Prevention of knee osteoarthritis in overweight females: the first preventive randomized controlled trial in osteoarthritis

X-ray with finite element analysis is a viable alternative for MRI to predict knee osteoarthritis: Data from the Osteoarthritis Initiative

Magnetic resonance imaging (MRI) offers superior soft tissue contrast compared to clinical X-ray imaging methods, while also providing accurate three-dimensional (3D) geometries, it could be reasoned to be the best imaging modality to create 3D finite element (FE) geometries of the knee joint. However, MRI may not necessarily be superior for making tissue-level FE simulations of internal stress distributions within knee joint, which can be utilized to calculate subject-specific risk for the onset and development of knee osteoarthritis (KOA). Specifically, MRI does not provide any information about tissue stiffness, as the imaging is usually performed with the patient lying on their back. In contrast, native X-rays taken while the patient is standing indirectly reveal information of the overall health of the knee that is not seen in MRI. To determine the feasibility of X-ray workflow to generate FE models based on the baseline information (clinical image data and subject characteristics), we compared MRI and X-ray-based simulations of volumetric cartilage degenerations (N = 1213) against 8-year follow-up data. The results suggest that X-ray-based predictions of KOA are at least as good as MRI-based predictions for subjects with no previous knee injuries. This finding may have important implications for preventive care, as X-ray imaging is much more accessible than MRI.

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.

The osteoarthritis prevention study (TOPS) - A randomized controlled trial of diet and exercise to prevent Knee Osteoarthritis: Design and rationale

Background

Osteoarthritis (OA), the leading cause of disability among adults, has no cure and is associated with significant comorbidities. The premise of this randomized clinical trial is that, in a population at risk, a 48-month program of dietary weight loss and exercise will result in less incident structural knee OA compared to control.

Methods/design

The Osteoarthritis Prevention Study (TOPS) is a Phase III, assessor-blinded, 48-month, parallel 2 arm, multicenter randomized clinical trial designed to reduce the incidence of structural knee OA. The study objective is to assess the effects of a dietary weight loss, exercise, and weight-loss maintenance program in preventing the development of structural knee OA in females at risk for the disease. TOPS will recruit 1230 ambulatory, community dwelling females with obesity (Body Mass Index (BMI) ​≥ ​30 ​kg/m2) and aged ≥50 years with no radiographic (Kellgren-Lawrence grade ≤1) and no magnetic resonance imaging (MRI) evidence of OA in the eligible knee, with no or infrequent knee pain. Incident structural knee OA (defined as tibiofemoral and/or patellofemoral OA on MRI) assessed at 48-months from intervention initiation using the MRI Osteoarthritis Knee Score (MOAKS) is the primary outcome. Secondary outcomes include knee pain, 6-min walk distance, health-related quality of life, knee joint loading during gait, inflammatory biomarkers, and self-efficacy. Cost effectiveness and budgetary impact analyses will determine the value and affordability of this intervention.

Discussion

This study will assess the efficacy and cost effectiveness of a dietary weight loss, exercise, and weight-loss maintenance program designed to reduce incident knee OA.

Trial registration

ClinicalTrials.gov Identifier: NCT05946044.

Impact of Prevention Strategies on Quality of Life in Patients with Osteoarthritis: A Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

To evaluate the impact of prevention strategies on the quality of life in patients with osteoarthritis (OA) through a comprehensive analysis of randomized controlled trials (RCTs).

METHODS

A systematic search was conducted in multiple electronic databases, including Cochrane Library, PubMed, Embase, and ClinicalTrials.gov, up to June 10th, 2023. Eligible studies were RCTs assessing the effectiveness of prevention strategies in adult patients diagnosed with OA, with validated instruments used to measure quality of life outcomes. A total of 10 RCTs met the inclusion criteria and were included in the meta-analysis. The analyzed prevention strategies encompassed enhanced exercise, education, or a combination of both. The quality of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation approach.

RESULTS

The pooled results revealed a significant improvement in the quality of life of OA patients who underwent enhanced exercise or education compared to control groups (standardized mean difference = 0.44, 95% confidence interval 0.08-0.8). However, the overall quality of evidence was graded as low according to the Grading of Recommendations Assessment, Development and Evaluation assessment.

CONCLUSIONS

This meta-analysis provides evidence that prevention strategies, particularly enhanced exercise or education, have a positive impact on the quality of life in patients with OA. Despite the observed benefits, the overall quality of evidence is limited, highlighting the need for larger, well-designed trials to strengthen the evidence base. These findings underscore the importance of implementing effective prevention strategies in the management of OA to improve patient outcomes and enhance their quality of life. Further research is warranted to optimize the selection and implementation of prevention strategies for OA patients.

Factors associated with meniscus volume in knees free of degenerative features

OBJECTIVES

To explore factors that were associated with meniscus volume in knees free of radiographic osteoarthritis (OA) features and symptoms of OA.

METHODS

In the third Rotterdam Study cohort, clinical, radiographic, and magnetic resonance data were obtained at baseline (BL) and after 5 years of follow-up. Meniscus volumes and their change over time were calculated after semi-automatic segmentation on Magnetic Resonance Imaging. Knees with radiographic OA features (Kellgren and Lawrence>0) or clinical diagnosis of OA (American College of Rheumatology) at BL were excluded. Ten OA risk factors were adjusted in the multivariable analysis (generalized estimating equations), treating two knees within subjects as repeated measurements.

RESULTS

From 1065 knees (570 subjects), the average (standard deviation) age and Body mass index (BMI) of included subjects were 54.3 (3.7) years and 26.5 (4.4) kg/m2. At BL, nine factors (varus alignment, higher BMI, meniscus pathologies, meniscus extrusion, cartilage lesions, injury, greater physical activity level, quadriceps muscle strength, and higher age) were significantly associated with greater meniscus volume. Five factors (injury, meniscus pathologies, meniscus extrusion, higher age, and change of BMI) were significantly associated with meniscus volume loss.

CONCLUSIONS

Modifiable factors (varus alignment, BMI, physical activity level, and quadriceps muscle strength) and non-modifiable factors (higher age, injury, meniscus pathologies, meniscus extrusion, and cartilage lesions) were all associated with meniscus volume or meniscus volume loss over time.

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

OBJECTIVE

To report the global, regional, and national estimates of knee osteoarthritis (OA) burden and associated risk factors (high body mass index [BMI]) by age, sex, and sociodemographic index (SDI) for 204 countries from 1990 to 2019.

METHODS

We analyzed the prevalence, incidence, years lived with disability (YLDs), and age-standardized rates of knee OA using data from the Global Burden of Diseases, Injuries, and Risk Factors Study 2019. Estimates of the knee OA burden were derived from data modeled using a Bayesian meta-regression analytical tool (DisMod-MR 2.1).

RESULTS

The global prevalence of knee OA in 2019 was ~364.6 million (95% uncertainty interval [95% UI] 315.3 to 417.4). The age-standardized prevalence in 2019 was 4,376.0 per 100,000 (95% UI 3,793.0 to 5,004.9), an increase of 7.5% between 1990 and 2019. There were ~29.5 million incident cases of knee OA in 2019 (95% UI 25.6 to 33.7), with an age-standardized incidence of 350.3 per 100,000 (95% UI 303.4 to 398.9). The global age-standardized YLD resulting from knee OA was 138.2 (95% UI 68.5 to 281.3) per 100,000 population in 2019, an increase of 7.8% (95% UI 7.1 to 8.4) from 1990. Globally in 2019, 22.4% (95% UI 12.1 to 34.2) of YLD resulting from knee OA was attributable to high BMI, an increase of 40.5% since 1990.

CONCLUSION

The prevalence, incidence, YLDs, and age-standardized rates of knee OA increased substantially in most countries and regions from 1990 to 2019. Continuous monitoring of this burden is important for establishing appropriate public prevention policies and raising public awareness, especially in high- and high-middle SDI regions.

