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Research Reports: Rita A Wong, Britta Schumann, Rose Townsend, and Crystal A Phelps A Survey of Therapeutic Ultrasound Use by Physical Therapists Who Are Orthopaedic Certified Specialists PHYS THER 2007; 87: 986-994 [Abstract] [Full text] [PDF]

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Ultrasound works and compliments therapy

David O. Draper   (21 December 2007)

Ultrasound therapy does work, but we are still not listening

Stuart J Warden   (30 November 2007)

Ultrasound: suggestions for moving forward

Val J Robertson   (11 September 2007)

Uncertainty of evidence and change in practice

Nurudeen T Amusat   (5 September 2007)

We Are Still Not Listening

John D Childs   (7 August 2007)

Ultrasound works and compliments therapy 21 December 2007
David O. Draper, professor Brigham Young University Send rapid response to journal: Re: Ultrasound works and compliments therapy david_draper{at}byu.edu David O. Draper	While many choose to cast a shadow on ultrasound, and conclude that it is a “worthless intervention,” I argue that the way some people use this medical device might be what makes it worthless. Regardless of whether or not you believe ultrasound assists with healing properties, we have proven that it increases deep tissue temperatures.1,2 Many in the profession use heat or exercise to decrease pain and increase blood flow prior to therapy. Why not use ultrasound if the therapy is targeted to a small area? Ultrasound prepares tissues for the therapy, thus it is especially helpful prior to joint mobilization and stretching of wrists, elbows, and ankles—prior to friction massage, etc. The key to keep from making ultrasound a useless modality is to use correct parameters. The article by Wong and colleagues3 clearly showed that clinicians are improving their knowledge regarding proper use of ultrasound, but there is room for improvement. Also, all of us need to be aware that there is great disparity between ultrasound machines and their ability to heat and provide energy to the tissues.4,5 Brigham Young University is a university with plenty of students who are healthy and periodically injure themselves. Thus we have plenty of temperature data, and are slowly building up our injury healing (evidence-based) data. By inserting thermocouples into human muscle and using the best equipment available, we have measured the temperature changes of several modalities. Our data are as follows: Hotpack: 1 cm deep, ~3°C temp increase; Hotpack: 3 cm deep, ~1°C temp increase; Whirlpool: 1 cm deep, ~3°C temp increase; Whirlpool: 3 cm deep, ~1°C temp increase; Paraffin bath: 1 cm deep, ~2°C temp increase; Paraffin bath: 3 cm deep <1°C temp increase6 When ultrasound is compared with the above data, the following is the typical trend: 3-MHz ultrasound at 1.5 W/cm2 for 7 minutes—~5-6°C increase at 1-2 cm1,2 1-MHz ultrasound at 1.5 W/cm2 for 12 minutes—~3-4°C increase at 3-5 cm.1,2 If you look at our results you can see 2 benefits to using ultrasound. Ultrasound not only provides deep heat, but it also provides more heat to superficial structures when the 3 MHz frequency is used. There is however one weakness to ultrasound, it can only heat small areas about twice the size of the soundhead. When deep heat is needed on a larger area, I suggest treating the area in sectors, or using pulsed short-wave diathermy. Those who oppose ultrasound often use flawed studies as examples to support their premise that ultrasound is worthless. The study failed, so ultrasound must be to blame. Here’s one example. Reed and Ashikaga7 attempted to determine whether or not ultrasound could heat and thus increase the extensibility of the medial and lateral collateral ligaments of the knee. Subjects received doses of 1 MHz ultrasound at 1.5 W/cm2 for 8 minutes. Immediately after the treatment, knee displacement was measured and compared with the baseline test. Although there were slight increases in displacement, they were not statistically different than the baseline. Why did Reed and Ashikaga fail? They used the wrong parameters. They treated too large an area to cause any heating—they covered the entire knee. I measured this area on an average-sized college student (5’ 10” and 170 lb) and it was 30 times the size of the soundhead. Second, they used