Clinical classification criteria for knee osteoarthritis: performance in the general population and primary care

Teaming up to overcome challenges toward translation of new therapeutics for osteoarthritis

As a leading global cause of musculoskeletal-related disability, osteoarthritis (OA) represents a public health urgency. Understanding of disease pathogenesis has advanced substantially in the past decade, yet no disease-modifying therapeutics have advanced to the clinic. To address this challenge, the CARE-AP (Cartilage Repair strategies to alleviate Arthritis Pain) collaborative research team was convened to bring together relevant multidisciplinary expertise and perspectives from across the VA research community nationwide. The first CARE-AP Annual Research Symposium took place (virtually) in February 2022 with roughly 90 participants. A number of innovative and therapeutic strategies were discussed, including siRNA approaches coupled with novel nanoparticle-based delivery systems, cellular engineering approaches to develop reparative cells that can probe the joint environment and respond to disease-specific cues, and novel biofabrication techniques to improve tissue engineering and effect "biological joint replacement." In addition, challenges and advances in rehabilitation approaches, imaging outcomes, and clinical studies were presented, which were integrated into a framework of recommendations for running "preclinical trials" to improve successful clinical translation.

Associations between biomarkers and skeletal muscle function in individuals with osteoarthritis: a systematic review and meta-analysis

OBJECTIVES

Skeletal muscle dysfunction is the primary cause of functional limitations in osteoarthritis, associated biomarkers have the potential as targets for early disease identification, diagnosis, and prevention of osteoarthritis disability. This review aimed to identify associations between biomarkers and lower limb skeletal muscle function in individuals with osteoarthritis.

METHODS

A systematic literature review and meta-analysis conducted in PubMed, MEDLINE, CINAHL, EMBASE, Scopus, SPORTDiscus and Web of Science databases from inception to 8th August 2023. Two independent reviewers performed the title, abstract, full-text screening, data extraction and methodological quality assessment. A meta-analysis was undertaken based on the available data.

RESULTS

Twenty-four studies with 4101 participants with osteoarthritis were included (females: 78%; age range; 49 to 71 years). One study reported muscle-specific biomarkers (n = 3), whilst six studies reported osteoarthritis-specific markers (n = 5). Overall, 93 biomarkers were reported, predominately characterised as inflammatory (n = 35), metabolic (n = 15), and hormones (n = 10). Muscle strength and vitamin D reported a significant association (Hedge's g: 0.58 (Standard Error (SE): 0.27; P = 0.03), k = 3 studies). Walking speed and high-sensitivity C-reactive protein reported no significant associations (Hedge's g: -0.02 (SE: 0.05; P = 0.73), k = 3 studies).

CONCLUSION

Associations between biomarkers and lower limb skeletal muscle function in individuals with osteoarthritis was limited, the few studies exploring lower limb muscle measures were mainly secondary outcomes. Furthermore, biomarkers were largely related to overall health, with a lack of muscle specific biomarkers. As such, the mechanistic pathways through which these associations occur are less evident, and difficult to draw clear conclusions on these relationships.

TRIAL REGISTRATION

Registered on PROSPERO (CRD42022359405).

Efficacy, Safety, and Tolerability of a Very Low-Calorie Ketogenic Diet in Women with Obesity and Symptomatic Knee Osteoarthritis: A Pilot Interventional Study

BACKGROUND/OBJECTIVES

Obesity is a major risk factor for knee osteoarthritis (OA), and weight loss is crucial for its management. This pilot study explores the effects of a Very Low-Calorie Ketogenic Diet (VLCKD) in women with obesity and symptomatic knee OA.

METHODS

Women with symptomatic knee OA and obesity, defined as a body mass index (BMI) ≥ 30 kg/m2, were eligible for the VLCKD protocol. The intervention included a ketogenic phase from baseline (T0) to the 8th week (T8), followed by a progressive reintroduction of carbohydrates over the next 12 weeks, ending at the 20th week (T20). Body mass index (BMI), the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index, the EuroQol 5D (EQ-5D), and the 36-item Short Form Health Survey (SF-36) were assessed at all time points. Generalized estimating equations were used to analyze the association between BMI and patient-reported outcomes across the study period.

RESULTS

Twenty participants started the study, but four discontinued the intervention, with two of these being due to adverse effects. The mean age of the 16 patients who completed the 20-week program was 57.3 ± 5.5 years, and their mean BMI was 40.0 ± 4.8 kg/m2. The mean BMI significantly decreased to 37.5 ± 4.5 at T4, 36.3 ± 4.6 at T8, and 34.8 ± 4.8 at T20 (all p < 0.001 compared to baseline). The total WOMAC score improved from a mean of 43.6 ± 16.9 at T0 to 30.2 ± 12.8 at T4 (p = 0.005) and further to 24.7 ± 10.6 at T8 (p = 0.001) and to 24.8 ± 15.9 at T20 (p = 0.005). The reduction in BMI was significantly correlated with the improvements in WOMAC, EQ-5D, and SF-36 over time. No major adverse effects were observed.

CONCLUSIONS

A 20-week VLCKD in women with obesity and knee OA significantly reduced their weight and improved their outcomes, warranting further research. This trial is registered with number NCT05848544 on ClinicalTrials.gov.

The Effectiveness of a Single Hyaluronic Acid Injection in Improving Symptoms and Muscular Strength in Patients with Knee Osteoarthritis: A Multicenter, Retrospective Study

Knee osteoarthritis (KOA) is a progressive and multifactorial disease that leads to joint pain, muscle weakness, physical disability, and decreased quality of life. In KOA, the quantity of hyaluronic acid (HA) and the molecular weight (MW) are decreased, leading to joint pain due to increased wear of the knee articular cartilage. Arthrogenic muscle inhibition, which is usually found in patients with KOA, is associated with joint inflammation, pain, and swelling, also causing muscle atrophy, primarily of the anterior thigh muscles, and hindering the rehabilitation process. The aim of our work was to determine if a single HA infiltration could minimize the effects of arthrogenic muscle inhibition in patients with KOA in the short term, using isokinetic dynamometry to evaluate the strength of the knee extensor and flexor muscles of the thigh. Thirty patients with KOA who underwent both clinical and isokinetic assessment, and that received a single injection of HA, were retrospectively included. Our results showed that a single intra-articular injection of HA significantly reduces pain and improves joint function at four weeks, while non-statistically significant improvements were observed for the reference isokinetic parameter (maximum torque) at both 90°/s and 180°/s. Further high-quality studies are necessary to confirm the results of our study.

Evaluation of the Diagnostic Performance of American College of Rheumatology, EULAR, and National Institute for Health and Clinical Excellence Criteria Against Clinically Relevant Knee Osteoarthritis: Data From the CHECK Cohort

OBJECTIVE

Our objective was to evaluate the diagnostic performance of the EULAR, American College of Rheumatology (ACR), and National Institute for Health and Care Excellence (NICE) criteria by using clinical experts' diagnosis of clinically relevant knee osteoarthritis (OA) as the outcome of interest.

METHODS

In a previous study, we recruited clinical experts to evaluate longitudinal (5-, 8-, and 10-year follow-up) clinical and radiographic data of symptomatic knees from the Cohort Hip and Cohort Knee (CHECK) study for the presence or absence of clinically relevant OA. In the current study, ACR, EULAR, and NICE criteria were applied to the same 5-, 8-, and 10-year follow-up data; then a knee was diagnosed with OA if fulfilling the criteria at one of the three time points (F1), two of the time points (F2), or at all three time points (F3). Using clinically relevant OA as the reference standard, the sensitivity, specificity, and positive and negative predictive values for the three criteria were assessed.

RESULTS

A total of 539 participants for a total of 833 examined knees were included. Thirty-six percent of knees were diagnosed with clinically relevant OA by experts. Sixty-seven percent to 74% of the knees received the same diagnosis (OA or non-OA) by the three criteria sets for the different definitions (F1 to F3). EULAR consistently (F1 through F3) had the highest specificity, and NICE consistently had the highest sensitivity.

CONCLUSION

The diagnoses only moderately overlapped among the three criteria sets. The EULAR criteria seemed to be more suitable for study enrollment (when aimed at recruiting clinically relevant OA knees), given the highest specificities. The NICE criteria, given the highest sensitivities, could be more useful for an initial diagnosis in clinical practice.

Randomized controlled trial of compressive cryotherapy versus standard cryotherapy after total knee arthroplasty: pain, swelling, range of motion and functional recovery

BACKGROUND

After total knee arthroplasty (TKA), patients have limited knee range of motion (ROM), trophic changes and pain. Cryotherapy and compression are recommended in the literature, but no study has shown that cryotherapy and compression combined leads to better results than cryotherapy alone. The primary objective was to compare knee ROM after 21 days of rehabilitation post-TKA between patients who underwent rehabilitation with compressive cryotherapy with those who had cryotherapy alone. The secondary objectives were to compare other trophic, pain and functional outcomes.

METHODS

Forty patients were randomized into two groups: Standard Cryotherapy (SC = 20, median age 77 years), which applied cold packs along with their rehabilitation; and Compressive Cryotherapy (CC = 20, median age 76 years), which received cold compression. Knee joint's passive and active ROM (primary outcome) were measured with a goniometer. Knee's circumference, fluctuation test, pain at rest and during activity, 6-minute walking test (6MWT) and KOOS questionnaire were secondary outcomes. The groups were compared on D1 (baseline) and D21 of rehabilitation. A survival analysis has compared the groups on D1, D8, D15, D21.

