Impact of Exercise Therapy on Molecular Biomarkers Related to Cartilage and Inflammation in Individuals at Risk of, or With Established, Knee Osteoarthritis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Fundamentals of osteoarthritis. Rehabilitation: Exercise, diet, biomechanics, and physical therapist-delivered interventions

Insights related to the pathogenesis of osteoarthritis (OA) have informed rehabilitative treatments that aim to mitigate the influence of several known impairments and risk factors for OA, with the goal to improve pain, function, and quality of life. The purpose of this invited narrative review is to provide fundamental knowledge to non-specialists about exercise and education, diet, biomechanical interventions, and other physical therapist-delivered treatments. In addition to summarizing the rationale for common rehabilitative therapies, we provide a synthesis of current core recommendations. Robust evidence based on randomized clinical trials supports exercise with education and diet as core treatments for OA. Structured, supervised exercise therapy is advised. The mode of exercise may vary but should be individualized. The dose should be based on an initial assessment, the desired physiological changes, and progressed when appropriate. Diet combined with exercise is strongly recommended and studies demonstrate a dose-response relationship between the magnitude of weight loss and symptom improvement. Recent evidence suggests the use of technology to remotely deliver exercise, diet and education interventions is cost-effective. Although several studies support the mechanisms for biomechanical interventions (e.g., bracing, shoe inserts) and physical therapist-delivered (passive) treatments (e.g., manual therapy, electrotherapeutic modalities) fewer rigorous randomized trials support their clinical use; these therapies are sometimes recommended as adjuncts to core treatments. The mechanisms of action for all rehabilitative interventions include contextual factors such as attention and placebo effects. These effects can challenge our interpretation of treatment efficacy from clinical trials, yet also provide opportunities to maximize patient outcomes in clinical practice. When evaluating rehabilitative interventions, the field may benefit from increased emphasis on research that considers contextual factors while evaluating mechanistic, longer-term, clinically-important and policy-relevant outcome measures.

Rehabilitation interventions in osteoarthritis

The goals of the management of osteoarthritis (OA) are to relieve joint pain and stiffness, maintain or increase joint mobility and stability, improve activities and participation, and enhance quality of life. The first step in the management is to make a comprehensive holistic assessment to understand the impact of the disease on the individual. Then, an individualized management plan can be set via a shared-decision making process between the patient and the clinician taking into account all components of functioning affected by the disease. Rehabilitation interventions serve as the basis of OA management whereas pharmacological modalities are usually administered for additional symptom control. This study aimed to overview the rehabilitation interventions used for people with OA with an update of the recent evidence. First, core management approaches that include patient education, physical activity and exercises, and weight loss were addressed; then adjunctive treatments including biomechanical interventions (e.g. orthoses, assistive devices) and physical modalities were overviewed.

Exercise Therapy for Knee and Hip Osteoarthritis: Is There An Ideal Prescription?

Purpose of review

Exercise therapy is the first line treatment for patients with knee and hip osteoarthritis (OA) but is consistently underutilized. In this review, we aim to provide health care professionals with an overview of the latest evidence in the areas of exercise therapy for OA, which can serve as a guide for incorporating the ideal exercise therapy prescription in the overall management plan for their patients with OA.

Recent findings

Evidence continues to be produced supporting the use of exercise therapy for all patients with knee or hip OA. Ample evidence exists suggesting exercise therapy is a safe form of treatment, for both joint structures and the patient overall. Several systematic reviews show that exercise therapy is likely to improve patient outcomes, regardless of disease severity or comorbidities. However, no single type of exercise therapy is superior to others.

Summary

Health care practitioners and patients should be encouraged to incorporate exercise therapy into treatment plans and can be assured of the safety profile and likelihood of improvement in important patient outcomes. Since no single exercise therapy program shows vastly superior benefit, patient preference and contextual factors should be central to the shared decision-making process when selecting and individualising appropriate exercise therapy prescriptions.

