment, as shown by studies reporting increases in KOOS pain scores over 6 months, which generally outperformed hyaluronic acid and saline treatments in pain reduction. Similarly, ASA treatment was associated with substantial improvements in physical function outcome scores, enhancing patients' ability to perform daily activities. Patient-reported outcomes also indicated higher quality of life and functional status, with most patients experiencing high levels of satisfaction. Additionally, ASA's safety profile was favorable, with adverse events primarily mild to moderate in nature, including a few transient events such as knee stiffness and myalgias. This systematic review highlights ASA as an effective therapeutic option for knee osteoarthritis, although further studies focusing on long-term radiographic outcomes and mechanisms of action are recommended to fully establish its benefits and optimize treatment protocols.

Associations between urinary glyphosate and arthritis: an US NHANES analysis

Objective

As the relationship between urine glyphosate and arthritis in adults in general is still unclear, the study set out to investigate it.

Methods

A total of 1,689 people volunteered in the National Health and Nutrition Examination Surveys (US NHANES). Utilizing a multivariate logistic regression model to explore the association between urine glyphosate concentrations (both continuous with categorical) and the risks of developing arthritis, as well as the risks of various types of arthritis. Non-linear correlations have been investigated using restricted cubic spline and smooth curve fitting. We also conducted additional subgroup analyses using categorical defining features.

Results

Patients with arthritis had urine glyphosate levels of 0.4 ng/mL, while non-arthritic individuals had levels of 0.3 ng/mL (p < 0.05). After adjusting for confounding variables, multivariate logistic regression continuous and categorical models demonstrated a significant positive association between elevated urinary glyphosate levels and arthritis risk [1.2 (1.0, 1.4)]. This association was observed in the osteoarthritis (OA) subgroup, with an odds ratio of 1.3 (95% CI: 1.1, 1.6), but was not found in the rheumatoid arthritis (RA) or other arthritis subgroups. Smooth curve fitting and RCS regression analyses further elucidate that urine glyphosate levels exhibit a dose-dependent relationship with the risks of both arthritis and OA, adhering to a linear trend (with a p-value for nonlinearity exceeding 0.05). Subsequent subgroup studies showed that in certain groups of people, the positive relationship between urine glyphosate and arthritis remained significant.

Conclusion

Increased exposure to urine glyphosate may be associated with an elevated risk of arthritis, particularly in the subgroup of osteoarthritis.

Mendelian randomization of serum micronutrients and osteoarthritis risk: focus on zinc

BACKGROUND

Osteoarthritis (OA) is an increasingly severe public health issue globally. Micronutrients are essential for maintaining normal physiological functions and metabolic balance; however, their relationship with OA is not fully understood.

METHODS

This study aimed to evaluate the potential causal relationships between 15 key micronutrients and the risk of OA using both two-sample and multivariate Mendelian randomization approaches. We gathered data from a large prospective cohort of genome-wide association studies on these micronutrients and OA. Comprehensive Mendelian randomization analyses were conducted using inverse variance weighting, MR Egger, weighted median, weighted models, and simple models. Through multivariate analyses, factors such as BMI and strenuous exercise were controlled to assess the independent associations between zinc and OA risk.

RESULTS

In the two-sample Mendelian randomization analysis, zinc was positively associated with OA risk (OR = 1.045, 95% CI: 1.009 to 1.082, P = 0.015). This association remained significant even after controlling for other confounding factors in multivariate analyses, indicating an independent effect of zinc. Other micronutrients, such as calcium, iron, and vitamin D, did not show significant associations with OA risk in this study.

CONCLUSION

This study provides new evidence of a positive association between the micronutrient zinc and the risk of OA, emphasizing the importance of considering micronutrients in osteoarthritis prevention and treatment strategies. Future research should further validate these findings and explore the specific biological mechanisms by which zinc influences the risk of osteoarthritis.

Topical Formulation of Tramadol 5% in the Management of Osteoarthritis of the Knee: A Double-Blind, Randomized, Prospective, Placebo-Controlled Clinical Trial

The goal of the present study was to evaluate the efficacy of topical tramadol in the management of knee osteoarthritis pain. Sixty patients with moderate to severe pain of knee osteoarthritis were enrolled. Patients were randomized to receive tramadol 5% or placebo along with oral diclofenac 100 mg/day. They were instructed to apply the ointment every 12 h on the knee for three weeks. To control breakthrough pain, the patients were allowed to take acetaminophen up to 650 mg per day. The measured variables were Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Visual Analog Scale (VAS). Sixty patients completed the study. At the end of follow-up period, VAS decreased by 21% (from 7.2 ± 2.1 to 5.7 ± 2.4, p-value < 0.05) and WOMAC score decreased by 23% (from 49.6 ± 17.4 to 38.4 ± 18.1, p-value < 0.05) in intervention group. Topical tramadol was significantly effective in reducing the intensity of pain and osteoarthritis symptoms in comparison to placebo considering VAS (5.7 ± 2.4 vs. 8.0 ± 2.9, p-value = 0.001) and WOMAC score (38.4 ± 18.1 vs. 46.0 ± 18.6, p-value = 0.007). Topical tramadol 5% appears to be effective in moderate to severe knee osteoarthritis pain.

Advances in GLP-1 receptor agonists for pain treatment and their future potential

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) show substantial efficacy in regulating blood glucose levels and lipid metabolism, initially as an effective treatment for diabetes mellitus. In recent years, GLP-1RAs have become a focal point in the medical community due to their innovative treatment mechanisms, robust therapeutic efficacy, and expansive development prospects. Notably, GLP-1RAs benefit pain management through their neuroprotective and metabolic regulatory properties, such as inhibiting inflammation responses and oxidative stress, promoting β-endorphin release and modulating several other crucial biological pathways. Hence GLP-1RAs hold promise for repurposing as treatments for pain disorders. In this narrative review, we thoroughly trace the current preclinical and clinical evidence of seven pain modalities, including inflammatory pain, osteoarthritis, visceral pain, neuropathic pain, diabetic neuropathy, cancer pain and headache, to support the efficacy and underlying biological mechanisms of GLP-1RAs as therapeutic agents for pain suffering. Despite these promising findings, further research is necessary to establish their long-term efficacy, optimal dosing strategies, and potential synergistic interactions of GLP-1RAs with existing pain management therapies. Future clinical trials should aim to distinguish the direct analgesic effects of GLP-1RAs from their metabolic benefits and explore their broader applications in pain conditions. The ongoing exploration of new indications for GLP-1RAs further highlights their transformative potential in advancing medical treatments across diverse clinical fields.

