Comparison of the Efficacy of Different Concentrations of Diclofenac Sodium Phonophoresis (1.16% vs 2.32%) in Patients with Knee Osteoarthritis: a Randomized Double-Blind Controlled Trial.

PURPOSE OF THE STUDY The objective of the present study is to compare the efficacy of two different concentrations of diclofenac sodium phonophoresis (DSPH) (1.16% vs 2.32%) in patients with knee osteoarthritis (OA). MATERIAL AND METHODS A randomized, double-blind, controlled design was applied. Ninety patients (mean age± SD, 59.98 ± 8.89 years) who had Kellgren-Lawrence (K-L) grades II to III knee OA were randomly allocated into three groups; 1.16% DSPH, 2.32% DSPH, TUS (30 in each group). Each patient was treated five sessions per week for two weeks. A 100-mm visual analogue scale (VAS) for usual pain and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were evaluated before and after treatment in all groups. RESULTS The VAS pain and WOMAC scores were significantly improved after treatment in all groups (p < 0.05). The 2.32% DSPH showed more significant effects than the 1.16% DSPH, both in improving WOMAC- pain and physical function scores (p = 0.020, p = 0.008) and reducing the VAS pain measure, although it did not reach the level of significance (p = 0.077). The 2.32% DSPH was superior to the TUS, both in reducing the VAS pain measure (p < 0.001) and in improving WOMAC-pain, stiffness, physical function and total scores (p = 0.022, p = 0.016, p < 0.001, p < 0.001 respectively). 1.16% DSPH significantly reduced stiffness and physical function scores compared with TUS (p = 0.042, p = 0.047). CONCLUSIONS DSPH and TUS are effective treatments for knee OA. Our results indicated that 2.32% DSPH produces additional benefits to functional improvement and pain reduction compared with 1.16% DSPH in K-L grades II to III knee OA. Key words: diclofenac sodium, knee osteoarthritis, phonophoresis, therapeutic ultrasound, topical formulation.