Efficacy of extracorporeal shockwave therapy for knee osteoarthritis: a randomized controlled trial.

BACKGROUND Extracorporeal shockwave therapy (ESWT) has been widely used for pain relief and treatment of musculoskeletal disorders. We aimed to assess ESWT for knee osteoarthritis (OA) over 12 wk by comparison with placebo treatment. MATERIALS AND METHODS We randomized 70 patients to receive placebo (n = 36) or ESWT (n = 34). For ESWT, patients received 4000 pulses of shockwave at 0.25 mJ/mm(2) weekly for 4 wk. In the placebo group, patients received shockwave at 0 mJ/mm(2) in the same area. The effect on OA was assessed by pain on a visual analog scale and disability on the Lequesne index, Western Ontario and McMaster University Osteoarthritis Index, and patient perception of the clinical severity of OA. Evaluation was performed at baseline and after 1, 4, and 12 wk. RESULTS We found no adverse events during and after ESWT. ESWT was more effective than placebo in reducing pain on movement at each period (P < 0.01). The mean visual analog scale score with ESWT was 3.83 at 12 wk versus 7.56 at baseline (P < 0.01). The Lequesne index and the Western Ontario and McMaster University Osteoarthritis Index score were reduced with ESWT. Moreover, patient perception of clinical severity of OA was significantly greater with ESWT than that with placebo (P < 0.01). CONCLUSIONS ESWT is effective in reducing pain and improving knee function, with better results than placebo during the 12-wk treatment. However, further pilot studies are needed to determine whether ESWT should be recommended at an early or later stage of OA or combined with conventional therapies.