Burden of Knee Osteoarthritis in 204 Countries and Territories, 1990-2019: Results From the Global Burden of Disease Study 2019

The First Use of the Washington Group Short Set in a National Survey of Japan: Characteristics of the New Disability Measure in Comparison to an Existing Disability Measure

A Japanese national representative survey-the comprehensive survey of living conditions (CSLC)-included the Washington Group Short Set (WGSS) in 2022. This study aimed to characterize the WGSS in comparison to an existing disability measure (EDM), regarding the difference between disability prevalence defined by these two measures and the factors attributable to disagreements between them. A cross-sectional analysis using secondary data from the CSLC (n = 32,212) was conducted. The disability prevalences and their ratios (WGSS to EDM) were computed overall and by demographic sub-groups. Binomial logistic regression analyses were performed to explore factors relating to disagreements that functioned to relatively lower/increase the prevalence defined by the WGSS. Consequently, the prevalences defined by the WGSS and EDM were 10.7% (95% confidence interval (CI): 10.4-11.1) and 13.1% (95%CI: 12.7-13.5), respectively. The ratios by the sub-groups were around 0.80-0.90, with the exception of the age-defined sub-group, whose ratios were 0.63 (older sub-group) to 1.23 (child sub-group). Age was the only independent factor associated with two types of disagreements: older age (odds ratios: 1.23-1.80) was associated with disagreement functioning to relatively lower the prevalence defined by the WGSS, and similarly, younger age (ORs: 1.42-2.79) increased the figure. The WGSS may be characterized as being less susceptible to the influence of aging compared to the EDM.

Physiotherapists' Experiences and Perceived Acceptability of Delivering a Knee Bracing Intervention for People With Symptomatic Knee Osteoarthritis in a Randomised Trial (PROP OA): A Qualitative Study

OBJECTIVES

To explore physiotherapists' experiences and perceived acceptability of delivering a bracing intervention for knee osteoarthritis (OA) in the 'PROvision of braces for Patients with knee OA' (PROP OA) randomised controlled trial.

METHOD

Semi-structured telephone interviews with consenting physiotherapists who received the PROP OA training programme and delivered the knee bracing intervention (advice, information and exercise instruction plus knee brace matched to patients' clinical and radiographic presentation and with adherence support). Interviews were recorded and transcribed verbatim. Two-stage analytic framework: inductive thematic analysis preceded mapping to constructs of the Theoretical Framework of Acceptability.

RESULTS

Eight physiotherapists were interviewed and six key themes were developed. Perceptions of the training programme were generally positive, but additional formal training and experiential learning consolidated confidence and skills in novel intervention components. Advice, information, and exercise instruction reflected usual physiotherapy care for knee OA. Physiotherapists were confident in delivering the knee brace, but determining the pattern of knee OA to inform brace type selection was challenging. Physiotherapists valued brace adherence enhancing strategies and the follow-up appointment to facilitate adherence. Perceived impact of the bracing intervention for people with OA was positive. The bracing intervention was perceived as acceptable, although improving self-efficacy to deliver novel intervention components (e.g., reading x-rays) would enhance acceptability.

CONCLUSION

The complex knee bracing intervention was broadly perceived as acceptable by physiotherapists. If implemented within clinical practice beyond the trial, physiotherapists might benefit from not only initial training in brace selection but also ongoing support and mentoring to increase self-efficacy in delivery.

Osteoarthritis year in review 2024: Epidemiology and therapy

This "Year in Review" presents a curated selection of research themes and individual studies within the clinical osteoarthritis (OA) field, focusing on epidemiology and therapy. The search was conducted in electronic database MEDLINE from March 4, 2023, to March 31, 2024, specifically targeting English-language articles involving human participants. Inclusions were based on perceived importance and relevance to identifying risk factors or advancing OA treatments. A total of 6539 studies were screened by the 5 authors, resulting in 157 studies considered for potential inclusion. Ultimately, 44 studies were selected, uncovering six key OA-related themes: i) the burden of OA (mostly from Global Burden of Disease studies), ii) pain drivers and trajectories, iii) impacts of sex/gender, iv) OA risk factors, and treatments for v) hand and vi) knee OA. The prevalence of OA continues to rise, particularly affecting women, with unclear distinctions in risk factors and treatment responses between sexes. Associations with atopy were demonstrated in two significant databases. Notably, the authors were particularly interested in recent high-quality methodology randomized controlled trials focusing on hand (methotrexate, denosumab, colchicine, topical betamethasone) and knee OA with conflicting results about stem cell injection. These findings collectively contribute to show the growing burden of OA, but also to help the understanding of OA pathophysiology and inform ongoing efforts to enhance management for people with OA.

Knee braces for knee osteoarthritis: A scoping review and narrative synthesis of interventions in randomised controlled trials

OBJECTIVE

To identify and synthesise the content of knee bracing interventions in randomised controlled trials (RCTs) of knee osteoarthritis (OA).

DESIGN

In this scoping review, three electronic databases (PubMed, Web of Science, Cochrane) were searched up to 10th June 2024. Nineteen previous systematic reviews of knee bracing for knee OA and four recent international clinical practice guidelines were also hand searched. Identified studies were screened for eligibility by two independent reviewers. Information on bracing interventions was extracted from included RCT reports, informed by Template for Intervention Description and Replication (TIDieR) guidelines. Data were synthesised narratively.

RESULTS

Thirty-one RCTs testing 47 different bracing interventions were included. Braces were broadly grouped as valgus/varus, patellofemoral, sleeve, neutral hinged, or control/placebo knee braces. Brace manufacturer and models varied, as did amount of recommended brace use. Only three interventions specifically targeted brace adherence. Information on brace providers, setting, number of treatment sessions, and intervention modification over time was poorly reported. Adherence to brace use was described for 32 (68%) interventions, most commonly via self-report. Several mechanisms of action for knee braces were proposed, broadly grouped as biomechanical, neuromuscular, and psychological.

CONCLUSIONS

Many different knee brace interventions have been tested for knee OA, with several proposed mechanisms of action, a lack of focus on adherence, and a lack of full reporting. These issues may be contributing to the heterogeneous findings and inconsistent guideline recommendations about the clinical effectiveness of knee bracing for knee OA to date.