Senile Osteoarthritis Regulated by the Gut Microbiota: From Mechanisms to Treatments

Osteoarthritis (OA) is a chronic, progressive degenerative joint disease that affects the entire synovial joint, leading to the progressive degeneration of articular cartilage. It seriously affects the quality of life and global disability of patients. OA is affected by a variety of factors; the most significant risk factor for OA is age. As individuals age, the risk and severity of OA increase due to the exacerbation of cartilage degeneration and wear and tear. In recent years, research has indicated that the gut microbiota may play a significant role in the aging and OA processes. It is anticipated that regulating the gut microbiota may offer novel approaches to the treatment of OA. The objective of this paper is to examine the relationship between the gut microbiota and senile OA, to investigate the potential mechanisms involved. This review also summarizes the therapeutic strategies related to gut flora in OA management, such as prebiotics and probiotics, diet, exercise, traditional Chinese medicine (TCM) modification, and fecal microbiota transplantation (FMT), highlighting the potential clinical value of gut flora and elucidating the current challenges. The foundation for future research directions is established through the summarization of current research progress.

The Expression Level of SOX Family Transcription Factors' mRNA as a Diagnostic Marker for Osteoarthritis

Background/Objectives:Osteoarthritis (OA) is the most common degenerative and chronic joint disease and is a leading cause of pain and disability in adults worldwide. The SRY-related HMG box (SOX) family transcription factors (TFs) play a crucial role during the pathogenesis of OA; however, their exact mechanisms remain unexplored. The aim of our study was to conduct a bioinformatics analysis of the common interactions of SOX-5, SOX-9, and SOX-11 with other proteins, as well as their role in OA pathogenesis. Methods:SOX5, SOX9, and SOX11 mRNA expression levels in articular cartilage with subchondral bone and synovium from knee OA patients were assessed using the qPCR method. The study group consisted of thirty-one patients (n = 31). Total RNA was isolated from the articular cartilage with subchondral bone and synovium from the affected and unaffected area of the knee joint. Results: Our results revealed a regulatory network between SOX-5, SOX-9, and SOX-11, and various proteins involved in the pathogenesis of knee OA and their collective interactions, which are involved in the regulation of cartilage extracellular matrix (ECM) organization, response to stimulus, regulation of gene expression, inflammatory response, cartilage condensation, and ossification in chondrocytes. Higher expression levels of SOX5, SOX9, and SOX11 mRNA were noted in OA-affected articular cartilage with subchondral bone compared to control tissue (p = 0.00015, p = 0.0024 and p > 0.05, respectively, Mann-Whitney U-test). All studied genes demonstrated elevated mRNA expression levels in the articular cartilage with subchondral bone from stage 4 patients than those with stage 3 (p > 0.05; Mann-Whitney U-test). Lower SOX5, SOX9, and SOX11 mRNA expression levels were found in OA-affected synovium compared to the control tissue (p = 0.0003, p > 0.05 and p = 0.0007, respectively, Mann-Whitney U-test). Decreased SOX9 mRNA expression levels in synovium were noted in patients with stage 4 disease than those with stage 3; however, SOX5 and SOX11 mRNA expression levels were higher in patients with stage 4 (p > 0.05; Mann-Whitney U-test). Conclusions: The results of our research show that the studied SOX TFs play a role in the development of OA, contributing to the formation of pathological changes not only in the articular cartilage, but also in the synovial membrane. The changes in the SOX5, SOX9, and SOX11 mRNA expression levels in the articular cartilage with subchondral bone and synovium may serve as potential molecular diagnostic biomarkers for detecting OA and could indicate the progression of this disease; however, our observations require further investigation.

MICRO-FRAGMENTED ADIPOSE TISSUE IN THE KNEE OSTEOARTHRITIS UNDER LOCAL ANESTHESIA

Objective

To assess the feasibility of the entire micro fragmented adipose tissue knee injection procedure under local anesthesia. From the subcutaneous harvesting and microfragmentation process to the intrarticular knee injection.

Methods

A patient with bilateral knee osteoarthritis underwent adipose tissue harvesting and bilateral intra-articular micro fragmented adipose tissue knee injection under local anesthesia. Patient-related outcomes were collected before the procedure, 12 months, and 24 months follow-up. Womac, Koos, and VAS were recorded.

Results

The visual analog scale, KOOS questionnaire, and WOMAC score all improved in the 12- and 24-month follow-ups.

Conclusion

Adipose tissue harvesting and micro fragmented adipose tissue knee injection are procedures that can be performed under local anesthesia and have good patient report outcomes. Level of Evidence IV; Therapeutic Study.

DXA images vs. pelvic radiographs: Reliability of hip morphology measurements

OBJECTIVE

Dual-energy x-ray absorptiometry (DXA) images are increasingly used to study hip morphology. Whether hip morphology measurements are consistent between DXA images and radiographs is unknown. Therefore, we investigated the agreement and reliability of the measurements performed on DXA images and radiographs.

DESIGN

We included participants from the Rotterdam study, a population-based cohort study, who received a hip DXA image and pelvic radiograph on the same day. The acetabular depth-width ratio (ADR), modified acetabular index (mAI), alpha angle (AA), Wiberg and lateral center edge angle (WCEA, LCEA), extrusion index (EI) and triangular index ratio (TIR) were automatically determined on both imaging modalities. The intraobserver and intermethod agreement were studied using Bland-Altman methods, and the reliability was assessed using intraclass correlation coefficients (ICC). Secondly, the diagnostic agreement regarding dysplasia, cam, and pincer morphology was assessed using percent agreement and Cohen's kappa.

RESULTS

A total of 750 hips from 411 individuals, median age 67.3 years (range 52.2 - 90.6), 45.5% male, were included. The following intermethod ICCs (95% CI) were obtained: ADR 0.85 (0.74-0.91), mAI 0.75 (0.52-0.85), AA 0.72 (0.68-0.75), WCEA 0.81 (0.74-0.85), LCEA 0.93 (0.91-0.94), EI 0.88 (0.84-0.91), and TIR 0.81 (0.79-0.84). We found comparable intraobserver ICCs for each morphological measurement.

CONCLUSION

DXA images and pelvic radiographs could both reliably be used to study hip morphology. Due to the lower radiation burden, DXA images could be an excellent alternative to pelvic radiographs for research purposes.

Efficacy and safety of intra-articular botulinum toxin injection therapy for joint pain: A systematic review and meta-analysis

BACKGROUND

Studies conducted in various animal models of joint pain showed an anti-nociceptive effect of intra-articular botulinum toxin type A (BoNT-A). Randomized controlled trials (RCTs) in humans suggest a potential effect but results are disparate.

OBJECTIVES

To assess the efficacy and safety of intra-articular BoNT-A for the treatment of joint pain.

