Far infrared emitting plaster in knee osteoarthritis: a single blinded, randomised clinical trial

Abstract

Objective: Therapeutic approach of osteoarthritis (OA) still represents a challenge in clinical practice. The aim of the study is to assess the efficacy of far infrared (FIR) emitting plaster in the treatment of knee OA.

Design: This is a randomized, single-blind, placebo-controlled, parallel group with equal randomization (1:1), clinical trial. Patients affected by knee OA were randomly allocated to 1 of 2 treatment groups, either placebo plaster or far infrared emitting plaster. Primary endpoint was to assess pain improvement from baseline to 1 months posttreatment in the visual analogue score (VAS). Secondary end point was to evaluate pain score after 1 week of treatment and to compare ultrasonographic findings after 1 month of treatment.

Results: Each group comprised 30 (in the FIR group) and 30 (in the placebo group) completers. VAS scores of the placebo and the FIR group were significantly lower at 1 week post-treatment (95% confidence interval CI = -1.14 to 0.31; P<0.05) and at the end of the study (95% confidence interval CI = -2.57 to -0.89; P=0.01). Effect size was -0.43 after one week of treatment and -1.38 after one month of treatment. The mean decrease in VAS values was ≥ 20% in the FIR group. The number of patients from the FIR group with joint effusion was lower (40%) compared to baseline (80%), while no changes were seen among the placebo group.

Conclusions: Far infrared emitting plaster could be considered an effective non-pharmacological choice for the therapeutic management of knee OA.