Moderators of the effects of therapeutic exercise for people with knee and hip osteoarthritis: A systematic review of sub-group analyses from randomised controlled trials

Reconsidering the Role of Weight Loss in Treatment for Chronic Pain: Knee Osteoarthritis as an Exemplar

Chronic pain is prevalent among individuals with higher body weight and associated with greater impairment. As a result, weight loss is a common recommendation for pain management among those with higher body weight. Body weight is an appealing target because it is modifiable and evidence-based treatments to produce weight loss are well-established. In the last 2 decades, there has been a growing line of scientific work investigating the application of weight loss to individuals with chronic pain. This represents an important step to integrate the conceptualization of pain and body weight and there is preliminary work suggesting treatment effects are enhanced when weight loss treatment is combined with pain coping skills. However, weight loss outcomes are variable and difficult to sustain, and access to evidence-based treatment is limited. These concerns are set against the backdrop of growing public and academic concern about the weight-centric approach to health care that dominates western medicine. This is a timely moment to reconsider the conceptualization of weight and pain, and the role of weight loss in chronic pain treatment. Using osteoarthritis as an exemplar, we review the evidence for and clinical uptake of weight loss as a chronic pain management strategy and conclude with key areas for consideration to advance the scientific understanding of these comorbid conditions and how to optimize pain management for individuals of higher body weight. PERSPECTIVE: This focus article critically considers the role of weight loss in management of chronic pain among individuals of higher body. Using knee osteoarthritis as an exemplar, the evidence and clinical uptake of weight loss for pain management is reviewed. Limitations are considered to guide future research and clinical care.

Osteoarthritis Year In Review 2024: Rehabilitation and outcomes

This Year in Review presents key highlights from recent research relating to osteoarthritis rehabilitation and its outcomes, defined as any non-pharmacological and non-surgical treatment that aims to improve osteoarthritis symptoms at any joint. Three databases (Medline, Embase, and CINAHL Plus) were searched between 1 March 2023 to 12 March 2024. Relevant studies were chosen based on the predefined inclusion/exclusion criteria, perceived clinical importance, quality, controversy in the field, or personal interest, and organised into four overarching themes (with 1-5 sub-themes each). The first theme related to uncertainties regarding exercise benefits. New work has challenged the clinical effectiveness of exercise on symptoms, as well as highlighted uncertainty around our understanding of both mechanisms of effects, how to enhance effectiveness and adherence, and which subgroups of people are more or less likely to improve with exercise. However, we also highlight new work confirming the role of exercise as a first-line management strategy. The second theme related to digital modes of service delivery. There was new evidence to support its effectiveness in improving symptoms and clear potential for creating and evaluating new mobile apps. New work also highlighted the potential future role artificial intelligence can have in providing treatment information and recommendations. The third theme related to patient education, and the call for change to the impairment-based narrative that prevails in osteoarthritis information. The fourth theme is related to weight loss. New work compared the effectiveness of different weight loss diets and explored alternative models of weight loss delivery.

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

OBJECTIVE

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

DESIGN

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

RESULTS

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

CONCLUSIONS

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

Total Hip Arthroplasty Versus Education and Exercise: A Propensity-Matched Analysis of 266 Patients Who Have Hip Osteoarthritis

BACKGROUND

Total hip arthroplasty (THA) for osteoarthritis (OA) is a major health system cost. Education and exercise (Edu + Ex) programs may reduce the number of THAs needed, but supporting data are limited. This study aimed to estimate the treatment effect of THA versus Edu + Ex on pain, function, and quality of life outcomes 3 and 12 months after treatment initiation for hip OA.

METHODS

Patients who had hip OA who underwent THA or an Edu + Ex program were included in this propensity-matched study. In 778 patients (Edu + Ex, n = 303; THA, n = 475), propensity scores were based on pretreatment characteristics, and patients were matched on a 1:1 ratio. Between-group treatment effects (pain, function, and quality of life) were estimated as the mean difference (MD) in change from pretreatment to 3-month and 12-month follow-up using linear mixed models.

RESULTS

The matched sample consisted of 266 patients (Edu + Ex, n = 133; THA, n = 133) who were balanced on all pretreatment characteristics except opioid use. At 12-month follow-up, THA resulted in significantly greater improvements in pain (MD 35.4; 95% confidence interval [CI] 31.4 to 39.4), function (MD 30.5; 95% CI 26.3 to 34.7), and quality of life (MD 33.6; 95% CI 28.8 to 38.4). Between 17% and 30% of patients receiving Edu + Ex experienced a surgical threshold for clinically meaningful improvement in outcomes, compared to 84% and 90% of THA patients.