METHODS

We conducted a systematic review of RCTs comparing the effects of intra-articular BoNT-A to other interventions on pain and activity limitations in the short (<3 months), intermediate (3-6 months) and long term (> 6 months), and their adverse effects, in people with joint pain. We performed a meta-analysis when appropriate. MEDLINE, EMBASE, ClinicalTrials.gov, CINHAL and ICTRP databases were searched from inception to July 9, 2023. Two independent reviewers selected eligible studies and extracted data in a standardized manner. The results of quantitative synthesis were expressed as the standardized mean difference (SMD) (95 % confidence interval).

RESULTS

We included 14 RCTs: 437 participants received an intra-articular injection of BoNT-A and 551 received another intervention. Overall, 7 RCTs (549 participants) compared intra-articular BoNT-A with an intra-articular treatment in the knee: short-, intermediate-, and long-term SMD were -0.35 (-0.82 to 0.12), -0.27 (-0.61 to 0.08), and -0.43 (-1.12 to 0.26) for pain and -0.44 (-0.96 to 0.07), -0.24 (-0.63 to 0.15) and -0.42 (-1.26 to 0.42) for activity limitations, respectively. Two RCTs (68 participants) in the shoulder and 1 RCT (60 participants) in the base-of-thumb showed reduced pain in the short term. Minor adverse events were not rare, but no serious adverse events related to intra-articular BoNT-A were reported.

CONCLUSIONS

Intra-articular BoNT-A may reduce joint pain in the short term for small and medium-sized joints (ie, base-of-thumb and shoulder), but not for large joints (ie, knee).

REGISTRATION

PROSPERO: CRD42021290157 (Date of first submission: 8 November 2021; Date of registration: 8 December 2021).

Tuning the Response of Synthetic Mechanogenetic Gene Circuits Using Mutations in TRPV4

Conventional gene therapy approaches for drug delivery generally rely on constitutive expression of the transgene and thus lack precise control over the timing and magnitude of delivery. Synthetic gene circuits with promoters that are responsive to user-defined stimuli can provide a molecular switch that can be utilized by cells to control drug production. Our laboratory has previously developed a mechanogenetic gene circuit that can deliver biological drugs, such as interleukin-1 receptor antagonist (IL-1Ra), on-demand through the activation of Transient receptor potential family, vanilloid 4 (TRPV4), a mechanosensory ion channel that has been shown to be activated transiently in response to physical stimuli such as physiological mechanical loading or hypo-osmotic stimuli. The goal of this study was to use mutations in TRPV4 to further tune the response of this mechanogenetic gene circuit. Human iPSC-derived chondrocytes harboring targeted gain-of-function mutations of TRPV4 were chondrogenically differentiated. Both mutants-V620I and T89I-showed greater total IL-1Ra production compared with wild type following TRPV4 agonist treatment, as well as mechanical or osmotic loading, but with altered temporal dynamics. Gene circuit output was dependent on the degree of TRPV4 activation secondary to GSK101 concentration or strain magnitude during loading. V620I constructs secreted more IL-1Ra compared with T89I across all experimental conditions, indicating that two mutations that cause similar functional changes to TRPV4 can result in distinct circuit activation profiles that differ from wild-type cells. In summary, we successfully demonstrate proof-of-concept that point mutations in TRPV4 that alter channel function can be used to tune the therapeutic output of mechanogenetic gene circuits.

The Efficacy and Brain Network Mechanism of Acupuncture for Knee Osteoarthritis: A Study Protocol for Randomized Controlled Neuroimaging Trial

Purpose

Knee osteoarthritis (KOA) is a prevalent degenerative bone and joint disease observed in clinical practice. While acupuncture has demonstrated efficacy in treating KOA, the central mechanisms underlying its effects remain ambiguous. Recently, functional magnetic resonance imaging (fMRI) has been extensively applied in studying the brain mechanisms of acupuncture analgesia. Currently, network analysis based on brain connectomics is a focal point in acupuncture imaging research. Therefore, this study uses KOA as the research vehicle, focuses on the abnormal connectivity patterns of brain functional networks, and integrates clinical pain assessments to thoroughly investigate the central mechanisms of acupuncture therapeutic effects on KOA.

Patients and Methods

In this parallel, randomized, sham-controlled neuroimaging trial, 60 KOA patients will be randomly divided into the acupuncture group and sham acupuncture group in a 1:1 ratio, treated three times weekly for a total of 12 sessions. Patients will undergo clinical symptom assessments and cranial fMRI scans at baseline (-1-0 weeks), post-treatment (4 weeks), and at the follow-up (16 weeks). Forty healthy subjects will be recruited for observation, with a single MRI scan conducted only at baseline (-1-0 week). The primary efficacy indicator will be the change in NRS score after four weeks of treatment, with secondary outcomes including WOMAC, STAI, and safety assessments. fMRI observations will employ independent component analysis, brain network construction, and functional connectivity, complemented by Pearson correlation analysis to explore the relationship between brain responses and clinical improvements.

Conclusion

This study will initially uncover how acupuncture intervention for chronic KOA pain centrally regulates and exerts therapeutic effects through the modulation of abnormal brain network functional connectivity patterns, with a demonstrated long-term effect.

Ethics and Dissemination

This study has been approved by the ethics committee of Shandong University of Traditional Chinese Medicine Affiliated Hospital ((2024) Lunshen No. (028) - KY).

Clinical Trial Registration

This study has been approved by registered in the Chinese Clinical Trial Registry (ChiCTR2400083695).

Efficacy and safety of laser acupuncture on osteoarthritis: a systematic review and meta-analysis

Objectives

To perform a meta-analysis of previous studies investigating the effects of laser acupuncture on osteoarthritis.

Study design

Systematic review and meta-analysis.

Methods

Randomized controlled trials (RCTS) on laser acupuncture for osteoarthritis were searched in the databases of PubMed, Embase, Cochrane Library, and Web of Science with a search deadline of 24 December 2023. After identifying 11 studies, we used Stata 15.0 to analyze the data.

Results

In the 11 studies identified, 931 patients were analyzed. Results showed that laser acupuncture significantly improved patients' pain and function compared to the placebo laser group. There were significant differences in VAS pain scores[SMD = -0.924, 95% CI (-1.200, -0.649), p = 0.000], WOMAC pain scores[SMD = -0.425, 95% CI (-0.652, -0.199), p = 0.000], WOMAC function scores[SMD = -0.307, 95% CI (-0.548, -0.065), p = 0.013], WOMAC stiffness scores[SMD = -0.235, 95% CI (-0.388, -0.083), p = 0.002] between the laser acupuncture group and the placebo laser group. The therapeutic effect of laser acupuncture disappeared at 8 weeks. In subgroup analysis, patients who received laser acupuncture with specific parameters had better VAS scores and WOMAC scores than patients in other subgroups.