Machine Learning Approaches to the Prediction of Osteoarthritis Phenotypes and Outcomes

PURPOSE OF REVIEW

Osteoarthritis (OA) is a complex heterogeneous disease with no effective treatments. Artificial intelligence (AI) and its subfield machine learning (ML) can be applied to data from different sources to (1) assist clinicians and patients in decision making, based on machine-learned evidence, and (2) improve our understanding of pathophysiology and mechanisms underlying OA, providing new insights into disease management and prevention. The purpose of this review is to improve the ability of clinicians and OA researchers to understand the strengths and limitations of AI/ML methods in applications to OA research.

RECENT FINDINGS

AI/ML can assist clinicians by prediction of OA incidence and progression and by providing tailored personalized treatment. These methods allow using multidimensional multi-source data to understand the nature of OA, to identify different OA phenotypes, and for biomarker discovery. We described the recent implementations of AI/ML in OA research and highlighted potential future directions and associated challenges.

Association between baseline meniscal extrusion and long-term incident knee osteoarthritis in two different cohorts

OBJECTIVE

Previously, we identified a significant association between meniscal extrusion and short-term incident knee osteoarthritis (KOA). To validate these findings, we evaluated long-term incident KOA in knees with meniscus extrusion, using two different cohorts.

METHODS

We used data from the PROOF study, which evaluated a high-risk population of overweight women, and a female subcohort of the population-based Rotterdam Study (RS). Meniscal extrusion was defined as ≥ 3 mm on MRI. Outcomes were incident radiographic (KL ≥ 2) or clinical KOA according to the ACR criteria, assessed at 6.6 years (PROOF) and 5.1 years (RS). With generalized estimating equations, we determined the association of knees with and without baseline meniscal extrusion and incident KOA, adjusting for confounders. Furthermore, we computed the population attributable risk percentage (PAR%) of meniscal extrusion.

RESULTS

PROOF: of 421 available knees 23% had baseline meniscal extrusion. Incident radiographic KOA was significantly higher in knees with meniscal extrusion compared to those without (adjusted OR 2.54, 95% CI 1.34, 4.80; p = 0.004; PAR 21%). Incident clinical KOA was also significantly higher (adjusted OR 2.44, 95% CI 1.29, 4.60; p = 0.006; PAR 19%). RS: 46% of 872 available knees had meniscal extrusion. Incident radiographic KOA was significantly higher (adjusted OR 9.86, 95% CI 2.13, 45.67; p = 0.002; PAR 77%). Incident clinical KOA was borderline significantly higher (adjusted OR 2.65, 95% CI 0.96, 7.30; p = 0.06; PAR 44%).

CONCLUSION

Meniscal extrusion is significantly associated with long-term incident KOA. A high number of incident cases were attributable to extrusion.

Intra-articular Injection of Autologous Adipose-Derived Stem Cells or Stromal Vascular Fractions: Are They Effective for Patients With Knee Osteoarthritis? A Systematic Review With Meta-analysis of Randomized Controlled Trials

BACKGROUND

Intra-articular injection of adipose-derived stem cells, which are divided into adipose-derived mesenchymal stem cells (ASCs) and adipose-derived stromal vascular fractions (ADSVFs), has been reported to be a viable treatment modality for knee osteoarthritis (OA); however, its efficacy remains limited.

PURPOSE

This study aimed to provide comprehensive information about the efficacy and safety of intra-articular injections of autologous ASCs and ADSVFs without adjuvant treatment in patients with knee OA.

STUDY DESIGN

Meta-analysis; Level of evidence, 1.

METHODS

A systematic search of the MEDLINE, Embase, Web of Science, and Cochrane Library databases was performed to identify randomized controlled trials (RCTs) that evaluated the efficacy and safety of intra-articular injections of autologous ASCs or ADSVFs without adjuvant treatments compared with placebo or hyaluronic acid in patients with knee OA. Clinically, the 100-mm visual analog scale for pain relief and the Western Ontario and McMaster Universities Osteoarthritis Index for functional improvement were implemented. Radiologically, cartilage status was assessed using magnetic resonance imaging (MRI). Procedure-related knee pain, swelling, and adverse events (AEs) were evaluated for safety. Additionally, we performed subgroup analyses comparing ASCs versus ADSVFs. Methodological quality was assessed using the modified Coleman Methodology Score (mCMS).

RESULTS

A total of 5 RCTs were included in this study. Based on the meta-analysis, ASCs or ADSVFs showed significantly better pain relief at 6 months (Z = 7.62; P < .0001) and 12 months (Z = 7.21; P < .0001) and functional improvement at 6 months (Z = 4.13; P < .0001) and 12 months (Z = 3.79; P = .0002), without a difference in procedure-related knee pain or swelling compared with controls. Although a meta-analysis with regard to cartilage improvements was not performed owing to heterogeneous MRI assessment, 3 studies reported significantly improved cartilage status after the injection. No serious AEs associated with ASCs or ADSVFs were reported. Subgroup analyses showed similar efficacy between ASC and ADSVF treatments. The median mCMS was 70 (range, 55-75).

CONCLUSION

For patients with knee OA, intra-articular injection of autologous ASCs or ADSVFs without adjuvant treatment showed remarkable clinical efficacy and safety at short-term follow-up. Some degree of efficacy has been shown for cartilage regeneration in knee OA, although the evidence remains limited. Further RCTs that directly compare ASCs and ADSVFs are needed.

Potential surrogate outcomes in individuals at high risk for incident knee osteoarthritis

OBJECTIVE

To study potential surrogate outcomes for osteoarthritis (OA) incidence by evaluating the association of short-term changes in clinical and imaging biomarkers with long-term clinical knee OA incidence.

DESIGN

Middle-aged women with overweight/obesity, but free of knee symptoms were recruited through their general practitioners. At baseline, after 2.5 years, and after 6.5 years, questionnaires, physical examination, radiographs, and Magnetic resonance imaging (MRI) scans were obtained. The percentage of knees with a minimal clinically important difference for knee pain severity, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain/stiffness/function, and joint space narrowing, and of those with progression/regression of medial knee alignment, chronic knee pain, radiographic osteophytes, and cartilage defects, bone marrow lesions, osteophytes, and effusion/synovitis on MRI were determined. For each of these potential surrogate outcomes with ≥10% improvement or progression in the population over 2.5 years, the association with incident clinical knee OA, defined using the combined ACR-criteria, after 6.5 years was determined.

RESULTS

Most pre-defined potential surrogate outcomes showed ≥10% change in the population over 2.5 years, but only worsening of TF cartilage defects, worsening of TF osteophytes on MRI, and an increase in pain severity were significantly associated with greater clinical knee OA incidence after 6.5 years. These potential surrogate outcomes had high specificity and negative predictive value (89-91%) and low sensitivity and positive predictive value (20-28%) CONCLUSIONS: Worsening of TF cartilage defects and TF osteophytes on MRI, and increased pain severity could be seen as surrogate outcomes for long-term OA incidence. However, higher positive predictive values seem warranted for the applicability of these factors in future preventive trials.

Development of Osteoarthritis in Adults With Type 2 Diabetes Treated With Metformin vs a Sulfonylurea

IMPORTANCE

Metformin may have a protective association against developing osteoarthritis (OA), but robust epidemiological data are lacking.

OBJECTIVE

To determine the risk of OA and joint replacement in individuals with type 2 diabetes treated with metformin compared with a sulfonylurea.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study used claims data from the Optum deidentified Clinformatics Data Mart Database between December 2003 and December 2019. Participants included individuals aged 40 years or older with at least 1 year of continuous enrollment and type 2 diabetes. Individuals with type 1 diabetes or a prior diagnosis of OA, inflammatory arthritis, or joint replacement were excluded. Time-conditional propensity score matching was conducted using age, sex, race, Charlson comorbidity score, and treatment duration to create a prevalent new-user cohort. Data were analyzed from April to December 2021.

EXPOSURES

Treatment with metformin or a sulfonylurea.

MAIN OUTCOMES AND MEASURES

The outcomes of interest were incident OA and joint replacement. Cox proportional hazard models were used to calculate adjusted hazard ratios (aHRs) of incident OA and joint replacement. In a sensitivity analysis, individuals only ever treated with metformin were compared with individuals only ever treated with a sulfonylurea, allowing for longer-term follow up of the outcome (even after stopping the medication of interest).

