RCT OF SHOCKWAVE THERAPY FOR CHRONIC ACHILLES TENDON PAIN

Abstract

The aim of this study was to test the efficacy of shock-wave therapy for chronic Achilles pain. Forty-nine patients with Achilles tendon pain for a minimum of 4 months were included in the study. Patients were randomised to either shockwave therapy (n=27) or placebo control (n=22). The treatment group were given 2000 shocks at up to 1500 mJ/mm2 per shock. The control (sham) treatment was applied using the same parametres but the shockwaves were dispersed before they reached the patient. Each patient was treated once a month over 3 months. The primary outcome measure was pain on walking indicated on a 100mm visual analogue score (VAS) at 3 months. The walking pain scores were very similar at baseline between the two groups. In the treatment group the mean (standard deviation) was 55.5 mm (30.6) and in the control group 55.6mm (26.5). By 3 months, the pain scores had reduced in both groups to a mean (standard deviation) of 34.5 mm (34.2) and 50.3 mm (36.3). Although lower in the treatment group this difference was not statistically significant at the 5% level (t-test, p=0.127, 95% CI : −4.7 to 36.2). Two elderly patients in the treatment group sustained spontaneous rupture of the tendon after falls during the course of the trial. The results of this trial provided no evidence for the use of shockwave therapy in the treatment of patients with chronic Achilles tendinopathy. However, a treatment effect cannot be ruled out since the 95% confidence interval included a potential clinically relevant difference. The two cases of rupture suggest extreme caution in treating the elderly.