CONCLUSIONS

A THA provides greater improvements in pain, function, and quality of life. A notable proportion of Edu + Ex patients had clinically meaningful improvements, suggesting Edu + Ex may result in THA deferral in some patients, but confirmatory trials are needed.

Total Knee Arthroplasty Versus Education and Exercise for Knee Osteoarthritis: A Propensity-Matched Analysis

OBJECTIVE

We estimate the treatment effect of total knee arthroplasty (TKA) versus an education and exercise (Edu+Ex) program on pain, function, and quality of life outcomes 3 and 12 months after treatment initiation for knee osteoarthritis (OA).

METHODS

Patients with knee OA who had undergone TKA were matched on a 1:1 ratio with participants in an Edu+Ex program based on a propensity score fitted to a range of pretreatment covariates. After matching, between-group differences in improvement (the treatment effect) in Knee Injury and Osteoarthritis Outcome Score 12-item version (0, worst to 100, best) pain, function, and quality of life from baseline to 3 and 12 months were estimated using linear mixed models, adjusting for unbalanced covariates, if any, after matching.

RESULTS

The matched sample consisted of 522 patients (Edu+Ex, n = 261; TKA, n = 261) who were balanced on all pretreatment characteristics. At 12-month follow-up, TKA resulted in significantly greater improvements in pain (mean difference [MD] 22.8; 95% confidence interval [95% CI] 19.7-25.8), function (MD 21.2; 95% CI 17.7-24.4), and quality of life (MD 18.3; 15.0-21.6). Even so, at least one-third of patients receiving Edu+Ex had a clinically meaningful improvement in outcomes at 12 months compared with 75% of patients with TKA.

CONCLUSION

TKA is associated with greater improvements in pain, function, and quality of life, but these findings also suggest that Edu+Ex may be a viable alternative to TKA in a meaningful proportion of patients, which may reduce overall TKA need. Confirmatory trials are needed.

Mediators of the effects of exercise and manual therapy for people with knee and hip osteoarthritis: A secondary, exploratory analysis of the MOA trial

Objective

To explore whether pain beliefs and functional strength mediate the treatment effect of manual therapy (MT) and exercise therapy (ET) on the Western Ontario and McMaster Osteoarthritis Index (WOMAC) composite scores and its subscales in individuals with hip and/or knee osteoarthritis in the MOA trial.

Design

Secondary analysis of a randomised controlled trial that compared the incremental effects of supervised MT and ET in addition to usual care in patients with osteoarthritis of the hip or knee. 206 participants enrolled in the MOA trial were analysed. The primary outcome measure was the WOMAC composite score after 1 year.

Results

Pain belief mediated the effect of MT (b: -10.7, 95 ​% CI: -22.3, -0.9), ET (b: -14.5 95%CI: -26.0, -4.4). Functional strength did not mediate the effect of MT, ET, or MT ​+ ​ET. Mediation sensitivity analyses suggest findings are likely to change if small confounding between those mediators and WOMAC composite score is present.

Conclusions

We identified possible mediators of MT and ET. Future confirmatory studies could be designed to assess the mechanisms through which manual therapy and exercise cause improvements in pain and function scores in patients with hip or knee osteoarthritis.

Absence of Improvement With Exercise in Some Patients With Knee Osteoarthritis: A Qualitative Study of Responders and Nonresponders

OBJECTIVE

To compare the perceptions of patients about why they did, or did not, respond to a physical therapist-supported exercise and physical activity program.

METHODS

This was a qualitative study within a randomized controlled trial. Twenty-six participants (of 40 invited) with knee osteoarthritis sampled according to response (n = 12 responders, and 14 nonresponders based on changes in both pain and physical function at 3 and 9 months after baseline) to an exercise and physical activity intervention. Semistructured individual interviews were conducted. Inductive thematic analysis was undertaken within each subgroup using grounded theory principles. A deductive approach compared themes and subthemes across subgroups. Findings were triangulated with quantitative data.

