Acupuncture for Knee Osteoarthritis: Evidence, Mechanisms, and Clinical Implications

​Introduction
 
In a previous blog, we discussed two non-pharmacological treatment options for osteoarthritis: exercise and low-dose radiation therapy. Today, we turn to the realm of alternative medicine and examine the role of acupuncture. Practitioners of Traditional East Asian Medicine (TEMA) would likely laugh and brush off the question of whether acupuncture works for osteoarthritis. Specific acupuncture points for treating knee, hip, and shoulder pain were described in classical texts centuries ago—although, of course, not in modern Western medical terms. TEMA practitioners do not question acupuncture’s efficacy; they rely on the accumulated experience of generations before them.
 
In the Western medical tradition, however, anecdotal experience alone is not accepted as proof of effectiveness. We expect evidence from rigorous clinical trials, ideally double-blinded and randomized. In this review, we will focus on the clinical evidence available to date regarding acupuncture’s efficacy in knee osteoarthritis, along with research into its potential mechanisms for pain reduction and functional improvement. We will also situate acupuncture within the context of current standards of care for knee osteoarthritis and compare these findings with recommendations from professional medical societies and governmental health agencies.
 
We will not address how to locate the “best” acupuncture practitioners for osteoarthritis, as recommendations from physicians, relatives, and friends are often the most reliable—though, of course, you may also consult your favorite AI chatbot.

The Effect of Acupuncture on Knee Osteoarthritis Pain
 
As discussed in the 02/24/2024 blog post, President Richard Nixon’s 1972 visit to China and the cultural exchanges that followed greatly increased Western interest in acupuncture. Scientific research and clinical trials expanded rapidly. To date, these trials support acupuncture as an effective, safe, and recommended therapy for the symptomatic management of pain, including osteoarthritis pain. However, most studies have been relatively small and heterogeneous in terms of patient selection, acupuncture techniques, treatment duration, and control group design (single-blind, double-blind, placebo, no treatment, etc.). High-quality randomized controlled trials and meta-analyses provide the most meaningful insights, summarized below. Comparisons between acupuncture and various control conditions (1) were as follows:
 

• Acupuncture versus sham acupuncture: Pooled results indicate that acupuncture may improve both overall pain and function for up to 4.5 months after treatment.
• Acupuncture versus usual care: Pain relief and improved function may last up to 5 months. “Usual care” typically includes some combination of patient education, weight management, exercise, orthotic devices, oral or topical analgesics, and physical therapy.

 

• Acupuncture versus diclofenac: Studies report pain relief and functional improvement lasting up to 6 months after treatment.

 

• Acupuncture versus no treatment: Results were less consistent. One study found significant pain reduction and functional improvement for up to 3 months, while another reported only modest pain reduction at the end of treatment and none at 9-month follow-up.

 

• Acupuncture + exercise-based physical therapy versus sham acupuncture + exercise-based physical therapy: No additional benefit from acupuncture was observed for up to 11.25 months.

 

• Acupuncture + exercise-based physical therapy versus exercise-based physical therapy alone: A significant reduction in overall pain was noted 0.75 months (approximately 3 weeks) after treatment.

 
Overall, current clinical evidence indicates that acupuncture can reduce pain and improve function in knee osteoarthritis patients for 3 to 6 months after treatment. Reported adverse events were mild and transient—mainly brief needling pain and small hematomas. Only a small percentage of participants experienced side effects, reinforcing that acupuncture is a generally safe treatment option. The studies included all three commonly used forms of acupuncture: manual, electroacupuncture, and dry needling. Acupuncture points used across studies were standard points traditionally selected for knee osteoarthritis.

Acupressure effectiveness
 
Acupressure is a less invasive variant of acupuncture in which pressure is applied to the same acupoints used in traditional needling. Recently, Yeung, W.-F. et al. (2) reported the results of a randomized, controlled clinical trial involving 314 middle-aged and older adults with probable knee osteoarthritis. Participants in the treatment group were trained to perform self-administered acupressure, while the control group received only knee health education.
 
The study found that acupressure produced meaningful pain reduction lasting up to 3 months. However, improvements in physical function did not reach statistical significance. Only 13% of participants reported mild, self-resolving adverse events.
 
Overall, acupressure appears to be a safe and effective method for managing knee osteoarthritis pain, and it is also highly cost-effective due to its self-care nature. Following are three Youtube videos for self-help.

