Acupuncture for peripheral joint osteoarthritis: A systematic review and meta-analysis

Acupuncture has traditionally been used for the treatment of chronic pain, including osteoarthritis, one of the most common forms of arthritis affecting millions of people worldwide. Osteoarthritis is characterized by degeneration of joint cartilage and remodeling of underlying bone, causing significant pain and functional limitation. This condition primarily affects weight-bearing joints such as knees and hips and is most common in people over 50 years of age. Conventional treatment for osteoarthritis includes anti-inflammatory medications, analgesics, and other therapies, but many of these treatments have important side effects, especially gastrointestinal irritation, renal and hepatic problems, and increased risk of hypertension.

These adverse effects are particularly concerning in older adults, precisely the group most affected by the disease. Faced with these challenges, non-pharmacologic treatments such as acupuncture become attractive and promising options for managing pain in osteoarthritis.

This study aimed to systematically evaluate the scientific evidence on the effectiveness of acupuncture in treating peripheral joint osteoarthritis. To this end, the researchers conducted a systematic review and meta-analysis of randomized controlled trials. The methodology involved comprehensive searches in multiple medical databases through July 2005, including Medline, Embase, AMED, Cochrane Library, CINAHL, British Nursing Index, PsychINFO, and CAMPAIN, without language restrictions. Only randomized controlled trials that tested needle acupuncture, manual or with electrical stimulation, in patients with peripheral joint osteoarthritis were considered.

The studies had to compare acupuncture with sham treatment or other control interventions. The methodological quality of each study was assessed using a modified version of the Jadad scale, and when possible, data were pooled in meta-analyses to provide more robust evidence.

The initial search identified 31 potentially relevant studies, of which 18 randomized controlled trials were included in the final analysis. Ten studies tested manual acupuncture and eight tested electroacupuncture. Overall, ten studies demonstrated greater pain reduction in groups treated with acupuncture compared with control groups. Meta-analysis of homogeneous data showed a significant effect of manual acupuncture compared with sham acupuncture, with a standardized mean difference of 0.24 and a 95% confidence interval of 0.01 to 0.47.

This result was confirmed specifically for knee osteoarthritis, where the benefits of acupuncture were most consistent. However, heterogeneity in the electroacupuncture studies prevented a meaningful meta-analysis of those data. Studies that reported the 'deqi' sensation — the tingling or numbing sensation during needle stimulation — showed more favorable results, suggesting that this physiologic response may be important for the therapeutic effect.

For patients suffering from osteoarthritis, especially of the knee, these results suggest that acupuncture may be a valid therapeutic option for pain control. The evidence indicates that acupuncture produces specific effects beyond placebo, offering significant pain relief. Considering acupuncture's favorable safety profile, with generally mild and rare adverse effects compared with conventional medications, it represents an attractive alternative for patients who do not tolerate anti-inflammatory drugs well or who seek complementary treatments. For healthcare professionals, these findings provide scientific evidence supporting consideration of acupuncture as part of a comprehensive treatment plan for osteoarthritis.

Acupuncture may be especially valuable for older patients who are at greater risk of adverse effects from conventional medications, or for those who prefer less invasive approaches.

It is important to recognize the limitations of this study for appropriate interpretation of the results. The total number of included studies is still relatively small, and there is considerable variability in methodological quality among them. Many studies presented challenges in adequate participant blinding, which is a difficulty inherent to acupuncture studies but can influence results. In addition, evidence was more robust for knee osteoarthritis than for other joints, such as the hip, where more studies are needed.

Follow-up duration in most studies was limited, not allowing conclusions about the long-term effects of acupuncture. The researchers also noted that not all relevant research may have been identified, a common limitation in systematic reviews. Despite these limitations, the results provide encouraging evidence that acupuncture offers specific benefits for pain control in osteoarthritis, particularly of the knee, justifying its consideration as a safe and potentially effective complementary therapeutic option.