RESULTS

(Sub)themes common to responders and nonresponders included the intervention components that facilitated engagement, personal attitudes and expectations, beliefs about osteoarthritis and exercise role, importance of adherence, and perceived strength gains with exercise. In contrast to responders who felt empowered to self-manage, nonresponders accepted responsibility for lack of improvement in pain and function with exercise, acknowledging that their adherence to the intervention was suboptimal (confirmed by quantitative adherence data). Nonresponders believed that their excess body weight (supported by quantitative data) contributed to their outcomes, encountered exercise barriers (comorbidities, stressors, and life events), and perceived that the trial measurement tools did not adequately capture their response to exercise.

CONCLUSION

Responders and nonresponders shared some similar perceptions of exercise. However, along with perceived limitations in trial outcome measurements, nonresponders encountered challenges with excess weight, comorbidities, stressors, and life events that led to suboptimal adherence and collectively were perceived to contribute to nonresponse.

Moderators of the effect of therapeutic exercise for knee and hip osteoarthritis: a systematic review and individual participant data meta-analysis

BACKGROUND

Many international clinical guidelines recommend therapeutic exercise as a core treatment for knee and hip osteoarthritis. We aimed to identify individual patient-level moderators of the effect of therapeutic exercise for reducing pain and improving physical function in people with knee osteoarthritis, hip osteoarthritis, or both.

METHODS

We did a systematic review and individual participant data (IPD) meta-analysis of randomised controlled trials comparing therapeutic exercise with non-exercise controls in people with knee osteoathritis, hip osteoarthritis, or both. We searched ten databases from March 1, 2012, to Feb 25, 2019, for randomised controlled trials comparing the effects of exercise with non-exercise or other exercise controls on pain and physical function outcomes among people with knee osteoarthritis, hip osteoarthritis, or both. IPD were requested from leads of all eligible randomised controlled trials. 12 potential moderators of interest were explored to ascertain whether they were associated with short-term (12 weeks), medium-term (6 months), and long-term (12 months) effects of exercise on self-reported pain and physical function, in comparison with non-exercise controls. Overall intervention effects were also summarised. This study is prospectively registered on PROSPERO (CRD42017054049).

FINDINGS

Of 91 eligible randomised controlled trials that compared exercise with non-exercise controls, IPD from 31 randomised controlled trials (n=4241 participants) were included in the meta-analysis. Randomised controlled trials included participants with knee osteoarthritis (18 [58%] of 31 trials), hip osteoarthritis (six [19%]), or both (seven [23%]) and tested heterogeneous exercise interventions versus heterogeneous non-exercise controls, with variable risk of bias. Summary meta-analysis results showed that, on average, compared with non-exercise controls, therapeutic exercise reduced pain on a standardised 0-100 scale (with 100 corresponding to worst pain), with a difference of -6·36 points (95% CI -8·45 to -4·27, borrowing of strength [BoS] 10·3%, between-study variance [τ2] 21·6) in the short term, -3·77 points (-5·97 to -1·57, BoS 30·0%, τ2 14·4) in the medium term, and -3·43 points (-5·18 to -1·69, BoS 31·7%, τ2 4·5) in the long term. Therapeutic exercise also improved physical function on a standardised 0-100 scale (with 100 corresponding to worst physical function), with a difference of -4·46 points in the short term (95% CI -5·95 to -2·98, BoS 10·5%, τ2 10·1), -2·71 points in the medium term (-4·63 to -0·78, BoS 33·6%, τ2 11·9), and -3·39 points in the long term (-4·97 to -1·81, BoS 34·1%, τ2 6·4). Baseline pain and physical function moderated the effect of exercise on pain and physical function outcomes. Those with higher self-reported pain and physical function scores at baseline (ie, poorer physical function) generally benefited more than those with lower self-reported pain and physical function scores at baseline, with the evidence most certain in the short term (12 weeks).

INTERPRETATION

There was evidence of a small, positive overall effect of therapeutic exercise on pain and physical function compared with non-exercise controls. However, this effect is of questionable clinical importance, particularly in the medium and long term. As individuals with higher pain severity and poorer physical function at baseline benefited more than those with lower pain severity and better physical function at baseline, targeting individuals with higher levels of osteoarthritis-related pain and disability for therapeutic exercise might be of merit.

FUNDING

Chartered Society of Physiotherapy Charitable Trust and the National Institute for Health and Care Research.

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.

