BACKGROUND: Knee osteoarthritis (OA) is a major public health issue causing chronic pain, impaired physical function, and reduced quality of life. As there is no cure, self-management of symptoms via exercise is recommended by all current international clinical guidelines. This review updates one published in 2015.
OBJECTIVES: We aimed to assess the effects of land-based exercise for people with knee osteoarthritis (OA) by comparing: 1) exercise versus attention control or placebo; 2) exercise versus no treatment, usual care, or limited education; 3) exercise added to another co-intervention versus the co-intervention alone.
SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and two trial registries (ClinicalTrials.gov and World Health Organisation International Clinical Trials Registry Platform), together with reference lists, from the date of the last search (1st May 2013) until 4 January 2024, unrestricted by language.
SELECTION CRITERIA: We included randomised controlled trials (RCTs) that evaluated exercise for knee OA versus a comparator listed above. Our outcomes of interest were pain severity, physical function, quality of life, participant-reported treatment success, adverse events, and study withdrawals.
DATA COLLECTION AND ANALYSIS: We used the standard methodological procedures expected by Cochrane for systematic reviews of interventions.
MAIN RESULTS: We included 139 trials (12,468 participants): 30 (3065 participants) compared exercise to attention control or placebo; 60 (4834 participants) compared exercise with usual care, no intervention or limited education; and 49 (4569 participants) evaluated exercise added to another intervention (e.g. weight loss diet, physical therapy, detailed education) versus that intervention alone. Interventions varied substantially in duration, ranging from 2 to 104 weeks. Most of the trials were at unclear or high risk of bias, in particular, performance bias (94% of trials), detection bias (94%), selective reporting bias (68%), selection bias (57%), and attrition bias (48%). Exercise versus attention control/placebo Compared with attention control/placebo, low-certainty evidence indicates exercise may result in a slight improvement in pain immediately post-intervention (mean 8.70 points better (on a scale of 0 to 100), 95% confidence interval (CI) 5.70 to 11.70; 28 studies, 2873 participants). Moderate-certainty evidence indicates exercise likely results in an improvement in physical function (mean 11.27 points better (on a scale of 0 to 100), 95% CI 7.64 to 15.09; 24 studies, 2536 participants), but little to no improvement in quality of life (mean 6.06 points better (on a scale of 0 to 100), 95% CI -0.13 to 12.26; 6 studies, 454 participants). There was moderate-certainty evidence that exercise likely increases participant-reported treatment success (risk ratio (RR) 1.46, 95% CI 1.11 to 1.92; 2 studies 364 participants), and likely does not increase study withdrawals (RR 1.08, 95% CI 0.92 to 1.26; 29 studies, 2907 participants). There was low-certainty evidence that exercise may not increase adverse events (RR 2.02, 95% CI 0.62 to 6.58; 11 studies, 1684 participants). Exercise versus no treatment/usual care/limited education Compared with no treatment/usual care/limited education, low-certainty evidence indicates exercise may result in an improvement in pain immediately post-intervention (mean 13.14 points better (on a scale of 0 to 100), 95% CI 10.36 to 15.91; 56 studies, 4184 participants). Moderate-certainty evidence indicates exercise likely results in an improvement in physical function (mean 12.53 points better (on a scale of 0 to 100), 95% CI 9.74 to 15.31; 54 studies, 4352 participants) and a slight improvement in quality of life (mean 5.37 points better (on a scale of to 100), 95% CI 3.19 to 7.54; 28 studies, 2328 participants). There was low-certainty evidence that exercise may result in no difference in participant-reported treatment success (RR 1.33, 95% CI 0.71 to 2.49; 3 studies, 405 