The efficacy of interferential current treatment on knee osteoarthritis

Objectives: We aimed to investigate the effects of different carrier frequencies of interferential current (IFC) treatment on visual analog scale (VAS) for pain, The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), 10 meter walk test and the amount of paracetamol taken. Materials and method: 61 patients presenting to our outpatient clinic with knee pain and who were shown to have grade 2 or 3 knee osteoarthritis (OA) according to the Kellgren-Lawrence scale were enrolled in the study. Subjects were randomized to 3 treatment groups namely 2000 Hz, 4000 Hz and 8000 Hz. Subjects received IFC treatment for 20 minutes, 5 times per week for 3 weeks. All subjects were prescribed a home exercise program. Patients were evaluated at baseline and on weeks 3 and 7. Findings: We observed that IFC treatment yielded significant results in VAS pain, WOMAC pain and WOMAC function parameters in all three groups but no significant difference was shown among the three groups. WOMAC stiffness parameter was found to benefit from the treament only in the first group while 10 meter walk test improved for the first and third groups. The amount of paracetamol tablets taken did not differ significantly neither in nor among the treatment groups. Discussion: IFC treatment which is frequently employed in clinical practice is useful in alleviating both acute and chronic painful conditions. Previous trials have found significant reduction in knee pain levels and increase in function with IFC treatment although there is no consensus on which carrier frequencies and duration to choose for IFC treatment. In this study we detected significant benefits for all the different carrier frequenciy groups but were not able to show any one to be superior to the others. For this reason there is still need for further studies with longer follow up periods and with larger sample sizes.