Do imaging findings modify the effect of non-surgical treatment in patients with knee and hip osteoarthritis? A systematic literature review

OBJECTIVES

To review the available evidence on diagnostic imaging findings in knee and hip osteoarthritis (OA) as treatment effect modifiers in non-surgical OA interventions.

METHODS

MEDLINE, Embase and The Cochrane Central Register of Controlled Trials were searched from the earliest records published to 22 March 2022. Studies in knee and hip OA reporting subgroup analyses in randomised controlled trials with imaging findings as potential treatment effect modifiers were included. Studies were critically appraised using the Cochrane risk of bias tool and a subgroup analysis quality assessment.

RESULTS

Of 10 014 titles and abstracts screened, eight studies met the inclusion criteria, six on knee OA and two on hip OA. The studies investigated effect modifiers in exercise therapy, intra-articular injections and unloading shoes. Imaging findings assessed as potential treatment effect modifiers were radiographic OA severity, hip effusion (ultrasound), bone marrow lesions and meniscal pathology (MRI). Two studies fulfilled the methodological quality criteria for assessing effect modification. One reported that radiographic knee OA severity modified the effect of unloading shoes on walking pain. Those with more severe radiographic knee OA had a greater response to shoe inserts. One reported no interaction between radiographic OA severity or joint effusion and the effect of intraarticular injections of corticosteroid or hyaluronic acid in hip OA, indicating no difference in response in people with greater hip joint effusion or radiographic OA severity compared with those with less severe joint disease.

CONCLUSION

Overall, methodological limitations and very few studies do not permit conclusions on diagnostic imaging findings as effect modifiers in non-surgical interventions in knee and hip OA.Radiographic severity of knee OA potentially modifies the effect of unloading shoes.

PROSPERO REGISTRATION NUMBER

CRD42020181934.

Exploring the modification factors of exercise therapy on biomechanical load in patients with knee osteoarthritis: a systematic review and meta-analysis

The objective of this systematic review and meta-analysis is to clarify the effect of exercise therapy on the first peak knee adduction moment (KAM), as well as other biomechanical loads in patients with knee osteoarthritis (OA), and identify physical characteristics that influence differences in biomechanical load after exercise therapy. The data sources are PubMed, PEDro, and CINAHL, from study inception to May 2021. The eligibility criteria include studies evaluating the first peak (KAM), peak knee flexion moment (KFM), maximal knee joint compression force (KCF), or co-contraction during walking before and after exercise therapy in patients with knee OA. The risk of bias was independently assessed by two reviewers using PEDro and NIH scales. Among 11 RCTs and nine non-RCTs, 1119 patients with knee OA were included (average age: 63.7 years). As the results of meta-analysis, exercise therapy tended to increase the first peak KAM (SMD 0.11; 95% CI: -0.03-0.24), peak KFM (SMD 0.13; 95% CI: -0.03-0.29), and maximal KCF (SMD 0.09; 95% CI -0.05-0.22). An increased first peak KAM was significantly associated with a larger improvement in knee muscle strength and WOMAC pain. However, the quality of evidence regarding the biomechanical loads was low-to-moderate according to the GRADE approach. The improvement in pain and knee muscle strength may mediate the increase in first peak KAM, suggesting difficulty in balancing symptom relief and biomechanical load reduction. Therefore, exercise therapy may satisfy both aspects simultaneously when combined with biomechanical interventions, such as a valgus knee brace or insoles. Registration: PROSPERO (CRD42021230966).

Can we really say getting stronger makes your tendon feel better? No current evidence of a relationship between change in Achilles tendinopathy pain or disability and changes in triceps Surae structure or function when completing rehabilitation: a systematic review

OBJECTIVES

Determine if improvements in pain and disability in patients with mid-portion Achilles tendinopathy relate to changes in muscle structure and function whilst completing exercise rehabilitation.

DESIGN

A systematic review exploring the relationship between changes in pain/disability and muscle structure/function over time, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

METHODS

Six online databases and the grey literature were searched from database inception to 16th December 2022 whereas clinical trial registries were searched from database inception to 11th February 2020. We included clinical studies where participants received exercise rehabilitation (±placebo interventions) for mid-portion Achilles tendinopathy if pain/disability and Triceps Surae structure/function were measured. We calculated Cohen's d (95 % confidence intervals) for changes in muscle structure/function over time for individual studies. Data were not pooled due to heterogeneity. Study quality was assessed using a modified Newcastle-Ottawa Scale.