RESULTS

After time-conditional propensity score matching, the metformin and control groups each included 20 937 individuals (mean [SD] age 62.0 [11.5] years; 24 379 [58.2%] males). In the adjusted analysis, the risk of developing OA was reduced by 24% for individuals treated with metformin compared with a sulfonylurea (aHR, 0.76; 95% CI, 0.68-0.85; P < .001), but there was no significant difference for risk of joint replacement (aHR, 0.80; 95% CI, 0.50-1.27; P = .34). In the sensitivity analysis, the risk of developing OA remained lower in individuals treated with metformin compared with a sulfonylurea (aHR, 0.77; 95% CI, 0.65-0.90; P < .001) and the risk of joint replacement remained not statistically significant (aHR, 1.04; 95% CI, 0.60-1.82; P = .89).

CONCLUSIONS AND RELEVANCE

In this cohort study of individuals with diabetes, metformin treatment was associated with a significant reduction in the risk of developing OA compared with sulfonylurea treatment. These results further support preclinical and observational data that suggest metformin may have a protective association against the development of OA; future interventional studies with metformin for the treatment or prevention of OA should be considered.

Dry needling on latent and active myofascial trigger points versus oral diclofenac in patients with knee osteoarthritis: a randomized controlled trial

BACKGROUND

Latent and active myofascial trigger points (MTrPs) in knee-associated muscles may play a key role in pain management among patients with knee osteoarthritis (KOA). The aim of this study was to investigate the effect of dry needling treatment on pain intensity, disability, and range of motion (ROM) in patients with KOA.

METHODS

This randomized, single-blinded, clinical trial was carried out for 6 weeks of treatment and 6-month follow-up. A total of 98 patients met the entry criteria and were randomly assigned to the dry needling latent and active myofascial trigger point (MTrPs) with the stretching group or the oral diclofenacwith the stretching group. Numeric Pain Rating Scale (NPRS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and ROM were statistically analyzed before and after treatment and at the 6-month follow-up.

RESULTS

A total of 42 patients in the dry needling group (DNG) and 35 patients in the diclofenac group (DG), respectively, completed the study, and there was no significant difference in the general data between the two groups. After treatments, both the groups showed a good effect in knee pain, function, and ROM, However, the DNG showed a significantly better result than the DG. Especially in the results of the 6-month follow-up, the DNG showed much better results than the DG.

CONCLUSIONS

Dry needling on latent and active MTrPs combined with stretching and oral diclofenac combined with stretching can effectively relieve pain, improve function, and restore knee ROM affected by KOA. However, the effects of dry needling and stretching are better and longer lasting than those of oral diclofenac and stretching for at least 6 months.

TRIAL REGISTRATION

Registered in the Chinese Clinical Trial Registry ( www.chictr.org.cn ) in 17/11/2017 with the following code: ChiCTR-INR-17013432.

The KNee OsteoArthritis Prediction (KNOAP2020) challenge: An image analysis challenge to predict incident symptomatic radiographic knee osteoarthritis from MRI and X-ray images

OBJECTIVES

The KNee OsteoArthritis Prediction (KNOAP2020) challenge was organized to objectively compare methods for the prediction of incident symptomatic radiographic knee osteoarthritis within 78 months on a test set with blinded ground truth.

DESIGN

The challenge participants were free to use any available data sources to train their models. A test set of 423 knees from the Prevention of Knee Osteoarthritis in Overweight Females (PROOF) study consisting of magnetic resonance imaging (MRI) and X-ray image data along with clinical risk factors at baseline was made available to all challenge participants. The ground truth outcomes, i.e., which knees developed incident symptomatic radiographic knee osteoarthritis (according to the combined ACR criteria) within 78 months, were not provided to the participants. To assess the performance of the submitted models, we used the area under the receiver operating characteristic curve (ROCAUC) and balanced accuracy (BACC).

RESULTS

Seven teams submitted 23 entries in total. A majority of the algorithms were trained on data from the Osteoarthritis Initiative. The model with the highest ROCAUC (0.64 (95% confidence interval (CI): 0.57-0.70)) used deep learning to extract information from X-ray images combined with clinical variables. The model with the highest BACC (0.59 (95% CI: 0.52-0.65)) ensembled three different models that used automatically extracted X-ray and MRI features along with clinical variables.

CONCLUSION

The KNOAP2020 challenge established a benchmark for predicting incident symptomatic radiographic knee osteoarthritis. Accurate prediction of incident symptomatic radiographic knee osteoarthritis is a complex and still unsolved problem requiring additional investigation.

Accelerated menopausal changes as human disease model 'FOCUM' for the development of osteoarthritis and other degenerative disorders: protocol for a prospective cohort study

INTRODUCTION

The incidence of degenerative disorders, including osteoarthritis (OA), increases rapidly in women after menopause. However, the influence of the menopause is still insufficiently investigated due to the slowness of menopausal transition. In this study, a novel human model is used in which it is expected that menopausal-related changes will occur faster. This is the Females discontinuing Oral Contraceptives Use at Menopausal age model. The ultimate aim is to link these changes to OA and other degenerative disorders, including cardiovascular diseases, diabetes, osteoporosis and tendinopathies.

METHODS AND ANALYSIS

This is a pilot observational prospective cohort study with 2 years of follow-up. Fifty women aged 50-60 who use oral contraceptive (OC) and have the intention to stop are included. Measurements are performed once before stopping OC, and four times thereafter at 6 weeks, 6 months, 1 year and 2 years. At every time point, a questionnaire is filled in and a sample of blood is drawn. At the first and final time points, a physical examination, hand radiographs and a MRI scan of one knee are performed. The primary OA outcome is progression of the MRI Osteoarthritis Knee Score. Secondary OA outcomes are the development of clinical knee and hand OA, development of knee OA according to the MRI definition, and progression of radiographic features for hand OA. Principal component analysis will be used to assess which changes occur after stopping OC. Univariate and multivariate generalised estimating equation models will be used to test for associations between these components and OA.

ETHICS AND DISSEMINATION

The study has been approved by the Medical Ethics Committee of the Erasmus MC University Medical Center Rotterdam (MEC-2019-0592). All participants must give informed consent before data collection. Results will be disseminated in national and international journals.

TRIAL REGISTRATION NUMBER

NL70796.078.19.

Risk assessment for hip and knee osteoarthritis using polygenic risk scores

Objective

Polygenic risk scores (PRS) allow risk stratification using common single‐nucleotide polymorphisms (SNPs), and clinical applications are currently explored for several diseases. This study was undertaken to assess the risk of hip and knee osteoarthritis (OA) using PRS.

Methods

We analyzed 12,732 individuals from a population‐based cohort from the Rotterdam Study (n = 11,496), a clinical cohort (Cohort Hip and Cohort Knee [CHECK] study; n = 908), and a high‐risk cohort of overweight women (Prevention of Knee OA in Overweight Females [PROOF] study; n = 328), for the association of the PRS with prevalence/incidence of radiographic OA, of clinical OA, and of total hip replacement (THR) or total knee replacement (TKR). The hip PRS and knee PRS contained 44 and 24 independent SNPs, respectively, and were derived from a recent genome‐wide association study meta‐analysis. Standardized PRS (with Z transformation) were used in all analyses.

Results

We found a stronger association of the PRS for clinically defined OA compared to radiographic OA phenotypes, and we observed the highest PRS risk stratification for TKR/THR. The odds ratio (OR) per SD was 1.3 for incident THR (95% confidence interval [95% CI] 1.1–1.5) and 1.6 (95% CI 1.3–1.9) for incident TKR in the Rotterdam Study. The knee PRS was associated with incident clinical knee OA in the CHECK study (OR 1.3 [95% CI 1.1–1.5]), but not for the PROOF study (OR 1.2 [95% CI 0.8–1.7]). The OR for OA increased gradually across the PRS distribution, up to 2.1 (95% CI 1.4–3.2) for individuals with the 10% highest PRS compared to the middle 50% of the PRS distribution.

