Background: Ultrasound is used in the treatment of a wide variety of musculoskeletal disorders.
Objectives: To evaluate the effects of ultrasound therapy in the treatment of acute ankle sprains.
Search strategy: We searched the Cochrane Musculoskeletal Injuries Group specialised register (November 15th 2001), the Cochrane Controlled Trials Register (The Cochrane Library Issue 3, 2001), MEDLINE (1966 to October 2001), EMBASE (1983 to 2001 week 45), CINAHL (1982 to October week 4 2001), and PEDro - The Physiotherapy Evidence Database (http://ptwww.cchs.usyd.edu.au/pedro/ accessed 15.11.01). We also searched the Cochrane Rehabilitation and Related Therapies Field database, reference lists of articles, and contacted colleagues.
Selection criteria: Randomised or pseudo-randomised trials were included in the review if the following conditions were met: at least one study group was treated with active ultrasound; the study included patients with acute lateral ankle sprains; and outcome measures included general improvement, pain, swelling, functional disability, or range of motion. Final selection of papers was conducted by two independent reviewers.
Data collection and analysis: Two reviewers independently assessed trial quality using a standardised checklist, and extracted data. Whenever possible, the results were analysed on an intention-to-treat basis. Relative risks together with 95 per cent confidence intervals were calculated for dichotomous outcomes, and weighted or, where different scales were used, standardised mean differences together with 95 per cent confidence intervals for continuous outcome measures. Pooling of data was undertaken where there was clinical homogeneity in terms of subjects, treatments, outcomes, and follow-up time points.
Main results: Five trials were included, involving 572 patients. Four of these trials were only of modest methodological quality and one placebo-controlled trial was considered to be of good quality. None of the four placebo-controlled trials (sham ultrasound) could demonstrate statistically significant differences between true and sham ultrasound therapy for any outcome measure at seven to 14 days of follow-up. The pooled relative risk for general improvement was 1.04 (random effects model, 95% confidence interval 0.92 to 1.17) for the comparison between ultrasound and sham ultrasound. The differences between intervention groups were generally small, between zero and six per cent for most dichotomous outcomes. However, one trial reported relatively large differences for pain free status (20%) and swelling (25%) in favour of ultrasound treatment.
Reviewer's conclusions: The extent and quality of the available evidence for the effects of ultrasound therapy for acute ankle sprains is limited. The results of four placebo-controlled trials do not support the use of ultrasound in the treatment of ankle sprains. The magnitude of most reported treatment effects appeared to be small, and may be of limited clinical importance. As yet, only few trials are available and no conclusions can be made regarding an optimal and adequate dosage schedule for ultrasound therapy, and whether such a schedule would improve on the reported effectiveness of ultrasound for ankle sprains.