Comparative Analysis of Osteoarthritis Therapeutics: A Justification for Harnessing Retrospective Strategies via an Inverted Pyramid Model Approach

In this review, we seek to explore two distinct approaches to the clinical management of OA: a prospective approach, addressing primarily one's genetic predisposition to OA and generating early intervention options, and the retrospective approach, aimed at halting or reversing OA progression post-symptom onset. The clinical management of OA remains challenging, largely due to the limited availability of preventative treatments and failure of existing therapies to modify or reverse the underlying pathophysiology. The prospective approach involves the identification of genetic markers associated with OA and utilizes in vitro and in vivo models to characterize the underlying disease mechanism. Further, this approach focuses on identifying genetic predispositions and unique molecular subtypes of OA to develop individualized treatment plans based on patient genotypes. While the current literature investigating this strategy has been notable, this approach faces substantial challenges, such as extensive time burdens and utilization of extensive genetic testing that may not be economically feasible. Additionally, there is questionable justification for such extensive investigations, given OA's relatively low mortality rates and burden when contrasted with diseases like specific forms of cancer, which rely heavily on the prospective approach. Alternatively, the retrospective approach primarily focuses on intervention following symptom onset and aims to utilize novel therapeutics to slow or reverse the inflammatory cascade typically seen in disease progression. These treatments, like Hippo pathway inhibitors, have shown initial promise in halting OA progression and alleviating OA symptomology by modulating cellular processes to preserve articular cartilage. In comparison to the prospective approach, the retrospective strategy is likely more cost-effective, more widely applicable, and does not necessitate thorough and invasive genetic screening. However, this approach must still be weighed against the typical natural history of disease progression, which frequently results in total knee arthroplasty and unacceptable outcomes for 15-20% of patients. From a comparative analysis of these two approaches, this review argues that the retrospective strategy, with ideally lower time and economic burden and greater accessibility, offers a more reasonable and effective solution in the context of OA management. Using a similar approach to other management of chronic diseases, we suggest an "Inverted Pyramid" model algorithm, a structured research and development regimen that prioritizes generating widely effective therapies first, with subsequent refinement of treatments based on the development of patient resistance to these therapies. We argue that this strategy may reduce the need for total knee arthroplasty while improving patient outcomes and accessibility.

Beyond Boundaries of a Trial: Post-Market Clinical Follow-Up of SOYA Patients

Background/Objectives: osteoarthritis (OA) is a leading cause of disability. With an aging population and rising obesity rates, OA presents a growing challenge to health systems worldwide. Current OA treatments involve a mix of pharmacological and nonpharmacological interventions. Viscosupplementation with hyaluronic acid (HA) has proven effective, especially in knee OA, leading to its recommendation in international guidelines. This study investigates the sustained benefits of a single intra-articular HA injection beyond one year in patients coming from the SOYA trial, considering the EU MDR 2017/745 emphasis on post-market follow-up. Methods: A prospective, observational, open, post-marketing study in a cohort of patients that participated in the SOYA trial. Follow-up was carried out by means of a telephone survey, and the data were anonymized and coded so that patients could not be identified. The study was approved by the Alcorcón Hospital Institutional Review Board (Alcorcón, Madrid, Spain). Results: In the follow-up of the SOYA trial, 81.5% of patients sustained positive effects for over 6 months after the trial ended. This correlated with improved daily functioning, enhanced mood, and high patient satisfaction. Younger age and milder OA grades were associated with prolonged treatment effects. Notably, 82% of patients with >6 months of improvement did not require additional medication. Conclusions: the results of this study support the safety and performance of Adant® Plus as a treatment for patients with mild and moderate knee OA, with results lasting more than one year. Post-marketing studies are particularly relevant to examine the experience gained with the use of the device in routine clinical practice.

Development of a 12-Week Unsupervised Online Tai Chi Program for People With Hip and Knee Osteoarthritis: Mixed Methods Study

BACKGROUND

Osteoarthritis is a leading contributor to global disability. While evidence supports the effectiveness of Tai Chi in improving symptoms for people with hip/knee osteoarthritis, access to in-person Tai Chi classes may be difficult for many people. An unsupervised online Tai Chi intervention for people with osteoarthritis can help overcome accessibility barriers. The Approach to Human-Centered, Evidence-Driven Adaptive Design (AHEAD) framework provides a practical guide for co-designing such an intervention.

OBJECTIVE

This study aims to develop an unsupervised online Tai Chi program for people with hip/knee osteoarthritis.

METHODS

An iterative process was conducted using the AHEAD framework. Initially, a panel of Tai Chi instructors and people with osteoarthritis was assembled. A literature review was conducted to inform the content of a survey (survey 1), which was completed by the panel and additional Australian Tai Chi instructors to identify Tai Chi movements for potential inclusion. Selection of Tai Chi movements was based on 3 criteria: those that were appropriate (for people with hip/knee osteoarthritis aged 45+ years), safe (to be performed at home unsupervised), and practical (to be delivered online using prerecorded videos). Movements that met these criteria were then ranked in a second survey (survey 2; using conjoint analysis methodology). Survey findings were discussed in a focus group, and the Tai Chi movements for program use were identified. A draft of the online Tai Chi program was developed, and a final survey (survey 3) was conducted with the panel to rate the appropriateness and safety of the proposed program. The final program was developed, and usability testing (think-aloud protocol) was conducted with people with knee osteoarthritis.

RESULTS

The panel consisted of 10 Tai Chi instructors and 3 people with osteoarthritis. The literature review identified Yang Style 24 as a common and effective Tai Chi style used in hip/knee osteoarthritis studies. Surveys 1 (n=35) and 2 (n=27) produced a ranked list of 24 Tai Chi movements for potential inclusion. This list was refined and informed by a focus group, with 10 Tai Chi movements being selected for inclusion (known as the Yang Style 10 form). Survey 3 (n=13) found that 92% (n=12) of the panel members believed that the proposed draft Tai Chi program was appropriate and safe, resulting in its adoption. The final program was produced and hosted on a customized website, "My Joint Tai Chi," which was further refined based on user feedback (n=5). "My Joint Tai Chi" is currently being evaluated in a randomized controlled trial.