RESULTS

Seventeen studies were included for synthesis. No studies reported the relationship between muscle structure/function and pain/disability changes. Twelve studies reported muscle structure/function outcome measures at baseline and at least one follow-up time-point. Three studies reported improvements in force output after treatment; eight studies demonstrated no change in structure or function; one study did not provide a variation measure, precluding within group change over time calculation. All studies were low quality.

CONCLUSIONS

No studies explored the relationship between changes in tendon pain and disability and changes in muscle structure and function. It is unclear whether current exercise-based rehabilitation protocols for mid-portion Achilles tendinopathy improve muscle structure or function.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO (registration number: CRD42020149970).

Effect of exercise therapy in patients with hip osteoarthritis: A systematic review and cumulative meta-analysis

Objective

To evaluate the existing evidence on the effect of exercise therapy in patients with hip osteoarthritis (OA) compared to no treatment and explore whether a further trial will change the current evidence.

Design

Systematic review and cumulative meta-analysis using randomized controlled trials (RCT) to determine the effect on pain and function post-treatment, and at 6-9 months after treatment. Standardized mean difference (SMD) ​≤ ​-0.37 was considered clinically worthwhile. Extended funnel plots were used to simulate the impact of a new trial on the pooled effect size of pain and function.

Results

18 RCTs were included. Post-treatment we found a beneficial effect of exercise therapy on pain (SMD -0.38, 95% Confidence Interval (CI): 0.55 to -0.22) and function (SMD -0.31, 95% CI -0.49 to -0.11). A beneficial effect of exercise therapy on pain (SMD -0.23, 95% CI: 0.41 to -0.05) and function (SMD -0.29, 95% CI: 0.45 to -0.12) was found 6-9 months after treatment. Most effect estimates were small, and it is unclear whether these are clinically meaningful. Extended funnel plots and a simulation of a new trial showed that only a new trial with a larger effect than the current pooled effect or a trial including 74,843 participants would change the pooled effect estimate from an unclear to a clearly clinically worthwhile effect.

Conclusions

We found a beneficial effect of exercise therapy on pain and function in hip OA. It is unlikely a new trial added to current evidence will change the conclusion.

Effectiveness of an Unsupervised Online Yoga Program on Pain and Function in People With Knee Osteoarthritis : A Randomized Clinical Trial

BACKGROUND

Yoga is a mind-body exercise typically done in groups in person, but this delivery method can be inconvenient, inaccessible, and costly. Effective online programs may increase access to exercise for knee osteoarthritis.

OBJECTIVE

To evaluate the effectiveness of an unsupervised 12-week online yoga program.

DESIGN

Two-group superiority randomized trial. (Australian New Zealand Clinical Trials Registry: ACTRN12620000012976).

SETTING

Community.

PARTICIPANTS

212 adults with symptomatic knee osteoarthritis.

INTERVENTION

Both groups received online osteoarthritis information (control). The yoga group also received access to an unsupervised online yoga program delivered via prerecorded videos over 12 weeks (1 video per week, with each session to be performed 3 times per week), with optional continuation thereafter.

MEASUREMENTS

Primary outcomes were changes in knee pain during walking (0 to 10 on a numerical rating scale) and physical function (0 to 68 on the Western Ontario and McMaster Universities Osteoarthritis Index) at 12 weeks (primary time point) and 24 weeks, analyzed using mixed-effects linear regression models. Secondary outcomes were self-reported overall knee pain, stiffness, depression, anxiety, stress, global change, quality of life, self-efficacy, fear of movement, and balance confidence. Adverse events were also collected.

RESULTS

A total of 195 (92%) and 189 (89%) participants provided 12- and 24-week primary outcomes, respectively. Compared with control at 12 weeks, yoga improved function (between-group mean difference in change, -4.0 [95% CI, -6.8 to -1.3]) but not knee pain during walking (between-group mean difference in change, -0.6 [CI, -1.2 to 0.1]), with more yoga participants than control participants achieving the minimal clinically important difference (MCID) for both outcomes. At 12 weeks, knee stiffness, quality of life, and arthritis self-efficacy improved more with yoga than the control intervention. Benefits were not maintained at 24 weeks. Adverse events were minor.

LIMITATION

Participants were unblinded.