Conclusion

The application of laser acupuncture can improve knee pain and function in patients with osteoarthritis in the short term. It is recommended to use a laser with a power greater than 100 mW and a wavelength greater than 1,000 nm. CO2 lasers and solid-state lasers were shown to be more effective in the results than other types of lasers.

Characteristics of eligible patients with knee osteoarthritis accepting versus declining participation in a randomised trial investigating the effect of weight loss versus knee arthroplasty to explore generalisability: A cross-sectional study

BACKGROUND

The INtensive diet versus Knee Arthroplasty (INKA) trial is a randomised trial assessing weight loss as an alternative to knee arthroplasty (KA) in obese patients with severe knee osteoarthritis (OA) awaiting KA (NCT05172843). The external validity of the INKA trial may be hampered if the patients who participate differ from those who decline participation.

OBJECTIVE

To compare baseline characteristics between patients who enrol in the INKA trial and those who decline participation (i.e., non-INKA [nINKA] group).

METHODS

We applied a cross-sectional study design, collecting and comparing baseline characteristics among all patients eligible for enrolment in the INKA trial from two clinics in Copenhagen. Imbalance between accepting (INKA) and declining (nINKA) groups was assessed using standardised differences (StdDs). We were prespecified that StdD values < 0.20 would indicate a clinically insignificant imbalance between groups, whereas values > 0.80 indicate incomparability.

RESULTS

Of the 913 patients scheduled for KA, 888 were screened for INKA trial eligibility. Of the 217 eligible patients, 92 (42%) were enroled in the INKA trial, while 37 (17%) participated in the nINKA cross-sectional sample only. Patients enroled in INKA had on average a less severe Oxford knee score (OKS) of 22.0 (standard deviation = 6.7) compared to declining participants in nINKA with 18.6 (7.2), corresponding to an StdD of 0.50, and an absolute difference of 3.45 (95% confidence interval = 0.64-6.26, p = 0.017). A consistent similar pattern was noted across all secondary patient-reported outcomes applied in the INKA trial.

CONCLUSIONS

We observed discrepancies in patient-reported outcomes, with those who declined enrolment reporting more severe symptoms. These differences, however, were below the minimally important difference between groups for OKS, which is set to 4.84 points.

LEVEL OF EVIDENCE

Level II-III cross-sectional study in a randomised control trial.

Wharton's Jelly Mesenchymal Stem Cells: Shaping the Future of Osteoarthritis Therapy with Advancements in Chitosan-Hyaluronic Acid Scaffolds

This review explores the potential of Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) in cartilage regeneration and osteoarthritis treatment. It covers key factors influencing chondrogenesis, including growth factors, cytokines, and hypoxia, focusing on precise timing. The effectiveness of three-dimensional cultures and scaffold-based strategies in chondrogenic differentiation is discussed. Specific biomaterials such as chitosan and hyaluronic acid are highlighted for tissue engineering. The document reviews clinical applications, incorporating evidence from animal research and early trials and molecular and histological assessments of chondrogenic differentiation processes. It addresses challenges and strategies for optimizing MSC-derived chondrocyte therapy, emphasizing the immunomodulatory properties of these cells. The review concludes as a comprehensive road map for future research and clinical applications in regenerative medicine.

Therapeutic Controlled Release Strategies for Human Osteoarthritis

Osteoarthritis is a progressive, irreversible debilitating whole joint disease that affects millions of people worldwide. Despite the availability of various options (non-pharmacological and pharmacological treatments and therapy, orthobiologics, and surgical interventions), none of them can definitively cure osteoarthritis in patients. Strategies based on the controlled release of therapeutic compounds via biocompatible materials may provide powerful tools to enhance the spatiotemporal delivery, expression, and activities of the candidate agents as a means to durably manage the pathological progression of osteoarthritis in the affected joints upon convenient intra-articular (injectable) delivery while reducing their clearance, dissemination, or side effects. The goal of this review is to describe the current knowledge and advancements of controlled release to treat osteoarthritis, from basic principles to applications in vivo using therapeutic recombinant molecules and drugs and more innovatively gene sequences, providing a degree of confidence to manage the disease in patients in a close future.

Design, Evaluation, and Implementation of a Novel Magnetic Resonance Imaging-Compatible Physiologic Loading Simulator for Ex-Vivo Joints

Quantitative magnetic resonance imaging (qMRI), in combination with mechanical testing, offers potential to investigate how loading (e.g., from daily physical exercise) is related to joint and tissue function. However, current testing devices compatible with magnetic resonance imaging (MRI) are often limited to uniaxial compression, often applying low loads, or loading individual tissues (instead of multiple), while more complex simulators do not facilitate MRI. Hence, in this work, we designed, built and tested (N = 1) an MRI-compatible multi-axial load-control system, which enables scanning cadaveric joints (healthy or pathologic) loaded to physiologically relevant levels. Testing involved estimating and validating physiologic loading conditions before implementing them experimentally on cadaver knees to simulate and image gait loading (stance and swing). The resulting design consisted of a portable loading device featuring pneumatic actuators to reach a combined loading scenario, including axial compression (≤2.5 kN), shear (≤1 kN), bending (≤30 N·m) and muscle tension. Initial laboratory testing was carried out; specifically, the device was instrumented with force and pressure sensors to evaluate loading and contact response repeatability in one cadaver knee specimen. This loading system was able to simulate healthy or pathologic gait with reasonable repeatability (e.g., 1.23-2.91% coefficient of variation for axial compression), comparable to current state-of-the-art simulators, leading to generally consistent contact responses. Contact measurements demonstrated a tibiofemoral to patellofemoral load transfer with knee flexion and large contact pressures concentrated over small sites between the femoral cartilage and menisci, agreeing with experimental studies and numerical simulations in the literature.

Enhanced Pain Reduction at Different Stages of Knee Osteoarthritis via Repeated Injections of Hyaluronic Acid with Niacinamide: A Comparative Study

Background: Osteoarthritis (OA) of the knee is the most common joint disease, characterized by the degeneration of joint cartilage. Intra-articular hyaluronic acid (IAHA) injections are a well-established non-surgical treatment. Methods: This retrospective study analyzed knee OA patients receiving IAHA combined with niacinamide injections, assessing pain reduction in relation to patient data, the number of injections, and radiological findings. Results: IAHA injections led to significant pain reduction on the numeric rating scale (NRS) (0-10), with a mean decrease of 3.34 ± 1.65. Pain relief was greater with multiple injections. A comparison of subgroups by injection frequency (1, 2, or >2) showed significant pain reduction between 1 and 2 injections (p = 0.027) and between 1 and >2 injections (p = 0.032). The OA grade measured using the Kellgren-Lawrence (p = 0.95) and Vallotton MRI classifications (p = 0.50) did not correlate with pain reduction. However, patients with meniscal damage (p = 0.02) showed a greater benefit. A strong positive correlation was found between baseline pain intensity and pain reduction (p < 0.001; r = 0.61). Conclusions: IAHA with niacinamide significantly reduces knee OA pain, with more injections enhancing pain relief. Greater benefits were observed in patients with higher baseline pain and meniscal damage. The favorable safety profile and potential for repeated treatments make IAHA a valuable option in knee OA management.