RESULTS

All subjects had a significant improvement in all the parameters on D21 relative to D1 (p < .05), except for pain at rest (p = .065 for CC and p = .052 for SC). On D21, the CC group had a significantly larger improvement in the joint effusion (p = .002), pain during activity (p = .005), 6MWT (p = .018) and KOOS (p = .004) than the SC group. Based on the survival analysis, the CC group had significantly faster improvement in the joint ROM (p = .011 for flexion and p = .038 for extension) and knee circumference (p = .013) than the SC group.

CONCLUSIONS

Both cryotherapy methods improved joint ROM, trophic changes, pain and function. Adding dynamic compression to a cryotherapy protocol provided further benefits: a significantly faster improvement in passive knee flexion ROM, a greater reduction of swelling, and pain during activity. Similarly, walking distance and KOOS questionnaire were significantly better for CC.

TRIALS REGISTRATION

The study was registered in the ClinicalTrials.gov database on 14/09/2023 (identifier: NCT06037824).

Effects of the combination of pulsed electromagnetic field with progressive resistance exercise on knee osteoarthritis: A randomized controlled trial

BACKGROUND

Knee osteoarthritis (OA) is a common and disabling disease among the elderly population. The optimal conservative treatment for knee OA is not well established.

OBJECTIVE

This study aimed to assess the effectiveness of pulsed electromagnetic field (PEMF) combined with progressive resistance exercise (PRE) in improving physical function and pain in patients with knee OA.

METHODS

Thirty-four patients with knee OA (17 in each group) participated in a single-blind randomized control study. Patients were randomly assigned to receive 24 sessions of either combined PEMF and PRE (treatment group) or PRE only (control group). Patients were evaluated at pre-treatment, post-treatment (2 months), and at 3-month and 6-month follow-ups using the Knee Injury and Osteoarthritis Outcome Score (KOOS), Numeric Pain Rating Scale (NPRS); walking speed and 5-times chair stand test. Mixed ANOVA was used for statistical analysis with Bonferroni adjustments.

RESULTS

There was no significant group-by-time interaction for any outcome (P> 0.05). However, both groups scored significantly higher on the NPRS and KOOS at post-treatment, 3-, and 6-month follow-up compared to their baseline. Further, both groups completed the 5-times chair stand test and walking speed test with significantly less time at all post-treatment time points than the pre-treatment. None of the study outcomes (NPRS, KOOS, walking speed, and 5 times chair stand) were significantly different between groups at any of the time points.

CONCLUSION

Both treatment options, PRE only versus PRE with PEMF, were equally effective in decreasing pain and improving physical function in patients with knee OA. This would suggest that the optimal parameters for PEMF that may show beneficial effects for knee OA when added to PRE training need to be determined.

Synthetic Knee MRI T1p Maps as an Avenue for Clinical Translation of Quantitative Osteoarthritis Biomarkers

A 2D U-Net was trained to generate synthetic T1p maps from T2 maps for knee MRI to explore the feasibility of domain adaptation for enriching existing datasets and enabling rapid, reliable image reconstruction. The network was developed using 509 healthy contralateral and injured ipsilateral knee images from patients with ACL injuries and reconstruction surgeries acquired across three institutions. Network generalizability was evaluated on 343 knees acquired in a clinical setting and 46 knees from simultaneous bilateral acquisition in a research setting. The deep neural network synthesized high-fidelity reconstructions of T1p maps, preserving textures and local T1p elevation patterns in cartilage with a normalized mean square error of 2.4% and Pearson's correlation coefficient of 0.93. Analysis of reconstructed T1p maps within cartilage compartments revealed minimal bias (-0.10 ms), tight limits of agreement, and quantification error (5.7%) below the threshold for clinically significant change (6.42%) associated with osteoarthritis. In an out-of-distribution external test set, synthetic maps preserved T1p textures, but exhibited increased bias and wider limits of agreement. This study demonstrates the capability of image synthesis to reduce acquisition time, derive meaningful information from existing datasets, and suggest a pathway for standardizing T1p as a quantitative biomarker for osteoarthritis.

The assessment of musculoskeletal disorders, quality of life, and comorbidities in older people in Bangladesh

Musculoskeletal disorders are debilitating conditions that significantly impact the state of health, especially in older people. The study, which employed a cross-sectional design and practical sampling, included 206 participants among them 124 (62.2%) were men and 82 (39.8%) were women, from all over Bangladesh with musculoskeletal issues of varying severity and impact. The mean age of the participants was 64.9 (SD 4.3). The study was carried out between January and June of 2022. The majority of participants experienced musculoskeletal pain. Back pain was the most commonly complained of symptom among the participants (74.9%). It was also common to have limited mobility as a result of arthritic change, which eventually affected daily activities like taking care of oneself. To improve the health of the older adult population, more studies must be conducted to identify the many factors that contribute to musculoskeletal issues. The development of effective prevention and rehabilitation programs must then be based on this knowledge.

Unsupervised domain adaptation for automated knee osteoarthritis phenotype classification

Background

Osteoarthritis (OA) is a global healthcare problem. The increasing population of OA patients demands a greater bandwidth of imaging and diagnostics. It is important to provide automatic and objective diagnostic techniques to address this challenge. This study demonstrates the utility of unsupervised domain adaptation (UDA) for automated OA phenotype classification.

Methods

We collected 318 and 960 three-dimensional double-echo steady-state magnetic resonance images from the Osteoarthritis Initiative (OAI) dataset as the source dataset for phenotype cartilage/meniscus and subchondral bone, respectively. Fifty three-dimensional turbo spin echo (TSE)/fast spin echo (FSE) MR images from our institute were collected as the target datasets. For each patient, the degree of knee OA was initially graded according to the MRI Knee Osteoarthritis Knee Score before being converted to binary OA phenotype labels. The proposed four-step UDA pipeline included (I) pre-processing, which involved automatic segmentation and region-of-interest cropping; (II) source classifier training, which involved pre-training a convolutional neural network (CNN) encoder for phenotype classification using the source dataset; (III) target encoder adaptation, which involved unsupervised adjustment of the source encoder to the target encoder using both the source and target datasets; and (IV) target classifier validation, which involved statistical analysis of the classification performance evaluated by the area under the receiver operating characteristic curve (AUROC), sensitivity, specificity and accuracy. We compared our model on the target data with the source pre-trained model and the model trained with the target data from scratch.

Results

For phenotype cartilage/meniscus, our model has the best performance out of the three models, giving 0.90 [95% confidence interval (CI): 0.79-1.02] of the AUROC score, while the other two model show 0.52 (95% CI: 0.13-0.90) and 0.76 (95% CI: 0.53-0.98). For phenotype subchondral bone, our model gave 0.75 (95% CI: 0.56-0.94) at AUROC, which has a close performance of the source pre-trained model (0.76, 95% CI: 0.55-0.98), and better than the model trained from scratch on the target dataset only (0.53, 95% CI: 0.33-0.73).

Conclusions

By utilising a large, high-quality source dataset for training, the proposed UDA approach enhances the performance of automated OA phenotype classification for small target datasets. As a result, our technique enables improved downstream analysis of locally collected datasets with a small sample size.

Hip and Knee Osteoarthritis in Patients with Chronic Myeloproliferative Neoplasms: A Cross-Sectional Study

BACKGROUND

Osteoarthritis (OA) is a progressive degenerative disease with an inflammatory background. Chronic myeloproliferative neoplasms (MPN) are clonal hematopoietic disorders characterized by chronic inflammation and a tendency for connective tissue remodeling.

AIM

This study aimed to investigate the prevalence and associated risk factors of symptomatic OA (sOA) in MPN patients.

PATIENTS AND METHODS

A total of 100 consecutive MPN (39 essential-thrombocythemia, 34 polycythemia-vera, 27 myelofibrosis) patients treated in two community hematologic centers were cross-sectionally evaluated. Patients were required to have both symptoms attributable to hip and/or knee OA and radiographic confirmation to be considered as having sOA.

RESULTS

The prevalence of hip and/or knee sOA was significantly higher among MPN patients than the previously reported prevalence in the general population of similar age (61% vs. 22%, p < 0.001). Hip sOA was present in 50%, knee sOA in 51% and sOA of both localizations in 41% of patients. A high proportion of MPN patients had radiographic signs of hip OA (94%) and knee OA (98%) in the presence of attributable symptoms. Among the other factors, sOA was univariately associated with the presence of JAK2 mutation, myelofibrosis phenotype, older age, higher body weight, and higher MPN-SAF score (p < 0.050 for all analyses). In the multivariate analysis, older age (odds ratio = 1.19, 95% confidence interval-CI 1.06-1.33) and higher body weight (OR = 1.15, 95% CI 1.06-1.25) were recognized as independent risk factors for sOA. On the other hand, cytoreductive treatment was a protective factor for sOA (OR = 0.07, 95% CI 0.006-0.86).

CONCLUSIONS

The prevalence of sOA in MPN patients was higher than that in the general population and seems to correlate with older age, increased myeloproliferation and a higher inflammatory state. Whether cytoreductive treatment may postpone OA development in MPN patients warrants additional confirmation.

Efficacy of Intramuscular Injection of Calcitonin on Pain Functional Status of Patients with Knee Osteoarthritis

Background

Recently, increased attention has been paid to calcitonin for the management of osteoarthritis (OA) regarding its metabolic properties for bone turnover and cartilage.

Objectives

This study was designed to assess the efficacy of intramuscular calcitonin injection in the functional status of individuals suffering from knee OA.