Molecular Assessment of Healthy Pathological Articular Cartilages in Physically Active People: A Scoping Review

Physiological aging triggers a cascade of negative effects on the human body and the human joint is only one of the several compartments affected by this irreversible and natural process. Osteoarthritis and cartilage degeneration can cause pain and disability; therefore, identifying the molecular processes underlying these phenomena and the biomarkers produced during physical activity is of critical importance. In the present review, the main goal was to identify and discuss the articular cartilage biomarkers analyzed in studies in which physical or sports activities were adopted and eventually to propose a standard operating procedure for the assessment. Articles collected from Pubmed, Web of Science, and Scopus were scrutinized to detect reliable cartilage biomarkers. The principal articular cartilage biomarkers detected in these studies were cartilage oligomeric matrix protein, matrix metalloproteinases, interleukins, and carboxy-terminal telopeptide. The articular cartilage biomarkers identified in this scoping review may aid in a better comprehension of where research on the topic is heading and offer a viable instrument for streamlining investigations on cartilage biomarker discovery.

Exercise & Sports Science Australia (ESSA) updated Position Statement on exercise and physical activity for people with hip/knee osteoarthritis

This Position Statement is an update to the existing statement. It is intended for all health practitioners who manage people with hip/knee osteoarthritis. It synthesises the most recent evidence (with a focus on clinical guidelines and systematic reviews) for exercise in people with hip/knee osteoarthritis, and provides guidance to practitioners about how best to implement exercise in clinical practice. Clinical practice guidelines for hip/knee osteoarthritis advocate physical activity and exercise as fundamental core components of evidence-based management. Research evidence indicates that exercise can reduce joint pain, increase physical function, and improve quality of life in hip/knee osteoarthritis, and that a range of exercise types (both supervised and unsupervised) may be beneficial. Exercise dosage should be guided by the principles of the American College of Sports Medicine. As people with osteoarthritis experience many barriers to exercise, practitioners should take an active role in monitoring and promoting adherence to exercise in order to optimise therapeutic benefits.

Risk of total hip arthroplasty after elite sport: linking 3304 former world-class athletes with the Norwegian Arthroplasty Register

OBJECTIVES

At present, there is no cure for osteoarthritis (OA), but severe hip joint degeneration can require total hip arthroplasty (THA). The literature on OA after elite sport is limited. We hypothesise that elite athletic activity increases the risk of receiving a THA later in life.

METHODS

We linked a cohort of former Norwegian world-class athletes (1402 females and 1902 males, active 1936-2006) to the Norwegian Arthroplasty Register (THA performed 1987-2020). We used standardised incidence ratio (SIR), one-minus Kaplan-Meier and relative Cox regression (relative HR, RHR), with 95% CIs, and funnel plots at age 75, to assess THA risk for different sport disciplines, joint impact categories of sport disciplines and sex. The risk of THA for the corresponding general Norwegian population was used as reference.

RESULTS

We found an overall increased risk for THA for the former elite athletes (SIR 2.11, 95% CI 1.82 to 2.40) at age 75 years, compared with the general population. THA risk at age 75 years was 11.6% for female athletes and 8.3% for male athletes. SIR was 1.90 (95% CI 1.49 to 2.31) for female and 2.28 (95% CI 1.87 to 2.70) for male athletes. Among males, high joint impact sport disciplines were associated with increased risk compared with low-impact sport disciplines (RHR 1.81, 95% CI 1.06 to 3.08, p=0.029).

CONCLUSION

Having been an elite athlete was associated with a doubling of THA risk compared with the general population for both sexes. High joint impact sport disciplines were associated with subsequent THA for male athletes.

Clinicians' beliefs and attitudes to physical activity and exercise therapy as treatment for knee and/or hip osteoarthritis: a scoping review

OBJECTIVE

To explore clinicians' attitudes and beliefs about physical activity and exercise therapy as treatment for individuals with knee and/or hip osteoarthritis (OA).

METHOD

This was a scoping review, mapping available knowledge about the topic derived from qualitative research designs and methods. A comprehensive search of selected databases (MEDLINE, EMBASE; CINAHL; Web of Science) was conducted and data were analysed thematically.