Conclusion

Our findings validated the association of PRS across OA definitions. Since OA is becoming frequent and primary prevention is not commonly applicable, PRS‐based risk assessment could play a role in OA prevention. However, the utility of PRS is dependent on the setting. Further studies are needed to test the integration of genetic risk assessment in diverse health care settings.

Cross-Cohort Automatic Knee MRI Segmentation With Multi-Planar U-Nets

Background

Segmentation of medical image volumes is a time‐consuming manual task. Automatic tools are often tailored toward specific patient cohorts, and it is unclear how they behave in other clinical settings.

Purpose

To evaluate the performance of the open‐source Multi‐Planar U‐Net (MPUnet), the validated Knee Imaging Quantification (KIQ) framework, and a state‐of‐the‐art two‐dimensional (2D) U‐Net architecture on three clinical cohorts without extensive adaptation of the algorithms.

Study Type

Retrospective cohort study.

Subjects

A total of 253 subjects (146 females, 107 males, ages 57 ± 12 years) from three knee osteoarthritis (OA) studies (Center for Clinical and Basic Research [CCBR], Osteoarthritis Initiative [OAI], and Prevention of OA in Overweight Females [PROOF]) with varying demographics and OA severity (64/37/24/53/2 scans of Kellgren and Lawrence [KL] grades 0–4).

Field Strength/Sequence

0.18 T, 1.0 T/1.5 T, and 3 T sagittal three‐dimensional fast‐spin echo T1w and dual‐echo steady‐state sequences.

Assessment

All models were fit without tuning to knee magnetic resonance imaging (MRI) scans with manual segmentations from three clinical cohorts. All models were evaluated across KL grades.

Statistical Tests

Segmentation performance differences as measured by Dice coefficients were tested with paired, two‐sided Wilcoxon signed‐rank statistics with significance threshold α = 0.05.

Results

The MPUnet performed superior or equal to KIQ and 2D U‐Net on all compartments across three cohorts. Mean Dice overlap was significantly higher for MPUnet compared to KIQ and U‐Net on CCBR (0.83±0.04 vs. 0.81±0.06 and 0.82±0.05), significantly higher than KIQ and U‐Net OAI (0.86±0.03 vs. 0.84±0.04 and 0.85±0.03), and not significantly different from KIQ while significantly higher than 2D U‐Net on PROOF (0.78±0.07 vs. 0.77±0.07, P=0.10, and 0.73±0.07). The MPUnet performed significantly better on N=22 KL grade 3 CCBR scans with 0.78±0.06 vs. 0.75±0.08 for KIQ and 0.76±0.06 for 2D U‐Net.

Data Conclusion

The MPUnet matched or exceeded the performance of state‐of‐the‐art knee MRI segmentation models across cohorts of variable sequences and patient demographics. The MPUnet required no manual tuning making it both accurate and easy‐to‐use.

Level of Evidence

3

Technical Efficacy

Stage 2

A lifespan approach to osteoarthritis prevention

Prevention is an attractive solution for the staggering and increasingly unmanageable burden of osteoarthritis. Despite this, the field of osteoarthritis prevention is relatively immature. To date, most of what is known about preventing osteoarthritis and risk factors for osteoarthritis is relative to the disease (underlying biology and pathophysiology) of osteoarthritis, with few studies considering risk factors for osteoarthritis illness, the force driving the personal, financial and societal burden. In this narrative review we will discuss what is known about osteoarthritis prevention, propose actionable prevention strategies related to obesity and joint injury which have emerged as important modifiable risk factors, identify where evidence is lacking, and give insight into what might be possible in terms of prevention by focussing on a lifespan approach to the illness of osteoarthritis, as opposed to a structural disease of the elderly. By targeting a non-specialist audience including scientists, clinicians, students, industry employees and others that are interested in osteoarthritis but who do not necessarily focus on osteoarthritis, the goal is to generate discourse and motivate inquiry which propel the field of osteoarthritis prevention into the mainstream.

Factors associated with longitudinal change of meniscal extrusion in overweight women without clinical signs of osteoarthritis

OBJECTIVES

To identify variables associated with longitudinal change in meniscal extrusion, which might be used as possible targets for knee osteoarthritis (KOA) prevention.

METHODS

In a high-risk population of middle-aged overweight women, meniscal extrusion was assessed with magnetic resonance imaging (1.5 T, coronal proton density, in-plane resolution 0.5 mm2, Sante DICOM Editor) at baseline and after 30 months. Outcomes were the absolute change in medial and lateral extrusion (mm) and relative change in extrusion (%). Based upon literature, 11 factors were hypothesized to be associated with longitudinal change. Generalized estimating equations were used to model the effect on meniscal change (P <0.05).

RESULTS

In total, 677 knees of 343 women were available for analysis, with a mean age of 55.7 years (+/-3.2) and a mean BMI of 32.3 kg/m2 (+/-4.2). The greatest change in meniscal extrusion appeared medially with incident meniscal tear (4.4%; absolute 0.9 mm (95% CI: 0.3, 1.5; P =0.004); relative 14.5% (4.4, 24.7; 0.005)). Varus malalignment was associated with an increase of medial extrusion of 0.6 mm (37.6%; 0.1, 1.0; 0.009). A 5 kg/m2 higher baseline BMI was associated with absolute and relative increase of medial extrusion of 0.2 mm and 2.96% (0.1, 0.3; <0.001 and 1.3, 4.8; 0.002). Less explicit but significant changes in extrusion appeared with longitudinal change in BMI.

CONCLUSION

Meniscal tears, varus malalignment and BMI were significantly associated with change in meniscal extrusion in middle-aged overweight women, providing viable therapeutic targets to prevent or reduce extrusion and thereby decelerate KOA development.

Are changes in meniscus volume and extrusion associated to knee osteoarthritis development? A structural equation model

OBJECTIVE

To explore the interplay between (changes in) medial meniscus volume, meniscus extrusion and radiographic knee osteoarthritis (OA) development over 30 months follow-up (FU).

METHODS

Data from the PRevention of knee Osteoarthritis in Overweight Females study were used. This cohort included 407 middle-aged women with a body mass index ≥27 kg/m², who were free of knee OA at baseline. Demographics were collected by questionnaires at baseline. All menisci at both baseline and FU were automatically segmented from MRI scans to obtain the meniscus volume and the change over time (delta volume). Baseline and FU meniscus body extrusion was quantitatively measured on mid-coronal proton density MR images. A structural equation model was created to assess the interplay between both medial meniscus volume and central extrusion at baseline, delta volume, delta extrusion, and incident radiographic knee OA at FU.

RESULTS

The structural equation modeling yielded a fair to good fit of the data. The direct effects of both medial meniscus volume and extrusion at baseline on incident OA were statistically significant (Estimate = 0.124, p = 0.029, and Estimate = 0.194, p < 0.001, respectively). Additional indirect effects on incident radiographic OA through delta meniscus volume or delta meniscus extrusion were not statistically significant.

CONCLUSION

Baseline medial meniscus volume and extrusion were associated to incidence of radiographic knee OA at FU in middle-aged overweight and obese women, while their changes were not involved in these effects. To prevent knee OA, interventions might need to target the onset of meniscal pathologies rather than their progression.

Epidemiological study of post-traumatic ankle osteoarthritis after ankle sprain in 195,393 individuals over middle age using the National Health Insurance Database: A retrospective design

OBJECTIVES

This study aimed to determine the risk of ankle OA onset after an incidence of sprain, relative to the risk of onset in healthy population, and to investigate the effect of gender, age, BMI, and exercise on the development of ankle OA after sprain.

DESIGN

Retrospective cohort study.

METHODS

Using a sample cohort dataset from 2002 to 2013 provided by the Korean National Health Insurance Sharing Service, we calculated the mean survival time and cumulative incidence rate in sprained and healthy populations using Kaplan-Meier analysis. A Cox proportional hazards model was used to analyze the adjusted hazard ratio (HR) of sprain for the development of OA with 95% confidence intervals (CIs). Adjusted HRs of gender, age, BMI, and exercise (yes/no) were analyzed in the sprained group.