Methods

A total of 40 eligible cases with OA were randomly assigned into intervention and control groups. At baseline, pain intensity and functional ability were evaluated based on the Numeric Rating scale (NRS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaires. Both groups were prescribed with AcetaGel (500 mg) and piroxicam (0.5% topical gel) every 8 hours as needed, and the patients were instructed about conservative treatments and lifestyle modifications. In the case group, the patients received calcitonin (50 IU/mL solution for injection; Aburaihan Pharmaceutical Co., Iran) intramuscularly (gluteal muscle) once a week for 4 consecutive weeks. One month after the last dose, the patients were evaluated based on NRS and WOMAC questionnaires.

Results

Demographic data did not show any statistically significant difference. A total of 40 cases (male and female) with mean age values of 53.10 ± 5.28 and 54.55 ± 5.26 years were included in the case and control groups, respectively. The mean body mass index values of the case and control groups were 27.45 ± 1.57 and 27.15 ± 1.53 kg/m2, respectively. After 1 month of treatment with calcitonin, significant improvements were observed in NRS outcomes (P < 0.001). The total WOMAC score was also statistically improved (P < 0.001).

Conclusions

The findings of the present study revealed that the weekly administration of 50 IU calcitonin for 28 days could significantly improve physical ability and pain intensity in OA patients.

Basic Properties of Adipose-Derived Mesenchymal Stem Cells of Rheumatoid Arthritis and Osteoarthritis Patients

Rheumatoid arthritis (RA) and osteoarthritis (OA) are destructive joint diseases, the development of which are associated with the expansion of pathogenic T lymphocytes. Mesenchymal stem cells may be an attractive therapeutic option for patients with RA or OA due to the regenerative and immunomodulatory abilities of these cells. The infrapatellar fat pad (IFP) is a rich and easily available source of mesenchymal stem cells (adipose-derived stem cells, ASCs). However, the phenotypic, potential and immunomodulatory properties of ASCs have not been fully characterised. We aimed to evaluate the phenotype, regenerative potential and effects of IFP-derived ASCs from RA and OA patients on CD4+ T cell proliferation. The MSC phenotype was assessed using flow cytometry. The multipotency of MSCs was evaluated on the basis of their ability to differentiate into adipocytes, chondrocytes and osteoblasts. The immunomodulatory activities of MSCs were examined in co-cultures with sorted CD4+ T cells or peripheral blood mononuclear cells. The concentrations of soluble factors involved in ASC-dependent immunomodulatory activities were assessed in co-culture supernatants using ELISA. We found that ASCs with PPIs from RA and OA patients maintain the ability to differentiate into adipocytes, chondrocytes and osteoblasts. ASCs from RA and OA patients also showed a similar phenotype and comparable abilities to inhibit CD4+ T cell proliferation, which was dependent on the induction of soluble factors The results of our study constitute the basis for further research on the therapeutic potential of ASCs in the treatment of patients with RA and OA.

Passive stiffness of the quadriceps predicts the incidence of clinical knee osteoarthritis in twelve months

BACKGROUND

Quadriceps weakness is a known risk factor for the onset of knee osteoarthritis (OA). In addition to muscle weakness, increased passive stiffness of the quadriceps may affect knee biomechanics and hence contribute to the pathogenesis of knee OA. However, the association between quadriceps stiffness and the risk of knee OA development has not been prospectively investigated.

AIM

The aim of this study was to investigate how baseline quadriceps passive stiffness predicts the incidence of clinical knee OA at the 12-month follow-up.

DESIGN

Prospective cohort study.

SETTING

University laboratory.

POPULATION

Community-dwelling adults aged 60-80 years were recruited. We excluded participants with: 1) knee pain or known arthritis; 2) knee injury; 3) knee or hip joint replacement, 4) cognitive impairment; or 5) neurological conditions.

METHODS

At baseline, passive stiffness of the three superficial quadriceps muscle heads (rectus femoris [RF], vastus lateralis [VL], and vastus medialis oblique [VMO]) was evaluated using shear-wave ultrasound elastography. Knee muscle (quadriceps and hamstrings) strength was tested using a Cybex dynamometer. Knee OA was defined based on clinical criteria 12 months after baseline measurements. Generalized estimating equations were used to examine the associations of quadriceps stiffness and knee muscle strength with the risk of knee OA, controlling for age, sex, Body Mass Index, comorbidities, and activity level.

RESULTS

The analyses included 158 knees (58.2% females, age: 65.6±4.1 years). Twenty-eight knees (17.7%) were classified as having clinical OA at 12 months. Compared with the lowest stiffness tertiles, the highest stiffness tertiles of the RF (relative risk =5.31, 95% CI: 1.34-21.0), VMO (4.15, 1.04-16.6), and total superficial quadriceps (6.35, 1.48-27.3) at baseline were significantly associated with a higher risk of knee OA at the follow-up. The highest strength tertile of quadriceps has a trend of association with a lower risk of knee OA than the lowest tertile (0.18, 0.03-1.25, P=0.083).

CONCLUSIONS

Greater passive stiffness of the quadriceps at baseline was associated with a higher risk of clinical knee OA incidence at the 12-month follow-up.

CLINICAL REHABILITATION IMPACT

Interventions for reducing the passive stiffness of the quadriceps should be included in preventative training programs for older adults.

Neuromuscular joint function in knee osteoarthritis: A systematic review and meta-analysis

BACKGROUND

Neuromuscular alterations are common in people with knee osteoarthritis (KOA). A comprehensive understanding of these alterations is important to enable targeted rehabilitation strategies.

OBJECTIVES

This systematic review and meta-analysis aimed to comprehensively understand the neuromuscular alterations around the knee joint in people with KOA.

METHODS

Moderate- and high-quality studies based on a modified version of the Downs and Black checklist, comparing neuromuscular function of peri‑articular muscles between people with KOA and controls were retrieved from five databases from inception to October 2020. Outcomes included normalized isokinetic strength, muscle size, voluntary activation, cortical and spinal-reflex excitability, and torque-related outcomes. Data were pooled according to structural KOA severity with sensitivity analysis based on sex. Evidence levels are presented in evidence gap maps.

RESULTS

A total of 7 high-quality and 22 moderate-quality studies were retained (1146 people with KOA and 1353 age- and sex-matched controls). Studies demonstrated quadriceps and hamstring strength deficits and increased hamstring-to-quadriceps strength ratios across KOA severities. Women presented lower quadriceps strength at early KOA (very limited evidence) and lower voluntary activation at end stage KOA (very limited evidence) as compared with controls, whereas men did not (moderate evidence). People with KOA also demonstrated lower quadriceps force control ability with no change in rapid force production (very limited evidence). Voluntary activation deficits for quadriceps were evident (moderate evidence), with no change in quadriceps cortical excitability (very limited evidence) or soleus spinal reflexes (very limited evidence). No muscle size change was demonstrated except for the vastus medialis (limited evidence). Evidence gaps were found for neural and torque-related measures and differences in hamstring, gastrocnemius, soleus, and popliteus.

CONCLUSIONS

Neuromuscular deficits are evident across different structural KOA severities and are seen in muscle strength, voluntary activation, muscle size, and force control ability. Women may exhibit these alterations to a greater extent than men.

PROSPERO REGISTRATION NUMBER

CRD42019160845.

Factors affecting pain and physical functions in patients with knee osteoarthritis: An observational study

Knee osteoarthritis (KOA) is more common as people age and have a higher body mass index (BMI). We must know the role of various factors in pain and physical functions in patients with KOA. Therefore, the present study sought to examine the factors associated with pain and physical functions in individuals with KOA. This cross-sectional observational study included patients with KOA (n = 125; 57 men, 68 women; mean age 52.9 years). Using the visual analogue scale and a reduced version of the Western Ontario McMaster Universities Osteoarthritis Index, pain severity and physical functions were assessed. Demographic factors such as age, BMI, sex, and Kellgren-Lawrence (K/L) radiographic grade of KOA were analyzed. Age (R = 0.263, P < .001), BMI (R = 0.379, P < .001), and K/L grade (R = 0.844, P < .001) were significantly associated with knee pain. Similarly, age (R = 0.310, P < .001), BMI (R = 0.374, P < .001), and K/L grade (R = 0.862, P < .001) were associated with physical functions. No significant association of sex with pain (R = 0.071, P = .440) and physical functions (R = 0.055, P = .545) was observed. Age, BMI, and K/L grade explained 71% and 74% of knee pain and physical functions, respectively. Age, BMI, and radiographic (K/L) grades were associated with pain and physical functions in patients with KOA. K/L grade was the most significant predictor of pain and physical functions in KOA.

Synovial Macrophages Expression of OX40L Is Required for Follicular Helper T Cells Differentiation in the Joint Microenvironment

Signaling via the OX40/OX40L axis plays a key role in CD4⁺ T cell development, and OX40L expression is primarily restricted to antigen-presenting cells (APCs). This study was designed to assess the role of APC-mediated OX40L expression in the context of the development of rheumatoid arthritis (RA)-associated CD4⁺ T cell subsets. For these analyses, clinical samples were harvested from patients with osteoarthritis and RA, with additional analyses performed using OX40^−/− mice and mice harboring monocyte/macrophage-specific deletions of OX40L. Together, these analyses revealed tissue-specific roles for OX40/OX40L signaling in RA. Specifically, higher levels of synovial macrophage OX40L expression were associated with the enhanced development of T follicular helper cells in the joint microenvironment, thereby contributing to the pathogenesis of RA. This Tfh differentiation was found to be OX40/OX40L-dependent in this synovial setting. Overall, these results indicate that the expression of OX40L by synovia macrophages is necessary to support Tfh differentiation in the joint tissues, thus offering new insight regarding the etiological basis for RA progression.