CONCLUSIONS

This study demonstrates the use of the AHEAD framework to develop an unsupervised online Tai Chi intervention ("My Joint Tai Chi") for people with hip/knee osteoarthritis. This intervention is now being tested for effectiveness and safety in a randomized controlled trial.

The association between accelerated biological aging and the risk of osteoarthritis: a cross-sectional study

Background

Biological age (BA) offers an effective assessment of true aging state. The progression of Osteoarthritis (OA) is closely associated with an increase in chronological age, the correlation between BA and OA has not been fully elucidated.

Methods

This study analyzed data from the National Health and Nutrition Examination Survey (NHANES) 2005-2018. Thirteen commonly used clinical traits were employed to calculate two measures of BA: the Klemera-Doubal method age (KDM-Age) and phenotypic age (Pheno-Age). The residuals of the regression of these ages based on chronological age were calculated as KDM-Age or Pheno-Age acceleration, respectively. OA was determined through self-reported prior diagnoses. The prevalence of OA across different quartiles of BA was compared using weighted chi-square tests and linear trend tests. The association between BA and OA was assessed using weighted multivariate logistic regression models.

Results

A total of 30,547 participants aged ≥20 years were included in this study, 3,922 (14%) were diagnosed with OA. Participants with OA exhibited higher chronological age, KDM-Age, Pheno-Age, KDM-Age advance, and Pheno-Age advance compared to those without OA (p < 0.001). The prevalence of OA significantly increased with higher quartiles of KDM-Age advance and Pheno-Age advance (P for trend < 0.001). In the fully adjusted model, compared to the lowest quartile (Q1) of KDM-Age advance, the highest quartile (Q4) was associated with a 36.3% increased risk of OA (OR = 1.363; 95% CI = 1.213 to 1.532, p < 0.001). The highest quartile of Pheno-Age advance (Q4) was associated with a 24.3% increased risk of OA compared to Q1 (OR = 1.243; 95% CI = 1.113 to 1.389, p < 0.001). In males and young people, no statistical differences were found in OA risk between the highest and the lowest quartiles of KDM-Age advance (p = 0.151) and Pheno-Age advance (p = 0.057), respectively.

Conclusion

Adults with accelerated biological aging have an increased risk of OA, particularly among females and older adults.

Microfragmented adipose tissue injection reduced pain compared to a saline control among patients with symptomatic knee osteoarthritis during one-year follow-up: a randomized, controlled trial

PURPOSE

To evaluate the effectiveness of microfragmented adipose tissue (MFAT) for pain relief and improved joint functionality in knee OA in a randomized, controlled clinical trial with 1-year follow-up.

METHODS

Seventy-five patients were stratified by baseline pain level, and randomized to one of three treatment groups: MFAT, corticosteroid (CS), or saline control (C) injection. Patients 18 years of age or older, diagnosed with symptomatic knee osteoarthritis, with radiographic evidence of knee osteoarthritis and a visual analog pain scale (VAS) score of 3/10 or greater were included. Patients were excluded if they had any prior intra-articular knee injection, current knee ligamentous instability or an allergy to lidocaine/corticosteroid. The VAS pain scale, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the Knee Injury and Osteoarthritis Outcome score (KOOS) were recorded pre-procedure and at 2 weeks, 6 weeks, 3 and 6 months, and 1 year follow-up.

RESULTS

MFAT demonstrated consistent and statistically significant improvements across all primary outcome measures for joint pain and functionality compared to C. For MFAT, there was a significant improvement over baseline at each follow-up, with median (95% CI) KOOS Pain score changes of 18.1 (11.1, 26.4) at week 2 to 27.8 (19.4, 37.5) at 1 year. For CS, the median KOOS pain score reached a maximum of 22.2 (15.3, 30.6) at week 2, only to level off to 13.9 (-2.8, 29.2), a level not statistically different from baseline, at 1 year. The median changes for C hovered around 6-11 points, with statistically significant improvements over baseline indicating a placebo effect. Similar trends were seen for the WOMAC Pain score and VAS Pain score.

CONCLUSIONS

In this study, MFAT demonstrated a clinically significant improvement in primary outcome scores compared with a saline control group, while the corticosteroid group only showed statistically significant improvement compared to the control group at 2 and 6 weeks. This finding indicates that MFAT may be a viable alternative treatment for patients with knee OA that fall into the orthopaedic treatment gap.

The effect of intra-articular autologous protein solution on knee osteoarthritis symptoms

Aims

Knee osteoarthritis (OA) is characterized by a chronic inflammatory process involving multiple cytokine pathways, leading to articular cartilage degeneration. Intra-articular therapies using pharmaceutical or autologous anti-inflammatory factors offer potential non-surgical treatment options. Autologous protein solution (APS) is one such product that uses the patient's blood to produce a concentrate of cells and anti-inflammatory cytokines. This study evaluated the effect of a specific APS intra-articular injection (nSTRIDE) on patient-reported outcome measures compared to saline in moderate knee OA.

Methods

A parallel, double-blinded, placebo-controlled randomized controlled trial was conducted, where patients with unilateral moderate knee OA (Kellgren-Lawrence grade 2 or 3) received either nSTRIDE or saline (placebo) injection to their symptomatic knee. The primary outcome was the difference in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total score at 12 months post-intervention. Secondary outcomes included WOMAC component scores, Knee injury and Osteoarthritis Outcome Score (KOOS), and visual analogue scale (VAS) scores at all follow-up timepoints (three, six, and 12 months).

Results

A total of 40 patients were analyzed (21 nSTRIDE; 19 saline) in the study. No significant difference was found between nSTRIDE and saline groups for WOMAC total score at 12 months (mean difference -10.4 (95% CI -24.4 to 3.6; p = 0.141). There were no significant differences in WOMAC or KOOS scores across all timepoints. VAS scores favoured the saline group for both rest and worst pain scales at 12 months post-injection (mean difference (worst) 12 months 21.5 (95% CI 6.2 to 36.8; p = 0.008); mean difference (rest) 12 months 17.8 (95% CI 2.2 to 33.4; p = 0.026)). There were no adverse events recorded in either study group.

