Moxibustion versus diclofenac sodium gel for the treatment of knee osteoarthritis: a study protocol for a double-blinded, double-placebo, randomised controlled trial

Introduction Knee osteoarthritis is a common form of arthritis in elderly patients that is characterised by pain and functional limitation. Moxibustion has been employed to relieve chronic pain as an alternative therapy for knee osteoarthritis. However, the evidence of its efficacy is equivocal due to the low methodological quality in most clinical studies. Therefore, we are performing a double-blinded, double-placebo, randomised controlled trial to evaluate the efficacy of moxibustion in participants with knee osteoarthritis. Methods and analysis This is a multicentre, double-blinded, double-placebo, randomised controlled clinical trial. 144 eligible participants with knee osteoarthritis will be randomly assigned to two different groups in a 1:1 ratio. Participants in the moxibustion group will undergo active moxibustion plus placebo gel, whereas participants in the control group will receive diclofenac sodium gel plus placebo moxibustion. Each participant will receive 12 sessions of active/placebo moxibustion at three acupoints (ST35, ST36 and EX-LE4) as well as 2 months of follow-up. Diclofenac sodium gel or placebo gel at a dose of 4 g per knee will be applied three times per day for 4 weeks. The primary outcome measure will be the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score change at the end of the intervention period from baseline. The secondary outcome measures include changes of other subscales (pain, stiffness and function) of WOMAC, visual analogue scale and patient globalassessment. The safety of moxibustion and diclofenac sodium gel will be assessed at every visit. Ethics and dissemination This trial has been approved by the Sichuan Regional Ethics Review Committee (permission number: 2015KL-014). The results of this study are expected to provide clinical evidence on the efficacy of moxibustion for pain relief and physical function improvement in patients with knee osteoarthritis. The findings will be submitted for publication in peer-reviewed medical journals and presented at relevant academic conferences. Trial registration number NCT02769572.