participants). There was moderate-certainty evidence that exercise likely results in no difference in study withdrawals (RR 1.03, 95% CI 0.88 to 1.20; 53 studies, 4408 participants). There was low-certainty evidence that exercise may increase adverse events (RR 3.17, 95% CI 1.17 to 8.57; 18 studies, 1557 participants). Exercise added to another co-intervention versus the co-intervention alone Moderate-certainty evidence indicates that exercise when added to a co-intervention likely results in improvements in pain immediately post-intervention compared to the co-intervention alone (mean 10.43 points better (on a scale of 0 to 100), 95% CI 8.06 to 12.79; 47 studies, 4441 participants). It also likely results in a slight improvement in physical function (mean 9.66 points better, 95% CI 7.48 to 11.97 (on a 0 to 100 scale); 44 studies, 4381 participants) and quality of life (mean 4.22 points better (on a 0 to 100 scale), 95% CI 1.36 to 7.07; 12 studies, 1660 participants) immediately post-intervention. There was moderate-certainty evidence that exercise likely increases participant-reported treatment success (RR 1.63, 95% CI 1.18 to 2.24; 6 studies, 1139 participants), slightly reduces study withdrawals (RR 0.82, 95% CI 0.70 to 0.97; 41 studies, 3502 participants), and slightly increases adverse events (RR 1.72, 95% CI 1.07 to 2.76; 19 studies, 2187 participants). Subgroup analysis and meta-regression We did not find any differences in effects between different types of exercise, and we found no relationship between changes in pain or physical function and the total number of exercise sessions prescribed or the ratio (between exercise group and comparator) of real-time consultations with a healthcare provider. Clinical significance of the findings To determine whether the results found would make a clinically meaningful difference to someone with knee OA, we compared our results to established 'minimal important difference' (MID) scores for pain (12 points on a 0 to 100 scale), physical function (13 points), and quality of life (15 points). We found that the confidence intervals of mean differences either did not reach these thresholds or included both a clinically important and clinically unimportant improvement.
AUTHORS' CONCLUSIONS: We found low- to moderate-certainty evidence that exercise probably results in an improvement in pain, physical function, and quality of life in the short-term. However, based on the thresholds for minimal important differences that we used, these benefits were of uncertain clinical importance. Participants in most trials were not blinded and were therefore aware of their treatment, and this may have contributed to reported improvements.
BACKGROUND: Individuals with osteoarthritis (OA) of the knee can be treated with a knee brace or a foot/ankle orthosis. The main purpose of these aids is to reduce pain, improve physical function and, possibly, slow disease progression. This is the second update of the original review published in Issue 1, 2005, and first updated in 2007.
OBJECTIVES: To assess the benefits and harms of braces and foot/ankle orthoses in the treatment of patients with OA of the knee.
SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE (current contents, HealthSTAR) up to March 2014. We screened reference lists of identified trials and clinical trial registers for ongoing studies.
SELECTION CRITERIA: Randomised and controlled clinical trials investigating all types of braces and foot/ankle orthoses for OA of the knee compared with an active control or no treatment.
DATA COLLECTION AND ANALYSIS: Two review authors independently selected trials and extracted data. We assessed risk of bias using the 'Risk of bias' tool of The Cochrane Collaboration. We analysed the quality of the results by performing an overall grading of evidence by outcome using the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach. As a result of heterogeneity of studies, pooling of outcome data was possible for only three insole studies.
