Wearable TENS More Effective Than Weak Opioids for Knee Osteoarthritis

Wearable transcutaneous electrical nerve stimulation (TENS) was more effective and better tolerated than weak opioids in the treatment of moderate-to-severe nociceptive knee osteoarthritis (OA) pain, according to a study presented at the Virtual 2021 Annual Meeting of the European League Against Rheumatism (EULAR).

While the first pharmacologic analgesic line is generally considered to be paracetamol (acetaminophen), its low efficacy frequently leads to the use of opioids despite their poor tolerance, especially in elderly patients.

In the phase 3 arthroTENS study, patients were randomized to a wearable TENS group or a group receiving a weak opioid prescription (codeine, opium powder, and tramadol, with or without paracetamol) for 3 months. A total of 110 patients (55 per group) were randomized and 48/55 (87.3%) and 44/55 (80.0%) patients, respectively, completed the 3-month follow-up. All patients were more than 55 years old and had failed to achieve relief from knee OA pain with non-opioid analgesics, including non-steroidal anti-inflammatory drugs.

In the wearable TENS group, users received high-frequency (100 Hz) and low-frequency (2 Hz) stimulations that were delivered with standardized positioning of electrodes via an advanced mobile app.

Primary endpoints were efficacy, mean pain intensity, and safety during the trial period. A non-inferiority analysis was performed on the primary efficacy endpoint using a predefined non-inferiority margin (0.825-point) on pain intensity, below the minimal clinically significant improvement.

A planned superiority analysis was performed showing that wearable transcutaneous electrical nerve stimulation was significantly superior to weak opioids at month 3 for pain intensity (P = .0124). Moreover, the number of adverse events (AEs) was significantly lower in the electrical nerve stimulation group than in the opioids group (7 vs 26; P < .001).

Of the patients assigned to wearable TENS, 39 (70.9%) chose to extend the use of wearable TENS treatment for 3 additional months. (See: Maheu E, Soriot-Thomas S, Noel E on behalf of arthroTENS, et al. Wearable transcutaneous electrical nerve stimulation demonstrated better efficacy and safety than weak opioids in the treatment of moderate to severe, chronic nociceptive pain in knee osteoarthritis: a randomized, controlled, non-inferiority trial. Annals of the Rheumatic Diseases. 2021;80:364-365. https://ard.bmj.com/content/80/Suppl_1/364.)