RESULTS

Twelve articles met inclusion criteria. Thematic analysis identified three interrelated main themes: 1) Understandings of OA and its trajectory and management; 2) Attitudes to activity and exercise as part of OA management; 3) Clinicians' perceived knowledge of and expertise in OA management. Findings highlight that many clinicians involved in knee/hip OA management, particularly general practitioners and physiotherapists, perceive OA to be a low priority 'wear-and-tear' disease with expected progression of symptoms, making joint replacement surgery eventually inevitable. Further, many clinicians appear to lack knowledge about and interest in physical activity and exercise therapy in the management of knee/hip OA, and seem to show uncertainty about the effectiveness and safety of physical activity and exercise therapy on joint health.

CONCLUSION

Clinicians' attitudes and beliefs about physical activity and exercise therapy in OA seem to reflect an outdated narrative which describes OA as a wear-and-tear disease with inevitable disease progression to joint replacement surgery. Clinicians need to adopt a contemporary narrative, which accurately reflects current knowledge and evidence-based practice, thereby ensuring consistent utilisation of exercise therapy as first-line care as recommended in OA guidelines.

Associations Between Physical Activity, Self-reported Joint Function, and Molecular Biomarkers in Working Age Individuals With Hip and/or Knee Osteoarthritis

Objective:

Previous research has suggested an association between physical activity (PA), joint function, and molecular biomarkers, but more studies are needed. The aim of this study was to explore the associations between PA or self-reported joint function and molecular biomarkers of cartilage and inflammation in individuals with hip and/or knee osteoarthritis (OA). Specific objectives were to explore the correlations between (1) the change over 3 months in self-reported PA/joint function and the change in molecular biomarkers (2) objectively measured PA and molecular biomarkers measured at 3-month follow-up.

Design:

Working age participants (n = 91) were recruited from a cluster randomized controlled trial. Self-reported PA, joint function, and serum samples were collected at baseline and after 3 months. Serum concentrations of the inflammatory marker C-reactive protein (CRP) and the cartilage markers Alanine-Arginine-Glycine-Serine (ARGS)-aggrecan, cartilage oligomeric matrix protein (COMP), and type II collagen C2C were analyzed by immunoassays. Objectively measured PA (steps/day) was collected during 12 weeks from activity trackers used by 53 participants. Associations were analyzed with Spearman’s rank correlation.

Results:

There was a weak negative correlation between the change in self-reported PA and the change in COMP (r_s = −0.256, P = .040) but not for the other molecular biomarkers. There were no correlations between the change in self-reported joint function and the change in molecular biomarkers or between the average steps/day and the molecular biomarkers at follow-up (r_s ⩽ −0.206, P ⩾ .06).

Conclusion:

In general, no or only weak associations were found between PA/joint function and molecular biomarkers. Future research recommends including participants with lower PA, extend the follow-up, and use a design that allows comparisons.

Effects of Exercise Training Alone and in Combination With Kinesio Taping on Pain, Functionality, and Biomarkers Related to the Cartilage Metabolism in Knee Osteoarthritis

OBJECTIVE

To investigate the effects of exercise training alone and in combination with kinesio taping on pain, functionality, and circulating cartilage oligomeric matrix protein (COMP), and matrix metalloproteinase (MMP)-1, and -3 at rest and immediately after walking exercise in knee osteoarthritis (OA).

DESIGN

A total of 22 female patients diagnosed with knee OA were randomly divided into the exercise training (ET) or exercise training plus kinesio taping (ET + KT) groups. The patients in the ET performed exercise training for 6 weeks. The patients in the ET + KT group were applied with kinesio tape in addition to the exercise training for 6 weeks. In both groups, 20 minutes of walking exercise were performed before and after the interventions. The pain and functional status of the patients were assessed using visual analogue scale (VAS) and Western Ontario McMasters Osteoarthritis Index (WOMAC) before and after the intervention at rest, respectively. Blood samples were taken at rest and immediately after the walking exercise before and after the interventions for the analysis of COMP, MMP-1, and MMP-3 levels.

RESULTS

In both groups, pain and functionality scores were significantly improved after the interventions (P < 0.05). COMP, MMP-1 and MMP-3 levels were higher immediately after walking exercise when compared with rest in both groups before and after the intervention (P < 0.05).

CONCLUSIONS

Exercise training and exercise training plus kinesio taping improved pain and physical function; however, the COMP, MMP-1, and MMP-3 levels did not change.

