Clinical Efficacy of Pulsed Electromagnetic Field Therapy on Thumb Carpometacarpal Joint Pain: A Double-Blind, Randomized, Controlled Trial.

Background: Thumb carpometacarpal (CMC) osteoarthritis (OA) is a common source of hand pain with limited nonoperative treatment options. Pulsed electromagnetic field (PEMF) therapy has been recently shown in studies to be effective in providing sustained pain relief in knee osteoarthritis. This study aimed to assess the efficacy of PEMF therapy for treating thumb CMC OA pain.

Methods: This single-center, double-blind, randomized controlled trial included adults with radiographically and/or clinically diagnosed CMC OA who reported an average Numeric Pain Rating Scale (NPRS) score between 3 and 8. Participants were randomized to either a PEMF device or an identical sham device that was used for 8 hours each night for 4 weeks. The primary outcome measure was the change in average daily NPRS from baseline to 4 weeks. Secondary outcome measures included Patient-Rated Wrist/Hand Evaluation (PRWHE) and Single Assessment Numeric Evaluation at 4 and 6 weeks.

Results: Sixty-one participants were recruited, and 51 participants completed the study at 4 weeks. Both the PEMF therapy and sham device groups showed improvements in average NPRS and PRWHE at 4 weeks, but there was not a significant improvement between groups. At 6 weeks, there was a significantly greater change in average NPRS from baseline in the PEMF therapy group compared with the sham device group (P = .02).

Conclusions: Pulsed electromagnetic field therapy may improve thumb CMC OA pain with sustained relief beyond the treatment period. Future studies will need to assess if adjusting treatment duration or other factors can enhance its efficacy.