The Role of Mechanosensitive Piezo Channels in Chronic Pain

Purpose of Review

Mechanosensitive Piezo channels are ion channels activated by mechanical stimuli, playing a crucial role in mechanotransduction processes and mechanical hypersensitivity. When these channels are subjected to mechanical loading, membrane currents rise instantaneously, depolarizing and activating voltage-gated calcium channels. This results in an increase in intracellular Ca2+, which contributes to heightened sensitivity to mechanical stimuli. This review delves into the characteristics and mechanisms of Piezo channels in chronic pain.

Recent Findings

The findings suggest that Piezo channels are integral to the occurrence and development of chronic pain, including neuropathic pain, visceral pain, musculoskeletal pain, headache or orofacial pain, and inflammatory pain. Piezo channels significantly impact pain perception and transmission. These channels' critical involvement in various pain types highlights their potential as promising targets for chronic pain therapy.

Summary

This review discusses the role of Piezo channels in chronic pain. By understanding these pain mechanisms, new therapeutic strategies can be developed to alleviate chronic pain, offering hope for patients suffering from these debilitating conditions.

Infiltration of micro-fragmented adipose tissue under local anesthesia for knee osteoarthritis treatment is a safe procedure: A case series

INTRODUCTION

Knee osteoarthritis is a debilitating disease that has been increasing in prevalence, especially due to the aging population and rising incidence of obesity. Biological therapies (orthobiologics) have emerged, demonstrating efficacy in improving functional scores, including the injection of microfragmented Adipose Tissue (mFAT). The purpose of this study is to evaluate the safety of adipose tissue harvesting and mFAT injection under local anesthesia.

MATERIALS/METHODS

A case series involving 34 patients who underwent adipose tissue collection from the abdomen under local anesthesia, without sedation, in a sterile environment, and who received the infiltration of microfragmented adipose tissue after single-time preparation, using a fat washing and microfragmentation kit.

RESULTS

Evaluation was performed at the time of the procedure and after 7 days of follow-up. Only ecchymosis (76.5 %) and mild discomfort at the harvested site (70.6 %), as well as mild discomfort at the infiltrated knee (61.8 %), were identified. No major adverse events were identified.

CONCLUSION

The harvesting and injection of mFAT under local anesthesia is safe, with no major adverse events identified during this procedure.

Obesity-induced fibrosis in osteoarthritis: Pathogenesis, consequences and novel therapeutic opportunities

Osteoarthritis (OA) is a significant global burden, affecting more than half a billion people across the world. It is characterized by degeneration and loss of articular cartilage, synovial inflammation, and subchondral bone sclerosis, leading to pain and functional impairment. After age, obesity is a major modifiable risk factor for OA, and it has recently been identified as a chronic disease by the World Health Organization (WHO). Obesity is associated with high morbidity and mortality, imposing a significant cost on individuals and society. Obesity increases the risk of knee OA through increased joint loading, altered body composition, and elevated pro-inflammatory adipokines in the systemic circulation. Moreover, obesity triggers fibrotic processes in different organs and tissues, including those involved in OA. Fibrosis in OA refers to the abnormal accumulation of fibrous tissue within and around the joints. It can be driven by increased adiposity, low-grade inflammation, oxidative stress, and metabolic alterations. However, the clinical outcomes of fibrosis in OA are unclear. This review focuses on the link between obesity and OA, explores the mechanism of obesity-driven fibrosis, and examines potential therapeutic opportunities for targeting fibrotic processes in OA.

β2-adrenoceptors kick osteoarthritis - Time to rethink prevention and therapy

Although, during the past decades, substantial advances emerged in identifying major local and systemic factors contributing to initiation and progression of osteoarthritis (OA), some neuroendocrine mechanisms are still not understood or even neglected when thinking about novel therapeutic options. One of which is the sympathetic nervous system that exhibits various OA-promoting effects in different tissues of the joint. Interestingly, the β2-adrenoceptor (AR) mediates the majority of these effects as demonstrated by several in vitro, in vivo as well as in clinical studies. This review article does not only summarize studies of the past two decades demonstrating that the β2-AR plays an OA-promoting role in different tissues of the joint but also aims to encourage the reader to think about next-level research to discover novel and innovative preventive and/or therapeutic strategies targeting the β2-AR in OA.

Bone Marrow Aspirate Concentrate Injections for the Treatment of Knee Osteoarthritis: A Systematic Review of Randomized Controlled Trials

Background

Osteoarthritis (OA) poses a significant global burden, with conventional treatments like corticosteroid and hyaluronic acid (HA) injections commonly used. Emerging injectable biologics, including bone marrow aspirate concentrate (BMAC), show promise in OA management.

Purpose

To investigate the clinical efficacy of BMAC injection compared with other injection treatments for knee OA.

Study Design

Systematic review; Level of evidence, 1.

Methods

A systematic review was conducted using PubMed, Embase, Cochrane Library, and Google Scholar to identify randomized controlled trials with Level 1 evidence that compared the clinical efficacy of BMAC with other injections. The visual analog scale for pain and the Pain subscale of the Knee injury and Osteoarthritis Outcome Score (KOOS) were used as clinical scores representing pain. For functional assessment, the Western Ontario and McMaster Universities Osteoarthritis Index and the International Knee Documentation Committee subjective form were used. For studies comparing BMAC with HA, each clinical score was standardized to pain and function scales based on the minimal clinically important difference (MCID).

Results

Eight studies, consisting of a total of 937 patients, were included. Patients treated with BMAC showed a significant improvement in clinical scores compared with baseline, starting at 1 month postinjection. For pain scores at 6-month (P = .033) and 12-month follow-up (P = .011), BMAC demonstrated favorable results over HA, with a statistically significant difference. However, these differences did not exceed the MCID. When BMAC was compared with other injections, no significant differences were observed in the degree of clinical score improvement. No serious adverse events or events significantly associated with BMAC compared with other treatments were reported.

Conclusion

BMAC injections demonstrated effectiveness in providing pain relief and functional improvement for patients with knee OA. When BMAC was compared with other intra-articular injection options, distinct differences surpassing the MCID were not evident. Further research is deemed necessary to investigate the role of BMAC in the treatment of knee OA.