Muscle strength gains after strengthening exercise explained by reductions in serum inflammation in women with knee osteoarthritis

Background Individuals with knee osteoarthritis have elevated circulating inflammatory markers and altered cartilage properties but it is unclear if these features adapt to exercise. We aimed to determine (1) whether inflammatory markers, cartilage transverse relaxation time and thickness mediate the effect of body mass index (BMI) on quadriceps strength at baseline; and (2) whether these changes explain variance in quadriceps strength improvements after 12 weeks of exercise in women with knee osteoarthritis. Methods This secondary analysis (17 women with clinical knee osteoarthritis) of a randomized control trial compared supervised group interventions, 3 times/week for 12 weeks (36 sessions): (a) weight-bearing progressive resistive quadriceps exercise or (b) attention control. (1) From baseline, separate linear regressions were conducted with strength (Nm/kg) as the dependent, BMI as the predictor, and c-reactive protein, tumor necrosis factor, interleukin-6, cartilage transverse relaxation time or thickness as potential mediators. (2) Multiple linear regression analyses were completed with 12-week strength change (post-pre) as the dependent, change in serum inflammatory markers and cartilage measurements as predictors, and age, BMI and adherence as covariates. Findings (1) At baseline, there was no mediation. (2) A decrease in each of interleukin-6 (β = -0.104 (95% confidence intervals: -0.172, -0.036), R² = 0.51, P < 0.007) and tumor necrosis factor (β = -0.024 (-0.038, -0.009), R² = 0.54, P < 0.005) was associated with strength gains. Interpretation At baseline, inflammatory markers and cartilage measurements do not act as mediators of BMI on quadriceps strength. After 12 weeks of exercise, reduced interleukin-6 and tumor necrosis factor were associated with increased quadriceps strength in women with knee osteoarthritis.

Aerobic capacity and fatigability are associated with activity levels in women with hip osteoarthritis

Physical activity is important for physical function and pain relief in people with lower extremity osteoarthritis (OA). Unfortunately, people with OA are not as active as their peers without OA. The objective of this study was to determine whether aerobic capacity and fatigability are associated with physical activity in women with hip OA. We conducted a cross-sectional analysis of 36 women with hip OA. We assessed aerobic fitness as predicted VO₂ max from a 6-min walk test. We assessed fatigability using a treadmill test. Finally, we assessed self-reported physical activity using the UCLA activity scale and quantified steps per day and activity intensity using accelerometers. We used Pearson correlations to determine associations. We used regression analysis to determine whether fatigability mediated the association between aerobic fitness and physical activity. On average, subjects were moderately active via the UCLA score (5.2 ± 1.3 out of 10). Aerobic fitness (R = 0.582, p < .001) and fatigability (R = 0.516, p =.003) were significantly correlated with UCLA scores. However, aerobic fitness was the best predictor of UCLA scores, as well as sedentary time, and time spent in light activity. Fatigability was not a mediator between aerobic fitness and UCLA scores. Aerobic fitness and fatigability may be modifiable barriers to physical activity in people with OA. Future interventional studies should examine whether improving aerobic fitness improves physical activity or fatigability.

Effect of exercise on pain processing and motor output in people with knee osteoarthritis: a systematic review and meta-analysis

OBJECTIVE

Guidelines recommend exercise as a core treatment for knee osteoarthritis. However, it is unclear how exercise affects measures of pain processing and motor function. The aim was to evaluate the effect of exercise on measures of pain processing and motor function in people with knee osteoarthritis.

METHODS

We searched five electronic databases (MEDLINE, EMBASE, CINAHL, SCOPUS and Cochrane Central Register of Controlled Trials) for studies on knee osteoarthritis, of any design, evaluating pain processing and motor function before and after exercise. Data were pooled with random-effects meta-analysis. Study quality was assessed using the Downs and Black and quality of evidence was assessed using the GRADE.

