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Strength training for treatment of osteoarthritis of the knee: a systematic review |
Lange AK, Vanwanseele B, Fiatarone Singh MA |
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CRD summary This review concluded that resistance training improved muscle strength, pain, and physical function and there was insufficient data on health-related quality of life and depression. The authors' conclusions appear to be appropriate, but the review was vulnerable to bias and errors. Authors' objectives To assess the safety and effectiveness of resistance training in improving symptoms, physical performance, and psychological impairments associated with osteoarthritis of the knee. Searching MEDLINE, CINAHL, EBM Reviews, SPORTDiscus, AMED, Web of Knowledge, and Physiotherapy Evidence Database were searched for articles from 1830 to December 2007. The search engine Google Scholar was also used and reference lists of included studies, review articles, and position statements were manually searched. Experts were consulted for additional studies. The search terms were reported and only full-text articles published in English were eligible. Study selection Randomised controlled trials (RCTs) investigating resistance training for primary osteoarthritis of the knee in patients over 18 years old were included in this review. Trials with co-interventions and those without a non-exercise control group were excluded.
In the included trials, the mean age ranged from 55.3 to 74.6 years. Most of the trials included more women than men and included overweight or obese patients. They generally had mixed populations of duration of knee osteoarthritis, ranging from six months to 45 years. Comorbidities included hypertension, diabetes, and heart or respiratory disease. The intervention strategies varied and trial duration ranged from one to 30 months, with session duration ranging from 10 minutes to one hour. Dynamic or isotonic training was the most common form of exercise. The level of supervision appeared to vary greatly.
Two reviewers independently selected the included trials. Assessment of study quality The authors assessed trial quality using criteria for blinding of outcome assessors, method of allocation concealment, drop-outs reported from intervention group, use of intent-to-treat analysis, eligibility criteria specified, similarity at baseline for important prognostic factors, whether the exercise sessions were supervised, presentation of intervention details, compliance reported, adverse events reported, whether measures of variability were presented for the primary outcome, and between-group analysis conducted.
The authors did not state how many reviewers performed this assessment. Data extraction One author extracted the data to enable the calculation of relative effect size estimates and 95% confidence intervals for each trial. Trial authors were contacted for missing data whenever possible. Methods of synthesis The results were synthesised narratively and grouped by outcome. Results of the review Eighteen (n=2,832) RCTs were included. On average, eight out of 12 quality criteria were met by the included trials and seven trials reported concealment of allocation to treatment.
Ten of the 18 trials showed an improvement in pain in the intervention group. Five trials assessed joint stiffness, with two reporting significant improvements in the resistance training group. Improvements in physical disability were found in 11 of 14 trials (ES 0.31, range -3.58 to 2.15). Nine of 14 trials reported improvements in muscle strength, on average by 17.4% (range -10.5 to 49.5) and there were significant improvements in challenging physical tasks in the resistance training groups compared with controls. The effects of resistance training on psychological outcomes were inconsistent (six RCTs). Increasing compliance was associated with improved outcomes for activities of daily living, self-reported disability, pain, walking endurance, stair climbing performance, and muscle strength (five RCTs).
The results for other outcomes were reported. Cost information Those exercise interventions that were supervised by a physiotherapist were more costly than unsupervised interventions (one RCT). Exercise interventions cost more than telephone contact, but were more effective in improving pain (one RCT). There was evidence that resistance training was more cost-effective than aerobic training for improving self-reported disability and physical function. Authors' conclusions There was reasonably extensive and robust literature supporting the efficacy of resistance training in patients with knee osteoarthritis. Over half of the trials included in this review found knee symptoms, physical function, and strength were improved by clinically meaningful amounts by resistance training compared with usual care. CRD commentary This review addressed a clear research question and was supported by well-defined inclusion criteria. The literature search was reasonably extensive. Several sources were searched and specific attempts were made to identify unpublished studies by consulting experts, but only published trials were included, which might have introduced publication bias. Also, only articles in English were eligible, which might have introduced language bias. The authors stated that the main difficulty in comparing trials was the limited data available for some relative effect estimates; attempts were made to contact the authors of these trials. Some of the details of the review process were poorly reported, such as how many reviewers performed the quality assessment, and the data extraction was performed by one author. Given the heterogeneity of the interventions, it was appropriate to combine trials in a narrative synthesis.
The authors' conclusions appear to be appropriate, but language bias, the moderate quality of included trials, and the lack of minimisation of errors and bias, mean that these conclusions must be treated with caution. Implications of the review for practice and research Practice: The authors stated that participation in a resistance training programme could counteract the functional limitations of knee osteoarthritis.
Research: Large trials were required to establish the effectiveness of resistance training at different intensities and to establish the efficacy and feasibility of resistance training. The reporting of these trials should be improved to include adverse events, session and intensity compliance, and treatment effect estimates. Future trials should include outcome measures, such as magnetic resonance imaging and cartilage biomarkers, to assess the long-term morphology of the articular cartilage and surrounding bone. Long-term trials in high-risk groups, such as patients with severe knee osteoarthritis, multiple comorbidities, or the frail, were also required. Bibliographic details Lange AK, Vanwanseele B, Fiatarone Singh MA. Strength training for treatment of osteoarthritis of the knee: a systematic review. Arthritis and Rheumatism (Arthritis Care and Research) 2008; 59(10): 1488-1494 Indexing Status Subject indexing assigned by NLM MeSH Exercise Therapy; Humans; Muscle Strength; Osteoarthritis, Knee /physiopathology /therapy AccessionNumber 12008107781 Date bibliographic record published 29/07/2009 Date abstract record published 16/06/2010 Record Status This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn. |
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