Frequency-Dependent Effects of Warm Needle Acupuncture in Patients With Knee Osteoarthritis With Cold-Dampness...

Knee osteoarthritis (KOA) is a common chronic degenerative joint disease. Its rising incidence, driven by population aging and increasing obesity rates, imposes a growing socioeconomic burden. As a therapy integrating the dual merits of acupuncture regulation and thermal stimulation, warm acupuncture has been widely adopted for KOA, accompanied by a growing body of relevant research. However, standardized recommendations regarding optimal treatment frequency and course duration of warm needle acupuncture for KOA remain lacking.

A total of 84 eligible KOA patients were enrolled and randomly assigned to either a high-frequency group or a low-frequency group. The high-frequency group received 5 treatments per week for the first 2 weeks, whereas the low-frequency group received 2 treatments per week during the same period. The primary outcome was the between-group difference in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score at the end of Week 2. Secondary outcomes included the WOMAC stiffness and function scores, active range of motion of the knee joint, medical infrared thermography data, quantitative scoring of traditional Chinese medicine (TCM) syndrome classification, and the Patient Health Questionnaire-9 (PHQ-9). Analyses were performed using generalized estimating equations.

The WOMAC pain score in the high-frequency group after 2 weeks of treatment showed a statistically significant difference compared to the low-frequency group (difference, 3.07 [95% CI, 1.86 to 4.28], p < 0.001). Secondary outcome results indicated that acupuncture, compared to the low-frequency group, significantly alleviated the WOMAC stiffness score (difference, 0.90 [95% CI, 0.26 to 1.55], p = 0.006) and WOMAC functional scores (difference, 6.86 [95% CI, 2.58 to 11.13], p = 0.002), as well as active knee range of motion (difference, -11.00 [95% CI, -16.31 to -5.69], p < 0.001) and the quantified score for traditional Chinese medicine syndrome grading (difference, 1.71, 95% CI, 0.88 to 2.55, p < 0.001). However, no statistically significant differences were observed in the PHQ-9 total score or knee-related regional temperature (p > 0.05). The incidence of adverse events was similar between the two groups.

Both high- and low-frequency warm acupuncture significantly improved clinical symptoms in patients with KOA. However, high-frequency warm acupuncture demonstrated markedly superior efficacy compared to low-frequency treatment in alleviating pain, enhancing joint function, increasing active knee range of motion, and improving TCM syndromes. These findings provide evidence-based support for optimizing treatment frequency in warm needle acupuncture as a safe and effective non-pharmacological intervention for KOA.

International Traditional Medicine Clinical Trial Registry: ITMCTR2024000269.