RESULTS

Eighteen studies were eligible and 16 were included. Following acute exercise, pressure pain threshold increased local to the study limb (standardised mean difference [95% confidence interval (CI)] 0.26, [0.02, 0.51], n = 159 from 5 studies), but there was no statistically significant change remote from the study limb (0.09, [-0.11, 0.29], n = 90 from 4 studies). Following an exercise program (range 5-12 weeks) there were no statistically significant changes in pressure pain threshold (local 0.23, [-0.01, 0.47], n = 218 from 8 studies; remote 0.33 [-0.13, 0.79], n = 76 from 4 studies), temporal pain summation (0.38 [-0.08, 0.85], n = 122 from 3 studies) or voluntary quadriceps muscle activation (4.23% [-1.84 to 10.30], n = 139 from 4 studies).

CONCLUSION

Very-low quality evidence suggests that pressure pain threshold increases following acute exercise. Very-low quality evidence suggests that pressure pain threshold, temporal pain summation or voluntary quadriceps activation do not change statistically significantly following exercise programs.

Effects of Edible Oils with Different n-6/n-3 PUFA Ratios on Articular Cartilage Degeneration via Regulating the NF-κB Signaling Pathway

Osteoarthritis (OA), a common chronic disease, is characterized by articular cartilage degeneration and inflammation. Recent studies report that n-3 polyunsaturated fatty acids (PUFAs) exhibit protective effects against OA, while n-6 PUFAs are more likely to damage cartilage. However, the effects of edible oils with different n-6/n-3 PUFA ratios on OA are rarely reported. This study investigates the effect of linseed oil (LO), soybean oil (SO), and peanut oil (PO) on cartilage changes in mice joints following destabilization of the medial meniscus. We determined the n-6/n-3 PUFA ratios of LO, SO, and PO used in this experiment to be 1:3.85, 9.15:1, and 372.73:1, respectively. After 12 weeks of LO or SO feeding, OA mice showed increased cartilage thickness and decreased TNF-α in both the serum and cartilage, whereas no improvement was found in the PO group. This may be due to the fact that LO and SO optimized the fatty acid composition of articular cartilage. We further demonstrated that LO or SO activated GPR120 and attenuated EP4, which was followed by inhibition of the NFκB pathway and its downstream matrix-degrading enzymes: MMP13 and ADAMTS5. In conclusion, edible oils with low n-6/n-3 PUFA retard OA progression via inhibiting the NFκB pathway. This study provides a dietary guidance for OA patients.

Nonsurgical Management of Cartilage Defects of the Knee: Who, When, Why, and How?

The nonoperative practitioner managing individuals with cartilage defects should use a patient-centered, multifaceted approach that aims to individualize treatment to provide optimal benefit. These include addressing modifiable risk factors for disease progression and instituting interventions such as weight loss, nutrition, physical activity, and potentially regenerative medicine strategies. This review will focus on these nonoperative treatment strategies with a focus on when treatments are necessary, who will benefit from these approaches, why they are specifically appropriate, and, finally, how these treatments directly modify the structure of a patient's cartilage and resulting symptoms.

Anti-inflammatory effects of naproxen sodium on human osteoarthritis synovial fluid immune cells

OBJECTIVE

To evaluate the anti-inflammatory effects of clinically relevant naproxen sodium (Nx) concentrations on human monocyte-derived macrophages in a controlled in vitro system and human primary synovial fluid (SF) cells.

DESIGN

Using phorbol 12-myristate 13-acetate, THP-1 human monocytic cells were differentiated into mature monocyte-derived macrophages in vitro then treated with Nx pre- or post-activating an inflammatory response with lipopolysaccharide (LPS) and hyaluronan (HA) fragments (n = 8/group). Cell culture supernatants were assessed for NF-κB activity and prostaglandin E₂ (PGE₂), indicating cyclooxygenase enzyme activity. Under Duke IRB approval, primary human SF cells were collected at the time of knee joint replacement (n = 19 individuals) for osteoarthritis (OA), and cultured with LPS, HA and Nx; SF cells were characterized by polychromatic flow cytometry for cell surface markers and intracellular cytokines.