RESULTS

Among the selected population of 195,393 individuals, 40,876 (20.9%) were diagnosed with an ankle sprain, and 1543 (3.85%) of those individuals developed ankle OA. Of the 154,517 healthy individuals (79.1%), 4062 (2.66%) cases had progressed to OA. The sprained group had 46% (HR, 1.46; 95% CI, 1.38-1.55) greater rate of progression to ankle OA than did healthy individuals. In the sprain group, individuals who were female, obese, and overweight had 40% (HR, 1.40; 95% CI, 1.26-1.55), 43% (HR, 1.43; 95% CI, 1.12-1.82), and 22% (HR, 1.22; 95% CI, 1.10-1.35) higher incidence to develop ankle OA, respectively, compared to those who were male, underweight and normal.

CONCLUSIONS

This study found that ankle sprain was a significant risk factor for a diagnosis of early OA. Female gender and high BMI increased the incidence of ankle OA after sprain.

Diagnosis of early stage knee osteoarthritis based on early clinical course: data from the CHECK cohort

Background

Early diagnosis of knee osteoarthritis (OA) is important in managing this disease, but such an early diagnostic tool is still lacking in clinical practice. The purpose of this study was to develop diagnostic models for early stage knee OA based on the first 2-year clinical course after the patient’s initial presentation in primary care and to identify whether these course factors had additive discriminative value over baseline factors.

Methods

We extracted eligible patients’ clinical and radiographic data from the CHECK cohort and formed the first 2-year course factors according to the factors’ changes over the 2 years. Clinical expert consensus-based diagnosis, which was made via evaluating patients’ 5- to 10-year follow-up data, was used as the outcome factor. Four models were developed: model 1, included clinical course factors only; model 2, included clinical and radiographic course factors; model 3, clinical baseline factors + clinical course factors; and model 4, clinical and radiographic baseline factors + clinical and radiographic course factors. All the models were built by a generalized estimating equation with a backward selection method. Area under the receiver operating characteristic curve (AUC) and its 95% confidence interval (CI) were calculated for assessing model discrimination. Delong’s method compared AUCs.

Results

Seven hundred sixty-one patients with 1185 symptomatic knees were included in this study. Thirty-seven percent knees were diagnosed as OA at follow-up. Model 1 contained 6 clinical course factors; model 2: 6 clinical and 3 radiographic course factors; model 3: 6 baseline clinical factors combined with 5 clinical course factors; and model 4: 4 clinical and 1 radiographic baseline factors combined with 5 clinical and 3 radiographic course factors. Model discriminations are as follows: model 1, AUC 0.70 (95% CI 0.67–0.74); model 2, 0.74 (95% CI 0.71–0.77); model 3, 0.77 (95% CI 0.74–0.80); and model 4, 0.80 (95% CI 0.77–0.82). AUCs of model 3 and model 4 were slightly but significantly higher than corresponding baseline-factor models (model 3 0.77 vs 0.75, p = 0.031; model 4 0.80 vs 0.76, p = 0.003).

Conclusions

Four diagnostic models were developed with “fair” to “good” discriminations. First 2-year course factors had additive discriminative value over baseline factors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02598-5.

Association between meniscal volume and development of knee osteoarthritis

OBJECTIVE

To assess the association between meniscal volume, its change over time and the development of knee OA after 30 months in overweight/obese women.

METHODS

Data from the PRevention of knee Osteoarthritis in Overweight Females study were used. This cohort included 407 women with a BMI ≥ 27 kg/m2, free of OA-related symptoms. The primary outcome measure was incident OA after 30 months, defined by one out of the following criteria: medial or lateral joint space narrowing (JSN)  ≥ 1.0 mm, incident radiographic OA [Kellgren and Lawrence (K&L)  ≥ 2], or incident clinical OA. The secondary outcomes were either of these items separately. Menisci at both baseline and follow-up were automatically segmented to obtain meniscal volume and delta-volumes. Generalized estimating equations were used to evaluate associations between the volume measures and the outcomes.

RESULTS

Medial and lateral baseline and delta-volumes were not significantly associated to the primary outcome. Lateral meniscal baseline volume was significantly associated to lateral JSN [odds ratio (OR) = 0.87; 95% CI: 0.75, 0.99], while other measures were not. Medial and lateral baseline volume were positively associated to K&L incidence (OR = 1.32 and 1.22; 95% CI: 1.15, 1.50 and 1.03, 1.45, respectively), while medial and lateral delta-volume were negatively associated to K&L incidence (OR = 0.998 and 0.997; 95% CI: 0.997, 1.000 and 0.996, 0.999, respectively). None of the meniscal measures were significantly associated to incident clinical OA.

CONCLUSION

Larger baseline meniscal volume and the decrease of meniscal volume over time were associated to the development of structural OA after 30 months in overweight and obese women.

Towards sex-specific osteoarthritis risk models: evaluation of risk factors for knee osteoarthritis in males and females

Objectives

The aim of this study was to identify sex-specific prevalence and strength of risk factors for the incidence of radiographic knee OA (incRKOA).

Methods

Our study population consisted of 10 958 Rotterdam Study participants free of knee OA in one or both knees at baseline. One thousand and sixty-four participants developed RKOA after a median follow-up time of 9.6 years. We estimated the association between each available risk factor and incRKOA using sex stratified multivariate regression models with generalized estimating equations. Subsequently, we statistically tested sex differences between risk estimates and calculated the population attributable fractions (PAFs) for modifiable risk factors.

Results

The prevalence of the investigated risk factors was, in general, higher in women compared with men, except that alcohol intake and smoking were higher in men and high BMI showed equal prevalence. We found significantly different risk estimates between men and women: high level of physical activity [relative risk (RR) 1.76 (95% CI: 1.29–2.40)] or a Kellgren and Lawrence score 1 at baseline [RR 5.48 (95% CI: 4.51–6.65)] was higher in men. Among borderline significantly different risk estimates was BMI ≥27, associated with higher risk for incRKOA in women [RR 2.00 (95% CI: 1.74–2.31)]. The PAF for higher BMI was 25.6% in women and 19.3% in men.

Conclusion

We found sex-specific differences in both presence and relative risk of several risk factors for incRKOA. Especially BMI, a modifiable risk factor, impacts women more strongly than men. These risk factors can be used in the development of personalized prevention strategies and in building sex-specific prediction tools to identify high risk profile patients.

Obesity as a multisystem disease: Trends in obesity rates and obesity-related complications

Obesity is a chronic multisystem disease associated with increased morbidity and mortality. The increasing prevalence of obesity makes it a major healthcare challenge across both developed and developing countries. Traditional measures such as body mass index do not always identify individuals at increased risk of comorbidities, yet continue to be used in deciding who qualifies for weight loss treatment. A better understanding of how obesity is associated with comorbidities, in particular non-metabolic conditions, is needed to identify individuals at risk in order to prioritize treatment. For metabolic disorders such as type 2 diabetes (T2D), weight loss can prevent T2D in individuals with prediabetes. It can improve and reverse T2D if weight loss is achieved early in the course of the disease. However, access to effective weight loss treatments is a significant barrier to improved health for people with obesity. In the present paper, we review the rising prevalence of obesity and why it should be classed as a multisystem disease. We will discuss potential mechanisms underlying its association with various comorbidities and how these respond to treatment, with a particular focus on cardiometabolic disease, malignancy and mental health.

