A review of therapeutic ultrasound: effectiveness studies

Background and Purpose. Therapeutic ultrasound is one of the most widely an d frequently used electrophysical agents. Despite over 60 years of clinical use, the effectiveness of ultrasound for treating people with pain, muscul oskeletal injuries, and soft tissue lesions remains questionable. This arti cle presents a systematic review of randomized controlled trials (RCTs) in which ultrasound was used to tr eat people with tl-lose conditions. Each tr ial was designed to investigate the contributions of active and placebo ult rasound to the patient outcomes measured. Depending on die condition, ultra sound (active and placebo) was used alone or in conjunction with other inte rventions in a manner designed to identify its contribution and distinguish it from those of other interventions. Methods. Thirty-five English-languag e RCTs were published between 1975 and 1999. Each RCT identified was scruti nized for patient outcomes and methodological adequacy. Results. Ten of the 35 RCTs were judged to have acceptable methods using criteria based on tho se developed by Sackett et al. Of these RCTs, the results of 2 trials sugge st that therapeutic ultrasound is more effective in treating some clinical problems (carpal tunnel syndrome and calcific tendinitis of the shoulder) t han placebo ultrasound, and the results of 8 trials suggest that it is not. Discussion and Conclusion. There was little evidence that active therapeut ic ultrasound is more effective than placebo ultrasound for treating people with pain or a range of musculoskeletal injuries or for promoting soft tis sue healing. The few studies deemed to have adequate methods examined a wid e range of patient problems. The dosages used in these studies varied consi derably, often for no discernable reason.