A form of transcutaneous electrical neuro-stimulation is both effective and safe in relieving pain due to knee osteoarthritis, according to a study presented here at the World Congress on Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (WCO).
Dynamic electrical neuro-stimulation delivers weak (200 to 400 mkA) and low frequency (10 to 200 Hz) pulses of electricity to localised targets on the skin, usually via a hand-held device.
Olga Lesnyak, MD, Ural State Medical University, Ekaterinburg, Russian Federation, and colleagues assessed the technique as a form of pain relief for 132 subjects with knee osteoarthritis.
Inclusion criteria were visual analogue scale (VAS) rated pain severity exceeding 40 mm and Lequesne index score of knee osteoarthritis discomfort between 4 and 12.
Of the patients, 66 were randomised to receive dynamic electrical neuro-stimulation on the painful knee using 77 Hz frequency and 15 mA current intensity of the current. The other 66 patients received a sham procedure. For both groups the treatment duration was 30 minutes per session with 10 sessions done.
The outcome was VAS ranked severity of knee pain severity measured before treatment, at day 1, 3, 6, and 10 of treatment, and 2 and 4 weeks after the end of the final treatment session.
“A distinct analgesic effect associated directly with the treatment procedure was found in the [dynamic electrical neuro-stimulation] group,” said Dr. Lesnyak, MD.
Each session of treatment produced a 5 to 8 mm drop in VAS ranked pain. The benefit was most pronounced after the first and sixth treatment session, with a VAS reduction of 8.73 mm and 6.28 mm, respectively. An immediate analgesic effect was not evident in the placebo group.
A statistically significant difference between the 2 groups was noted after the first (P = .014), third (P = .018), and sixth (P = .047) treatment sessions. Both groups experienced significant reduction in pain (P< .0001), although the difference in pain intensity remained significantly throughout the study, with less pain in the treatment group (P = .003).
The use of non-steroidal anti-inflammatory drugs did not differ appreciably during the course of the study and the frequency of side effects was similar in both groups.
“Dynamic electrical neuro-stimulation is an effective and safe method of pain relief in patients with knee osteoarthritis,” the authors concluded.