MAIN RESULTS: We included 13 studies (n = 1356): four studies in the first version, three studies in the first update and six additional studies (n = 529 participants) in the second update. We included studies that reported results when study participants with early to severe knee OA (Kellgren & Lawrence grade I-IV) were treated with a knee brace (valgus knee brace, neutral brace or neoprene sleeve) or an orthosis (laterally or medially wedged insole, neutral insole, variable or constant stiffness shoe) or were given no treatment. The main comparisons included (1) brace versus no treatment; (2) foot/ankle orthosis versus no treatment or other treatment; and (3) brace versus foot/ankle orthosis. Seven studies had low risk, two studies had high risk and four studies had unclear risk of selection bias. Five studies had low risk, three studies had high risk and five studies had unclear risk of detection bias. Ten studies had high risk and three studies had low risk of performance bias. Nine studies had low risk and four studies had high risk of reporting bias.Four studies compared brace versus no treatment, but only one provided useful data for meta-analysis at 12-month follow-up. One study (n = 117, low-quality evidence) showed lack of evidence of an effect on visual analogue scale (VAS) pain scores (absolute percent change 0%, mean difference (MD) 0.0, 95% confidence interval (CI) -0.84 to 0.84), function scores (absolute percent change 1%, MD 1.0, 95% CI -2.98 to 4.98) and health-related quality of life scores (absolute percent change 4%, MD -0.04, 95% CI -0.12 to 0.04) after 12 months. Many participants stopped their initial treatment because of lack of effect (24 of 60 participants in the brace group and 14 of 57 participants in the no treatment group; absolute percent change 15%, risk ratio (RR) 1.63, 95% CI 0.94 to 2.82). The other studies reported some improvement in pain, function and health-related quality of life (P value ≤ 0.001). Stiffness and treatment failure (need for surgery) were not reported in the included studies.For the comparison of laterally wedged insole versus no insole, one study (n = 40, low-quality evidence) showed a lower VAS pain score in the laterally wedged insole group (absolute percent change 16%, MD -1.60, 95% CI -2.31 to -0.89) after nine months. Function, stiffness, health-related quality of life, treatment failure and adverse events were not reported in the included study.For the comparison of laterally wedged versus neutral insole after pooling of three studies (n = 358, moderate-quality evidence), little evidence was found of an effect on numerical rating scale (NRS) pain scores (absolute percent change 1.0%, MD 0.1, 95% CI -0.45 to 0.65), Western Ontario-McMaster Osteoarthritis Scale (WOMAC) stiffness scores (absolute percent change 0.1%, MD 0.07, 95% CI -4.96 to 5.1) and WOMAC function scores (absolute percent change 0.9%, MD 0.94, 95% CI - 2.98 to 4.87) after 12 months. Evidence of an effect on health-related quality of life scores (absolute percent change 1.0%, MD 0.01, 95% CI -0.05 to 0.03) was lacking in one study (n = 179, moderate-quality evidence). Treatment failure and adverse events were not studied for this comparison in the included studies.Data for the comparison of laterally wedged insole versus valgus knee brace could not be pooled. After six months' follow-up, no statistically significant difference was noted in VAS pain scores (absolute percent change -2.0%, MD -0.2, 95% CI -1.15 to 0.75) and WOMAC function scores (absolute percent change 0.1%, MD 0.1, 95% CI -7.26 to 0.75) in one study (n = 91, low-quality evidence); however both groups showed improvement. Stiffness, health-related quality of life, treatment failure and adverse events were not reported in the included studies for this comparison.
AUTHORS' CONCLUSIONS: Evidence was inconclusive for the benefits of bracing for pain, stiffness, function and quality of life in the treatment of patients with medial compartment knee OA. On the basis of one laterally wedged insole versus no treatment study, we conclude that evidence of an effect on pain in patients with varus knee OA is lacking. Moderate-quality evidence shows lack of an effect on improvement in pain, stiffness and function between patients treated with a laterally wedged insole and those treated with a neutral insole. Low-quality evidence shows lack of an effect on improvement in pain, stiffness and function between patients treated with a valgus knee brace and those treated with a laterally wedged insole. The optimal choice for an orthosis remains unclear, and long-term implications are lacking.
BACKGROUND: This is an update of a Cochrane review first published in 2002. Osteoarthritis is a disease that affects the synovial joints, causing degeneration and destruction of hyaline cartilage and subchondral bone. Electromagnetic field therapy is currently used by physiotherapists and may promote growth and repair of bone and cartilage. It is based on principles of physics which include Wolff's law, the piezoelectric effect and the concept of streaming potentials.
OBJECTIVES: To assess the benefits and harms of electromagnetic fields for the treatment of osteoarthritis as compared to placebo or sham.
SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 9), PreMEDLINE for trials published before 1966, MEDLINE from 1966 to October 2013, CINAHL and PEDro up to and including October 2013. Electronic searches were complemented by handsearches.
SELECTION CRITERIA: Randomised controlled trials of electromagnetic fields in osteoarthritis, with four or more weeks treatment duration. We included papers in any language.
DATA COLLECTION AND ANALYSIS: Two review authors independently assessed studies for inclusion in the review and resolved differences by consensus with a third review author. We extracted data using pre-developed data extraction forms. The same review authors assessed the risk of bias of the trials independently using the Cochrane 'Risk of bias' tool. We extracted outcomes for osteoarthritis from the publications according to Outcome Measures in Rheumatology Clinical Trials (OMERACT) guidelines. We expressed results for continuous outcome measures as mean difference (MD) or standardised mean difference (SMD) with 95% confidence interval (CI). We pooled dichotomous outcome measures using risk ratio (RR) and calculated the number needed to treat (NNT).
MAIN RESULTS: Nine studies with a total of 636 participants with osteoarthritis were included, six of which were added in this update of the review. Selective outcome reporting was unclear in all nine included studies due to inadequate reporting of study design and conduct, and there was high risk of bias for incomplete outcome data in three studies. The overall risk of bias across the nine studies was low for the other domains.
Participants who were randomised to electromagnetic field treatment rated their pain relief 15.10 points more on a scale of 0 to 100 (MD 15.10, 95% CI 9.08 to 21.13; absolute improvement 15%) after 4 to 26 weeks' treatment compared with placebo. Electromagnetic field treatment had no statistically significant effect on physical function (MD 4.55, 95% CI -2.23 to 11.32; absolute improvement 4.55%) based on the Western Ontario and McMaster Universities osteoarthritis index (WOMAC) scale from 0 to 100 after 12 to 26 weeks' treatment. We also found no statistically significant difference in quality of life on a scale from 0 to 100 (SMD 0.09, 95% CI -0.36 to 0.54; absolute improvement 0.09%) after four to six weeks' treatment, based on the SF-36. No data were available for analysis of radiographic changes. Safety was evaluated in four trials including up to 288 participants: there was no difference in the experience of any adverse event after 4 to 12 weeks of treatment compared with placebo (RR 1.17, 95% CI 0.72 to 1.92). There was no difference in participants who withdrew because of adverse events (measured in one trial) after four weeks of treatment (RR 0.90, 95% CI 0.06 to 13.92). No participants experienced any serious adverse events.
AUTHORS' CONCLUSIONS: Current evidence suggests that electromagnetic field treatment may provide moderate benefit for osteoarthritis sufferers in terms of pain relief. Further studies are required to confirm whether this treatment confers clinically important benefits in terms of physical function and quality of life. Our conclusions are unchanged from the previous review conducted in 2002.