Risk factors of knee osteoarthritis in Bangladeshi adults: a national survey

BACKGROUND

Knee osteoarthritis was reported as the second most prevalent condition in the national musculoskeletal survey. The purpose of this extended study was to identify risk factors for knee osteoarthritis in Bangladeshi adults.

METHODS

This cross-sectional study was conducted in rural and urban areas of Bangladesh using stratified multistage cluster sample of 2000 adults aged 18 years or older recruited at their households. The Modified Community Oriented Program for Control of Rheumatic Disorders (COPCORD) questionnaire was used to collect data. The diagnosis of knee osteoarthritis was made using the decision tree clinical categorization criteria of the American College of Rheumatology. Univariate and multivariate logistic regression analyses were done to identify the risk factors for knee osteoarthritis.

RESULTS

A total of 1843 individuals (892 men and 951 women) participated, and 134 had knee osteoarthritis yielding a prevalence of 7.3% (95% confidence interval (CI) 4.9 to 9.6%). The mean (standard deviation) age of the knee osteoarthritis patients was 51.7 (11.2) years. Multivariate logistic regression analysis found a significant association with increasing age (≥38 years OR 8.9, 95% CI 4.8-16.5; ≥58 years OR 13.9, 95% CI 6.9-28.0), low educational level (OR 1.7, 95% CI 1.0-2.7) and overweight (OR 1.9, 95% CI 1.2-2.9) with knee osteoarthritis. Knee osteoarthritis patients had a high likelihood of having work loss preceding 12 months (age and sex-adjusted OR 2.3; 95% CI 1.4-3.8; P < 0.01).

CONCLUSIONS

Knee osteoarthritis is a commonly prevalent musculoskeletal problem among Bangladeshi adults having link to work loss. Increasing age, low education and overweight are significant risk factors of knee osteoarthritis.

A Multicenter, Randomized, Double-Blinded, Parallel-Group, Placebo-Controlled Phase I/IIa Study to Evaluate the Efficacy and Safety of a Single Intra-Articular Injection of YYD302 in Patients with Knee Osteoarthritis

This study was a phase I/IIa, multicenter, randomized, double-blinded, parallel, placebo-controlled clinical trial that aimed to assess the efficacy and safety of a single intra-articular injection of YYD302, a novel high-molecular-weight hyaluronic acid with divinyl sulfone cross-linking. Thirty adults with knee osteoarthritis were randomized to receive a single 2 mL intra-articular injection of YYD302 (test group 1), 3 mL of YYD302 (test group 2), or 3 mL of the placebo (placebo group). We compared the changes from the baseline in the weight-bearing pain of 100 mm using the Visual Analog Scale (VAS), the Knee Injury and Osteoarthritis Outcome Score (KOOS), the Rheumatology-Osteoarthritis Research Society International (OMERACT-OASRSI) responder rates, and the use of rescue analgesics to assess the safety of this novel drug. A total of 26 subjects (10 in test group 1, 10 in test group 2, and 6 in the placebo group) were included in the full analysis set. At 12 weeks, only test groups 1 and 2 showed significant changes in the weight-bearing pain VAS scores (p = 0.0015 and p = 0.0085), symptoms, and average daily KOOS values compared to the baseline (p < 0.001, p = 0.0124, and p = 0.0018, p = 0.0426, respectively). While the rate and frequency of consuming the rescue drug continued to increase in the placebo group until 12 weeks, there was no change in the test groups. Our findings showed that YYD302, especially 2 mL of YYD302, reduced pain and improved knee joint function compared to the placebo.

Tai Chi Improves Brain Functional Connectivity and Plasma Lysophosphatidylcholines in Postmenopausal Women With Knee Osteoarthritis: An Exploratory Pilot Study

Objective: A pre/post pilot study was designed to investigate neurobiological mechanisms and plasma metabolites in an 8-week Tai-Chi (TC) group intervention in subjects with knee osteoarthritis.

Methods: Twelve postmenopausal women underwent Tai-Chi group exercise for 8 weeks (60 min/session, three times/week). Outcomes were measured before and after Tai Chi intervention including pain intensity (VAS), Brief Pain Inventory (BPI), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), plasma metabolites (amino acids and lipids), as well as resting-state functional magnetic resonance imaging (rs-fMRI, 10 min, eyes open), diffusion tensor imaging (DTI, 12 min), and structural MRI (4.5 min) in a subgroup. Clinical data was analyzed using paired t-tests; plasma metabolites were analyzed using Wilcoxon signed-rank tests; and rs-fMRI data were analyzed using seed-based correlations of the left and right amygdala in a two-level mixed-effects model (FSL software). Correlations between amygdala-medial prefrontal cortex (mPFC) connectivity and corresponding changes in clinical outcomes were examined. DTI connectivity of each amygdala was modeled using a Bayesian approach and probabilistic tractography. The associations between neurobiological effects and pain/physical function were examined.

Results: Significant pre/post changes were observed with reduced knee pain (VAS with most pain: p = 0.018; WOMAC-pain: p = 0.021; BPI with worst level: p = 0.018) and stiffness (WOMAC-stiffness, p = 0.020), that likely contributed to improved physical function (WOMAC-physical function: p = 0.018) with TC. Moderate to large effect sizes pre/post increase in rs-fMRI connectivity were observed between bilateral mPFC and the amygdala seed regions (i.e., left: d = 0.988, p = 0.355; right: d = 0.600, p = 0.282). Increased DTI connectivity was observed between bilateral mPFC and left amygdala (d = 0.720, p = 0.156). There were moderate-high correlations (r = 0.28–0.60) between TC-associated pre-post changes in amygdala-mPFC functional connectivity and pain/physical function improvement. Significantly higher levels of lysophosphatidylcholines were observed after TC but lower levels of some essential amino acids. Amino acid levels (alanine, lysine, and methionine) were lower after 8 weeks of TC and many of the lipid metabolites were higher after TC. Further, plasma non-HDL cholesterol levels were lower after TC.

Conclusion: This pilot study showed moderate to large effect sizes, suggesting an important role that cortico-amygdala interactions related to TC have on pain and physical function in subjects with knee osteoarthritis pain. Metabolite analyses revealed a metabolic shift of higher lyso-lipids and lower amino acids that might suggest greater fatty acid catabolism, protein turnover and changes in lipid redistribution in response to TC exercise. The results also support therapeutic strategies aimed at strengthening functional and structural connectivity between the mPFC and the amygdala. Controlled clinical trials are warranted to confirm these observed preliminary effects.

Neuropathic pain in the IMI-APPROACH knee osteoarthritis cohort: prevalence and phenotyping

Objectives

Osteoarthritis (OA) patients with a neuropathic pain (NP) component may represent a specific phenotype. This study compares joint damage, pain and functional disability between knee OA patients with a likely NP component, and those without a likely NP component.

Methods

Baseline data from the Innovative Medicines Initiative Applied Public-Private Research enabling OsteoArthritis Clinical Headway knee OA cohort study were used. Patients with a painDETECT score ≥19 (with likely NP component, n=24) were matched on a 1:2 ratio to patients with a painDETECT score ≤12 (without likely NP component), and similar knee and general pain (Knee Injury and Osteoarthritis Outcome Score pain and Short Form 36 pain). Pain, physical function and radiographic joint damage of multiple joints were determined and compared between OA patients with and without a likely NP component.

Results

OA patients with painDETECT scores ≥19 had statistically significant less radiographic joint damage (p≤0.04 for Knee Images Digital Analysis parameters and Kellgren and Lawrence grade), but an impaired physical function (p<0.003 for all tests) compared with patients with a painDETECT score ≤12. In addition, more severe pain was found in joints other than the index knee (p≤0.001 for hips and hands), while joint damage throughout the body was not different.

Conclusions

OA patients with a likely NP component, as determined with the painDETECT questionnaire, may represent a specific OA phenotype, where local and overall joint damage is not the main cause of pain and disability. Patients with this NP component will likely not benefit from general pain medication and/or disease-modifying OA drug (DMOAD) therapy. Reserved inclusion of these patients in DMOAD trials is advised in the quest for successful OA treatments.

Trial registration number

The study is registered under clinicaltrials.gov nr: NCT03883568.

Association of polymorphisms in ADAMTS-5 gene with the susceptibility to knee osteoarthritis: A protocol for systematic review and meta-analysis

BACKGROUND

To systematically review literature evidence to discover the association of ADAMTS5 (A Disintegrin And Metalloproteinase with Thrombospondin-like motifs 5) gene polymorphisms and the risk of developing KOA (knee osteoarthritis).

METHODS

We systematically searched the related randomized controlled trials in 4 databases from inception to August 2021, including the Embase, Web of Science, PubMed, and CNKI (Chinese National Knowledge Infrastructure) databases. No language and publication status restrictions. Two reviewers will independently screen all included studies, and the meta-analysis will be conducted using the Review Manager (RevMan 5.3, Cochrane Collaboration, Nordic Cochrane Center, Copenhagen, Denmark).

RESULTS

The gathered evidence suggests that there may be a close relationship between the SNP in the ADAMTS5 gene and KOA development. This study will provide a high-quality and convincing evaluation of the treatment of KOA from the consideration of ADAMTS5 gene and will be published in a peer-reviewed journal.

CONCLUSION

ADAMTS5 polymorphism is likely an important risk factor for the development of KOA. Our study will provide a more accurate treatment method for the treatment of KOA.