the wrong frequency (1 MHz). Their goal was to heat the medial and lateral collateral ligaments of the knee. Because these structures are more shallow than 2.5 cm, the 3 MHz frequency should have been used, not 1 MHz. Third, they treated the area for eight minutes. Based on several ultrasound heating rate studies, their protocol (1 MHz at 1.5 W/cm2 for 8 minutes) would have resulted in only ~2°C temperature increase above baseline. And that is if they had limited their treatment area to twice the size of the soundhead, and used our top-rated equipment. Typically, temperature increases of 4°C are needed to increase ligament extensibility. Baker and colleagues8 used this study and other poorly designed ones like it to support their premise that ultrasound doesn’t work. I’m of the opinion that they were too busy discrediting ultrasound and instead should have been informing the reader why ultrasound didn’t work under certain circumstances. When I treat areas this large, I use pulsed short-wave diathermy and have had excellent results.9 Be cautious in assuming that ultrasound is worthless, especially when many of the studies supporting this premise are flawed to begin with. Apparently, the jury is still out in the debate over how effective ultrasound is. Although the ideal situation might be databased research on patients with clinical conditions, such research is difficult to perform. Institutional review boards struggle with it, and it often takes years to obtain enough subjects. For those who want to test ultrasound in clinical conditions, use appropriate parameters. References 1 Draper DO, Castel JC, Castel D. Rate of temperature increase in human muscle during 1 MHz and 3 MHz continuous ultrasound. J Orthop Sports Phys Ther. 1995;22:142–150. 2 Wells AM, Draper DO, Vincent WJ. The regression equation of the Omnisound 3000 is valid: ultrasound treatments should be temperature dependent not time dependent. J Athl Train. 2004;39:S24. 3 Wong RA, Schumann B, Townsend R, Phelps CA. A survey of therapeutic ultrasound use by physical therapists who are orthopaedic certified specialists. Phys Ther. 2002;87:986–994. 4 Merrick MA, Bernard KD, Devor ST, Williams MJ. Identical 3-MHz ultrasound treatments with different devices produce different intramuscular temperatures. J Orthop Sports Phys Ther. 2003;33:379–385. 5 Holcomb WR, Joyce CJ. A comparison of temperature increases produced by 2 commonly used ultrasound units. J Athl Train. 2003;38:24–27. 6 Knight KL, Draper DO. Therapeutic Modalities: The Art and Science. Baltimore, Md: Lippincott Williams & Wilkins; 2008. 7 Reed B, Ashikaga T. The effects of heating with ultrasound on knee joint displacement. J Orthop Sports Phys Ther. 1997;26:131–137. 8 Baker KG, Robertson VJ, Duck FA. A review of therapeutic ultrasound: biophysical effects. Phys Ther. 2001;81:1351–1358. 9 Seiger C, Draper DO. Use of pulsed shortwave diathermy and joint mobilization to increase ankle range of motion in the presence of surgical implanted metal: a case series. J Orthop Sports Phys Ther. 2006;36:669–677.
Ultrasound therapy does work, but we are still not listening 30 November 2007
Stuart J Warden, Assistant Professor and Director of Research Department of Physical Therapy, Indiana University Send rapid response to journal: Re: Ultrasound therapy does work, but we are still not listening stwarden{at}iupui.edu Stuart J Warden	Wong and colleagues[1] published an interesting overview of the current use of therapeutic ultrasound in clinical physical therapist practice. The data are basically in agreement with those we previously published from an equivalent cohort of therapists in Australia[2] and indicate that, although ultrasound therapy is widely used in clinical practice, this use is not evidenced based. Childs[3] suggests that this ongoing prevalent use of ultrasound despite apparent lack of evidence is "attributable to the 15- to 20-year 'evidence gap' that exists in health care" and that "we are still not listening" to the evidence. Although I agree with this opinion, I strongly disagree with the contention that therapeutic ultrasound is a "worthless intervention." There is an abundant and rapidly growing body of evidence demonstrating the clinical efficacy of ultrasound therapy. For instance, 3 well designed randomized controlled trials have demonstrated