BACKGROUND: Osteoarthritis is the most common form of joint disease and the leading cause of pain and physical disability in the elderly. Therapeutic ultrasound is one of several physical therapy modalities suggested for the management of pain and loss of function due to osteoarthritis (OA). OBJECTIVES: To compare therapeutic ultrasound with sham or no specific intervention in terms of effects on pain and function safety outcomes in patients with knee or hip OA. SEARCH STRATEGY: We updated the search in CENTRAL, CINAHL, EMBASE, MEDLINE and PEDro up to 23 July 2009, checked conference proceedings, reference lists, and contacted authors. SELECTION CRITERIA: Studies were included if they were randomised or quasi-randomised controlled trials that compared therapeutic ultrasound with a sham intervention or no intervention in patients with osteoarthritis of the knee or hip. DATA COLLECTION AND ANALYSIS: Two independent review authors extracted data using standardized forms. Investigators were contacted to obtain missing outcome information. Standardised mean differences (SMDs) were calculated for pain and function, relative risks for safety outcomes. Trials were combined using inverse-variance random-effects meta-analysis. MAIN RESULTS: Compared to the previous version of the review, four additional trials were identified resulting in the inclusion of five small sized trials in a total of 341 patients with knee OA. No trial included patients with hip OA. Two evaluated pulsed ultrasound, two continuous and one evaluated both pulsed and continuous ultrasound as the active treatment. The methodological quality and the quality of reporting was poor and a high degree of heterogeneity among the trials was revealed for function (88%). For pain, there was an effect in favour of ultrasound therapy, which corresponded to a difference in pain scores between ultrasound and control of -1.2 cm on a 10-cm VAS (95% CI -1.9 to -0.6 cm). For function, we found a trend in favour of ultrasound, which corresponded to a difference in function scores of -1.3 units on a standardised WOMAC disability scale ranging from 0 to 10 (95% CI -3.0 to 0.3). Safety was evaluated in two trials including up to 136 patients; no adverse event, serious adverse event or withdrawals due to adverse events occurred in either trial. AUTHORS' CONCLUSIONS: In contrast to the previous version of this review, our results suggest that therapeutic ultrasound may be beneficial for patients with osteoarthritis of the knee. Because of the low quality of the evidence, we are uncertain about the magnitude of the effects on pain relief and function, however. Therapeutic ultrasound is widely used for its potential benefits on both knee pain and function, which may be clinically relevant. Appropriately designed trials of adequate power are therefore warranted.
BACKGROUND: Osteoarthritis is the most common form of joint disease and the leading cause of pain and physical disability in the elderly. Transcutaneous electrical nerve stimulation (TENS), interferential current stimulation and pulsed electrostimulation are used widely to control both acute and chronic pain arising from several conditions, but some policy makers regard efficacy evidence as insufficient. OBJECTIVES: To compare transcutaneous electrostimulation with sham or no specific intervention in terms of effects on pain and withdrawals due to adverse events in patients with knee osteoarthritis. SEARCH STRATEGY: We updated the search in CENTRAL, MEDLINE, EMBASE, CINAHL and PEDro up to 5 August 2008, checked conference proceedings and reference lists, and contacted authors. SELECTION CRITERIA: Randomised or quasi-randomised controlled trials that compared transcutaneously applied electrostimulation with a sham intervention or no intervention in patients with osteoarthritis of the knee. DATA COLLECTION AND ANALYSIS: We extracted data using standardised forms and contacted investigators to obtain missing outcome information. Main outcomes were pain and withdrawals or dropouts due to adverse events. We calculated standardised mean differences (SMDs) for pain and relative risks for safety outcomes and used inverse-variance random-effects meta-analysis. The analysis of pain was based on predicted estimates from meta-regression using the standard error as explanatory variable. MAIN RESULTS: In this update we identified 14 additional trials resulting in the inclusion of 18 small trials in 813 patients. Eleven trials used TENS, four interferential current stimulation, one both TENS and interferential current stimulation, and two pulsed electrostimulation. The methodological quality and the quality of reporting was poor and a high degree of heterogeneity among the trials (I(2) = 80%) was revealed. The funnel plot for pain was asymmetrical (P < 0.001). The predicted SMD of pain intensity in trials as large as the largest trial was -0.07 (95% CI -0.46 to 0.32), corresponding to a difference in pain scores between electrostimulation and control of 0.2 cm on a 10 cm visual analogue scale. There was little evidence that SMDs differed on the type of electrostimulation (P = 0.94). The relative risk of being withdrawn or dropping out due to adverse events was 0.97 (95% CI 0.2 to 6.0). AUTHORS' CONCLUSIONS: In this update, we could not confirm that transcutaneous electrostimulation is effective for pain relief. The current systematic review is inconclusive, hampered by the inclusion of only small trials of questionable quality. Appropriately designed trials of adequate power are warranted.