TRIAL REGISTRATION NUMBER

CRD42021276317.

Early-stage symptomatic osteoarthritis of the knee - time for action

Osteoarthritis (OA) remains the most challenging arthritic disorder, with a high burden of disease and no available disease-modifying treatments. Symptomatic early-stage OA of the knee (the focus of this Review) urgently needs to be identified and defined, as efficient early-stage case finding and diagnosis in primary care would enable health-care providers to proactively and substantially reduce the burden of disease through proper management including structured education, exercise and weight management (when needed) and addressing lifestyle-related risk factors for disease progression. Efforts to define patient populations with symptomatic early-stage knee OA on the basis of validated classification criteria are ongoing. Such criteria, as well as the identification of molecular and imaging biomarkers of disease risk and/or progression, would enable well-designed clinical studies, facilitate interventional trials, and aid the discovery and validation of cellular and molecular targets for novel therapies. Treatment strategies, relevant outcomes and ethical issues also need to be considered in the context of the cost-effective management of symptomatic early-stage knee OA. To move forwards, a multidisciplinary and sustained international effort involving all major stakeholders is required.

Low Rates of Radiographic Knee Osteoarthritis 5 Years After ACL Reconstruction or Rehabilitation Alone: The Delaware-Oslo ACL Cohort Study

BACKGROUND

Patients and clinicians often struggle to choose the optimal management strategy for posttraumatic knee osteoarthritis (OA) after an anterior cruciate ligament (ACL) injury. An evaluation of radiographic outcomes after a decision-making and treatment algorithm applicable in clinical practice can help to inform future recommendations and treatment choices.

PURPOSE

To describe and compare 5-year radiographic outcomes and knee pain in individuals who had gone through our decision-making and treatment algorithm and chosen (1) early (<6 months) ACL reconstruction (ACLR) with pre- and postoperative rehabilitation, (2) delayed (>6 months) ACLR with pre- and postoperative rehabilitation, or (3) progressive rehabilitation alone.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

We included 276 patients with unilateral ACL injury from a prospective cohort study. Patients chose management using a shared decision-making process and treatment algorithm, and 5-year postoperative radiographs of the index and contralateral knees were assessed using the Kellgren and Lawrence (K&L) classification and minimum joint space width measurements. We defined radiographic tibiofemoral OA as K&L grade ≥2 and knee pain as a Knee injury and Osteoarthritis Outcome Score for Pain ≤72. To further explore early radiographic changes, we included alternative cutoffs for radiographic knee OA using K&L grade ≥2/osteophyte (definite osteophyte without joint space narrowing) and K&L grade ≥1.

RESULTS

At 5 years, 64% had undergone early ACLR; 11%, delayed ACLR; and 25%, progressive rehabilitation alone. Radiographic examination was attended by 187 patients (68%). Six percent of the cohort had radiographic tibiofemoral OA (K&L grade ≥2) in the index knee; 4%, in the contralateral knee. Using the alternative cutoffs at K&L grade ≥2/osteophyte and K&L grade ≥1, the corresponding numbers were 20% and 33% in the index knee and 18% and 29% in the contralateral knee. Six percent had a painful index knee. There were no statistically significant differences in any radiographic outcomes or knee pain among the 3 management groups.

CONCLUSION

There were no statistically significant differences in any 5-year radiographic outcomes or knee pain among the 3 management groups. Very few of the patients who participated in our decision-making and treatment algorithm had knee OA or knee pain at 5 years.

The effect of Wuqinxi exercises on the balance function and subjective quality of life in elderly, female knee osteoarthritis patients

OBJECTIVE

To investigate the balance function and subjective quality of life in elderly female knee osteoarthritis patients KOAKOA treated with Wuqinxi exercises.

METHODS

A total of 284 elderly female patients with knee osteoarthritis (KOA) were randomly divided into an experimental group, which did Wuqinxi exercises for 24-weeks (n=132), and a control group, which didn't do any regular physical exercises (n=134). The experimental group did Wuqinxi exercises for 24 weeks, and the control group didn't engage in any regular physical exercise. We performed limits of stability (LOS) tests, static posture stability (SPS) tests, and dynamic fall index (DFI) tests to assess the patients' balance, and we administered the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire to evaluate the physical functioning of the patients' knees.

RESULTS

The limits of stability (LOS) test, the static posture stability (SPS) test, and the dynamic fall index (DFI) test results were improved in the experimental group compared with the control group (P < 0.05). From baseline to the week 24 follow-up, the WOMAC tests, and the pain, joint stiffness, and lower limb muscle strength showed significant differences between the two groups (P < 0.05).

CONCLUSIONS

Wuqinxi exercises are an effective treatment for elderly female patients with knee osteoarthritis, and can improve their balance and subjective quality of life. The therapy effectively alleviates the clinical symptoms of the elderly female knee osteoarthritis patients.

Lack of association between MMP13 (rs3819089), ADAM12 (rs3740199-rs1871054) and ADAMTS14 (rs4747096) genotypes and advanced-stage knee osteoarthritis

Objectives

The aim of this study was to investigate the relationship between MMP13 rs3819089, ADAM12 rs3740199 and rs1871054, and ADAMTS14 rs4747096 genotypes in patients with radiologically diagnosed knee osteoarthritis (OA).

Patients and methods

A total of 300 patients (68 males, 232 females; mean age: 61.6 years; range, 25 to 89 years) who were admitted to the orthopedics and traumatology clinic and diagnosed with knee OA according to the 2000 American College of Rheumatology (ACR) criteria between October 2018 and March 2019 were prospectively analyzed. Patients with Grades III-IV OA according to the Kellgren- Lawrence (K-L) grading system were included in the patient group (n=150) and those without radiological features of knee OA (K-L Grades I-II) were included in the control group (n=150) voluntarily. The presence of single nucleotide polymorphisms (SNPs) in the targeted genes in both groups was assessed by real-time polymerase chain reaction in the peripheral blood sample.

Results

The most common nucleotides in both the control and patient groups were CG for rs3740199 and CT for rs1871054 in the ADAM12 gene, and the most common nucleotides in alleles were GG for MMP13 rs3819089 and AA for ADAMTS14 rs4747096. No statistically significant relationship was detected between the gene polymorphisms and advanced OA.

Conclusion

The study results suggest that ADAM12 rs3740199 and rs1871054, MMP13 rs3819089, and ADAMTS14 rs4747096 polymorphisms have no relationship with knee OA susceptibility in the Turkish population. However, as this is the first study to investigate the relationship between the SNPs of ADAM12, ADAMTS14, and MMP13 genes and the development of OA in the Turkish population, it would contribute to our understanding of the molecular bases of OA.

Towards developing diagnostic criteria for early knee osteoarthritis: data from the CHECK study

Objectives

There is a general consensus that a shift in focus towards early diagnosis and treatment of knee OA is warranted. However, there are no validated and widely accepted diagnostic criteria for early knee OA available. The current study aimed to take the first steps towards developing diagnostic criteria for early knee OA.

Methods

Data of 761 individuals with 1185 symptomatic knees at baseline were selected from the CHECK study. For CHECK, individuals with pain/stiffness of the knee, aged 45–65 years, who had no prior consultation or a first consultation with the general practitioner for these symptoms in the past 6 months were recruited and followed for 10 years. A group of 36 experts (17 general practitioners and 19 secondary care physicians) evaluated the medical records in pairs to diagnose the presence of clinically relevant knee OA 5–10 years after enrolment. A backward selection methods was used to create predictive models based on pre-defined baseline factors from history taking, physical examination, radiography and blood testing, using the experts’ diagnoses as gold standard outcome.

Results

Prevalence of clinically relevant knee OA during follow-up was 37%. Created models contained 7–11 baseline factors and obtained an area under the curve between 0.746 (0.002) and 0.764 (0.002).

Conclusion

The obtained diagnostic models for early knee OA had ‘fair’ predictive ability in individuals presenting with knee pain in primary care. Further modelling and validation of the identified predictive factors is required to obtain clinically feasible and relevant diagnostic criteria for early knee OA.

Pharmacological Targeting of Heme Oxygenase-1 in Osteoarthritis

Osteoarthritis (OA) is a common aging-associated disease that clinically manifests as joint pain, mobility limitations, and compromised quality of life. Today, OA treatment is limited to pain management and joint arthroplasty at the later stages of disease progression. OA pathogenesis is predominantly mediated by oxidative damage to joint cartilage extracellular matrix and local cells such as chondrocytes, osteoclasts, osteoblasts, and synovial fibroblasts. Under normal conditions, cells prevent the accumulation of reactive oxygen species (ROS) under oxidatively stressful conditions through their adaptive cytoprotective mechanisms. Heme oxygenase-1 (HO-1) is an iron-dependent cytoprotective enzyme that functions as the inducible form of HO. HO-1 and its metabolites carbon monoxide and biliverdin contribute towards the maintenance of redox homeostasis. HO-1 expression is primarily regulated at the transcriptional level through transcriptional factor nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2), specificity protein 1 (Sp1), transcriptional repressor BTB-and-CNC homology 1 (Bach1), and epigenetic regulation. Several studies report that HO-1 expression can be regulated using various antioxidative factors and chemical compounds, suggesting therapeutic implications in OA pathogenesis as well as in the wider context of joint disease. Here, we review the protective role of HO-1 in OA with a focus on the regulatory mechanisms that mediate HO-1 activity.

