Clinical Effects of Acupuncture in the Treatment of Knee Osteoarthritis: An Umbrella Review of Level I Evidence

OBJECTIVE: To evaluate the effectiveness of acupuncture for knee osteoarthritis across different comparators, including usual care, sham acupuncture, waiting-list, pharmacological treatments, and other non-pharmacological interventions. METHODS: An umbrella review of systematic reviews/meta-analyses of acupuncture in adults with knee osteoarthritis was performed. MEDLINE, Embase, Cochrane Library, CNKI, WanFang, and VIP databases were searched. Comparisons were conducted among different acupuncture types. Methodological quality was assessed using Revised Assessment of Multiple Systematic Reviews (R-AMSTAR), and the best available evidence was selected. RESULTS: Twenty-three systematic reviews were included, with a mean R-AMSTAR score of 30.87. Most acupuncture modalities showed consistent improvements in pain and physical function. Compared with sham acupuncture, usual care, and waiting-list, acupuncture produced clinically meaningful improvements in pain and joint function. Compared with pharmacological treatments, acupuncture demonstrated effects similar to non-steroidal anti-inflammatory drugs, while electroacupuncture was superior in improving joint stiffness and overall response rates. Compared with Tui Na or massage, acupuncture showed a slower onset of effect and similar or slightly inferior improvements in function and stiffness. Adverse events were generally mild and local, with a lower risk of gastrointestinal complications. Treatment effects were most evident at the end of treatment and during short-term follow-up (<3 months), whereas long-term evidence remained limited. CONCLUSIONS: Acupuncture of all modalities relieves pain and improve function in knee osteoarthritis patients, thus is a key non-pharmacological option or add-on therapy when medications are unsuitable. For optimal and sustained effect of acupuncture treatment in knee osteoarthritis, more rigorous sham acupuncture-controlled designs and long-term follow-up are needed.