This review aims to assess by meta-analysis of randomised controlled trials (RCTs) changes in pain and function when overweight patients with knee osteoarthritis (OA) achieve a weight loss. Systematic searches were performed and reference lists from the retrieved trials were searched. RCTs were enclosed in the systematic review if they explicitly stated diagnosis of knee OA and reported a weight change as the only difference in intervention from the control group. Outcome Measures for Arthritis Clinical Trials III outcome variables were considered for analysis. Effect size (ES) was calculated using RevMan, and meta-regression analyses were performed using weighted estimates from the random effects analyses. Among 35 potential trials identified, four RCTs including five intervention/control groups met our inclusion criteria and provided data from 454 patients. Pooled ES for pain and physical disability were 0.20 (95% CI 0 to 0.39) and 0.23 (0.04 to 0.42) at a weight reduction of 6.1 kg (4.7 to 7.6 kg). Meta-regression analysis showed that disability could be significantly improved when weight was reduced over 5.1%, or at the rate of >0.24% reduction per week. Clinical efficacy on pain reduction was present, although not predictable after weight loss. Meta-regression analysis indicated that physical disability of patients with knee OA and overweight diminished after a moderate weight reduction regime. The analysis supported that a weight loss of >5% should be achieved within a 20-week period--that is, 0.25% per week.
OBJECTIVE: Osteoarthritis (OA) is the most prevalent health condition among seniors and it causes significant pain and disability. We assessed the influence of patient education and exercise regimens on the well-being of patients with knee OA.
METHODS: A metaanalysis was conducted on 16 studies reporting exercise and/or self-management interventions for patients with knee OA. The effects on physical and psychological well-being were assessed immediately after the interventions.
RESULTS: Compared to control conditions, exercise regimens led to improvement in physical health (by self-report and direct measures) and in overall impact of OA. Perceived psychological health remained unchanged by the exercise programs. Although the effect sizes for the self-management programs were significant for psychological outcomes and for the overall effect of OA, there was a significant difference between self-management and control groups only in psychological outcomes.
CONCLUSION: Overall, both patient education and exercise regimens had a modest, yet clinically important, influence on patients' well-being.
Knee osteoarthritis (OA) affects approximately one third of older adults in the United States. The pain accompanying its progression reduces quality of life and leads to activity restriction and physical disability. Evidence suggests that exercise represents a promising treatment for pain among older knee-OA patients. The article provides an overview of the extant research examining the effectiveness of exercise interventions in reducing pain symptoms among older adults with knee OA. Critical evaluation of the literature reveals that aerobic training, strength training, and combination aerobic and strength training result in improvements in pain. The magnitude of pain reduction accompanying exercise interventions varies considerably across studies, however. In addition, most trials have focused on short-term (<6 months) interventions, and the limited number of long-term (>6 months) trials have been plagued by high attrition and poor postintervention maintenance of treatment effects. Given the variability in the effectiveness of exercise interventions, future research is necessary to determine the individual differences that influence older OA patients' responsiveness to exercise interventions and identify more efficacious strategies for promoting the maintenance of long-term exercise.
OBJECTIVE: To evaluate the evidence for the effectiveness of acupuncture in peripheral joint osteoarthritis (OA). METHODS: Systematic searches were conducted on Medline, Embase, AMED, Cochrane Library, CINAHL, British Nursing Index, PsychINFO and CAMPAIN until July 2005. Hand-searches included conference proceedings and our own files. There were no restrictions regarding the language of publication. All randomized controlled trials (RCTs) of acupuncture for patients with peripheral joint OA were considered for inclusion. Trials assessing needle acupuncture with or without electrical stimulation were considered if sham- or placebo-controlled or controlled against a comparator intervention. Trials testing other forms of acupuncture were excluded. Methodological quality was assessed and, where possible, meta-analyses were performed. RESULTS: Thirty-one possibly relevant studies were identified and 18 RCTs were included. Ten trials tested manual acupuncture and eight trials tested electro-acupuncture. Overall, ten studies demonstrated greater pain reduction in acupuncture groups compared with controls. The meta-analysis of homogeneous data showed a significant effect of manual acupuncture compared with sham acupuncture (standardized mean difference 0.24, 95% confidence interval 0.01-0.47, P = 0.04, n = 329), which is supported by data for knee OA. The extent of heterogeneity in trials of electro-acupuncture prevented a meaningful meta-analysis. CONCLUSIONS: Sham-controlled RCTs suggest specific effects of acupuncture for pain control in patients with peripheral joint OA. Considering its favourable safety profile acupuncture seems an option worthy of consideration particularly for knee OA. Further studies are required particularly for manual or electro-acupuncture in hip OA.