Comparison with other non-pharmacological therapies
 
A natural next question is how acupuncture compares with other non-pharmacological therapies for knee osteoarthritis. Numerous clinical studies have evaluated one non-pharmacological treatment against another. More recently, Cao, S. et al. (3) conducted a network meta-analysis comparing the clinical efficacy of seven distinct non-pharmacological therapies for knee osteoarthritis, including acupuncture. The other therapies evaluated were needle-knife therapy (acupotomy), exercise, transcutaneous electrical nerve stimulation (TENS), ultrasound, shock wave therapy, and laser therapy.
Pain and symptom assessments were based on two standard tools: the Visual Analog Scale (VAS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC).
 

• VAS is a simple 100-mm line used to measure pain intensity, anchored by “no pain” (0) and “worst possible pain” (100).

 

• WOMAC is a patient-reported questionnaire assessing pain, stiffness, and physical function. Scores range from 0 to 4, with higher scores indicating more severe symptoms.

 
The results of the network meta-analysis were as follows:
 
Efficacy rankings based on VAS pain scores:
shock wave therapy > needle-knife > laser therapy > acupuncture > ultrasound > exercise > transcutaneous electrical nerve stimulation
 
Efficacy rankings based on total WOMAC score:
shock wave therapy > needle-knife > laser therapy > acupuncture > ultrasound > transcutaneous electrical nerve stimulation > exercise
 
Efficacy rankings based on WOMAC subscales:
 

• Pain: shock wave therapy > needle-knife > laser therapy > acupuncture > exercise > transcutaneous electrical nerve stimulation > ultrasound

 

• Stiffness: laser therapy > exercise > shock wave therapy > acupuncture > needle-knife > ultrasound > transcutaneous electrical nerve stimulation

 

• Physical function: shock wave therapy > laser therapy > needle-knife > acupuncture > ultrasound > transcutaneous electrical nerve stimulation > exercise

 
In nearly all ranking systems—except for the WOMAC stiffness subscale—shock wave therapy emerged as the most effective treatment. Acupuncture consistently ranked in the middle tier. TENS, exercise, and ultrasound generally ranked the lowest, depending on the specific measure.
 
What these rankings mean for patient care and clinical practice remains uncertain. Importantly, the authors of the study explicitly caution that additional rigorous, well-designed randomized controlled trials are still needed to validate and refine these conclusions.

Mechanistic aspects
 
Multiple animal and human studies have shown that acupuncture exerts anti-inflammatory effects in the synovium, influences cartilage homeostasis, and modulates neural pathways involved in pain perception (4–6).
 

• Anti-inflammatory effects: Acupuncture and electroacupuncture have been shown to reduce pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) while increasing anti-inflammatory cytokines such as IL-10. These shifts are believed to contribute to pain reduction and slower cartilage degradation.

 

• Effects on cartilage metabolism: Animal and in vitro studies have demonstrated acupuncture-associated changes in the expression of matrix metalloproteinases (MMPs) and their inhibitors, suggesting a decrease in proteoglycan and collagen breakdown. However, translating these findings from animal histology to human clinical outcomes remains limited.

 

• Cartilage regeneration: Evidence that acupuncture can regenerate human cartilage—such as increasing cartilage thickness or restoring hyaline cartilage—is currently insufficient. Most supportive data come from preclinical studies in animal models or small human biomarker studies. Large clinical trials with MRI-based structural endpoints are lacking. Therefore, the most defensible current claim is chondroprotection and anti-catabolic modulation, rather than proven cartilage regeneration in humans.

 

• Analgesic mechanisms: Acupuncture stimulates somatic sensory afferent nerves and activates central descending pain-inhibitory pathways, including endogenous opioid, serotonergic, and noradrenergic systems.

 

• Molecular signaling pathways: Acupuncture exerts its effects by modulating several key molecular pathways, including norepinephrine (NE) signaling, the TLR/NF-κB pathway, the MCP-1/CCR2 axis, the NLRP3 inflammasome, and the Ras–Raf–MEK1/2–ERK1/2 cascade. Advances in understanding these pathways may help identify molecular targets for future drug development.

 
Much progress has been made in elucidating the mechanisms underlying acupuncture’s clinical benefits. Future human studies, particularly those focusing on optimal dosing and the key pathways involved in synovial stabilization, will improve our understanding of knee osteoarthritis and help solidify acupuncture’s role as an evidence-based treatment option.