CONCLUSION

Compared with online education, an unsupervised online yoga program improved physical function but not knee pain at 12 weeks in people with knee osteoarthritis, although the improvement did not reach the MCID and was not sustained at 24 weeks.

PRIMARY FUNDING SOURCE

National Health and Medical Research Council and Centres of Research Excellence.

Moderators of the Effect of a Self-directed Digitally Delivered Exercise Program for People With Knee Osteoarthritis: Exploratory Analysis of a Randomized Controlled Trial

BACKGROUND

A 24-week self-directed digitally delivered intervention was found to improve pain and function in people with knee osteoarthritis (OA). However, it is possible that this intervention may be better suited to certain subgroups of people with knee OA compared to others.

OBJECTIVE

The aim of this study was to explore whether certain individual baseline characteristics moderate the effects of a self-directed digitally delivered intervention on changes in pain and function over 24 weeks in people with knee OA.

METHODS

An exploratory analysis was conducted on data from a randomized controlled trial involving 206 people with a clinical diagnosis of knee OA. This trial compared a self-directed digitally delivered intervention comprising of web-based education, exercise, and physical activity program supported by automated exercise behavior change mobile phone text messages to web-based education alone (control). The primary outcomes were changes in overall knee pain (assessed on an 11-point numerical rating scale) and physical function (assessed using the Western Ontario and McMaster Universities Osteoarthritis Index function subscale [WOMAC]) at 24 weeks. Five baseline patient characteristics were selected as the potential moderators: (1) number of comorbidities, (2) number of other painful joints, (3) pain self-efficacy, (4) exercise self-efficacy, and (5) self-perceived importance of exercise. Separate linear regression models for each primary outcome and each potential moderator were fit, including treatment group, moderator, and interaction between treatment group and moderator, adjusting for the outcome at baseline.

RESULTS

There was evidence that pain self-efficacy moderated the effect of the intervention on physical function compared to the control at 24 weeks (interaction P=.02). Posthoc assessment of the mean change in WOMAC function by treatment arm showed that each 1-unit increase in baseline pain self-efficacy was associated with a 1.52 (95% CI 0.27 to 2.78) unit improvement in the control group. In contrast, a reduction of 0.62 (95% CI -1.93 to 0.68) units was observed in the intervention group with each unit increase in pain self-efficacy. There was only weak evidence that pain self-efficacy moderated the effect of the intervention on pain and that number of comorbidities, number of other painful joints, exercise self-efficacy, or exercise importance moderated the effect of the intervention on pain or function.

CONCLUSIONS

With the exception of pain self-efficacy, which moderated changes in function but not pain, we found limited evidence that our selected baseline patient characteristics moderated intervention outcomes. This indicates that people with a range of baseline characteristics respond similarly to the unsupervised digitally delivered exercise intervention. As these findings are exploratory in nature, they require confirmation in future studies.

Guidance for implementing best practice therapeutic exercise for people with knee and hip osteoarthritis: what does the current evidence base tell us?

OBJECTIVE

Therapeutic exercise is a recommended first-line treatment for people with knee and hip osteoarthritis. However, there is little specific advice or practical resources to guide clinicians in its implementation. As the first in a series of projects by the Osteoarthritis Research Society International Rehabilitation Discussion Group to address this gap, we aim to synthesize current literature informing the implementation of therapeutic exercise for people with knee and hip osteoarthritis.

METHODS

Narrative review focusing on evidence from systematic reviews and randomized controlled trials.

RESULTS

Therapeutic exercise is safe for people with knee and hip osteoarthritis. Numerous types of therapeutic exercise (including aerobic, strengthening, neuromuscular, mind-body exercise) may be utilised at varying doses and in different settings to improve pain and function. Benefits from therapeutic exercise appear greater when dosage recommendations from general exercise guidelines for healthy adults are met. However, interim therapeutic exercise goals may also be useful, given that many barriers to achieving these dosages exist among this patient group. Theoretically-informed strategies to improve adherence to therapeutic exercise, such as patient education, goal setting, monitoring and feedback, may help maintain participation and optimise clinical benefits over the longer-term. Sedentary behaviour is also a risk factor for disability and lower quality of life in people with knee and hip osteoarthritis, although limited evidence exists regarding how best to reduce this behaviour.

CONCLUSION

Current evidence can be used to inform how to implement best practice therapeutic exercise, at a sufficient and appropriate dose, for people with knee and hip osteoarthritis.