ultrasound therapy to accelerate clinical and radiological healing of acute bone injuries by 30% to 38% [4-6]. By pooling the data from these trials using a meta-analysis approach, a weighted average effect size can be calculated to be 6.41 (95% confidence interval [CI]=0.01–11.81), which converts into a mean improvement in healing time with ultrasound of 64 days[7]. This is quite remarkable considering that fracture repair is considered to be a naturally optimized process. Added to these data are those demonstrating that ultrasound therapy stimulates union in more than 85% of non-united fractures--fractures that had failed to heal in an average of 755 days following initial injury[8]. As a result of these cumulative findings, ultrasound therapy has gained the approval of the FDA and third- party payers for the intervention of both acute and chronic bone injuries. The significant benefits of ultrasound therapy when introduced to injured bone yet apparent absence of an effect as currently being introduced by physical therapists raises the question of the reason for this disparity. There currently is no direct evidence indicating a reason; however, an obvious trend is present when the methods of studies that have demonstrated a beneficial ultrasound effect are compared to those that have not found such an effect. Studies demonstrating a beneficial ultrasound effect[4-10] all have something in common that contrasts with how physical therapists are currently using and studying ultrasound therapy: they all introduce ultrasound for longer durations and greater frequency. For instance, in our previous survey, we found therapists to use ultrasound clinically for 5 minutes per treatment and, presumably, fewer than 3 treatments per week[2]. Likewise, in methodologically sound randomized controlled trials that failed to establish a beneficial effect, ultrasound was introduced infrequently, for treatment periods of less than 10 minutes[11]. In contrast, studies demonstrating beneficial effects all introduced ultrasound for periods longer than 15 minutes per treatment and for 5 or more treatments per week. These studies suggest that ultrasound can have beneficial effects when used at appropriate dosages and suggest that therapists should start studying the effects of ultrasound when introduced more frequently and for longer durations. We have started doing this in preclinical animal studies and have found that ultrasound units as used in physical therapy can potentially have beneficial clinical effects during fracture repair[12] and during stress fracture[13] and ligament[14] healing. In summary, I agree with Childs[3] that "we are still not listening" to the evidence regarding the efficacy of ultrasound therapy; however, I disagree that the evidence is telling us that ultrasound therapy does not work. Instead, I contend that “we are not still not listening” to the evidence that ultrasound therapy DOES work. This is evident within the recent clinical use surveys[1,2] that demonstrate that therapists continue to apply ultrasound at dosages based more on tradition than on the evidence provided by well-designed randomized controlled trials. The later trials repeatedly suggest the presence of a potentially more optimal dosage than is currently being used clinically by physical therapists. References 1 Wong RA, et al. A survey of therapeutic ultrasound use by physical therapists who are orthopaedic certified specialists. Phys Ther. 2007;87:986-994. 2 Warden SJ and McMeeken JM. Ultrasound usage and dosage in sports physiotherapy. Ultrasound Med Biol. 2002;28:1075-1080. 3 Childs J. On "a survey of therapeutic ultrasound..." Phys Ther. 2007;87:1558. Letter to the editor. 4 Heckman JD, et al. Acceleration of tibial fracture-healing by non-invasive, low-intensity pulsed ultrasound. J Bone Joint Surg Am. 1994;76:26–34. 5 Kristiansen TK, et al. Accelerated healing of distal radius fractures with the use of specific, low-intensity ultrasound. J Bone Joint Surg Am 1997;79:961–973. 6 Mayr E, et al. Beschleunigt niedrig intensiver, gepulster Ultraschall die Heilung von Skaphoidfrakturen? Handchir Mikrochir Plast Chir 2000;32:115–122. 7 Busse JW, et al. The effect of low-intensity pulsed ultrasound therapy on time to fracture healing: a meta-analysis. Can Med Assoc J. 2002;166:437–441. 