Electroacupuncture versus manual acupuncture for knee osteoarthritis: a randomized controlled pilot trial

Knee osteoarthritis is one of the most common chronic conditions worldwide, especially among elderly people, and is one of the leading causes of lower-limb disability. This disease is characterized by a prolonged and progressive course, affecting more women than men, with prevalences of 10.3% and 5.7% respectively. With population aging, osteoarthritis is estimated to become the fourth leading cause of disability by 2020. Conventional treatment is based mainly on symptom relief through analgesics and nonsteroidal anti-inflammatory drugs, but prolonged use of these medications raises concerns due to gastrointestinal and cardiovascular side effects.

For this reason, many patients seek therapeutic alternatives, with acupuncture being an increasingly considered option.

Acupuncture, used for more than 3,000 years in China and other Asian countries, has demonstrated potential for the effective management of chronic pain. There are two main modalities: manual acupuncture, in which needles are manipulated manually, and electroacupuncture, in which an electrical device is connected to the needles to provide continuous electrical stimulation. Although previous studies have shown that both techniques can be effective for knee osteoarthritis, few studies have directly compared their effects. This study was developed to fill this gap in scientific knowledge.

The objective of this research was to compare the efficacy of electroacupuncture versus manual acupuncture in the treatment of knee osteoarthritis. To do this, researchers conducted a randomized controlled pilot study at three hospitals in Beijing, between September 2017 and January 2018. Sixty participants with knee osteoarthritis were selected following specific criteria: age between 45-75 years, grade II or III osteoarthritis confirmed by radiograph, symptom duration greater than six months, and pain intensity equal to or greater than 40 points on a 0-100 scale. Participants were randomly divided into two groups of 30 people each.

The electroacupuncture group received real electrical stimulation at the needles, while the manual acupuncture group received a simulated procedure in which the device appeared to be working but did not deliver electrical current. Both groups received 24 treatment sessions over 8 weeks, with needles inserted at the same acupuncture points. The main outcome assessed was the response rate, defined as an improvement of at least 50% in total WOMAC scores (which assesses pain, stiffness, and physical function) after 8 weeks of treatment.

Results showed that both treatments were well tolerated by patients, with 88% completing the study. The response rate was 43% in the electroacupuncture group and 30% in the manual acupuncture group, a difference that was not statistically significant. This means that, although electroacupuncture showed numerically superior results, this difference may have occurred by chance and does not necessarily indicate real superiority of the method. Both groups showed significant improvements in pain, stiffness, and physical function compared with baseline.

In quality-of-life assessment, the electroacupuncture group showed significantly better scores at all follow-up evaluations. Adverse events were rare and similar between groups, mainly including small hematomas at the application site and post-needling sensation, with no occurrence of serious events. No participant required rescue medication during the study.

For patients with knee osteoarthritis, these results suggest that both electroacupuncture and manual acupuncture may be safe and potentially beneficial therapeutic options. Both modalities demonstrated capacity to reduce pain and improve joint function, offering alternatives to conventional treatments for those seeking to avoid medication side effects or wishing complementary approaches. For healthcare professionals, the study indicates that both techniques can be incorporated into the therapeutic arsenal for knee osteoarthritis, with the choice between them possibly based on therapist experience, equipment availability, and patient preference. The fact that there are no significant safety differences between the modalities is reassuring for clinical practice.

This study has some important limitations that should be considered when interpreting the results. First, this is a pilot study with only 60 participants, a small number that limits the statistical power to detect differences between groups. The researchers themselves calculated that at least 269 participants per group would be needed for a definitive study. Second, the research was conducted only in the Beijing region, which may limit the generalizability of the results to other populations.

Third, the study did not include a control group with simulated treatment, which could have helped to better assess the specific effects of acupuncture. Finally, the follow-up period was relatively short, not allowing assessment of long-term treatment effects.

In conclusion, this pilot study demonstrates that both electroacupuncture and manual acupuncture are viable and safe options for the treatment of knee osteoarthritis. Although there was a numerical trend in favor of electroacupuncture, definitive superiority of one technique over the other could not be established. The results provide valuable data for the planning of larger and more conclusive future studies. For patients considering acupuncture as a treatment for knee osteoarthritis, the findings are encouraging regarding the safety and potential efficacy of both modalities, with the choice to be discussed individually with qualified professionals, taking into account the specific characteristics of each case and personal preferences.