Comparison of Clinical and Imaging Outcomes of Different Doses of Adipose-Derived Stromal Vascular Fraction Cell Treatment for Knee Osteoarthritis

Favorable clinical outcomes of intra-articular injection of adipose-derived stromal vascular fraction (SVF) cells for knee osteoarthritis (OA) have been reported, but the effects of different doses of SVF cells have not been examined. This study aimed to compare the short-term clinical and imaging outcomes of different doses of SVF cells for knee OA treatment. This study included 60 patients with knee OA who underwent intra-articular injection of SVF cells. The follow-up period was at least 12 months. Thirty patients received an intra-articular injection of 2.5×107 SVF cells (low-dose group), and the remaining 30 patients received an intra-articular injection of 5.0×107 SVF cells (high-dose group). Clinical evaluations were performed for the Knee injury and Osteoarthritis Outcome Score (KOOS). Imaging evaluations, including the magnetic resonance imaging Osteoarthritis Knee Score (MOAKS) features (bone marrow lesions, cartilage defects, osteophytes, Hoffa's synovitis, and effusion synovitis), were also performed. All clinical and imaging evaluations were performed preoperatively and 12 months postoperatively and compared between the groups. In demographic data, no significant differences were found between the two groups. The total score of KOOS at 12 months postoperatively was significantly more favorable than the preoperative score in the high-dose groups. Pain and symptoms subscale scores of KOOS at 12 months postoperatively were significantly better in the high-dose group than in the low-dose group. The bone marrow lesions, Hoffa's synovitis, and effusion synovitis improved approximately 30-40% at 12 months postoperatively compared to baseline in both groups. However, there were no significant differences in imaging evaluations between the two groups. In conclusion, the pain and symptoms subscale scores of KOOS from baseline to 12 months postoperatively improved better in the high-dose group than in the low-dose group. Our findings suggest that intra-articular injection of SVF cells for knee OA is an innovative approach.

Dopamine/Phosphorylcholine Copolymer as an Efficient Joint Lubricant and ROS Scavenger for the Treatment of Osteoarthritis

Osteoarthritis (OA) is a chronic joint disease and its progression and pathogenesis are highly associated with the significant increase of joint friction and overproduction of reactive oxygen species (ROS) in inflammation. Combination of ROS elimination and lubrication enhancement may provide a novel strategy for the treatment of OA. In the present study, a pure biomaterial and nondrug system P(DMA-co-MPC), synthesized via free radical copolymerization, was designed and developed for the first time using 2-methacryloxyethyl phosphorylcholine (MPC) as a bioinspired lubricant and N-(3,4-dihydroxyphenethyl)methacrylamide (DMA) as an ROS scavenger. Our results showed that the P(DMA-co-MPC) aggregates could efficiently eliminate the ROS radicals and provide good lubrication property by adjusting the molar ratio of DMA and MPC in the copolymer. It is attributed to the antioxidant function of the hydroquinone moiety in DMA and the hydration lubrication effect of the zwitterionic phosphocholine group in MPC. Furthermore, the in vitro experiments demonstrated that the P(DMA-co-MPC) showed good biocompatibility with MC3T3-E1 cells and intracellular anti-inflammatory property by inhibiting the production of ROS and regulating the expression levels of pro-inflammatory cytokines, pain-related gene, anabolic genes, and catabolic genes. In conclusion, the drug-free P(DMA-co-MPC) aggregates developed herein can achieve dual functions of lubrication enhancement and anti-inflammatory effect and thus they may be representative as promising candidates for the treatment of OA.

Improved outcomes after mesenchymal stem cells injections for knee osteoarthritis: results at 12-months follow-up: a systematic review of the literature

PURPOSE

According to the World Health organization (WHO), more than 10% in people older than 60 years suffer from osteoarthritis (OA). Over the last years, there has been an increased interest around regenerative medicine, especially regarding stem cell treatments and related applications. We hypothesize that stem cell therapies can represent a feasible option for idiopathic knee OA, delaying or even avoiding the joint replacement. To emphasize the potential of percutaneous injections of mesenchymal stem cells for knee OA, a comprehensive systematic review of the literature was conducted.

MATERIAL AND METHODS

Two independent authors (FM, GC) performed the literature search. This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA). The main databases were accessed: Pubmed, Embase, Google Scholar, Cochrane Systematic Reviews, Scopus, AMED. For this systematic review, all articles treating percutaneous injections of mesenchymal stem cells for knee OA were considered. Because of the rapid advancements promoted by the scientific progress on stem cell expansion and processing, only articles published within the last five years were included. Solely articles reporting the outcomes of interest across 6- and 12-month follow-up were recruited for eligibility. We included only studies reporting quantitative data under the outcomes of interest. We referred for the quality assessment to the Coleman Methodology Score (CMS). The statistical analysis was performed with Review Manager Software 5.3 (The Nordic Cochrane Centre, Copenhagen).

RESULTS

A total of 18 studies were enrolled in the present study, comprising 1069 treated knees. The mean age of the samples was 57.39 ± 7.37 years. 72% of the included studies harvested the stem cells from the iliac crest (bone marrow-derived MSCs), the remaining 28% from the adipose tissue (adipose-derived MSCs). The mean visual analogic scale improved from 18.37 to 30.98 and 36.91 at 6- and 12-month follow-up, respectively. The mean WOMAC score improved from 25.66 to 25.23 and 15.60 at 6- and 12-month follow-up, respectively. The mean walking distance improved from 71.90 to 152.22 and 316.72 at 6- and 12-month follow-up, respectively. The mean Lequesne scale improved from 33.76 to 12.90 at 12-month follow-up. The KOOS score improved from 41.07 to 8.47% and 18.94 at 6- and 12-month follow-up. All the KOOS subscales improved significantly from the baseline. A total of 136 (12.7%) local complications were detected.

CONCLUSION

According to the current evidences and the main findings of this systematic review, we reported that MSC infiltrations for knee OA can represent a feasible option, leading to an overall remarkable improvement of all clinical and functional considered outcomes, regardless of the cell source. Patients treated at earlier-degeneration stages reported statistically significant greater outcomes. The pain and function scores were improved considerably, thus, leading to a significant improvement of patient participation in recreational activities and quality of life.

Development and evaluation of an osteoarthritis risk model for integration into primary care health information technology

BACKGROUND

We developed and evaluated a prognostic prediction model that estimates osteoarthritis risk for use by patients and practitioners that is designed to be appropriate for integration into primary care health information technology systems. Osteoarthritis, a joint disorder characterized by pain and stiffness, causes significant morbidity among older Canadians. Because our prognostic prediction model for osteoarthritis risk uses data that are readily available in primary care settings, it supports targeting of interventions delivered as part of clinical practice that are aimed at risk reduction.

METHODS

We used the CPCSSN (Canadian Primary Sentinel Surveillance Network) database, which contains aggregated electronic health information from a cohort of primary care practices, to develop and evaluate a prognostic prediction model to estimate 5-year osteoarthritis risk, addressing contextual challenges of data availability and missingness. We constructed a retrospective cohort of 383,117 eligible primary care patients who were included in the cohort if they had an encounter with their primary care practitioner between 1 January 2009 and 31 December 2010. Patients were excluded if they had a diagnosis of osteoarthritis prior to their first visit in this time period. Incident cases of osteoarthritis were observed. The model was constructed to predict incident osteoarthritis based on age, sex, BMI, previous leg injury, and osteoporosis. Evaluation of the model used internal 10-fold cross-validation; we argue that internal validation is particularly appropriate for a model that is to be integrated into the same context from which the data were derived.

RESULTS

The resulting prediction model for 5-year risk of osteoarthritis diagnosis demonstrated state-of-the-art discrimination (estimated AUROC 0.84) and good calibration (assessed visually.) The model relies only on information that is readily available in Canadian primary care settings, and hence is appropriate for integration into Canadian primary care health information technology.

CONCLUSIONS

If the contextual challenges arising when using primary care electronic medical record data are appropriately addressed, highly discriminative models for osteoarthritis risk may be constructed using only data commonly available in primary care. Because the models are constructed from data in the same setting where the model is to be applied, internal validation provides strong evidence that the resulting model will perform well in its intended application.

Associations of clinical outcomes and MRI findings in intra-articular administration of autologous adipose-derived stem cells for knee osteoarthritis

Introduction

Clinical studies of intra-articular injection of mesenchymal stem cells for osteoarthritis (OA) indicate its efficacy. Here, we retrospectively investigated the associations of pretherapeutic magnetic resonance imaging (MRI) findings with the clinical outcomes up to 6 months, after intra-articular administration of adipose-derived stem cells (ASCs) to knee OA patients.