Conclusion

Our study demonstrates no significant differences between nSTRIDE and saline groups in KOOS and WOMAC scores over time. Notably, APS injection resulted in significantly worse pain symptoms at 12 months compared to saline injection.

Pain Reduction With Oral Methotrexate in Knee Osteoarthritis : A Randomized, Placebo-Controlled Clinical Trial

BACKGROUND

Treatments for osteoarthritis (OA) are limited. Previous small studies suggest that the antirheumatic drug methotrexate may be a potential treatment for OA pain.

OBJECTIVE

To assess symptomatic benefits of methotrexate in knee OA (KOA).

DESIGN

A multicenter, randomized, double-blind, placebo-controlled trial done between 13 June 2014 and 13 October 2017. (ISRCTN77854383; EudraCT: 2013-001689-41).

SETTING

15 secondary care musculoskeletal clinics in the United Kingdom.

PARTICIPANTS

A total of 207 participants with symptomatic, radiographic KOA and knee pain (severity ≥4 out of 10) on most days in the past 3 months with inadequate response to current medication were approached for inclusion.

INTERVENTION

Participants were randomly assigned 1:1 to oral methotrexate once weekly (6-week escalation 10 to 25 mg) or matched placebo over 12 months and continued usual analgesia.

MEASUREMENTS

The primary end point was average knee pain (numerical rating scale [NRS] 0 to 10) at 6 months, with 12-month follow-up to assess longer-term response. Secondary end points included knee stiffness and function outcomes and adverse events (AEs).

RESULTS

A total of 155 participants (64% women; mean age, 60.9 years; 50% Kellgren-Lawrence grade 3 to 4) were randomly assigned to methotrexate (n = 77) or placebo (n = 78). Follow-up was 86% (n = 134; methotrexate: 66, placebo: 68) at 6 months. Mean knee pain decreased from 6.4 (SD, 1.80) at baseline to 5.1 (SD, 2.32) at 6 months in the methotrexate group and from 6.8 (SD, 1.62) to 6.2 (SD, 2.30) in the placebo group. The primary intention-to-treat analysis showed a statistically significant pain reduction of 0.79 NRS points in favor of methotrexate (95% CI, 0.08 to 1.51; P = 0.030). There were also statistically significant treatment group differences in favor of methotrexate at 6 months for Western Ontario and McMaster Universities Osteoarthritis Index stiffness (0.60 points [CI, 0.01 to 1.18]; P = 0.045) and function (5.01 points [CI, 1.29 to 8.74]; P = 0.008). Treatment adherence analysis supported a dose-response effect. Four unrelated serious AEs were reported (methotrexate: 2, placebo: 2).

LIMITATION

Not permitting oral methotrexate to be changed to subcutaneous delivery for intolerance.

CONCLUSION

Oral methotrexate added to usual medications demonstrated statistically significant reduction in KOA pain, stiffness, and function at 6 months.

PRIMARY FUNDING SOURCE

Versus Arthritis.

Effect of biological sex and short-term high-fat diet on cellular proliferation, ribosomal biogenesis, and targeted protein abundance in murine articular cartilage

Objective

To identify factors contributing to sex-differences in OA risk by evaluating the short-term effect of high-fat (HF) diet on sex-specific changes in cartilage cell proliferation, ribosomal biogenesis, and targeted extra-cellular and cellular protein abundance.

Materials and methods

Knee cartilage was harvested to the subchondral bone from 20-week-old female and male C57BL/6J mice fed a low-fat or HF diet for 4 weeks and labeled with deuterium oxide for 1, 3, 5, 7, 15, or 21 days. Deuterium enrichment was quantified in isolated DNA and RNA to measure cell proliferation and ribosomal biogenesis, respectively. Protein concentration was measured using targeted high resolution accurate mass spectrometry.

Results

HF diet increased the maximal deuterium incorporation into DNA from approximately 40 to 50%, albeit at a slower rate. These findings, which were magnified in female versus male mice, indicate a greater number of proliferating cells with longer half-lives under HF diet conditions. HF diet caused distinct sex-dependent effects on deuterium incorporation into RNA, increasing the fraction of ribosomes undergoing biogenesis in male mice and doubling the rate of ribosome biogenesis in female mice. HF diet altered cartilage protein abundance similarly in both sexes, except for matrilin-3, which was more abundant in HF versus LF conditions in female mice only. Overall, HF diet treatment had a stronger effect than sex on cartilage protein abundance, with most changes involving extracellular matrix and matrix-associated proteins.

Conclusions

Short-term HF diet broadly altered cartilage matrix protein abundance, while sex-dependent effects primarily involved differences in cell proliferation and ribosomal biogenesis.

Evaluation and management of knee osteoarthritis

Knee osteoarthritis (KOA) significantly contributes to the global disability burden, with its incidence expected to escalate by 74.9% by 2050. The urgency to comprehend and tackle this condition is critical, necessitating an updated and thorough review of KOA. A systematic review up to February 26, 2024, has elucidated the principal aspects of KOA's pathogenesis, risk factors, clinical manifestations, and contemporary management paradigms. The origins of KOA are intricately linked to mechanical, inflammatory, and metabolic disturbances that impair joint function. Notable risk factors include age, obesity, and previous knee injuries. Diagnosis predominantly relies on clinical assessment, with radiographic evaluation reserved conditionally. The significance of rehabilitation assessments, informed by the International Classification of Functioning, Disability, and Health framework, is highlighted. Treatment strategies are diverse, prioritizing nonpharmacological measures such as patient education, exercise, and weight management, with pharmacological interventions considered adjuncts. Intra-articular injections and surgical options are contemplated for instances where conventional management is inadequate. KOA stands as a predominant disability cause globally, characterized by a complex etiology and profound effects on individuals' quality of life. Early, proactive management focusing on nonpharmacological interventions forms the cornerstone of treatment, aiming to alleviate symptoms and enhance joint function. This comprehensive review underscores the need for early diagnosis, individualized treatment plans, and the integration of rehabilitation assessments to optimize patient outcomes. Further research is needed to refine prevention strategies and improve management outcomes for KOA patients.