Effects of dry cupping on pain, function and quality of life in women with knee osteoarthritis: a protocol for a sham-controlled randomised trial

INTRODUCTION

Knee osteoarthritis (KOA) is the most common cause of pain and disability worldwide. Dry cupping has been used as non-pharmacological approach to control pain and improve physical function. However, there is a lack of high-quality scientific evidence regarding its effects on this condition. This protocol describes a sham-controlled, randomised and simple blind study that aims to evaluate the effect of dry cupping on pain, function and quality of life in women with KOA.

METHODS AND ANALYSIS

Sixty-two women diagnosed with KOA, based on American College of Rheumatology clinical criteria, and aged from 50 to 75 years, will be randomly distributed into two groups (31 per group): real and sham dry cupping. Both applications will occur with acrylic cups around the knee. The intervention will last 15 min, two times a week over six consecutive weeks, for a total of 12 sessions. Both groups will be assessed at four different times: before the intervention (T0), after 3 weeks intervention (T3), at the end of the protocol (T6) and 4 weeks after the interventions (follow-up: T10). The primary outcome will be pain intensity (Numerical Pain Rating Scale), and secondary outcomes will be knee-related health status (Western Ontario and McMaster Universities Osteoarthritis Index), functional capacity (8-step stair climb test, 40-metre fast-paced walk test and 30-second chair stand test), quality of life (Short-Form 36) and global perceived effect.

ETHICS AND DISSEMINATION

This protocol was approved by the UFRN/FACISA Ethics Committee (number 3.737.688). The study results will be disseminated to the participants and submitted to a peer-reviewed journal and scientific meetings.

TRIAL REGISTRATION NUMBER

NCT04331158.

Prevalence of musculoskeletal conditions and related disabilities in Bangladeshi adults: a cross-sectional national survey

BACKGROUND

Nationally representative data on burden of musculoskeletal conditions (MSK) in Bangladesh are not available. The objective of this study was to determine the prevalence of MSK conditions and related disabilities in the adult population of Bangladesh.

METHODS

A total of 2000 individuals aged 18 years or older were targeted from 20 primary sampling units (urban and rural) of all former seven divisions of Bangladesh in 2015. Structured interviews were done using the modified Community Oriented Program for Control of Rheumatic Disorders questionnaire to detect positive respondents. Standard criteria were used for diagnosing MSK conditions by rheumatology residents. In case of uncertainty, opinion was taken from senior rheumatologists. A Bangla version of the Health Assessment Questionnaire was used to determine disability.

RESULTS

A total of 1843 (92.1%) participated. Among them, 892 men and 951 women participated from rural (n = 716) and urban (n = 1127) areas. Their mean age was 40.5 (standard deviation 14.7) years. Almost a third did not have any formal schooling. Overall, 30.4% (95% confidence interval, 28.3-32.5) had MSK conditions. Low back pain (18.6%, 16.9-20.5), knee osteoarthritis (7.3%, 6.1-8.5) and soft tissue rheumatism 3.8% (2.9-4.7) were the three top-ranking MSK conditions. Rheumatoid arthritis (1.6%, 1.0-2.1), spondyloarthritis (1.2%, 7-1.8) and adhesive capsulitis (1.4%, 0.9-1.9) were relatively uncommon. Among those who had MSK conditions, 24.8% (21.3-28.6) had some degree of disability. Of them, 24.4% (21.0-28.1) had history of work loss during last 12 months.

CONCLUSIONS

The high burden of MSK conditions and related disabilities in Bangladesh warrants greater attention of the health system. Further studies are needed to estimate the impact of this group of conditions particularly addressing related disabilities and loss of work.

Comparison of the prevalence of myofascial trigger points of muscles acting on knee between patients with moderate degree of knee osteoarthritis and healthy matched people

INTRODUCTION

Trigger points have been implicated in the development of several musculoskeletal disorders. Trigger points harbored in lower limb muscles might represent a ubiquitous source of pain in patients with knee osteoarthritis (OA). This study was carried out to evaluate the prevalence of Myofascial Trigger Points (MTrPs) in muscles acting on the knee in patients with OA.

METHODS

Thirty-seven patients aged at least 55 years old with a moderate degree of OA (grade III of Kellgren and Lawrence scale) were recruited. Thirty asymptomatic people, matched on age and body mass index, were considered as the control group. Ten muscles acting on the knee joint were selected. Taut bands were also identified using a skin rolling method. A pressure of 3 kg/cm² was used to identify myofascial trigger points in all muscles except the popliteus (8 kg/cm²).

RESULTS

Chi-square was performed to compare the prevalence of trigger points between the groups. The McNemar test was administered to compare the prevalence of trigger points in the right and left sides of participants. Prevalence of the trigger points was significantly higher in patients with knee OA compared with asymptomatic people in all muscles except for right (p = 0.17) and left (p = 0.41) rectus femoris, right (p = 0.61) and left (p = 0.22) sartorius and left biceps femoris (p = 0.08). Comparison of the prevalence of MTrPs bilaterally revealed that only the right and left sartorius differed significantly (p = 0.008).

CONCLUSIONS

The prevalence of MTrPs in the muscles acting on the knee joint is higher in patients with a moderate degree of knee OA compared with asymptomatic subjects.

Abortion is associated with knee osteoarthritis among older women in China: A STROBE-compliant article

The current studies revealed inconsistent relationship between reproductive factors and osteoarthritis. Community-based research has not been conducted in China. The study was to examine the association of reproductive factors with the prevalence of knee osteoarthritis (OA).Through a multistage stratified random sampling method, 10 streets or villages from 5 cities in Hunan province were randomly selected, a total 2746 eligible women aged 50 to 83 were recruited in this cross-sectional study. A structured questionnaire including demographic factors, socio-economic status, reproductive factors, and knee OA was used. According to the criteria of American College of Rheumatology, clinical knee OA was assessed by doctors in community or village health clinics for knee pain, age, morning stiffness, crepitus on active motion or for knee pain, morning stiffness, crepitus on active motion, and tenderness of the bony navigation of the joint. Self-reported age of menarche, parity, abortion history, and menopausal status were collected.The prevalence of knee OA was 13.44%. Abortion is associated with knee OA (odds ratio [OR] = 1.271, 95% confidence interval [CI] = 1.007, 1.606), but age at menarche, parity, and menopausal status were not the factors. Furthermore, age (OR = 1.040, 95% CI = 1.020, 1.060), weight (OR = 1.019, 95% CI = 1.004, 1.035), higher education level (OR = 1.530, 95% CI = 1.121, 2.088), higher monthly household income (OR = .583, 95% CI = 0.441, 0.770 for 3000-4999 ¥ and OR = 0.599, 95% CI = 0.431, 0.833 for 5000 ¥ or more), and chronic gastritis (OR = 3.364, 95% CI = 2.548, 4.442) were associated with knee OA.Abortion may increase the risk of knee OA. Special attention should be paid to women with a history of abortion, and women who are planning to abort should be informed of the risk of knee OA later in life. The relationship between abortion and knee OA should be interpreted with caution and further confirmed.

Comparison of three sets of clinical classification criteria for knee osteoarthritis: a cross-sectional study of 13,459 patients treated in primary care

OBJECTIVE

To determine and compare the proportion of patients treated in a primary care setting that have knee osteoarthritis (OA) according to the European League Against Rheumatism (EULAR), the American College of Rheumatology (ACR), and the National Institute for Health and Care Excellence (NICE) clinical classification criteria.

DESIGN

A cross-sectional analysis of baseline data from 13,459 patients with knee symptoms or functional limitations associated with OA participating in the Good Life with osteoArthritis in Denmark (GLA:D®) treatment program. The prevalence of knee OA according to the EULAR, ACR and NICE criteria were calculated in all participants and in the subgroup of patients with self-reported radiographic changes associated with knee OA (n = 10,651 or 79%).

RESULTS

Mean age (SD) was 65.3 (9.8) years, median (IQR) duration of symptoms 12 (6-36) months and mean pain intensity (0-100; SD) 46.5 (22.1) mm. 39% fulfilled all three sets of criteria. 48%, 52% and 89% fulfilled the EULAR, ACR, and NICE criteria for having knee OA, respectively. In the subgroup with self-reported radiographic changes, the corresponding numbers were 49%, 54% and 90%.

CONCLUSIONS

While the EULAR and ACR criteria only identified around half of those, with or without self-reported radiographic knee OA, that were treated because of symptoms or functional limitations associated with knee OA, the NICE criteria identified most patients. The results indicate that the NICE criteria are relevant and appropriate to identify individuals treated for knee OA in primary care.

A Stimulus-Response Framework to Investigate the Influence of Continuous Versus Interval Walking Exercise on Select Serum Biomarkers in Knee Osteoarthritis

OBJECTIVE

The aim of the study was to compare changes in the concentration of serum biomarkers in response to continuous versus interval walking exercise in participants with knee osteoarthritis.

DESIGN

This study used a two-phase sequential design. Twenty-seven participants with unilateral knee osteoarthritis completed two separate treadmill walking sessions: (1) continuous 45-min walking exercise and (2) three 15-min bouts of walking exercise separated by 1-hr rest periods for a total of 45 mins in an interval format. Participants reported their knee pain using the numeric pain rating scale and serum levels of biomarkers associated with tissue turnover (cartilage oligomeric matrix protein), inflammation (tumor necrosis factor α), and pain (neuropeptide Y) were evaluated at baseline and every 15 mins for both conditions.

RESULTS

Continuous walking resulted in a cumulative increase in cartilage oligomeric matrix protein concentration up to 45 mins, whereas interval walking was associated with return of cartilage oligomeric matrix protein concentrations back to baseline at 45 mins. There were no significant changes in tumor necrosis factor α and neuropeptide Y concentration during walking. There was a significant increase in pain compared with baseline in the continuous walking regimen only.