Methods

We first analyzed alterations of the visual analog scale (VAS) and knee injury and osteoarthritis outcome score (KOOS) in 57 knees of 34 patients from whom clinical scores were obtained before ASC therapy, and at 1, 3, and 6 months. Among the patients, we further examined MRI findings of 34 knees of 19 patients whose pretherapeutic MRI data were available.

Results

The mean improvement of VAS and KOOS-total during 6 months was 2.6 ± 4.0 (from 6.1 ± 2.5 to 3.5 ± 2.9, P < 0.001) and 10.2 ± 12.4 (from 54.4 ± 12.7 to 64.6 ± 13.8, P < 0.01), respectively. Scales related to pain and symptoms improved earlier than those related to activities of daily living (ADL) and sports/recreation. Improvement of VAS and KOOS-sports/recreation was significantly higher in patients with more severe cartilage lesions. Similarly, osteophyte lesions were associated significantly with improvement of VAS and KOOS-ADL, and BML was associated with KOOS-ADL and KOOS-sports/recreation.

Conclusions

In intra-articular administration of autologous ASCs for knee OA, improvement of VAS and KOOS-sports/recreation was significantly higher in patients with more severe cartilage lesions. Similarly, osteophyte lesions were associated significantly with improvement of VAS and KOOS-ADL, and BML was associated with KOOS-ADL and KOOS-sports/recreation. Clinical studies with larger numbers of patients and various kinds of data are necessary to predict therapeutic effects.

Osteoarthritis

Osteoarthritis is a leading cause of disability and source of societal cost in older adults. With an ageing and increasingly obese population, this syndrome is becoming even more prevalent than in previous decades. In recent years, we have gained important insights into the cause and pathogenesis of pain in osteoarthritis. The diagnosis of osteoarthritis is clinically based despite the widespread overuse of imaging methods. Management should be tailored to the presenting individual and focus on core treatments, including self-management and education, exercise, and weight loss as relevant. Surgery should be reserved for those that have not responded appropriately to less invasive methods. Prevention and disease modification are areas being targeted by various research endeavours, which have indicated great potential thus far. This narrative Seminar provides an update on the pathogenesis, diagnosis, management, and future research on osteoarthritis for a clinical audience.

Effect of weight change on progression of knee OA structural features assessed by MRI in overweight and obese women

OBJECTIVE

To evaluate the effects of weight change on progression of knee osteoarthritis (OA) structural features by magnetic resonance imaging (MRI) in overweight and obese women without clinical knee OA.

DESIGN

347 participants from the Prevention of Knee Osteoarthritis in Overweight Females (PROOF) study were classified with latent class growth analysis into a subgroup with steady weight (n = 260; +0.1 ± 4.0 kg, +0.2 ± 4.4%), weight gain (n = 43; +8.6 ± 4.0 kg, +9.8 ± 4.1%) or weight loss (n = 44; -9.0 ± 7.2 kg, -9.8 ± 7.5%) over 2.5 years. Baseline and follow-up 1.5T MRIs were scored with MRI Osteoarthritis Knee Score (MOAKS) for progression of bone marrow lesions (BMLs), cartilage defects, osteophytes, meniscal abnormalities, meniscal extrusion and synovitis. Associations between subgroups and change in MRI features at knee-level were assessed using adjusted Generalized Estimating Equations.

RESULTS

687 knees from 347 women (median age 55.2 years, interquartile range (IQR) 5.5, median body mass index (BMI) 31.2 kg/m², IQR 5.3) were analyzed. Progression of synovitis was 18% in the weight gain vs 7% in the stable weight subgroup (OR 2.88; 95%CI 1.39-5.94). The odds for progression of patellofemoral (PF) BMLs and cartilage defects increased with 62% (OR 1.62; 95%CI 0.92-2.84) and 53% (OR 1.53; 95%CI 0.92-2.56) in the weight gain vs the stable weight subgroup.

CONCLUSIONS

In overweight and obese women, progression of synovitis increased more than 2.5 times in a weight gain compared to a stable weight subgroup over 2.5 years. Large effect sizes were also found for the difference in progression of PF BMLs and PF cartilage defects between the weight gain and stable weight subgroup.

Intentional Weight Loss in Overweight and Obese Patients With Knee Osteoarthritis: Is More Better?

OBJECTIVE

To determine the dose response effect of weight loss on clinical and mechanistic outcomes in overweight and obese adults with knee osteoarthritis (OA).

METHODS

This is a secondary analysis of the diet-induced weight loss only (D) and diet-induced weight loss plus exercise (D + E) groups in the Intensive Diet and Exercise for Arthritis randomized controlled clinical trial. The 240 participants were overweight and obese older community-dwelling adults with pain and radiographic knee OA. Participants were assigned to 1 of 4 groups according to weight loss achieved over an 18-month period: <5% (<5% group), 5-10% (≥5% group), 10-20% (≥10% group), and >20% (≥20% group).

RESULTS

There were significant dose responses to weight loss for pain (P = 0.01), function (P = 0.0006), 6-minute walk distance (P < 0.0001), physical (P = 0.0004) and mental (P = 0.03) health-related quality of life (HRQoL), knee joint compressive force (P < 0.0001), and interleukin-6 (P = 0.002). Greater weight loss resulted in superior clinical and mechanstic outcomes, with the highest weight loss group (≥20% group) distinguishing itself on all measures compared with the <5% and ≥5% groups; the ≥20% group had 25% less pain and better function compared with the ≥10% group and significantly (P = 0.006) better physical HRQoL.

CONCLUSION

Long-term weight loss of 10-19.9% of baseline body weight has substantial clinical and mechanistic benefits compared with less weight loss. The value of an additional 10% weight loss includes significantly improved physical HRQoL and a clinically important reduction of pain and improvement in function.

Therapeutic potential of hyaluronic acid/chitosan nanoparticles for the delivery of curcuminoid in knee osteoarthritis and an in vitro evaluation in chondrocytes

Knee osteoarthritis (OA) is the main cause of leg pain in middle-aged and elderly individuals. Hyaluronic acid (HA), as well as curcuminoid, has been used in the treatment of knee OA. In the present study, HA/chitosan nanoparticles (CNPs) were prepared for the delivery of curcuminoid, in order to investigate whether HA and curcuminoid can act synergistically as a better treatment option. The knee OA model was established by the Hulth method, and a knee OA chondrocyte model was constructed by the co-induction of interleukin-1β and tumor necrosis factor (TNF)-α. The drug loading capacity of HA/CNP for the delivery of curcuminoid was measured by an ultraviolet assay, and the cytotoxicity to chondrocytes was measured by an MTT assay. Collagen II was detected by immunofluorescence, and the expression levels of nuclear factor (NF)-κB and inflammation-related genes in cartilage tissue and chondrocytes were detected. Chondrocyte proliferation was determined by an EdU assay, and chondrocyte apoptosis was determined by flow cytometry. The Mankin pathological score of the Outerbridge classification was obtained. The results demonstrated that the optimum drug loading capacity of HA/CNP for the delivery of curcuminoid was 38.44%, with a good sustained release function. HA/CNP treatment resulted in inhibition of the NF-κB pathway, as well as the expression of matrix metalloproteinase (MMP)-1 and MMP-13, but it increased collagen II expression. HA/CNP for the delivery of curcuminoid significantly decreased the Outerbridge classification and Mankin pathological scores to close to normal until the 4th week. Furthermore, it was also observed that all the effects of HA/CNP on the delivery of curcuminoid were more prominent compared with the effects of HA or curcuminoid treatment individually. Taken together, these findings demonstrated that HA/CNP for the delivery of curcuminoid may suppress inflammation and chondrocyte apoptosis in knee OA via repression of the NF-κB pathway.

