Efficacy of acupuncture combined with active exercise training in improving pain and function of knee osteoarthritis individuals: a systematic review and meta-analysis

Knee osteoarthritis is one of the most common degenerative joint diseases, causing joint pain, swelling, stiffness, restricted movement, and even disability. In China, the overall prevalence of this condition in people over 40 years of age is 46.3%, reaching 62.2% in people over 60. The disease severely affects patients' quality of life, and its rising medical costs represent a significant burden on families and society. Although the exact cause of knee osteoarthritis is not yet fully understood, studies suggest that factors such as age, sex, body mass index, heredity, and occupation may be related to its development.

Currently, the main treatments include surgery, nonsteroidal anti-inflammatory drugs, physical therapy, and exercise therapy. However, many patients face difficulties with the high costs of surgical treatment and associated anxiety, while drug treatments frequently cause digestive side effects. For this reason, complementary therapies such as acupuncture and therapeutic exercise have gained acceptance as effective alternatives, offering significant clinical benefits with fewer adverse effects compared with traditional surgical and pharmacologic interventions.

This study aimed to conduct a systematic review and meta-analysis to investigate the clinical efficacy of acupuncture combined with active exercise training in pain relief and functional improvement in individuals with knee osteoarthritis. The researchers performed comprehensive searches in eight electronic databases, including PubMed, EMBASE, Cochrane Library, Web of Science, and several Chinese databases, from inception through April 2023. Only high-quality randomized controlled trials were included, defined by a Jadad scale score of 4 or higher. The rigorous criteria ensured that only studies of adequate methodological quality were analyzed, with two reviewers working independently on selection, data extraction, and quality assessment.

The analysis included 11 high-quality studies involving 774 individuals with knee osteoarthritis, published between 2011 and 2022. Outcomes were measured using several standardized scales: total efficacy rate, Visual Analogue Scale for pain, Western Ontario and McMaster Universities Osteoarthritis Index, and joint range of motion. Treatment groups received acupuncture combined with active exercise, while control groups received acupuncture alone, exercise alone, Western medications, or combinations of these therapies. Acupuncture types included traditional acupuncture, electroacupuncture, and Fu's subcutaneous needling, while active exercise included traditional Chinese practices such as Yijin Jing and Baduanjin, as well as knee-specific functional training.

The main results demonstrated statistically significant benefits of the combined treatment. Compared with acupuncture alone, the combined group showed superiority in total efficacy rate, with a risk ratio of 1.13 and 95% CI of 1.05 to 1.22. Pain reduction was more pronounced in the combined group, with a mean difference of -0.74 points on the Visual Analogue Scale. Knee function also improved significantly as measured by the WOMAC index, with a mean difference of -6.97 points favoring the combined treatment.

In addition, joint range of motion showed improvement of 6.25 degrees in favor of the combined therapy. Compared with groups that did not receive acupuncture, including exercise alone or medications alone, the combined treatment demonstrated even more pronounced efficacy, with improvements in total efficacy rate, significant pain reduction, and substantial improvement in knee function.

For patients with knee osteoarthritis, these results suggest that combining acupuncture with active exercise may offer superior benefits compared with any single therapy. Acupuncture acts through multiple mechanisms, including scavenging of free radicals, inhibition of inflammatory factors, and promotion of joint cartilage repair. Therapeutic exercises complement these effects by strengthening muscles, improving joint stability, and promoting local blood circulation. The combination appears to create a synergistic effect that maximizes the benefits of both modalities.

For health professionals, these findings suggest that integrative protocols may be more effective than monotherapy approaches, potentially reducing the need for more invasive interventions or dependence on medications with adverse effects.

However, it is important to recognize the limitations of this study. Many of the included trials had methodological shortcomings, particularly related to blinding of participants, therapists, and assessors, which is inherently challenging in studies of acupuncture and exercise. Most studies had small samples, with fewer than 50 participants, limiting generalization of the results. In addition, there was considerable variability in acupuncture protocols, including different acupuncture points, number of selected points, and specific modalities used.

Similarly, exercise programs varied in type, intensity, and duration, contributing to significant statistical heterogeneity in some outcomes. Follow-up time was also limited in most studies, with few reporting long-term outcomes, leaving questions about the durability of the observed benefits.

Despite these limitations, the meta-analysis provides promising evidence that acupuncture combined with active exercise training represents an effective and safe therapeutic approach for knee osteoarthritis. The results suggest consistent improvements in pain, joint function, range of motion, and overall treatment efficacy. For future studies, randomized controlled trials with larger samples, more standardized protocols, and longer follow-up periods are needed to confirm these findings and establish more specific clinical guidelines. The current evidence, while encouraging, requires confirmation through additional high-quality research that addresses the identified methodological limitations and explores the underlying mechanisms of this combined therapeutic approach.