Knee Osteoarthritis

Knee osteoarthritis (OA) typically presents with joint pain that is exacerbated by use and alleviated with rest. There is relatively brief, self-limited morning stiffness and absence of constitutional symptoms. Overweight and obesity are the most important modifiable risk factors. Although pharmacologic and nonpharmacologic interventions are generally effective at alleviating pain and improving physical function, they do not fundamentally reverse the pathologic and radiographic process of knee OA. As the severity of disease increases, the magnitude of pain and functional impairment intensifies. Surgical intervention should be pursued to relieve pain and restore functionality only when nonpharmacologic approaches and pharmacologic agents fail to control pain.

Pulsed electromagnetic fields potentiate bone marrow mesenchymal stem cell chondrogenesis by regulating the Wnt/β-catenin signaling pathway

BACKGROUND

Pulsed electromagnetic fields (PEMFs) show promise as a treatment for knee osteoarthritis (KOA) by reducing inflammation and promoting chondrogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs).

PURPOSE

To identify the efficacy window of PEMFs to induce BMSCs chondrogenic differentiation and explore the cellular mechanism under chondrogenesis of BMSCs in regular and inflammatory microenvironments.

METHODS

BMSCs were exposed to PEMFs (75 Hz, 1.6/2/3/3.8 mT) for 7 and 14 days. The histology, proliferation, migration and chondrogenesis of BMSCs were assessed to identify the optimal parameters. Using these optimal parameters, transcriptome analysis was performed to identify target genes and signaling pathways, validated through immunohistochemical assays, western blotting, and qRT-PCR, with or without the presence of IL-1β. The therapeutic effects of PEMFs and the effective cellular signaling pathways were evaluated in vivo.

RESULTS

BMSCs treated with 3 mT PEMFs showed the optimal chondrogenesis on day 7, indicated by increased expression of ACAN, COL2A, and SOX9, and decreased levels of MMP3 and MMP13 at both transcriptional and protein levels. The advantages of 3 mT PEMFs diminished in the 14-day culture groups. Transcriptome analysis identified sFRP3 as a key molecule targeted by PEMF treatment, which competitively inhibited Wnt/β-catenin signaling, regardless of IL-1β presence or duration of exposure. This inhibition of the Wnt/β-catenin pathway was also confirmed in a KOA mouse model following PEMF exposure.

CONCLUSIONS

PEMFs at 75 Hz and 3 mT are optimal in inducing early-stage chondrogenic differentiation of BMSCs. The induction and chondroprotective effects of PEMFs are mediated by sFRP3 and Wnt/β-catenin signaling, irrespective of inflammatory conditions.

Trends and cross-country inequalities in the global burden of osteoarthritis, 1990-2019: A population-based study

OBJECTIVE

To evaluate the trends and cross-country inequalities of global osteoarthritis (OA) burden over the last 30 years, and further predicted its changes to 2035.

METHODS

The estimates and 95 % uncertainty intervals (UIs) for incidence, prevalence, and disability-adjusted life-years (DALYs) of OA were extracted from Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019. We described OA epidemiology at global, regional, and national levels, analyzed 1990-2019 trends in OA burden from overall, local, and multi-dimension scopes, decomposed OA burden according to population size, age structure, and epidemiologic changes, quantified cross-country inequalities in OA burden using standard health equity methods recommended by World Health Organization, and predicted changes of OA burden to 2035.

RESULTS

GBD 2019 estimated 527,811,871 (95 % UIs: 478,667,549 to 584,793,491) prevalent cases, 41,467,542 (95 % UIs: 36,875,471 to 46,438,409) incident cases and 18,948,965 (95 % UIs: 9,571,298 to 37,659,660) DALYs cases of OA worldwide in 2019, with the highest cases in East Asia and highest age-standardized rate (ASR) in high-income North America. The global burden of OA increased overall from 1990 to 2019 with the fastest growth observed in the first decade of the 21st century. Decomposition analysis revealed that OA knee (62.78 %), women (60.47 %), and middle sociodemographic index (SDI) quintile (32.35 %) were responsible for the most significant DALYs, whose changes were primarily driven by population growth and aging. A significant increase in SDI-related inequalities was detected, and the gap in DALYs between the highest SDI country and the lowest SDI country increased from 179.5 [95 % confidence interval (CI): 149.3-209.8] per 100,000 in 1990 to 341.9 (95 % CI: 309.5-374.4) per 100,000 in 2019. Notably, although the ASR of incidence, prevalence, and DALYs of OA was predicted to decrease annually from 2020 to 2035, the case number of these metrics was predicted to keeping increasing, with predicted values of 52,870,737 [95 % credible interval (Crl): 39,330,063 to 66,411,411], 727,532,373 (95 % Crl: 542,765,783 to 912,298,962), and 25,986,983 (95 % Crl: 19,216,928 to 32,757,038) in 2035, respectively.

CONCLUSIONS

As a major public health issue, the global burden of OA showed an overall increasing trend from 1990 to 2019, which was primarily driven by population growth and aging. Countries with high SDI shouldered disproportionately high OA burden, and the SDI-related inequalities across countries exacerbated over time. This study highlighted great challenges in the control and management of OA, including both growing case number and distributive inequalities worldwide, which may be instructive for better making public health policy and reasonably allocating medical source.

Influence of Internal and External Foot Rotation on Peak Knee Adduction Moments and Ankle Moments during Gait in Individuals with Knee Osteoarthritis: A Cross-Sectional Study

The aim of the study was to verify the effects of foot progression angle (FPA) modification during walking on the internal moments of the ankle and knee joints in individuals with knee osteoarthritis (OA). Biomechanical changes such as increased knee adduction moment (KAM) during walking are known to be involved in the development and severity of knee OA. Although various FPA modifications during gait have been applied to reduce peak KAM, few studies have investigated the effects of applying toe-in or toe-out walking modifications for knee OA on peak KAM and three-dimensional (3D) moments of the ankle joint. Kinetic moment variables were acquired from 35 individuals with medial knee compartment OA. A 3D motion analysis system and two force platforms were used to acquire KAM and 3D moments of both ankle joints during gait. Visual3D was used to obtain final moment data for statistical processing. Repeated-measures analysis of variance with Bonferroni adjustment was used to compare kinetic and kinematic values for each FPA walking condition. There was a significant decrease (p < 0.01) in first peak KAM when walking with an internal rotation foot position compared to normal foot position walking. Also, there was a significant decrease (p < 0.01) in second peak KAM when walking with an external rotation foot position compared to normal foot position walking. Compared to a normal foot position, peak ankle inversion moment of the external rotation foot position walking showed a significant decrease (p < 0.05). There were no interactive effects between FPA condition and limb sides for any KAM values (p > 0.05). The results showed no significant increase in the ankle joint moment value during gait for FPA modification conditions. Thus, the clinical implications of this study suggest that modification of the FPA in patients with OA to reduce KAM does not negatively impact the 3D ankle moments.