CONCLUSIONS

Incorporating rest breaks in walking regimens may affect the potential deleterious effects of longer continuous bouts on the knee joint as well as limit pain during exercise.

Risk factors for development of lower limb osteoarthritis in physically demanding occupations: A narrative umbrella review

Objectives

Osteoarthritis (OA) is a common disorder which affects the joints. As relationships between occupational factors and lower limb OA have been widely studied in systematic reviews, the aim of this umbrella review was to synthesize their key findings in the risk factors for development of lower limb OA.

Methods

A systematic search was conducted using the databases PUBMED, Cumulative Index of Nursing and Allied Health Literature, and Elton B Stevens Company to identify reviews examining associations between lower limb OA and occupational tasks. These reviews were rated for their methodological quality before key data were extracted and synthesized.

Results

Sixteen reviews were found, seven pertained to the knee, four to the hip, two to a variety of joints, and three to both the hip and knee. One was deemed to be of high methodological quality, one of critically low methodological quality, and the others of moderate methodological quality. The reviews found moderate to good evidence for heavy occupational lifting to be associated with an increased risk of OA at the knee and the hip. Kneeling, squatting, and climbing, previous injuries to joints, being overweight and obese were also predictive of lower limb OA.

Conclusion

Occupations which involve heavy physical workloads increase the risk of developing lower limb OA. Heavy lifting, squatting, knee bending, kneeling, and climbing may all increase the risk of developing OA in both the knees and hips. Efforts to reduce exposure to these tasks, reducing joint injuries, optimizing bodyweight may reduce the risks of lower limb OA for occupations which are physically demanding.

Consumption of dairy products in relation to the presence of clinical knee osteoarthritis: The Maastricht Study

PURPOSE

Observational studies showed inverse associations between milk consumption and knee osteoarthritis (knee OA). There is lack of information on the role of specific dairy product categories. We explored the association between dairy consumption and the presence of knee osteoarthritis in 3010 individuals aged 40-75 years participating in The Maastricht Study.

METHODS

The presence of knee OA was defined according to a slightly modified version of the American College of Rheumatology (ACR) clinical classification criteria. Data on dairy consumption were appraised by a 253-item FFQ covering 47 dairy products with categorization on fat content, fermentation or dairy type. Multivariable logistic regression analyses were performed to estimate odd ratios (ORs) and 95% confidence intervals (95%CI), while correcting for relevant factors.

RESULTS

427 (14%) participants were classified as having knee OA. Significant inverse associations were observed between the presence of knee OA and intake of full-fat dairy and Dutch, primarily semi-hard, cheese, with OR for the highest compared to the lowest tertile of intake of 0.68 (95%CI 0.50-0.92) for full-fat dairy, and 0.75 (95%CI 0.56-0.99) for Dutch cheese. No significant associations were found for other dairy product categories.

CONCLUSION

In this Dutch population, higher intake of full-fat dairy and Dutch cheese, but not milk, was cross-sectionally associated with the lower presence of knee OA. Prospective studies need to assess the relationship between dairy consumption, and in particular semi-hard cheeses, with incident knee OA.

The clinical and radiographic course of early knee and hip osteoarthritis over 10 years in CHECK (Cohort Hip and Cohort Knee)

OBJECTIVE

To describe the radiographic and symptomatic course in subjects with hip or knee complaints suspected of early osteoarthritis (OA).

DESIGN

CHECK (Cohort Hip and Cohort Knee) is a multicenter, prospective observational cohort study of 1,002 subjects with first complaints in knee(s) and/or hip(s) (age 56 ± 5 years; 79% female; body mass index (BMI) 26 ± 4 kg/m²). Visits took place at baseline and at 2, 5, 8, and 10 year follow-up. At each visit, questionnaires were administered, physical examination performed, and X-ray images obtained. Clinical OA was defined according to the clinical American College of Rheumatism (ACR) criteria. Radiographic OA (ROA) was defined as Kellgren and Lawrence score (K&L) ≥2.

RESULTS

83% of the subjects reported knee pain, 59% hip pain, and 42% reported both hip and knee pain at baseline. 85% of the subjects completed 10-year follow-up. Pain scores remained rather stable over time, although individual scores fluctuated. A total of 138 subjects never fulfilled the clinical American College of Rheumatology (ACR) criteria. 60% (n = 601) had ROA in one or both knees, and 51% (n = 513) had ROA in one or both hips at 10 years. Only 13.5% of the subjects did not develop ROA after 10 years. Most joint replacements (n = 52 (57%)) took place in subjects with multiple affected joints.

CONCLUSIONS

The symptomatic course in subjects with hip or knee complaints suspected of OA remained fairly stable on population level, though individual scores fluctuated. The radiological course was progressive, with joint replacements particularly in subjects with both hip and knee OA.

Identification of Knee Osteoarthritis Based on Bayesian Network: Pilot Study

Background

Early identification of knee osteoarthritis (OA) can improve treatment outcomes and reduce medical costs. However, there are major limitations among existing classification or prediction models, including abstract data processing and complicated dataset attributes, which hinder their applications in clinical practice.

Objective

The aim of this study was to propose a Bayesian network (BN)–based classification model to classify people with knee OA. The proposed model can be treated as a prescreening tool, which can provide decision support for health professionals.

Methods

The proposed model’s structure was based on a 3-level BN structure and then retrained by the Bayesian Search (BS) learning algorithm. The model’s parameters were determined by the expectation-maximization algorithm. The used dataset included backgrounds, the target disease, and predictors. The performance of the model was evaluated based on classification accuracy, area under the curve (AUC), specificity, sensitivity, positive predictive value (PPV), and negative predictive value (NPV); it was also compared with other well-known classification models. A test was also performed to explore whether physical fitness tests could improve the performance of the proposed model.

Results

A total of 249 elderly people between the ages of 60 and 80 years, living in the Kongjiang community (Shanghai), were recruited from April to September 2007. A total of 157 instances were adopted as the dataset after data preprocessing. The experimental results showed that the results of the proposed model were higher than, or equal to, the mean scores of other classification models: .754 for accuracy, .78 for AUC, .78 for specificity, and .73 for sensitivity. The proposed model provided .45 for PPV and .92 for NPV at the prevalence of 20%. The proposed model also showed a significant improvement when compared with the traditional BN model: 6.3% increase in accuracy (from .709 to .754), 4.0% increase in AUC (from .75 to .78), 6.8% increase in specificity (from .73 to .78), 5.8% increase in sensitivity (from .69 to .73), 15.4% increase in PPV (from .39 to .45), and 2.2% increase in NPV (from .90 to .92). Furthermore, the test results showed that the performance of the proposed model could be largely enhanced through physical fitness tests in 3 evaluation indices: 10.6% increase in accuracy (from .682 to .754), 16.4% increase in AUC (from .67 to .78), and 30.0% increase in specificity (from .60 to .78).

Conclusions

The proposed model presents a promising method to classify people with knee OA when compared with other classification models and the traditional BN model. It could be implemented in clinical practice as a prescreening tool for knee OA, which would not only improve the quality of health care for elderly people but also reduce overall medical costs.

BDNF and serum S100B levels according the spectrum of structural pathology in chronic pain patients

Central sensitivity syndrome (CSS) consists of adaptive pathophysiological changes associated with neuroplasticity in some chronic pain disorders. It could be grouped in two main conceptual conditions: one includes those chronic pain patients without overt structural pathology such as fibromyalgia, and the other subgroup includes conditions with recognizable structural abnormalities, both somatic (osteoarthritis) and visceral (endometriosis). In order to understand the role of neuromodulators in CCS we aim to determine whether brain-derived neurotrophic factor (BDNF) and S100B are associated to specific chronic pain disorders. Serum BDNF and S100B were measured in chronic pain women with different diagnosis: 88 with osteoarthritis, 36 with endometriosis, 117 with fibromyalgia, 33 with chronic tension type headache and in 41 healthy controls. ANCOVA analysis followed by heteroscedasticity-consistent covariance matrix was performed to evaluate BDNF and S100B levels, adjusted for depression severity, pain levels and use of analgesics according different pathologies. Serum BDNF concentrations were higher and not different in patients with fibromyalgia and headache, the CSS group without structural pathology. In contrast, the concentrations of S100B were higher in patients with osteoarthritis and endometriosis, in comparison to controls, fibromyalgia and tensional headache patients. This study supports the hypothesis that BDNF and S100B neuromodulators present different serum levels according to the background disease associated to the chronic pain. These have the potential to be studied as markers of active disease or treatment evolution.

Strawberries decrease circulating levels of tumor necrosis factor and lipid peroxides in obese adults with knee osteoarthritis

OBJECTIVE

Knee osteoarthritis (OA) is increasingly prevalent in obese people, who often have high cardio-metabolic risk factors. Among the few available non-surgical approaches, nutraceuticals have gained popularity, and dietary berries have mitigated arthritis symptoms in observational and animal studies. Clinical studies in OA are sparse, but recently we reported that strawberry supplementation can mitigate pain and reduce inflammatory markers in adults with knee OA. This study extends those observations.

METHODS

We conducted a randomized cross-over double-blind placebo-controlled trial on the effects of dietary freeze-dried strawberries on obesity-related hormones, biomarkers of inflammation and lipid peroxidation. Seventeen subjects (4 men, 13 women; age 57 ± 3 year) were randomized to strawberry supplements (50 g day-1 for 12 weeks) vs. placebo (50 g day-1, matched for calories and fiber), for two 12-week intervention periods, separated by 2-week washout phase.

