The effects of electro-acupuncture and transcutaneous electrical nerve stimulation on patients with painful osteoarthritic knees: a randomized controlled trial with follow-up evaluation.

Objectives: To examine the relative effectiveness of electro-acupuncture (EA) and transcutaneous electrical nerve stimulation (TENS) in alleviating osteoarthritic (OA)-induced knee pain.

Design: Single-blinded, randomized controlled study.

Subjects: Twenty-four (24) subjects (23 women and 1 man), mean age 85, were recruited from eight subsidized Care & Attention Homes for the elderly.

Interventions: Subjects were randomly assigned to the EA, TENS, or control groups. Subjects in the EA group (n = 8) received low-frequency EA (2 Hz) on two acupuncture points (ST-35, Dubi and EX-LE-4, Neixiyan) of the painful knee for 20 minutes. Subjects in the TENS group (n = 8) received low-frequency TENS of 2 Hz and pulse width of 200 micros on the same acupuncture points for 20 minutes. In both treatment groups, electrical treatment was carried out for a total of eight sessions in 2 weeks. Eight subjects received osteoarthritic knee care and education only in a control group. All subjects were evaluated before the first treatment, after the last treatment, and at 2-week follow-up periods.

Results: After eight sessions of treatment, there was significant reduction of knee pain in both EA group and TENS group, as measured by the Numeric Rating Scale (NRS) of pain (p < 0.01). Prolonged analgesic effect was maintained in the EA and the TENS groups at a 2-week follow-up evaluation. The Timed Up-and-Go Test (TUGT) score of the EA group was significantly lower than that of the control group (p < 0.05), but such change was not observed in the TENS group.

Conclusions: Both EA and TENS treatments were effective in reducing OA-induced knee pain. EA had the additional advantage of enhancing the TUGT results as opposed to TENS treatment or no treatment, which did not produce such corollary effect.