Should We Regularly Assess Hemoglobin Levels Following Elective Total Knee Arthroplasty, with the Administration of TXA and Without the Usage Tourniquet? An Observational Study from a Single Center

Background and Objectives: The aim of this study was to test whether there is a necessity for routine postoperative laboratory testing in patients undergoing primary elective unilateral total knee arthroplasty (TKA), with the administration of Tranexamic Acid (TXA) and without the use of tourniquet. Materials and Methods: This observational, retrospective cohort study was conducted at Meir Medical Center. The data were collected in 2018-2022. Patients were collected in a consecutive manner. There were no exclusion criteria for this study. The inclusion criteria were individuals who underwent elective TKA due to end-stage osteoarthritis (OA). We conducted a multivariable logistic regression analysis to determine the factors associated with postoperative hemoglobin (PoOHb) < 9 g/dL and the optimal cutoff to detect those patients postoperatively. Results: A total of 271 patients were included. The mean preoperative hemoglobin (PrOHb) was 13.02 ± 1.42 g/dL, and the mean PoOHb was 11.5 ± 1.34 g/dL. The mean decrease in Hbg levels following surgery was 1.52 ± 0.91 g/dL. In all, 271 patients had a PoOHb level ≥ 9 g/dL or above. A total of 16 patients received packed red blood cells following surgery. Patients with PoOHb < 9 g/dL had a significantly lower PrOHbg. In the current study, all 11 patients who had PoOHb < 9, 10 (90.9%) had PrOHb ≤ 1011.95 55 g/dL, compared to 25 (49.6%) of the 260 patients who had PoOHb ≥ 9. The odds ratio for having PrOHb ≤ 10.9511.55 g/dL if PoOHb < 9 g/dL was 206.6710.4 (95% CI 24.427.164 to 1749.01415.97). A cut-off of 11.2510.25 would have offered a sensitivity of 99% (specificity 93.5%). Conclusions: In conclusion, this study supports using selective post-TKR Hgb monitoring rather than adhering to routine practice. An association between postoperative anemia and the need for blood transfusion was found only when the preoperative baseline hemoglobin threshold was less than 10.95 g/dL.

Occupational mechanical exposures as risk factor for shoulder osteoarthritis: a systematic review

OBJECTIVES

The aim of this systematic review was to study the association between occupational mechanical exposures and shoulder osteoarthritis (OA).

METHODS

A protocol was registered in PROSPERO. Four databases were systematically searched based on PECOS criteria. Outcome was defined as shoulder OA (acromioclavicular (AC) and/or glenohumeral OA) and exposure as occupational mechanical exposures (vibration, upper arm elevation, force, lifting, repetition, and combined mechanical exposures). We included epidemiological studies estimating the prevalence of shoulder OA or the association between occupational mechanical exposures and shoulder OA. Two researchers independently screened articles, performed data extraction, and assessed the risk of bias and level of evidence using GRADE.

RESULTS

A total of 1642 articles were screened, of which 7 met the inclusion criteria. Four studies were assessed as having a high risk of bias, 1 with a moderate risk, and 2 with a low risk. Based on job titles, higher prevalence estimates (2.9% to 61.8%) were found in exposed job groups. For all occupational mechanical exposures, exposure-response relations were found in relation to AC OA. For vibration, the odds ratio (OR) ranged between 1.7 and 3.1 in the highest exposure groups, while the ORs for upper arm-elevation, force, lifting, repetition, and combined mechanical exposures ranged between 0.5 to 2.2, 1.3 to 1.8, 7.3 to 10.3, 2.4, and 2.2 to 2.9. Low or very low level of evidence was found for all exposures.

CONCLUSIONS

This systematic review found an indication of an association between occupational mechanical exposures and shoulder OA, especially AC OA. However, the level of evidence varied between low and very low. High-quality studies assessing the association and differentiating between the specific shoulder joints are highly warranted.

Meniscus Injury Induces Patellofemoral Osteoarthritis Development Mediated by Synovitis and Gait Kinematics: A Preclinical Study

OBJECTIVE

To investigate whether meniscal injury leads to the development of patellofemoral (PF) osteoarthritis (PFOA) and to explore how synovitis and gait kinematics mediate this relationship.

METHODS

Fifty-four male Wistar rats (12 weeks old) were randomly assigned to the control, sham, or destabilized medial meniscus (DMM) groups. The rats were subjected to gait analysis to assess the kinematic changes at 2, 4, and 8 weeks postoperatively. Subsequently, the rats were euthanized, and their right knees were harvested for histological analysis.

RESULTS

The Osteoarthritis Research Society International (OARSI) and modified Mankin (MM) scores in the DMM group were significantly higher than those in the control and sham groups at week 2 and significantly higher than those in the control group at week 4. The OARSI and MM scores in the sham group were significantly higher than those in the control group at weeks 2 and 4. The association between the DMM and OARSI scores was significantly mediated by the synovitis score and knee flexion angle at foot contact (proportion mediated: 58% and 10%, respectively). The association between the sham and OARSI scores was significantly mediated by the synovitis score and knee flexion angle (proportion mediated: 24% and 24%, respectively).

CONCLUSIONS

DMM surgery induced articular cartilage damage in the PF joint. Synovitis and the knee flexion angle significantly mediated the association between DMM or sham surgery and PFOA development.

Impact of knee geometry on joint contact mechanics after meniscectomy

Finite element modeling has served as a cornerstone in understanding knee joint mechanics post-meniscectomy, yet the influence of varying knee geometries remains unknown. The present study aimed to fill that gap by employing statistical shape modeling to generate knee models from MRI data of 31 human knees, capturing the population's knee size and shape variations. Finite element simulations were conducted to replicate intact, partial, and total medial meniscectomy conditions during standing. The results revealed a substantial shift in load distribution from the medial to lateral compartment following medial meniscectomy with its magnitude depending on knee geometry. Cartilages experienced variable degrees of pressure changes at different sites, which could also be different for fluid and contact pressures. While changes in joint size led to somewhat predictable alterations in contact pressure, variations in joint shape resulted in unexpected changes in contact and fluid pressures, emphasizing the need for computational simulations. The average knee geometry exhibited the lowest contact and fluid pressures under the given loading and boundary conditions, in contrast to knees with shapes deviating from the average. This study highlights the significance of individual knee shape in the biomechanical outcome of meniscectomy, potentially explaining the variability in clinical outcomes observed post-surgery.

Associations between urinary phytoestrogen mixed metabolites and osteoarthritis risk

BACKGROUND

This study aims to explore the relationship between urinary phytoestrogen mixed metabolites and the risk of osteoarthritis (OA).