BACKGROUND: The rehabilitation of knee osteoarthritis often includes electrotherapeutic modalities as well as advice and exercise. One commonly used modality is pulsed electromagnetic field therapy (PEMF). PEMF uses electro magnetically generated fields to promote tissue repair and healing rates. Its equivocal benefit over placebo treatment has been previously suggested however recently a number of randomised controlled trials have been published that have allowed a systematic review to be conducted. METHODS: A systematic review of the literature from 1966 to 2005 was undertaken. Relevant computerised bibliographic databases were searched and papers reviewed independently by two reviewers for quality using validated criteria for assessment. The key outcomes of pain and functional disability were analysed with weighted and standardised mean differences being calculated. RESULTS: Five randomised controlled trials comparing PEMF with placebo were identified. The weighted mean differences of the five papers for improvement in pain and function, were small and their 95% confidence intervals included the null. CONCLUSION: This systematic review provides further evidence that PEMF has little value in the management of knee osteoarthritis. There appears to be clear evidence for the recommendation that PEMF does not significantly reduce the pain of knee osteoarthritis.
Knee osteoarthritis (OA) is a major public health issue causing chronic pain, impaired physical function, and reduced quality of life. As there is no cure, self-management of symptoms via exercise is recommended by all current international clinical guidelines. This review updates one published in 2015.
OBJECTIVES:
We aimed to assess the effects of land-based exercise for people with knee osteoarthritis (OA) by comparing: 1) exercise versus attention control or placebo; 2) exercise versus no treatment, usual care, or limited education; 3) exercise added to another co-intervention versus the co-intervention alone.
SEARCH METHODS:
We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and two trial registries (ClinicalTrials.gov and World Health Organisation International Clinical Trials Registry Platform), together with reference lists, from the date of the last search (1st May 2013) until 4 January 2024, unrestricted by language.
SELECTION CRITERIA:
We included randomised controlled trials (RCTs) that evaluated exercise for knee OA versus a comparator listed above. Our outcomes of interest were pain severity, physical function, quality of life, participant-reported treatment success, adverse events, and study withdrawals.
DATA COLLECTION AND ANALYSIS:
We used the standard methodological procedures expected by Cochrane for systematic reviews of interventions.