RESULTS

Among 24 biomarkers of inflammation examined (Bioplex-Pro human inflammation panel), 12 were detectable in all samples. Among these, high-sensitivity TNF-α (hs-TNF-α) and the soluble tumor necrosis factor receptor (sTNF-R2) were significantly decreased after strawberry consumption (p < 0.05). There were no changes in other biomarkers of the TNF super family, such as APRIL and BAFF. Among serum biomarkers of oxidative stress, 4-hydroxy-2-nonenal (4-HNE) and conjugated dienes were also reduced (p < 0.05). No changes were observed in body weight, serum obesity-related hormones, or osteocalcin.

CONCLUSION

Strawberries lowered TNF-α, and lipid peroxidation products in obese adults with knee OA. Since, they also mitigate pain, these findings merit further investigation in larger trials.

Isofraxidin targets the TLR4/MD-2 axis to prevent osteoarthritis development

Osteoarthritis (OA) is a major cause of joint pain and disability, resulting in large socioeconomic costs worldwide. Isofraxidin (ISO), a bioactive coumarin compound isolated from the functional foods Siberian ginseng and Apium graveolens, exerts anti-inflammatory effects in a variety of diseases. However, no studies have reported the protective effects of ISO against OA development. Accordingly, this study aimed to assess the therapeutic effect of ISO in human OA chondrocytes, and in a mouse model of OA induced by destabilisation of the medial meniscus (DMM). In vitro, lipopolysaccharide (LPS)-induced overproduction of nitric oxide (NO), prostaglandin E2 (PGE2), tumour necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) was decreased by ISO pre-treatment. Furthermore, ISO attenuated the increased expression of inflammatory enzymes, including inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in response to LPS stimulation. Meanwhile, LPS-induced extracellular matrix (ECM) degradation was also reversed by ISO treatment. Mechanistically, ISO competitively inhibited Toll-like receptor 4 (TLR4)/myeloid differentiation protein-2 (MD-2) complex formation, and thus TLR4/nuclear factor kappa B (NF-κB) signalling cascades. In vivo, ISO treatment not only prevented the calcification and erosion of cartilage, as well as the thickening of subchondral bone, but also reduced the serum levels of inflammatory cytokines in the mouse OA model. Taken together, these data suggest that ISO has potential in the treatment of OA.

Prevalence and development of hip and knee osteoarthritis according to American College of Rheumatology criteria in the CHECK cohort

BACKGROUND

We aimed to evaluate the prevalence of hip and knee osteoarthritis (HOA and KOA) according to American College of Rheumatology (ACR) criteria among participants with suspected early symptomatic osteoarthritis (OA) in the CHECK cohort. We also assessed whether participants not fulfilling ACR criteria at baseline develop ACR-defined OA at 2-year and/or 5-year follow up, and which baseline factors are associated with this development.

METHODS

The CHECK cohort included 1002 subjects with first presentation of knee and/or hip complaints. The primary outcome was onset of HOA and/or KOA according to the ACR criteria, including the clinical classification criteria and the combined clinical and radiographic classification criteria at 2-year and/or 5-year follow up.

RESULTS

Of the participants with hip complaints, 63% (n = 370) were classified as having HOA at baseline according to the ACR criteria. Of those not classified with HOA at baseline, 40% developed HOA according to the clinical or combined clinical/radiographic ACR criteria after 2 and/or 5 years. Up to 92% of participants (n = 829) with knee complaints were classified as having KOA at baseline; of those not classified with KOA at baseline, 55% developed KOA according to the clinical ACR criteria or the clinical/radiographic ACR criteria after 2 and/or 5 years. The following factors were associated with development of HOA: morning stiffness (OR 2.39; 95% CI 1.14-4.98), painful internal rotation (OR 2.53; 95% CI 1.23-5.19), hip flexion < 115° (OR 2.33; 95% CI 1.17-4.64) and erythrocyte sedimentation rate (ESR) < 20 mm/h (OR 2.94; 95% CI 1.13-7.61). No variables were associated with development of KOA at 2-year and/or 5-year follow up.

CONCLUSIONS

A large proportion of persons with hip complaints not fulfilling the ACR criteria at baseline develop HOA after 2 and/or 5 years of follow up. Almost all persons with knee complaints already fulfill the clinical and/or radiographic ACR criteria for OA, and half of the persons not fulfilling criteria at baseline will do so after 5 years of follow up. Several individual ACR criteria for HOA at baseline were associated with the development of HOA at follow up. This association was not proven for KOA, probably because of the small number of subjects developing KOA in this study.

Urolithin A targets the PI3K/Akt/NF-κB pathways and prevents IL-1β-induced inflammatory response in human osteoarthritis: in vitro and in vivo studies

Osteoarthritis (OA) is a degenerative joint disease, whose progression is closely related to the inflammatory environment.

Performance of distinct knee osteoarthritis classification criteria in the ELSA-Brasil musculoskeletal study

OBJECTIVE

To compare the performance of different knee osteoarthritis (OA) classification criteria in a subsample of subjects of ELSA-Brasil Musculoskeletal cohort (ELSA-Brasil MSK) in comparison with the clinical-radiographic evaluation of an experienced rheumatologist.

METHOD

A cross-sectional study of the diagnostic accuracy of different knee OA classification criteria: radiographic OA, symptomatic OA, clinical and clinical-radiographic criteria of the American College of Rheumatology (ACR), and the definition proposed by the National Institute for Health and Care Excellence (NICE), UK. The study also evaluated some alternative definitions of OA including a combination of criteria. In total, 250 subjects participated. Only one knee per subject was included. When both or none of the knees were affected, one knee was randomly selected for analysis. OA prevalence, sensitivity, specificity, positive and negative predictive values, and accuracy were presented (CI 95%; α = 5%).

RESULTS

The mean age was 56.1 years (SD = 8.7), 48.8% female, and 39.2% presented knee OA according to the rheumatologist. The sensitivity and the specificity of radiographic OA were 51% and 96.7%, respectively, while the NICE definition showed 57.0% and 76.3%, respectively. The other OA criteria showed good levels of specificity, but the levels of sensitivity were below 30%. Considering NICE and/or X-ray result in combination, the sensitivity increased (73.4%), while the specificity reduced slightly (73.0%) in relation to the original NICE definition.

CONCLUSIONS

Radiographic OA showed the best performance, followed by NICE definition, especially in combination with X-ray results.

Integration of Gene Expression Profile Data to Screen and Verify Hub Genes Involved in Osteoarthritis

Osteoarthritis (OA) is one of the most common diseases worldwide, but the pathogenic genes and pathways are largely unclear. The aim of this study was to screen and verify hub genes involved in OA and explore potential molecular mechanisms. The expression profiles of GSE12021 and GSE55235 were downloaded from the Gene Expression Omnibus (GEO) database, which contained 39 samples, including 20 osteoarthritis synovial membranes and 19 matched normal synovial membranes. The raw data were integrated to obtain differentially expressed genes (DEGs) and were deeply analyzed by bioinformatics methods. The Gene Ontology (GO) and pathway enrichment of DEGs were performed by DAVID and Kyoto Encyclopedia of Genes and Genomes (KEGG) online analyses, respectively. The protein-protein interaction (PPI) networks of the DEGs were constructed based on data from the STRING database. The top 10 hub genes VEGFA, IL6, JUN, IL1β, MYC, IL4, PTGS2, ATF3, EGR1, and DUSP1 were identified from the PPI network. Module analysis revealed that OA was associated with significant pathways including TNF signaling pathway, cytokine-cytokine receptor interaction, and osteoclast differentiation. The qRT-PCR result showed that the expression level of IL6, VEGFA, JUN, IL-1β, and ATF3 was significantly increased in OA samples (p < 0.05), and these candidate genes could be used as potential diagnostic biomarkers and therapeutic targets of OA.

Harmonising measures of knee and hip osteoarthritis in population-based cohort studies: an international study

OBJECTIVE

Population-based osteoarthritis (OA) cohorts provide vital data on risk factors and outcomes of OA, however the methods to define OA vary between cohorts. We aimed to provide recommendations for combining knee and hip OA data in extant and future population cohort studies, in order to facilitate informative individual participant level analyses.

METHOD

International OA experts met to make recommendations on: 1) defining OA by X-ray and/or pain; 2) compare The National Health and Nutrition Examination Survey (NHANES)-type OA pain questions; 3) the comparability of the Western Ontario & McMaster Universities Osteoarthritis Index (WOMAC) scale to NHANES-type OA pain questions; 4) the best radiographic scoring method; 5) the usefulness of other OA outcome measures. Key issues were explored using new analyses in two population-based OA cohorts (Multicenter Osteoarthritis Study; MOST and Osteoarthritis Initiative OAI).

RESULTS

OA should be defined by both symptoms and radiographs, with symptoms alone as a secondary definition. Kellgren and Lawrence (K/L) grade ≥2 should be used to define radiographic OA (ROA). The variable wording of pain questions can result in varying prevalence between 41.0% and 75.4%, however questions where the time anchor is similar have high sensitivity and specificity (91.2% and 89.9% respectively). A threshold of 3 on a 0-20 scale (95% CI 2.1, 3.9) in the WOMAC pain subscale demonstrated equivalence with the preferred NHANES-type question.

CONCLUSION

This research provides recommendations, based on expert agreement, for harmonising and combining OA data in existing and future population-based cohorts.