The burden of knee osteoarthritis worldwide, regionally, and nationally from 1990 to 2019, along with an analysis of cross-national inequalities

OBJECTIVE

To describe the disease burden of knee osteoarthritis (KOA) globally, regionally, and in 204 countries by age, sex, and sociodemographic index (SDI) from 1990 to 2019, and to explore cross-national inequalities across SDI.

METHODS

The Global Burden of Disease (GBD) 2019 database collected data on KOA worldwide from 1990 to 2019, including prevalence, incidence, years lived with disability (YLDs). The average annual percentage change (AAPC) was used to measure temporal trends. In addition, the inequality slope index and the health concentration index were calculated to quantify the unequal distribution of the burden of KOA across 204 countries worldwide.

RESULTS

In 2019, the global age-standardized prevalence rate increased by 7.5% compared with 1990, and the age-standardized incidence rate increased by about 6.2%; The age-standardized YLDs rate increased by about 7.8%. In addition to the Republic of Korea and the United States of America, the disease burden of KOA has increased year by year in other countries around the world. The incidence of KOA was highest at ages 50-59, while the prevalence and rates of YLDs were highest at ages 75-84. The burden of KOA was higher in women than in men. Cross-country inequality suggests that the inequality in the burden of KOA between high SDI and low SDI countries becomes greater, and that countries with high SDI bear a disproportionately high burden.

CONCLUSION

The global KOA burden has risen steadily between 1990 and 2019, and cross-national inequality gaps remain large. Targeted measures must therefore be taken to address this inequality and the increasing global KOA disease burden.

Global burden of osteoarthritis in adults aged 30 to 44 years, 1990 to 2019: results from the Global Burden of Disease Study 2019

BACKGROUND

Osteoarthritis (OA) is a common orthopedic disorder, and its incidence has been increasing among young adults in recent years. The purpose of this study is to investigate the global, regional, and national trends in OA burden and variation among individuals aged 30 to 44 from 1990 to 2019.

METHODS

Data on the incidence, prevalence, and years lived with disability (YLDs) related to OA were sourced from the Global Burden of Disease Study 2019 among individuals aged 30 to 44. These measures were stratified by gender, region, country, and socio-demographic index (SDI). Additionally, we analyzed YLDs attributable to risk factors.

RESULTS

In 2019, there were a total of 32,971,701 cases of OA among individuals aged 30 to 44 years worldwide, with an additional 7,794,008 new incident cases reported. OA of the knee was the primary contributor to both incidence and prevalence rates over the past three decades. From 1990 to 2019, both males and females in countries with high SDI and high-middle SDI showed upward trends in age-standardized incidence, prevalence, and YLDs rates. In 2019, the United States of America had the highest age-standardized incidence, prevalence, and YLDs rates. Elevated body-mass index (BMI) was found to be the most prevalent risk factor for osteoarthritis-related YLDs. Age-standardized YLDs rates were positively associated with SDI.

CONCLUSIONS

OA remains a significant disease burden on individuals aged 30 to 44, with modifiable risk factors such as unhealthy lifestyle and obesity representing key targets for future interventions aimed at reducing the impact of this condition on younger generations.

Exploration beyond osteoarthritis: the association and mechanism of its related comorbidities

Osteoarthritis is the most prevalent age-related degenerative joint disease and a leading cause of pain and disability in aged people. Its etiology is multifaceted, involving factors such as biomechanics, pro-inflammatory mediators, genetics, and metabolism. Beyond its evident impact on joint functionality and the erosion of patients' quality of life, OA exhibits symbiotic relationships with various systemic diseases, giving rise to various complications. This review reveals OA's extensive impact, encompassing osteoporosis, sarcopenia, cardiovascular diseases, diabetes mellitus, neurological disorders, mental health, and even cancer. Shared inflammatory processes, genetic factors, and lifestyle elements link OA to these systemic conditions. Consequently, recognizing these connections and addressing them offers opportunities to enhance patient care and reduce the burden of associated diseases, emphasizing the need for a holistic approach to managing OA and its complications.

Navigating the New EU Medical Devices Regulation: Retrospective Post-Market Follow-Up of Hyaluronic Acid Injections for Knee Osteoarthritis

Purpose

The entry into force of the new Medical Device Regulation (EU) 2017/745 highlights the need for post-market clinical follow-up to ensure the safety and efficacy throughout the life cycle of medical devices. This study evaluates the efficacy and safety of a single intra-articular hyaluronic acid injection in knee osteoarthritis in real-world conditions, over a six-month period, aligning with the summary of safety and clinical performance (SSCP) required by the new regulation.

Patients and Methods

Patients over 18 years of age with knee osteoarthritis, treated with a single injection of HA (Adant® One, Meiji Pharma Spain, Spain) at a 3rd level hospital. Patients were treated and followed between January 1, 2020 and June 30, 2022. Demographic, clinical, and treatment-related data were collected, and efficacy regarding pain relief and/or function improvement was assessed using a Likert-type scale. Data were pseudo-anonymized and the comparison was performed using Fisher' or Mann Whitney' test. The study was approved by the Ethics Review Board of the Hospital Puerta de Hierro (Madrid, Spain).

Results

We followed 20 patients with knee osteoarthritis, with a mean age of 61 years, 80% women, and with a high burden of comorbidities (90%). A total of 60% of patients presented Kellgren-Lawrence grade III-IV. Four patients (20%) returned before 6 months due to lack of efficacy. Of the other patients, 65% showed a clinical response that lasted more than 12 months in 38.5% of cases. Time until medical appointment and taking concomitant medication for knee osteoarthritis were associated with better clinical response (p < 0.05).