Guidelines by professional societies and government health agencies
 
The American College of Rheumatology (ACR) and Arthritis Foundation, the American Academy of Orthopaedic Surgeons (AAOS), and the Osteoarthritis Research Society International (OARSI) all limit their recommendations for acupuncture to conditional, limited, or uncertain (7–9). The National Center for Complementary and Integrative Health (NCCIH) aligns its guidance with the ACR/Arthritis Foundation recommendations. Core non-pharmacological treatments for knee osteoarthritis continue to emphasize self-management programs, aerobic and/or strength-training exercise, and weight loss for individuals who are overweight. Notably, Tai Chi is strongly recommended as a form of therapeutic exercise.
 
The National Institute for Health and Care Excellence (NICE) in the UK stands out with its more definitive position, issuing a “not recommended” guideline for acupuncture in knee osteoarthritis (10). However, NICE acknowledges in its commentary that electroacupuncture may have potential benefits, while also noting that the specific patient population likely to respond is unclear. NICE additionally concluded that acupuncture is not cost-effective based on its economic assessments.
 
It is important to recognize that these guidelines may not reflect the most recent evidence. The ACR/Arthritis Foundation, AAOS, and OARSI recommendations were published in 2019, 2021 and 2019, respectively, while NICE’s guidance dates to 2022. The cautious and conservative positions of these organizations are understandable given the shortcomings of the acupuncture trials and the lack of large, industry-funded studies of the type commonly performed for pharmaceuticals.

Implications for the patients
 
Navigating the increasing amount of information on acupuncture for osteoarthritis depends greatly on the preferences and inclinations of both patients and their physicians. Incorporating this information into patient education programs can certainly help patients make more informed decisions.
 
From this author’s perspective, acupuncture is a reasonable and viable option when core recommendations and standard drug therapies fail to meet a patient’s needs. It is also an option worth considering before turning to more aggressive interventions such as radiation therapy or surgery.

References

1. Chen, H., Shi, H., Gao, S., Fang, J., Yi, J., Wu, W., ... & Liu, Z. (2024). Durable effects of acupuncture for knee osteoarthritis: a systematic review and meta-analysis. Current Pain and Headache Reports, 28(7), 709-722.
2. Yeung, W. F., Chen, S. C., Cheung, D. S. T., Wong, C. K. H., Chong, T. C., Ho, Y. S., ... & Lao, L. (2024). Self-administered acupressure for probable knee osteoarthritis in middle-aged and older adults: a randomized clinical trial. JAMA network open, 7(4), e245830-e245830.
3. Cao, S., Zan, Q., Wang, B., Fan, X., Chen, Z., & Yan, F. (2024). Efficacy of non-pharmacological treatments for knee osteoarthritis: A systematic review and network meta-analysis. Heliyon, 10(17).
4. Li, N., Guo, Y., Gong, Y., Zhang, Y., Fan, W., Yao, K., ... & Lyu, Z. (2021). The anti-inflammatory actions and mechanisms of acupuncture from acupoint to target organs via neuro-immune regulation. Journal of inflammation research, 7191-7224.
5. Ye, J. N., Su, C. G., Jiang, Y. Q., Zhou, Y., Sun, W. X., Zheng, X. X., ... & Zhu, J. (2023). Effects of acupuncture on cartilage p38MAPK and mitochondrial pathways in animal model of knee osteoarthritis: A systematic evaluation and meta-analysis. Frontiers in Neuroscience, 16, 1098311.
6. Cao, Q., & Li, Y. (2025). Signal Transduction Pathways Involved in Acupuncture-Mediated Inhibition of Synovitis in Knee Osteoarthritis: A Comprehensive Review. International Journal of General Medicine, 4105-4117.
7. Kolasinski, S. L., Neogi, T., Hochberg, M. C., Oatis, C., Guyatt, G., Block, J., ... & Reston, J. (2020). 2019 American College of Rheumatology/Arthritis Foundation guideline for the management of osteoarthritis of the hand, hip, and knee. Arthritis & rheumatology, 72(2), 220-233.
8. American Academy of Orthopaedic Surgeons, & American Academy of Orthopaedic Surgeons. (2021). Management of osteoarthritis of the knee (non-arthroplasty). Evidence-based clinical practice guideline.
9. Bannuru, R., Osani, M.C., Vaysbrot, E.E., Arden, N.K., Bennell, K. Bierma-Zeinstra, S.M.A., ... & McAlindon, T.E. (2019). OARSI guidelines for the non-surgical management of knee, hip and polyarticular osteoarthritis. Osteoarthritis and cartilage, 27(11), 1578-1589.
10. guideline NG226, N. I. C. E. (2022). Osteoarthritis in over 16s: diagnosis and management. Methods.