The aim of this trial was to evaluate the short-term effectiveness of ultrasound (US) therapy on pain, physical function, ambulation activity, disability and psychological status in patients with knee OA.
Forty-two inpatients with bilateral knee OA were randomized by an independent researcher not involved in the data assessment, to receive either therapeutic continuous US (group 1) or sham US (group 2). A 1-MHz US head was used, set to an intensity of 1 W/cm(2) for 10 min. All patients received 20 min of hot packs, 10 min of interferential current, and 15 min of quadriceps isometric exercise of both knees. Patients in each group received treatments five times weekly for 3 weeks. Patients were evaluated at baseline and at the end of the treatment sessions. Outcome measures included visual analogue scale (VAS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), 50-m walking speed, Lequesne index, Hospital Anxiety and Depression Scale (HADS).
The patients with knee OA had significant improvements in pain, stiffness, functional activity, walking time, disability, depression and anxiety scores with therapeutic US and sham US (P < 0.05). The improvement in pain VAS scores, WOMAC scores, Lequesne index and HADS scores were not significantly different in patients treated with US and sham US (P > 0.05). No side-effects were reported during or after the US treatment periods.
US therapy is safe but use of US in addition to conventional physical therapy programs seems to have no further significant effect in people with knee OA.