Conclusion

The administration of a Adant® One single intra-articular hyaluronic acid injection in knee osteoarthritis is effective, safe, and maintains the improvement over a six-month period. Our findings also emphasize the need of using standardized tools for accurate efficacy assessment and optimal patient care.

Network analysis, in vivo, and in vitro experiments identified the mechanisms by which Piper longum L. [Piperaceae] alleviates cartilage destruction, joint inflammation, and arthritic pain

Osteoarthritis (OA) is characterized by irreversible joint destruction, pain, and dysfunction. Piper longum L. [Piperaceae] (PL) is an East Asian herbal medicine with reported anti-inflammatory, analgesic, antioxidant, anti-stress, and anti-osteoporotic effects. This study aimed to evaluate the efficacy of PL in inhibiting pain and progressive joint destruction in OA based on its anti-inflammatory activity, and to explore its potential mechanisms using in vivo and in vitro models of OA. We predicted the potential hub targets and signaling pathways of PL through network analysis and molecular docking. Network analysis results showed that the possible hub targets of PL against OA were F2R, F3, MMP1, MMP2, MMP9, and PTGS2. The molecular docking results predicted strong binding affinities for the core compounds in PL: piperlongumine, piperlonguminine, and piperine. In vitro experiments showed that PL inhibited the expression of LPS-induced pro-inflammatory factors, such as F2R, F3, IL-1β, IL-6, IL-17A, MMP-1, MMP-2, MMP-3, MMP-9, MMP-13, NOS2, PTGS2, PGE2, and TNF-β. These mechanisms and effects were dose-dependent in vivo models. Furthermore, PL inhibited cartilage degradation in an OA-induced rat model. Thus, this study demonstrated that multiple components of PL may inhibit the multilayered pathology of OA by acting on multiple targets and pathways. These findings highlight the potential of PL as a disease-modifying OA drug candidate, which warrants further investigation.

Finding the Goldilocks Zone of Mechanical Loading: A Comprehensive Review of Mechanical Loading in the Prevention and Treatment of Knee Osteoarthritis

In this review, we discuss the interaction of mechanical factors influencing knee osteoarthritis (KOA) and post-traumatic osteoarthritis (PTOA) pathogenesis. Emphasizing the importance of mechanotransduction within inflammatory responses, we discuss its capacity for being utilized and harnessed within the context of prevention and rehabilitation of osteoarthritis (OA). Additionally, we introduce a discussion on the Goldilocks zone, which describes the necessity of maintaining a balance of adequate, but not excessive mechanical loading to maintain proper knee joint health. Expanding beyond these, we synthesize findings from current literature that explore the biomechanical loading of various rehabilitation exercises, in hopes of aiding future recommendations for physicians managing KOA and PTOA and athletic training staff strategically planning athlete loads to mitigate the risk of joint injury. The integration of these concepts provides a multifactorial analysis of the contributing factors of KOA and PTOA, in order to spur further research and illuminate the potential of utilizing the body's own physiological responses to mechanical stimuli in the management of OA.

Personalized Physical Activity Programs for the Management of Knee Osteoarthritis in Individuals with Obesity: A Patient-Centered Approach

Physical activity (PA) plays a vital role in knee osteoarthritis (KOA) management. However, engaging individuals with KOA in regular exercise is challenging, especially when they are affected by obesity. The aim of the current review is to elucidate how to increase adherence to exercise in this population. When implementing a PA program with patients with KOA and obesity, a specific multi-step approach can be adopted. In phase I (the baseline assessment), the patients' eligibility for exercise is ascertained and a physical fitness assessment, sarcopenic obesity screening and quantification of the pain experienced are undertaken. Phase II adopts a patient-centered approach in implementing a PA program that combines an active lifestyle (>6000 steps/day) with land- or water-based exercise programs performed over eight to twelve weeks, with a frequency of three to five sessions per week, each lasting 60 min. In phase III, several strategies can be used to increase the patients' adherence to higher levels of PA, including the following: (i) personalizing PA goal-setting and real-time monitoring; (ii) enhancing physical fitness and the management of sarcopenic obesity; (iii) building a sustainable environment and a supportive social network for an active lifestyle; and (iv) reducing pain, which can ameliorate the clinical severity of KOA and help with weight management in this population.

Toe-in and toe-out gait retraining interventions to reduce proxy measures of medial knee joint load in people with medial knee osteoarthritis: Protocol for a randomised placebo-controlled trial

OBJECTIVE

Our primary aim is to determine the effect of a six-week toe-in, toe-out and active placebo gait retraining program on proxy measures of medial knee joint load and varus thrust in people with medial knee osteoarthritis. Our secondary aim is to determine the intervention effects on patient reported outcomes and physical function and determine if changes are maintained at three-months follow-up.

METHODS

We will conduct a three-arm randomised placebo-controlled trial. Ninety participants with medial knee osteoarthritis will be randomised and stratified via varus thrust status (presence/absence) to: toe-in, toe-out or placebo gait retraining (an intervention that does not change proxy measures of medial knee joint load). The intervention involves weekly clinician-supervised sessions with biofeedback, knee osteoarthritis education, motor learning and behaviour change principles, and daily gait retraining practice. Primary outcomes are proxy measures of medial knee joint load: knee adduction moment (early- and late-stance peaks and impulse), and varus thrust (presence/absence). Secondary outcomes include pain, physical function, medication and health care utilisation, quality of life, work ability, treatment blinding, intervention credibility and other biomechanical outcomes. Assessment timepoints are at baseline, six weeks (post intensive training), and three-months following the six-week intervention.

CONCLUSION

Our trial will determine whether toe-in or toe-out gait retraining is most effective at reducing proxy measures of medial knee joint load and varus thrust in people with medial knee osteoarthritis. This study will also evaluate if toe-in or toe-out gait retraining interventions are superior at improving pain, physical function and quality of life compared to placebo.

CLINICAL TRIAL REGISTRATION

This clinical trial protocol is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12621000414819).