Can we prevent OA? Epidemiology and public health insights and implications

This narrative review discusses the potential of prevention of OA in different stages of the disease. The theoretical background for primary prevention (i.e. prevention of occurrence of definite structural or clinical OA in subjects free of the disease) and secondary prevention (i.e. prevention of progression of the disease in subjects with pre-clinical pathological changes to the joint) is provided and evidence for effective strategies is discussed. Since direct evidence for the prevention of OA development and progression is scarce, indirect evidence enhancing our current knowledge on the potential of OA prevention is additionally discussed. Also, implications of preventive strategies for study design and public health are considered. Prevention of OA has great potential, but as deliberated in the current review, there are still large gaps in our current knowledge and the implications of preventive strategies for the development and progression of OA require consideration.

Maximum lifetime body mass index is the appropriate predictor of knee and hip osteoarthritis

INTRODUCTION

In light of inconsistencies in the literature, this study aimed to investigate the relationship between obesity (current and historic) and osteoarthritis (OA) of the knee or hip.

MATERIALS AND METHODS

We examined 99 people (knee OA, hip OA and controls), age > 50 years, in a case-control study. The current weight, height and waist circumference were measured on site, and detailed weight changes over their lifetime were based on questionnaires and standardized interviews. We used binomial logistic regression to determine the predictive value for an osteoarthritis group membership of each derived indicator.

RESULTS

An increase in 'maximum-BMI' increased the odds ratio for both knee OA (OR 1.2; CI 1.1-1.4; p = 0.005; R ² = 0.36) and hip OA (OR 1.2; CI 1.0-1.3; p = 0.027; R ² = 0.16). Current BMI was significantly associated with knee OA but not with hip OA. A high "minimum-BMI" (over the age of 18 years) had the highest odds ratio of all calculated indicators for both osteoarthritis groups.

CONCLUSIONS

Based on our findings, it is concluded that the maximum BMI over one's lifespan is a better predictor of OA of the hip or the knee than the current BMI. The knee joint seems to be more sensitive to obesity as current BMI was associated only with knee OA but not with hip OA.

A machine learning approach for the identification of new biomarkers for knee osteoarthritis development in overweight and obese women

OBJECTIVE

Knee osteoarthritis (OA) is among the higher contributors to global disability. Despite its high prevalence, currently, there is no cure for this disease. Furthermore, the available diagnostic approaches have large precision errors and low sensitivity. Therefore, there is a need for new biomarkers to correctly identify early knee OA.

METHOD

We have created an analytics pipeline based on machine learning to identify small models (having few variables) that predict the 30-months incidence of knee OA (using multiple clinical and structural OA outcome measures) in overweight middle-aged women without knee OA at baseline. The data included clinical variables, food and pain questionnaires, biochemical markers (BM) and imaging-based information.

RESULTS

All the models showed high performance (AUC > 0.7) while using only a few variables. We identified both the importance of each variable within the models as well its direction. Finally, we compared the performance of two models with the state-of-the-art approaches available in the literature.

CONCLUSIONS

We showed the potential of applying machine learning to generate predictive models for the knee OA incidence. Imaging-based information were found particularly important in the proposed models. Furthermore, our analysis confirmed the relevance of known BM for knee OA. Overall, we propose five highly predictive small models that can be possibly adopted for an early prediction of knee OA.

Effects of weight loss interventions for adults who are obese on mortality, cardiovascular disease, and cancer: systematic review and meta-analysis

Objective To assess whether weight loss interventions for adults with obesity affect all cause, cardiovascular, and cancer mortality, cardiovascular disease, cancer, and body weight.Design Systematic review and meta-analysis of randomised controlled trials (RCTs) using random effects, estimating risk ratios, and mean differences. Heterogeneity investigated using Cochran's Q and I² statistics. Quality of evidence assessed by GRADE criteria.Data sources Medline, Embase, the Cochrane Central Register of Controlled Trials, and full texts in our trials' registry for data not evident in databases. Authors were contacted for unpublished data.Eligibility criteria for selecting studies RCTs of dietary interventions targeting weight loss, with or without exercise advice or programmes, for adults with obesity and follow-up ≥1 year.Results 54 RCTs with 30 206 participants were identified. All but one trial evaluated low fat, weight reducing diets. For the primary outcome, high quality evidence showed that weight loss interventions decrease all cause mortality (34 trials, 685 events; risk ratio 0.82, 95% confidence interval 0.71 to 0.95), with six fewer deaths per 1000 participants (95% confidence interval two to 10). For other primary outcomes moderate quality evidence showed an effect on cardiovascular mortality (eight trials, 134 events; risk ratio 0.93, 95% confidence interval 0.67 to 1.31), and very low quality evidence showed an effect on cancer mortality (eight trials, 34 events; risk ratio 0.58, 95% confidence interval 0.30 to 1.11). Twenty four trials (15 176 participants) reported high quality evidence on participants developing new cardiovascular events (1043 events; risk ratio 0.93, 95% confidence interval 0.83 to 1.04). Nineteen trials (6330 participants) provided very low quality evidence on participants developing new cancers (103 events; risk ratio 0.92, 95% confidence interval 0.63 to 1.36).Conclusions Weight reducing diets, usually low in fat and saturated fat, with or without exercise advice or programmes, may reduce premature all cause mortality in adults with obesity.Systematic review registration PROSPERO CRD42016033217.

Resveratrol ameliorates inflammatory damage and protects against osteoarthritis in a rat model of osteoarthritis

Resveratrol is a non-flavonoid polyphenol compound with a stilbene structure. As a type of phytoalexin produced under stress in plants, it improves the plant's resistance against pathogens and environment deterioration, and performs important functions beneficial to human health, such as anti-cancer, anti-oxidation, regulating blood lipid levels and prolonging life span. The effects of resveratrol were examined in a rat model of osteoarthritis (OA) and observed to ameliorate inflammatory damage and protect against OA. In the present study, resveratrol significantly inhibited the induction of clinical scores in rats with OA. Resveratrol inhibited tumor necrosis factor-α, interleukin (IL)-1β, IL-6 and IL-18 expression levels, and decreased caspase-3/9 activity in rats with OA. Inducible nitric oxide synthase, nuclear factor (NF)-κB, phosphorylated-(p)-AMP-activated protein kinase and sirtuin 1 protein expression were significantly suppressed and heme oxygenase 1 (HO-1) and nuclear factor erythroid 2-related factor 2 (Nrf-2) protein expression was stimulated in rats with OA treated with resveratrol. The current results indicate that resveratrol ameliorates inflammatory damage and protects against OA in a rat model of OA via NF-κB and HO-1/Nrf-2 signaling.

Baseline meniscal extrusion associated with incident knee osteoarthritis after 30 months in overweight and obese women

OBJECTIVE

To investigate the association between baseline meniscal extrusion and the incidence of knee osteoarthritis (KOA) after 30 months in a high-risk population of overweight and obese women, free of clinical and radiological KOA at baseline.

METHODS

407 middle-aged overweight women (body mass index - BMI ≥ 27 kg/m²) were evaluated at baseline and after 30 months of follow-up. Meniscal extrusion was defined as grade ≥2 on MRI according to MRI Osteoarthritis Knee Score (MOAKS). The primary outcome measure was KOA after 30 months follow-up, defined using the following criteria: either incidence of radiographic KOA (Kellgren & Lawrence grade 2 or higher), or clinical osteoarthritis (OA) according to the American College of Radiology (ACR) criteria, or medial or lateral joint space narrowing (JSN) of ≥1.0 mm. Using generalized estimating equations (GEE), we determined the association between knees with and without meniscal extrusion and both outcomes, corrected for the baseline differences.

RESULTS

640 knees were available at baseline of which 24% (153) had meniscal extrusion. There was a significantly higher incidence of KOA according to the primary outcome measure in women with meniscal extrusion compared to those without extrusion (28.8%, odds ratio - OR 2.39, 95% CI 1.53, 3.73). A significantly higher incidence was found for the development of radiographic KOA (12.4%, OR 2.61, 95% CI 1.11, 6.13) and medial JSN (11.8%, OR 3.19, 95% CI 1.59, 6.41). Meniscal extrusion was not significantly associated with clinical KOA and lateral JSN.

CONCLUSION

Meniscal extrusion was associated with a significantly higher incidence of KOA, providing an interesting target for early detection of individuals at risk for developing KOA.