RESULT

Compared to placebo treatment of THP-1 cells, low dose Nx (corresponding 27.5-440 mg/L orally) added both pre- and post-activation with LPS/HA, significantly reduced NF-κB activity and PGE2: mean reduction to 73%, 61%, 17% and 10% of placebo, respectively. LPS/HA treatment of primary OA SF cells significantly increased the number of IL-1β producing primary monocytes and macrophages, and by 24 h the overall production of secreted cytokines (IL-1β, IL-6, IL8, and TNF-α). Low dose Nx reduced the percentage of IL-1β producing primary monocytes and macrophages.

CONCLUSION

LPS/HA induced inflammation of THP-1 monocytic and primary human SF cells. Low dose Nx both prevented and reduced inflammatory responses of a human monocytic cell line and reduced IL-1β production by primary human SF monocytes and macrophages.

Repetitive Knee Bending and Synovitis in Individuals at Risk of and With Knee Osteoarthritis: Data From the Foundation for the National Institutes of Health Osteoarthritis Biomarkers Consortium

OBJECTIVE

To investigate associations between engagement in knee bending (stair climbing, kneeling, squatting, heavy lifting, getting in/out of a squatting position) and synovitis prevalence on noncontrast magnetic resonance imaging (MRI) in individuals at risk of and with knee osteoarthritis.

METHODS

We included baseline data from 594 participants (mean ± SD age 61.5 ± 8.9 years, 61% had Kellgren/Lawrence grade ≥2; 59% were female; mean ± SD body mass index was 30.7 ± 4.8 kg/m² ) of the Osteoarthritis Biomarker Consortium Foundation for the National Institutes of Health project. Knee bending activities were queried by a standard questionnaire, and the severity of Hoffa synovitis and effusion synovitis (surrogate outcomes of synovitis) were graded using the MRI OsteoArthritis Knee Scoring system. Logistic regression was used, unadjusted and adjusted, for metabolic syndrome, physical activity level, and sex. A grade ≥1 defined synovitis prevalence, with a grade ≥2 cutoff implemented in sensitivity analyses.

RESULTS

The prevalence of grade ≥1 Hoffa synovitis and effusion synovitis equaled 59% (n = 353) and 62% (n = 366), respectively. Adjusted for confounders, kneeling for ≥30 minutes during a single day was associated with grade ≥1 Hoffa synovitis prevalence (odds ratio [OR] 1.65 [95% confidence interval (95% CI) 1.11-2.47]). Participants engaging in this activity ≤1 day per week had greater odds for prevalent Hoffa synovitis than those who did not perform the activity (OR 1.88 [95% CI 1.11-3.18]). No other significant associations were found. Sensitivity analyses yielded similar findings.

CONCLUSION

In this selected sample with a preponderance of grade ≥1 Hoffa and/or effusion synovitis on noncontrast MRI, only prolonged kneeling was associated with Hoffa synovitis prevalence. Replication in other samples is warranted.

Osteoarthritis year in review 2019: rehabilitation and outcomes

OBJECTIVE

Inactivity and obesity are risk factors for osteoarthritis (OA) progression. The purpose of this review was to highlight intervention parameters of exercise and lifestyle diet interventions on clinical outcomes in OA that were published over 15 months, starting January 1, 2018.

DESIGN

Systematic literature searches were performed in Medline (Pubmed, OVID), Scopus, CINAHL, CENTRAL and Embase from January 1, 2018 to April 1, 2019. Key words included osteoarthritis, exercise, physical activity, diet and nutrition. Randomized controlled designs and data synthesis papers (systematic reviews, meta-analyses, clinical guidelines) written in English, that included humans with OA of any joint were included. Trials were evaluated using the Physiotherapy Evidence Database (PEDro) critical appraisal tool and the Template for Intervention Description and Replication (TIDieR). Systematic reviews and meta-analyses were evaluated using A MeaSurement Tool to Assess systematic Reviews 2 (AMSTAR 2). Intervention details (RCTs) and key finding from papers were summarized.

RESULTS

Of 540 titles and abstracts retrieved, 147 full articles were reviewed and 53 met the inclusion criteria, comprised of 39 RCTs and 14 synthesis papers. By addressing inactivity, exercise effectively improves clinical outcomes and, based on low-moderate quality evidence, without further damage to cartilage or synovial tissue. By comparison, much less work focused on minimizing obesity. Diet must be combined with exercise to improve pain, but alone, can improve physical function.