Clinically-accessible and laboratory-derived predictors of biomechanical response to standalone and supported lateral wedge insoles in people with knee osteoarthritis

BACKGROUND

Lateral wedge insoles (both standalone and those incorporating individualized arch support) have been frequently studied for the effects on knee joint loading and pain in people with knee osteoarthritis. It has been shown that many people who use these insoles do not obtain the intended biomechanical effect, and thus may not experience a clinical benefit. The ability to identify biomechanical responders to lateral wedge insoles before research or clinical intervention is an important objective for efficient resource use and optimizing patient outcomes. The purpose of our exploratory, hypothesis-generating study was to provide an initial assessment of variables that are associated with the biomechanical response to lateral wedge insoles in people with knee osteoarthritis.

METHODS

We collected a number of demographic (age, sex, body mass index, foot posture), clinical (knee pain, foot pain, radiographic disease severity), and walking-related (speed, knee alignment, frontal plane subtalar movement, and foot rotation) outcomes from 53 individuals with painful, radiographically-confirmed knee osteoarthritis. The walking-related outcomes were obtained using equipment both from the research laboratory and the clinical setting. We used logistic regression to generate predictive models to determine candidate variables associated with a reduction in the knee adduction moment during walking - a surrogate for tibiofemoral load distribution, and a known biomechanical risk factor for osteoarthritis progression - with the use of standalone and arch-supported lateral wedge insoles. Three different response thresholds (2%, 6%, and 10% reductions in the knee adduction moment) were used.

RESULTS

In general, biomechanical responders were those who walked faster, were female, had less varus alignment, and had less severe radiographic severity. Findings were similar between the standalone and arch-supported lateral wedge insoles, as well as between models using the laboratory-derived or clinically-available measures of walking performance.

CONCLUSIONS

Our hypothesis-generating study provides valuable information that will inform future research into the efficient and effective use of lateral wedge insoles in the conservative management of knee osteoarthritis.

Charting Aging Trajectories of Knee Cartilage Thickness for Early Osteoarthritis Risk Prediction: An MRI Study from the Osteoarthritis Initiative Cohort

Knee osteoarthritis (OA), a prevalent joint disease in the U.S., poses challenges in terms of predicting of its early progression. Although high-resolution knee magnetic resonance imaging (MRI) facilitates more precise OA diagnosis, the heterogeneous and multifactorial aspects of OA pathology remain significant obstacles for prognosis. MRI-based scoring systems, while standardizing OA assessment, are both time-consuming and labor-intensive. Current AI technologies facilitate knee OA risk scoring and progression prediction, but these often focus on the symptomatic phase of OA, bypassing initial-stage OA prediction. Moreover, their reliance on complex algorithms can hinder clinical interpretation. To this end, we make this effort to construct a computationally efficient, easily-interpretable, and state-of-the-art approach aiding in the radiographic OA (rOA) auto-classification and prediction of the incidence and progression, by contrasting an individual's cartilage thickness with a similar demographic in the rOA-free cohort. To better visualize, we have developed the toolset for both prediction and local visualization. A movie demonstrating different subtypes of dynamic changes in local centile scores during rOA progression is available at https://tli3.github.io/KneeOA/. Specifically, we constructed age-BMI-dependent reference charts for knee OA cartilage thickness, based on MRI scans from 957 radiographic OA (rOA)-free individuals from the Osteoarthritis Initiative cohort. Then we extracted local and global centiles by contrasting an individual's cartilage thickness to the rOA-free cohort with a similar age and BMI. Using traditional boosting approaches with our centile-based features, we obtain rOA classification of KLG ≤ 1 versus KLG = 2 (AUC = 0.95, F1 = 0.89), KLG ≤ 1 versus KLG ≥ 2 (AUC = 0.90, F1 = 0.82) and prediction of KLG2 progression (AUC = 0.98, F1 = 0.94), rOA incidence (KLG increasing from < 2 to ≥ 2; AUC = 0.81, F1 = 0.69) and rOA initial transition (KLG from 0 to 1; AUC = 0.64, F1 = 0.65) within a future 48-month period. Such performance in classifying KLG ≥ 2 matches that of deep learning methods in recent literature. Furthermore, its clinical interpretation suggests that cartilage changes, such as thickening in lateral femoral and anterior femoral regions and thinning in lateral tibial regions, may serve as indicators for prediction of rOA incidence and early progression. Meanwhile, cartilage thickening in the posterior medial and posterior lateral femoral regions, coupled with a reduction in the central medial femoral region, may signify initial phases of rOA transition.

Stem of Sorbus commixta Hedl. Extract Inhibits Cartilage Degradation and Arthritic Pain in Experimental Model via Anti-Inflammatory Activity

Osteoarthritis (OA) is a widespread joint disease that affects millions of people worldwide. Conventional treatments for OA, including non-steroidal anti-inflammatory drugs (NSAIDs) and steroids, have a risk of various adverse events, including liver, gastrointestinal, cardiovascular, and kidney disease, which are unsatisfactory in their effectiveness. In this study, Sorbus commixta Hedl. Stem extracts (SCE) were evaluated in animal models as potential inhibitors for the progression of OA. Sorbus commixta Hedl., which was found to have substantial anti-inflammatory and antioxidant activities in earlier investigations, has shown potential as a candidate for OA treatment. To mimic human OA symptoms, male rats were injected using sodium iodoacetate (MIA) in their knee joints. SCE significantly reduced MIA-induced weight-bearing loss in rats after the MIA injection and alleviated cartilage degradation and subchondral bone injury caused by MIA. In addition, SCE administration reduced levels of TNF-α and IL-1β such as pro-inflammatory cytokines in serum, as well as the levels of matrix metalloproteinases (MMPs) such as MMP-1, -3, -8 and -13 in the joint cartilage. SCE significantly inhibited the writhing responses in acetic acid-administered mice and was used to quantify pain. In lipopolysaccharide (LPS)-activated RAW264.7, SCE suppressed NO production and reduced the expression of TNF-α, PGE2, IL-6, IL-1β, MMP1, MMP3, MMP8, and MMP-13. Our study showed that SCE alleviated inflammation and cartilage degradation in arthritis through its anti-inflammatory activities on multiple targets.