One of the most frequent objections to using acupuncture for chronic pain is the question of durability: “Does the effect last after the end of treatment?” For knee osteoarthritis — a condition that affects more than 250 million people worldwide and is the leading cause of disability in adults over 65 — that question is clinically central. A systematic review and meta-analysis published in April 2024 in Current Pain and Headache Reports specifically addressed this question, consolidating data from 80 clinical trials with 9,933 participants with a focus on medium- and long-term outcomes — assessed after the end of the active treatment period.
The study took a methodological approach distinct from most acupuncture meta-analyses for osteoarthritis: rather than analyzing only the immediate outcomes at the end of treatment, the researchers focused on follow-up data — results measured weeks or months after the end of the acupuncture sessions. That distinction is clinically important because it reflects the patient’s real-world experience: what matters is not only whether the knee hurts less during sessions, but whether the improvement persists when treatment ends.
SCALE OF THE STUDY
Durable effect: what the follow-up data show
The review showed that patients who received acupuncture for knee osteoarthritis maintained clinically significant improvements in pain and function in the medium-term follow-up period (5–6 months), compared with usual care (analgesic medication, conventional physiotherapy without acupuncture, exercise guidance). That data point contrasts with the common perception that acupuncture offers only transient symptomatic relief and suggests a more durable modifying effect on pain processing mechanisms and on joint function.
The measurement instruments used included WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) — which assesses pain, stiffness, and physical function — the VAS pain scale, KOOS (Knee injury and Osteoarthritis Outcome Score), and LKSS (Lysholm Knee Scoring Scale). The consistency of results favoring acupuncture across multiple instruments and across studies from different countries strengthens the interpretation of a real, durable effect.
Practical implications: defining the treatment cycle
One of the most common questions from physicians and patients is: “If the effect lasts, how often should I return?” This review suggests that a well-structured cycle of acupuncture can produce benefits that extend for 5–6 months after the end — which has direct implications for treatment planning. Instead of indefinite weekly sessions, a cycle model (for example, 10–12 sessions over 6–8 weeks, followed by reassessment and a possible booster cycle if needed) may be more cost-effective and equally effective for maintaining results in knee osteoarthritis.
Knee osteoarthritis is, by definition, progressive — there is no treatment that reverses cartilage degeneration once established. The clinical value of acupuncture lies in offering pain control and maintenance of function over clinically relevant periods, delaying the need for analgesic escalation (opioids, joint injections) or surgery (total arthroplasty).
Frequently Asked Questions
This systematic review of 80 trials and 9,933 patients demonstrated that benefits in pain and function persist in the medium term (5–6 months) after the end of treatment, compared with usual care. In clinical practice, duration varies by patient — factors such as severity of osteoarthritis, body mass index, level of physical activity, and presence of obesity influence durability. Patients with moderate osteoarthritis (Kellgren-Lawrence II–III) tend to respond better than advanced cases (grade IV).
Although this meta-analysis did not directly evaluate progression to surgery as an outcome, the maintenance of pain and functional control for 5–6 months after treatment has direct clinical implications: it can extend the period of conservative osteoarthritis management, delaying the indication for total knee arthroplasty. There is no evidence that acupuncture reverses or halts structural cartilage degeneration — but sustained symptomatic control is valuable in clinical management.
Acupuncture has evidence of efficacy mainly for moderate knee osteoarthritis (Kellgren-Lawrence grades II and III). For advanced osteoarthritis (grade IV) with significant joint destruction, benefit tends to be more limited — pain at that stage has a major structural component that goes beyond neural modulation. That does not mean acupuncture is useless in grade IV: it can help control pain while the patient awaits surgery or to reduce the need for opioids in the postoperative period.
Fonte Original
Current Pain and Headache Reports(em inglês)Founded in 1989 by physicians trained at the University of São Paulo (USP) and specialized in China, CEIMEC is a Brazilian national reference in the teaching and practice of medical acupuncture. With more than 3,000 physicians trained over 35 years, it collaborates with HC-FMUSP and is recognized by the Brazilian Medical College of Acupuncture (CMBA/AMB).