CONCLUSIONS

Future work is necessary to identify the ideal exercise frequency and intensity and lifestyle diet intervention parameters. Improved adherence to reporting guidelines in future work will greatly enhance the OA rehabilitation field.

Frailty modifies the intervention effect of chair yoga on pain among older adults with lower extremity osteoarthritis: Secondary analysis of a nonpharmacological intervention trial

OBJECTIVE

In an 8-week nonpharmacological pain intervention trial among older adults with lower extremity osteoarthritis (OA), we aimed to examine: a) the baseline frailty level of the participants; b) whether such intervention is more beneficial for baseline frailer older adults than for their counterparts with less frailty; and c) whether the intervention could also alter frailty.

METHODS

Participants were randomly assigned to either chair yoga (CY) or health education program (HEP) groups and attended twice-weekly 45-minute CY or HEP sessions for 8 weeks. Following a standard procedure, 82 variables were used to construct a frailty index (FI, 0-1). Primary outcomes were: Western Ontario and McMaster Universities (WOMAC) pain and pain interference. Linear mixed-effects models were used to evaluate the modifying effect of baseline frailty on the intervention effect of CY on primary outcomes. Similar models were used to evaluate the effect of CY on frailty.

RESULTS

A total of 112 participants (n = 63 CY, n = 49 HEP; 75.3 [SD = 7.5] years) with 85 females (75.9%) were included. The mean values of baseline FI for the CY and HEP groups were similar (0.428 [0.05] and 0.433 [0.05], P = 0.355). Each 0.01 increment in baseline FI was associated with higher WOMAC pain (beta = 0.28, P < 0.001) and pain interference (beta = 0.51, P < 0.001). There was a significant interaction effect between intervention, time, and baseline FI (P = 0.020 for WOMAC pain; P = 0.010 for pain interference), indicating that participants with higher level of baseline FI had greater declines in WOMAC pain and pain interference. There was no significantly greater decline in FI for the CY group compared to the HEP group (between-group difference - 0.01; P = 0.509) and there were no significant trend changes in FI (P for interaction = 0.605).

CONCLUSIONS

Frailty modifies the intervention effect of CY on pain among older adults with lower extremity OA, underscoring the importance of assessing frailty to improve the management of pain in this population.

Patients report inferior quality of care for knee osteoarthritis prior to assessment for knee replacement surgery - a cross-sectional study of 517 patients in Denmark

Background and purpose - Clinical care pathways for knee osteoarthritis (OA) are not always in line with clinical guidelines. We investigated (1) the patient-perceived quality of OA management, (2) which physiotherapist-delivered treatments patients with knee OA have attempted, and (3) patients' expected subsequent treatment, at the time of referral to an orthopedic surgeon.Patients and methods - This cross-sectional study included all patients with scheduled first-time appointments for knee OA at an orthopedic outpatient clinic from April 2017 to February 2018. Postal questionnaires included the 16-item OsteoArthritis Quality Indicator (OA-QI) questionnaire and questions about physiotherapist-delivered treatment for knee OA.Results - 517 of 627 (82%) eligible patients responded. Responders' (63% female) mean age was 67 years. The mean pass rate for the 16 independent quality indicators was 32% (8-74%). Sub-grouped into 4 categories, pass rates for independent quality indicators ranged from 16-52% regarding information, 9-50% regarding pain and functional assessment, 8-35% regarding referrals, and 16-74% regarding pharmacological treatment. While half of responders felt informed of physical activity benefits, only one-third had consulted a physiotherapist during the past year. Commonest physiotherapist-delivered treatments were exercise therapy for 22% and participation in the Good Life with osteoArthritis in Denmark (GLA:D) program for12% of responding patients. 65% expected surgery as subsequent treatment.Interpretation - Patients with knee OA are undertreated in primary care in Denmark; however, our findings may only reflect healthcare settings that are comparably organized. Our results call for better structure and uniform pathways for primary care knee OA treatment before referral to an orthopedic surgeon.

