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A review of the literature on shortwave diathermy as applied to osteo-arthritis of the knee |
Marks R, Ghassemi M, Duarte R, Van Nguyen JP |
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Authors' objectives To examine the efficacy of shortwave diathermy (SWD) for alleviating the main symptoms of osteoarthritis (OA) of the knee.
Searching Medicine (sic, meaning MEDLINE probably), CINAHL and Excerpta Medica were searched from 1955 to 1997 overall. The keywords are listed. Manual searches were carried out on bibliographies of original and review articles and appropriate Internet resources. Only English language articles or articles with an English language abstract were included.
Study selection Study designs of evaluations included in the reviewRCTs and non-randomised comparative controlled studies.
Specific interventions included in the reviewShortwave diathermy or shortwave diathermy combined with exercise or shortwave diathermy combined with medication compared to ultrasound, exercise, ice, infra-red, Faradism, wax, ultrasound combined with exercise, placebo shortwave diathermy, no treatment, interferential current, galvanic current, longwave diathermy, placebo tablets and placebo injections. One trial compared shortwave diathermy alone to shortwave diathermy plus exercise.
Studies on both continuous SWD and pulsed SWD were included.
Participants included in the reviewPeople with osteoarthritis of the knee, both men and women. Age range 35-85 years (where reported).
Outcomes assessed in the reviewPain (including assessment by visual analogue scale), discomfort, degree of relief, range of motion, ability to squat, cross legged sitting, walking, stair climbing, presence of swelling, crepitus, deformity, kneeling, use of cane, endurance, stiffness, tenderness and swelling, knee girth, walk time, doctor's assessment, strength, knee torque, general health, exercise tolerance, rest pain, therapeutic effect as evaluated by patient and physician, subjective distress level, number of analgesic tablet taken daily, functional incapacity, activities of daily living.
How were decisions on the relevance of primary studies made?The authors do not state how the papers were selected for the review, or how many of the reviewers performed the selection.
Assessment of study quality The criteria of Beckerman et al. and Gam and Johannsen (see Other Publications of Related Interest nos.1-2) were used to assess validity, including randomisation, sample size, loss to follow up, heterogeneity, baseline characteristics, similarities between groups, blinding, outcome measures, intention to treat analysis. Three separate reviewers who were blind to the authors and institutions assessed validity using a standardised format.
Data extraction Three separate reviewers who were blind to the authors and institutions extracted data using a standardised format. Data presented in tables included: participant details (age, sex, sample size, diagnosis); study design; interventions; outcome measures; results.
Methods of synthesis How were the studies combined?A narrative synthesis was undertaken. Outcomes were categorised in terms of favourable, non-favourable and questionable effects on pain and mobility.
How were differences between studies investigated?There was no formal investigation of heterogeneity.
Results of the review Eleven studies (n=815), of which 9 were RCTs and 2 were non-randomised comparative controlled studies.
Three studies suggested a favourable effect of SWD, five showed questionable effects and three showed non-favourable results. All 11 papers were found lacking in most cases when assessed for methodological quality.
Authors' conclusions The prevailing clinical studies concerning the application of SWD for treating painful knee OA are essentially non-conclusive, given their poor methodological quality. Consequently, we conclude additional study is essential to determine whether SWD is indeed efficacious for knee OA in either its continuous or pulsed mode or both and if so for which osteo-arthritic symptoms favourable treatment effects are likely to occur. Additionally, if a specific form of SWD is found beneficial for treating knee OA patients the mechanism(s) underlying this should be explored with a view to exploiting appropriate cell-specific field intensities. Also, if short-term treatment efficacy can be demonstrated, long-term follow-up studies of SWD for treatment of knee OA would be indicated.
CRD commentary This is a reasonably good review, and the review question seems to have been represented by study selection criteria, although this is not reported very clearly. The literature search was adequate, however restriction to the English language may have led to some studies being missed (due to publication or language bias). Study details are well presented and studies are assessed for methodological quality. Pooling could have been performed separately for RCTs and non-randomised studies but a narrative synthesis seems appropriate in view of heterogeneity between control interventions and outcomes measured. The authors' conclusions do seem to follow from the results.
Implications of the review for practice and research Practice: The authors state that the value of using SWD as either a primary or an adjunctive physiotherapeutic measure for the treatment of knee OA, if any, should not be overlooked due to the lack of rigorously controlled trials with large homogeneous samples and clinically reliable and valid end points. They also state that generalisable conclusions which lead to effective control by physiotherapists of OA symptoms will not only help to reduce the personal disability associated with this disease but should help to control health care costs and could ensure a future role in the market place.
Research: The authors suggest that additional study is essential to determine whether SWD is indeed efficacious for knee OA in either its continuous or pulsed mode or both, and if so, for which osteoarthritic symptoms favourable treatment effects are likely to occur. Additionally, if a specific form of SWD is found beneficial for treating knee OA patients, the mechanism(s) underlying this should be explored with a view to exploiting appropriate cell-specific field intensities. Also, if short-term treatment efficacy can be demonstrated, long-term follow-up studies of SWD for treatment of knee OA would be indicated. The authors give details about the proposed design of recommended studies in the paper. In addition to double-blind, randomised controlled trials of large homogeneous samples using reliable and validated indices, the authors encourage preliminary experimental studies to determine possible positive and negative dose-effect relationships and optimal settings for SWD machine parameters. Sex and age effects that could influence dose-responsiveness to SWD of patients with knee OA also need investigation.
Bibliographic details Marks R, Ghassemi M, Duarte R, Van Nguyen JP. A review of the literature on shortwave diathermy as applied to osteo-arthritis of the knee. Physiotherapy 1999; 85(6): 304-316 Other publications of related interest 1. Beckerman H, Bie RA de, Bouter LM, De Cuyper HJ, Oostendorp RAB. The efficacy of laser therapy for musculoskeletal and skin disorders. A criteria-based meta-analysis of randomised clinical trials. Physical Therapy 1992;72:483-91. 2. Gam AN, Johannsen F. Ultrasound therapy in musculoskeletal disorders: A meta-analysis. Pain 1995;63:85-91.
Indexing Status Subject indexing assigned by CRD MeSH Diathermy; Knee Joint; Osteoarthritis /therapy AccessionNumber 11999005416 Date bibliographic record published 31/03/2001 Date abstract record published 31/03/2001 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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