This randomized, assessor-blinded, parallel-group controlled trial will compare the effectiveness and safety of thread-embedding acupuncture versus electroacupuncture in patients with primary knee osteoarthritis. Eligible participants will be adults aged 38 years or older diagnosed with primary knee osteoarthritis according to the 1986 American College of Rheumatology criteria, with chronic knee pain lasting more than 6 months and baseline pain intensity of at least 5 points on the Visual Analog Scale.
A total of 60 participants will be randomly assigned in a 1:1 ratio to receive either thread-embedding acupuncture or electroacupuncture. Both groups will receive the same background standard care, including lifestyle advice and therapeutic ultrasound. The intervention period will last 4 weeks. The primary outcome will be change in total Western Ontario and McMaster Universities Osteoarthritis Index score. Secondary outcomes will include pain intensity measured by the Visual Analog Scale, WOMAC subscale scores, Patient Global Impression of Change, treatment satisfaction, rescue analgesic use, and adverse events.