Effects of Physical Activity in Knee and Hip Osteoarthritis: A Systematic Umbrella Review

INTRODUCTION

We conducted a systematic umbrella review to evaluate the literature relating to effects of physical activity on pain, physical function, health-related quality of life, comorbid conditions and osteoarthritis (OA) structural disease progression in individuals with lower-extremity OA.

METHODS

Our primary search encompassed 2011 to February 2018 for existing systematic reviews (SR), meta-analyses (MA) and pooled analyses dealing with physical activity including exercise (not mixed with any other intervention and compared to a no-activity control group). A supplementary search encompassed 2006 to February 2018 for original research related to physical activity (including exercise) and lower limb OA progression. Study characteristics were abstracted, and risk of bias was assessed.

RESULTS

Physical activity decreased pain and improved physical function (strong evidence) and improved health-related quality of life (moderate evidence) among people with hip or knee OA relative to less active adults with OA. There was no evidence to suggest accelerated OA progression for physical activity below 10,000 steps per day. Both physical activity equivalent to the 2008 Physical Activity Guidelines for Americans (150 min·wk of moderate-intensity exercise in bouts ≥10 min) and lower levels of physical activity (at least 45 total minutes per week of moderate-intensity) were associated with improved or sustained high function. No SR/MA addressing comorbid conditions in OA were found. Measurable benefits of physical activity appeared to persist for periods of up to 6 months following cessation of a defined program.

CONCLUSIONS

People with lower-extremity OA should be encouraged to engage in achievable amounts of physical activity, of even modest intensities. They can choose to accrue minutes of physical activity throughout the entire day, irrespective of bout duration, and be confident in gaining some health and arthritis-related benefits.

Isorhamnetin ameliorates inflammatory responses and articular cartilage damage in the rats of monosodium iodoacetate-induced osteoarthritis

Context: Osteoarthritis (OA) is a degenerative joint disease with damage to the articular cartilage. Active production of inflammatory cytokine/chemokine and matrix metalloproteinases may be found during the progression of OA. Isorhamnetin had the effects of anti-inflammatory, antioxidant, anti-ischemia, anti-atherosclerotic hepatoprotective and anticancer activities. Objective: Our study was focused on the effects of isorhamnetin treatment in OA. Materials and methods: We used monosodium iodoacetate (MIA)-induced OA rats to evaluate the effects of isorhamnetin related anti-inflammatory process. The rats in all groups were sacrificed on four weeks post-MIA injection. The measurements of knee joint swelling, histological analysis, serum inflammatory biomarkers and western blot were evaluated. Results: We found that isorhamnetin may reduce MIA-induced knee swelling by significantly reduction of articular cartilage damage.in rats. Suppression of pro-inflammatory cytokines production was found after isohamnetin treatment. Isorhamnetin inhibited the production of NO and PGE2, and the expression of iNOS and COX-2. The production of COMP, CTX-II and osteopontin (OPN) were also inhibited in MIA-induced OA rats. Discussion and conclusions: Isorhamnetin may modulate the inflammatory progression of OA in MIA-induced OA rats. The prevention of cartilage damage was found in OA after adequate isorhamnetin treatment. Isorhamnetin may serve as a potential agent for the management of OA.

Skeletal Muscle Wasting and Its Relationship With Osteoarthritis: a Mini-Review of Mechanisms and Current Interventions

Purpose of Review

Osteoarthritis (OA) is a subset of joint disorders resulting in degeneration of synovial joints. This leads to pain, disability and loss of independence. Knee and hip OA are extremely prevalent, and their occurrence increases with ageing. Similarly, loss of muscle mass and function, sarcopenia, occurs during ageing.

Recent Findings

Little is known about the impact of muscle wasting on OA progression; nevertheless, it has been suggested that muscle wasting directly affects the stability of the joints and loss of mobility leads to gradual degeneration of articular cartilage. The molecular mechanisms underlying muscle wasting in OA are not well understood; however, these are probably related to changes in gene expression, as well as epigenetic modifications.

Summary

It is becoming clear that skeletal muscle wasting plays an important role in OA development and/or progression. Here, we discuss mechanisms, current interventions, such as exercise, and potentially novel approaches, such as modulation of microRNAs, aiming at ameliorating OA symptoms through maintaining muscle mass and function.