Ultrasound therapy for acute ankle sprains

Ultrasound is used in the treatment of a wide variety of musculoskeletal disorders.

To evaluate the effects of ultrasound therapy in the treatment of acute ankle sprains.

MEDLINE and EMBASE up to December 1998 and databases of the Cochrane Rehabilitation and Related Therapies Field and Musculoskeletal Injuries Group were searched. This was supplemented with citation tracking, and contact with colleagues. Date of the most recent search: April 1999.

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.

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. Fixed odds ratios together with 95% confidence intervals were calculated for dichotomous outcomes, and weighted or, where different scales were used, standardised mean differences together with 95% 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.

The four included trials, involving 514 patients, were only of modest methodological quality. None of the three placebo-controlled trials (sham ultrasound) could demonstrate statistically significant differences between true and sham ultrasound therapy for any outcome measure at seven days of follow-up. The pooled odds ratio for general improvement was 1.19 (Peto fixed effects model, 95% confidence interval 0.73 to 1.93) for the comparison between ultrasound and sham ultrasound. The differences between intervention groups were generally small, between 0 and 6% for most dichotomous outcomes. However, one trial reported relatively large differences for pain free status (20%) and swelling (25%) in favour of ultrasound treatment.

The extent and quality of the available evidence for the effects of ultrasound therapy for acute ankle sprains are limited. The results of three 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.