The ‘U Word’ (Therapeutic Ultrasound) has had a lot of press recently thanks to everyone’s favorite “doctor” and unfortunately this modality just cannot be put to rest. Li et al conducted a survey attempting to determine the typical treatment approaches used for patients suffering from low back pain of varying intensities (Acute, Sub-acute, and Acute with Sciatica). The results indicated that almost 80% of therapists used physical modalities for all three scenarios, with Ultrasound (US) being utilized by almost 1/3 of all therapists. Additionally, this study showed that spinal mobilization (40%) and manipulation (5%) were used sparingly, despite the evidence supporting their efficacy. Honestly, I thought it would be worse. A more recent survey by Wong et al sought out the practice patterns of Orthopaedic Certified Specialists (OCS) with regards to the use of ultrasound. This survey of certified experts in our field concluded that of the over 200 respondents, 83.6% use US to decrease soft-tissue inflammation, 70.9% to increase tissue extensibility, 68.8% to enhance scar tissue remodeling, 52.5% to increase soft-tissue healing, 49.3% to decrease pain, and 35.1% to decrease soft-tissue swelling. With such widespread use of this intervention for so many varying reasons, there has to be supporting evidence, doesn’t there?
It has been theorized that US has the ability to heat deeper anatomical structures (i.e. muscle, tendon, and bone), accelerate tissue regeneration, increase pain threshold, stimulate bone growth, and increase tendon extensibility. Sounds pretty good, right?
Problem number one: The majority of the supporting research was conducted between 1950 and 1980.
Problem number two: Results of recent efficacy studies.
Gam et al completed a meta-analysis investigating the use of ultrasound in musculoskeletal disorders. After pooling the outcomes of 29 randomized controlled trials, they concluded that US contributed a negligible amount to the subjects’ rehabilitation. Later, in 1999, van der Windt et al conducted a systematic review of US therapy for musculoskeletal disorders. Of the 18 placebo-controlled studies evaluated, only 2 yielded results that showed US to be beneficial. It was determined that the magnitude of the reported treatment effects were small, and were probably of little clinical importance. To build upon these findings, Robertson et al published a systematic review once again looking into the efficacy of therapeutic ultrasound in the treatment of common musculoskeletal disorders (as determined by randomized controlled trials). Not too surprisingly, of the ten studies that met the inclusion criteria, only 2 studies showed statistically significant benefits (carpal tunnel syndrome and calcific tendinitis of the shoulder).
But, these studies compared treatments of different pathologies… Surely there are pathologies where US is supported?
There have been a few high-quality systematic reviews conducted looking into ultrasound’s therapeutic effect on specific pathologies. Seco et al investigated its efficacy in the treatment of low back pain (remember the Li study?). 242 patients were included in the 4 studies that met the inclusion criteria and none of these studies showed statistically significant benefits. In addition, one of the studies included (Mohseni-Bandpei et al) looked into the effectiveness of US versus spinal manipulation. They evaluated the outcomes of 116 patients over 6 months and found that spinal manipulation demonstrated greater improvements in pain, disability, flexion ROM, and extension ROM (remember the Li study?). It is postulated that only tissues that are superficial can be affected, so maybe that’s why the effects on LBP are minuscule.
The lateral ankle ligaments are superficial, so surely US will be of benefit, right? A Cochrane Review was published by van den Bekerom et al investigating just that hypothesis. This review included 6 studies and over 600 patients, but once again US did not provide the benefits that many are led to believe. No statistically significant benefits were found for improvements in pain, swelling, functional disability, or range of motion in any of the 6 studies.
Clinical instructors and colleagues continue to use this poorly supported intervention, but shy away from those interventions supported by current research. The Li and Wong studies say it all. We need to educate our fellow colleagues about the ineffectiveness of what has become a mainstay in many outpatient physical therapy and chiropractic offices. Why do we continue to utilize old, outdated interventions? Is it fear of change? Is it stubbornness? Is it a lack of awareness?
Regardless of the reason, our clinical practice patterns need to change. The evidence is lopsided contrary to previous beliefs regarding ultrasound’s efficacy in treating musculoskeletal pain/dysfunction and we, as a profession, must adapt and move on. So, unless you are treating a huge proportion of calcific tendonitis of the shoulder or carpal tunnel syndrome, just keep your ultrasound machine in the storage closet.