METHODS

Using data from the National Health and Nutrition Examination Survey (NHANES), a Weighted Quantile Sum (WQS) regression analysis was conducted to determine the dominant metabolites. Additionally, a Bayesian kernel machine regression (BKMR) model was utilized to explore the combined effects of phytoestrogen mixed metabolites on OA.

RESULTS

Compared to the lowest quartile group, the highest quartile group of Enterodiol showed a 46% increased risk of OA (OR = 1.46, 95% CI: 1.09-1.96), while the highest quartile group of Enterlactone showed a 30% decreased risk of OA (OR = 0.70, 95% CI: 0.52-0.96). The WQS regression model analysis revealed a positive relationship between urinary phytoestrogen mixed metabolites and OA risk, with Enterodiol found to have the highest weight in this association. The BKMR model indicated that the association between urinary phytoestrogens and OA increased with concentration but did not reach statistical significance. The univariate exposure-response function demonstrated a positive association between Enterodiol and OA.

CONCLUSIONS

There is a positive relationship between urinary phytoestrogen mixed metabolites and OA, with Enterodiol being an important factor influencing OA risk.

Proteomic characterization of regenerated cartilage following knee joint distraction; a human case-study

PURPOSE

Knee joint distraction is a surgical procedure with cartilage-regenerating properties. The composition of joint distraction-regenerated cartilage in human patients is poorly documented. In this case-study, provided a unique opportunity to biomolecularly characterize the regenerated tissue from a patient who underwent bilateral distraction and later knee replacements.

METHODS

Knee joint distraction was conducted using an external fixation frame and total knee arthroplasty was performed several years later. Radiographic imaging was performed to assess the status of the knee joint prior, during and after clinical interventions. Following total knee replacement, cartilage biopsies were collected and processed for tissue sectioning and histochemical staining. Tandem mass-spectrometry proteomics analysis was used to characterize and compare the proteomic composition.

RESULTS

Both knee joints showed joint-space improvement pre- and post-knee joint distraction. Regenerated cartilage was white with an irregular surface, while native (lateral) cartilage had a yellow appearance and smooth surface. Histochemical staining showed higher Safranin-O positivity in native cartilage compared to regenerated cartilage, and differences in collagen structure. Proteomic analysis did not reveal major differences in cartilage extracellular matrix protein abundance. Bioinformatic analyses revealed enrichment in ribosomal proteins (regenerated cartilage) and RNA Polymerase II Transcription Termination (native cartilage).

CONCLUSION

Histologically, knee joint distraction-regenerated cartilage showed less glycosaminoglycans and disorganized collagen compared to native cartilage. However, mass-spectrometry has no major differences in extracellular matrix protein abundance, with proteomic clues suggesting protein translation regulation as a potential mechanism for regeneration.

Polydeoxyribonucleotide ameliorates IL-1β-induced impairment of chondrogenic differentiation in human bone marrow-derived mesenchymal stem cells

Osteoarthritis (OA) is a degenerative disease of the joints, prevalent worldwide. Polydeoxyribonucleotide (PDRN) is used for treating knee OA. However, the role of PDRN in IL-1β-induced inflammatory responses in human bone marrow-derived mesenchymal stem cells (hBMSCs) remains unknown. Here, we investigated the role of PDRN in IL-1β-induced impairment of chondrogenic differentiation in hBMSCs. hBMSCs treated with PDRN showed a large micromass, enhanced safranin O and alcian blue staining intensity, and increased expression of chondrogenic genes in IL-1β-induced inflammatory responses, in addition to regulation of catabolic and anabolic genes. In addition, PDRN treatment suppressed the expression of inflammatory cytokines and mitigated IL-1β-induced apoptosis in hBMSCs. Mechanistically, PDRN treatment increased the formation of cyclic adenosine monophosphate (cAMP) and upregulated the phosphorylation of cAMP-dependent protein kinase A (PKA)/cAMP response element binding protein (CREB) through the adenosine A2A receptor in hBMSCs and thus blocked the nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) signaling pathway. Thus, IL-1β-induced expression of inflammatory cytokines in hBMSCs was directly reduced by adenosine A2A receptor activation. Based on our results, we suggest that PDRN may be a promising MSC-based therapeutic agent for OA.

Maximizing Knee OA Treatment: A Comparative Look at Physiotherapy and Injections

BACKGROUND

Knee osteoarthritis (OA) is a prevalent and disabling condition often managed with physiotherapy or intra-articular injections. However, the comparative effectiveness of these treatments remains unclear. This systematic review aimed to evaluate and compare the efficacy of physiotherapy and intra-articular injections in managing knee OA.

METHODS

A systematic search of PubMed, Scopus, Web of Science, PEDro, and Cochrane Library was conducted. Randomized controlled trials (RCTs) comparing physiotherapy and intra-articular injections in knee OA patients were included. Key outcomes included pain (VAS), function (WOMAC, KOOS), range of motion (ROM), and quality of life. Data from five studies with a total of 552 participants were analyzed.

RESULTS

Intra-articular injections, particularly botulinum toxin and hyaluronic acid, were found to provide rapid pain relief, outperforming physiotherapy in short-term pain management. However, physiotherapy contributed significantly to long-term functional improvements, particularly in early-stage OA. Combination therapy of injections and physiotherapy yielded the best short-term pain relief and functional outcomes. Heterogeneity in study designs and follow-up periods limited the generalizability of findings.

CONCLUSIONS

Intra-articular injections are effective for immediate pain control, while physiotherapy plays a crucial role in maintaining joint function, especially for long-term management. Combining both interventions may offer the most comprehensive benefits. Further research is needed to determine the long-term efficacy of these treatments.

Osteoarthritis with depression: mapping publication status and exploring hotspots

Depression is a common psychological complication in osteoarthritis (OA) patients, and its incidence gets more and more attention year by year worldwide. This study investigates the association between OA and depression through a bibliometric analysis of published studies. It aims to identify leading authors, institutions, and countries to highlight research hotspots and suggest potential future directions. We collected publications on OA and depression from 1994 to 2024 using the Web of Science Core Collection (WOSCC) database. Bibliographic information, including authorship, country of origin, citation frequency, and visualizations, was generated using VOSviewer, R software, and CiteSpace. A total of 2,342 articles were identified. The United States led in publications with 906 articles, Boston University was the most prolific institution with 56 publications, BMC Musculoskeletal Disorders was the top journal with 71 publications, and Stefania Maggi was the most productive author with 19 publications. The primary research hotspots identified were: "The relationship between depression and OA," "Disability and prevalence," and "Characteristics of older people suffering depression after OA." Predicted future research frontiers include: "Treating depression in OA patients with multimorbidity," "Psychometric properties of instruments for assessing depression and anxiety in OA patients," "Depression or anxiety in patients with surgical intervention," and "Other mental diseases in OA patients." This bibliometric analysis underscores the importance of understanding the link between OA and depressive disorders, potentially guiding new research directions.

