Electro-acupuncture resulted in significant improvement in pain and function, compared with sham acupuncture, in a randomized trial of more than 400 adults with knee OA.
The socioeconomic burden of knee OA (KOA) remains high, and will likely increase with the aging population and rising rates of obesity, wrote first author Jian-Feng Tu, MD, PhD, of Beijing University of Chinese Medicine and colleagues. “Since no disease-modifying pharmaceutical agents have been approved, current KOA treatments are mainly symptomatic,” and identifying new therapies in addition to pharmacological agents or surgery is a research priority, they added. The research on acupuncture as a treatment for KOA has increased, but remains controversial as researchers attempt to determine the number of sessions needed for effectiveness.
In a study published in Arthritis & Rheumatology, the researchers recruited 480 adults aged 45-75 years with confirmed KOA who reported knee pain for longer than 6 months. Participants were randomized to three groups: electroacupuncture (EA), manual acupuncture (MA), or sham acupuncture (SA). Each group received three treatment sessions per week. In all groups, electrodes were attached to selected acupuncture needles, but the current was turned on only in the EA treatment group.
The primary outcome was the response rate after 8 weeks of treatment, defined as patients who achieved the minimal clinically important improvement (MCII) on both the Numeric Rating Scale and the Western Ontario and McMaster Universities Osteoarthritis Index function subscale.
Overall, response rates at 8 weeks were 60.3%, 58.6%, and 47.3% for the EA, MA, and SA groups, respectively.
Between-group differences were statistically significant for EA versus SA (13%, P = .0234) but not for MA versus SA (11.3%, P = .0507) at 8 weeks; however, both EA and MA groups showed significantly higher response rates, compared with the SA group at 16 and 26 weeks. “Although a clinically meaningful response rate for KOA is not available in the literature, the difference of 11.3%, which indicates the number needed to treat of 9, is acceptable in clinical practices,” the researchers noted.
Adverse events occurred in 11.5% of the EA group, 14.2% of the MA group, and 10.8% of the SA group, and included subcutaneous hematoma, post-needling pain, and pantalgia. All adverse events related to acupuncture resolved within a week and none were serious, the researchers wrote.
The study findings were limited by several factors, including the potential burden on patients of three sessions per week, the limited study population of patients with radiologic grades of II or III only, the use of self-reports, and the lack of blinding for outcome assessors, the researchers noted.
However, the results show persistent effects in reducing pain and improving function with EA or MA, compared with SA, the researchers wrote. The findings were strengthened by “adequate dosage of acupuncture, the use of the primary outcome at an individual level, and the rigorous methodology.” The use of the MCII in the primary outcome “can provide patients and policy makers with more straightforward information to decide whether a treatment should be used.”