Effects of Dangguixu-san on acute lateral ankle sprain: study protocol for a randomized controlled trial

BACKGROUND: Ankle sprain is a common musculoskeletal injury. In Korean medicine, blood stasis is thought to be the main cause of pain and swelling in patients with ankle sprain. Dangguixu-san (DS), a herbal extract, is widely used in Korean medicine for the treatment of traumatic ecchymosis and pain by promoting blood circulation and relieving blood stasis. However, the effects of DS on ankle sprain have not been evaluated in a randomized clinical trial. Here, we describe the protocol for a randomized controlled trial that will evaluate the efficacy and safety of DS for the treatment of ankle sprain. METHODS/DESIGN: In this randomized, double-blinded, placebo-controlled, parallel-arm clinical trial with a 1:1 allocation ratio, participants (n = 48) with acute lateral ankle sprain (ALAS) that occurred within 72 h before enrollment will be randomly assigned to a DS (n = 24) or a placebo (n = 24) group. Both groups will receive acupuncture treatment once a day for 5 days a week (excluding Saturday and Sunday) and the trial medication (DS/placebo capsule) three times a day for seven consecutive days. The primary outcome measure will be pain relief evaluated using a Visual Analog Scale (VAS). Secondary outcome measures will include Foot and Ankle Outcome Scores (FAOS), edema, European Quality of Life Five-Dimension-Five-Level Scale (EQ-5D-5 L) scores, and the number of recurrent ankle sprains. VAS, FAOS, edema, and EQ-5D-5 L scores will be recorded before, at the end of, and at 4 weeks after treatment completion. EQ-5D-5 L scores will be additionally recorded at 26 weeks after treatment completion. The number of recurrent ankle sprains will be recorded at 4, 8, 12, and 26 weeks after treatment completion. DISCUSSION: This study is expected to provide evidence regarding the efficacy, safety, and usefulness of DS for the treatment of ALAS. TRIAL REGISTRATION: cris.nih.go.kr, registration number: KCT 0002374. Registered on 11 July, 2017 and approved by the Ministry of Food and Drug Safety (registration number, 31244). ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s13063-018-2571-1) contains supplementary material, which is available to authorized users.