MAIN RESULTS:
We included 139 trials (12,468 participants): 30 (3065 participants) compared exercise to attention control or placebo; 60 (4834 participants) compared exercise with usual care, no intervention or limited education; and 49 (4569 participants) evaluated exercise added to another intervention (e.g. weight loss diet, physical therapy, detailed education) versus that intervention alone. Interventions varied substantially in duration, ranging from 2 to 104 weeks. Most of the trials were at unclear or high risk of bias, in particular, performance bias (94% of trials), detection bias (94%), selective reporting bias (68%), selection bias (57%), and attrition bias (48%). Exercise versus attention control/placebo Compared with attention control/placebo, low-certainty evidence indicates exercise may result in a slight improvement in pain immediately post-intervention (mean 8.70 points better (on a scale of 0 to 100), 95% confidence interval (CI) 5.70 to 11.70; 28 studies, 2873 participants). Moderate-certainty evidence indicates exercise likely results in an improvement in physical function (mean 11.27 points better (on a scale of 0 to 100), 95% CI 7.64 to 15.09; 24 studies, 2536 participants), but little to no improvement in quality of life (mean 6.06 points better (on a scale of 0 to 100), 95% CI -0.13 to 12.26; 6 studies, 454 participants). There was moderate-certainty evidence that exercise likely increases participant-reported treatment success (risk ratio (RR) 1.46, 95% CI 1.11 to 1.92; 2 studies 364 participants), and likely does not increase study withdrawals (RR 1.08, 95% CI 0.92 to 1.26; 29 studies, 2907 participants). There was low-certainty evidence that exercise may not increase adverse events (RR 2.02, 95% CI 0.62 to 6.58; 11 studies, 1684 participants). Exercise versus no treatment/usual care/limited education Compared with no treatment/usual care/limited education, low-certainty evidence indicates exercise may result in an improvement in pain immediately post-intervention (mean 13.14 points better (on a scale of 0 to 100), 95% CI 10.36 to 15.91; 56 studies, 4184 participants). Moderate-certainty evidence indicates exercise likely results in an improvement in physical function (mean 12.53 points better (on a scale of 0 to 100), 95% CI 9.74 to 15.31; 54 studies, 4352 participants) and a slight improvement in quality of life (mean 5.37 points better (on a scale of to 100), 95% CI 3.19 to 7.54; 28 studies, 2328 participants). There was low-certainty evidence that exercise may result in no difference in participant-reported treatment success (RR 1.33, 95% CI 0.71 to 2.49; 3 studies, 405 participants). There was moderate-certainty evidence that exercise likely results in no difference in study withdrawals (RR 1.03, 95% CI 0.88 to 1.20; 53 studies, 4408 participants). There was low-certainty evidence that exercise may increase adverse events (RR 3.17, 95% CI 1.17 to 8.57; 18 studies, 1557 participants). Exercise added to another co-intervention versus the co-intervention alone Moderate-certainty evidence indicates that exercise when added to a co-intervention likely results in improvements in pain immediately post-intervention compared to the co-intervention alone (mean 10.43 points better (on a scale of 0 to 100), 95% CI 8.06 to 12.79; 47 studies, 4441 participants). It also likely results in a slight improvement in physical function (mean 9.66 points better, 95% CI 7.48 to 11.97 (on a 0 to 100 scale); 44 studies, 4381 participants) and quality of life (mean 4.22 points better (on a 0 to 100 scale), 95% CI 1.36 to 7.07; 12 studies, 1660 participants) immediately post-intervention. There was moderate-certainty evidence that exercise likely increases participant-reported treatment success (RR 1.63, 95% CI 1.18 to 2.24; 6 studies, 1139 participants), slightly reduces study withdrawals (RR 0.82, 95% CI 0.70 to 0.97; 41 studies, 3502 participants), and slightly increases adverse events (RR 1.72, 95% CI 1.07 to 2.76; 19 studies, 2187 participants). Subgroup analysis and meta-regression We did not find any differences in effects between different types of exercise, and we found no relationship between changes in pain or physical function and the total number of exercise sessions prescribed or the ratio (between exercise group and comparator) of real-time consultations with a healthcare provider. Clinical significance of the findings To determine whether the results found would make a clinically meaningful difference to someone with knee OA, we compared our results to established 'minimal important difference' (MID) scores for pain (12 points on a 0 to 100 scale), physical function (13 points), and quality of life (15 points). We found that the confidence intervals of mean differences either did not reach these thresholds or included both a clinically important and clinically unimportant improvement.
AUTHORS' CONCLUSIONS:
We found low- to moderate-certainty evidence that exercise probably results in an improvement in pain, physical function, and quality of life in the short-term. However, based on the thresholds for minimal important differences that we used, these benefits were of uncertain clinical importance. Participants in most trials were not blinded and were therefore aware of their treatment, and this may have contributed to reported improvements.