MuscleMap: An Open-Source, Community-Supported Consortium for Whole-Body Quantitative MRI of Muscle

Disorders affecting the neurological and musculoskeletal systems represent international health priorities. A significant impediment to progress in trials of new therapies is the absence of responsive, objective, and valid outcome measures sensitive to early disease changes. A key finding in individuals with neuromuscular and musculoskeletal disorders is the compositional changes to muscles, evinced by the expression of fatty infiltrates. Quantification of skeletal muscle composition by MRI has emerged as a sensitive marker for the severity of these disorders; however, little is known about the composition of healthy muscles across the lifespan. Knowledge of what is 'typical' age-related muscle composition is essential to accurately identify and evaluate what is 'atypical'. This innovative project, known as the MuscleMap, will achieve the first important steps towards establishing a world-first, normative reference MRI dataset of skeletal muscle composition with the potential to provide valuable insights into various diseases and disorders, ultimately improving patient care and advancing research in the field.

Metabolic reprogramming in skeletal cell differentiation

The human skeleton is a multifunctional organ made up of multiple cell types working in concert to maintain bone and mineral homeostasis and to perform critical mechanical and endocrine functions. From the beginning steps of chondrogenesis that prefigures most of the skeleton, to the rapid bone accrual during skeletal growth, followed by bone remodeling of the mature skeleton, cell differentiation is integral to skeletal health. While growth factors and nuclear proteins that influence skeletal cell differentiation have been extensively studied, the role of cellular metabolism is just beginning to be uncovered. Besides energy production, metabolic pathways have been shown to exert epigenetic regulation via key metabolites to influence cell fate in both cancerous and normal tissues. In this review, we will assess the role of growth factors and transcription factors in reprogramming cellular metabolism to meet the energetic and biosynthetic needs of chondrocytes, osteoblasts, or osteoclasts. We will also summarize the emerging evidence linking metabolic changes to epigenetic modifications during skeletal cell differentiation.

The future of in-field sports biomechanics: wearables plus modelling compute real-time in vivo tissue loading to prevent and repair musculoskeletal injuries

This paper explores the use of biomechanics in identifying the mechanistic causes of musculoskeletal tissue injury and degeneration. It appraises how biomechanics has been used to develop training programmes aiming to maintain or recover tissue health. Tissue health depends on the functional mechanical environment experienced by tissues during daily and rehabilitation activities. These environments are the result of the interactions between tissue motion, loading, biology, and morphology. Maintaining health of and/or repairing musculoskeletal tissues requires targeting the "ideal" in vivo tissue mechanics (i.e., loading and deformation), which may be enabled by appropriate real-time biofeedback. Recent research shows that biofeedback technologies may increase their quality and effectiveness by integrating a personalised neuromusculoskeletal modelling driven by real-time motion capture and medical imaging. Model personalisation is crucial in obtaining physically and physiologically valid predictions of tissue biomechanics. Model real-time execution is crucial and achieved by code optimisation and artificial intelligence methods. Furthermore, recent work has also shown that laboratory-based motion capture biomechanical measurements and modelling can be performed outside the laboratory with wearable sensors and artificial intelligence. The next stage is to combine these technologies into well-designed easy to use products to guide training to maintain or recover tissue health in the real-world.

Exploring the Causal Relationship between Ibuprofen Use and Osteoarthritis Risk: A Mendelian Randomization Study

This study explored the potential causal relationship between ibuprofen (IBU) use and the risk of developing osteoarthritis, a prevalent joint disorder characterized by pain and stiffness. We conducted a two-sample MR analysis using four distinct OA GWAS datasets as outcomes and single-nucleotide polymorphisms (SNPs) associated with IBU metabolism as exposures. The inverse variance weighted (IVW) and weighted median methods were utilized to assess the causal association by meta-analysis, while pleiotropy and heterogeneity were evaluated using MR-Egger regression and Cochran's Q statistics. The MR analysis provided strong evidence for a causal association between IBU use and an increased risk of OA. A meta-analysis of the IVW and weighted median results across all datasets demonstrated an OR = 1.116 (95% CI = 1.063-1.170) and an OR = 1.110 (95% CI = 1.041-1.184). The consistency of the results obtained from different methods enhanced the reliability of the findings. Low pleiotropy and minimal heterogeneity were observed, further validating the results. The study supports a causal link between IBU use and an increased risk of OA, suggesting that IBU may accelerate the progression of OA while relieving symptoms. These findings highlight the importance of cautious use of IBU in clinical practice, especially considering its potential impact on long-term joint health.

Effects of transcranial direct current stimulation on pain and physical function in patients with knee osteoarthritis: a systematic review and meta-analysis

BACKGROUND

Keen Osteoarthritis (KOA) is a common chronic disabling disease characterized by joint pain and dysfunction, which seriously affects patients' quality of life. Recent studies have shown that transcranial direct current stimulation (tDCS) was a promising treatment for KOA.

PURPOSE

Investigate the effects of tDCS on pain and physical function in patients with KOA.

METHODS

Randomized controlled trials related to tDCS and KOA were systematically searched in the PubMed, Embase, Medline, Cochrane Library, CINHL, and Web of Science databases from inception to July 23, 2024. The pain intensity was evaluated using the visual analog scale or the numeric rating scale, and the pain sensitivity was assessed using conditioned pain modulation, pressure pain threshold, heat pain threshold, or heat pain tolerance. The physical function outcome was evaluated using the Western Ontario and McMaster Universities Osteoarthritis Index or the Knee injury and Osteoarthritis Outcome Score. Statistical analysis was performed using Review Manager 5.4.

RESULTS

Seven studies with a total of 503 participants were included. Compared to sham tDCS, tDCS was effective in reducing the short-term pain intensity (SMD: -0.58; 95% CI: -1.02, -0.14; p = 0.01) and pain sensitivity (SMD: -0.43; 95% CI: -0.70, -0.16; p = 0.002) but failed to significantly improve the long-term pain intensity (SMD: -0.26; 95% CI: -0.59, 0.08; p = 0.13) in KOA patients. In addition, tDCS did not significantly improve the short-term (SMD: -0.13; 95% CI: -0.35, 0.08; p = 0.22) and long-term (SMD: 0.02; 95% CI: -0.22, 0.25; p = 0.90) physical function in patients with KOA.

CONCLUSIONS

The tDCS can reduce short-term pain intensity and sensitivity but fails to significantly relieve long-term pain intensity and improve the physical function in patients with KOA. Thus, tDCS may be a potential therapeutic tool to reduce short-term pain intensity and pain sensitivity in patients with KOA.