8 Mayr E, et al. Ultrasound: an alternative healing method for nonunions? Arch Orthop Trauma Surg 2000;120:1-8. 9 Ebenbichler GR, et al. Ultrasound treatment for treating the carpal tunnel syndrome: randomised "sham" controlled trial. BMJ 1998;316:731–735. 10 Ebenbichler GR, et al. Ultrasound therapy for calcific tendinitis of the shoulder. N Engl J Med 1999;340:1533-1538. 11 Robertson V and Baker KG. A review of therapeutic ultrasound: effectiveness studies. Phys Ther 2001;81:1339-1350. 12 Warden SJ, et al. Ultrasound produced by a conventional therapeutic ultrasound unit accelerates fracture repair. Phys Ther. 2006;86:1118-1127. 13 Li J, et al. Low-intensity pulsed ultrasound and nonsteroidal anti-inflammatory drugs have opposing effects during stress fracture repair. J Orthop Res. (in press). 14 Warden SJ, et al. Low-intensity pulsed ultrasound accelerates and a nonsteroidal anti- inflammatory drug delays knee ligament healing. Am J Sports Med. 2006;34:1094-1102.
Ultrasound: suggestions for moving forward 11 September 2007
Val J Robertson, Professor University of Newcastle, NSW, Australia Send rapid response to journal: Re: Ultrasound: suggestions for moving forward Val.Robertson{at}newcastle.edu.au Val J Robertson	The equivocal nature of evidence supporting how most PTs use US is longstanding. Amusat's response provides no reasons why we should keep on re-weighing the evidence [1]. Systematic reviews have already done this for at least a decade, so the time for this approach is surely past. We are an evidence-based profession. Therefore, we modify practice in response to a sufficiently convincing body of evidence. The evidence on how we use ultrasound has not been supportive of many practices for too long already. In his response, Childs provides possible reasons why---despite the evidence---ultrasound continues to be used so often [2]. What we know: the ultrasound dosages most therapists apply are ineffective for most uses examined to date. Existing evidence supports some uses under limited conditions [3-5], but I am unaware of published replications of these interventions. Heat and electrical stimulation offer more effective interventions that can address many patient needs. Also, rethink ultrasound: ‘Ultrasound offers many clinical users considerable potential’ [6]. This is not a contradiction. There is a growing body of evidence regarding longer duration applications of low- intensity pulsed ultrasound (LIPUS). This is where we should put our efforts now, continuing the work of researchers such as Warden et al [7] and establishing the contributions LIPUS may offer our patients. Consider also the growing use that physical therapists make of diagnostic ultrasound [8-12]. These, rather than the traditional uses made of ultrasound, are the future. References 1 Amusat N. Uncertainty of evidence and change in practice. Rapid Response. Phys Ther. 2007. 87(9). E-pub. 2 Childs J. We are still not listening. Rapid Response. Phys Ther. 2007;87(9). E-pub. 3 Ebenbichler G, et al. Ultrasound treatment for treating the carpal tunnel syndrome: randomised "sham" controlled trial. BMJ. 1998. 316(7March):731-735. 4 Ebenbichler G. Author's reply. BMJ. 1998;317(7158):601. 5 Ebenbichler G, et al., Ultrasound therapy for calcific tendinitis of the shoulder. New Engl J Med. 1999;340(20):1533-1538. 6 Robertson V. Ultrasound use in orthopedic physical therapy. Invited commentary. Physical Therapy, 2007. 87(8): p. 995-999. 7 Warden S, et al. Ultrasound produced by a conventional therapeutic ultrasound unit accelerates fracture repair. Phys Ther. 2006;86(8):1118-1127. 8 Bo K, Sherburn M. Evaluation of female pelvic-floor muscle function and strength. Phys Ther. 2005;85(3):269-282. 9 Chipchase L, Williams M, Robertson V. A survey of electrophysical agents' curricula in entry-level physiotherapy programs in Australia and New Zealand. New Zealand Journal of Physiotherapy. 2005;33(2):34-47. 10 Henry SM, Westervelt KC. The use of real-time ultrasound feedback in teaching abdominal hollowing exercises to healthy subjects. J Orthop Sports Phys Ther. 2005;35(6):338-345. 11 Hodges PW. Ultrasound imaging in rehabilitation: just a fad? J Orthop Sports Phys Ther. 2005;35(6):333-337. 12 Whittaker JL, et al. Rehabilitative ultrasound imaging of pelvic floor muscle function. J Orthop Sports Phys Ther. 2007;37(8):489-498.
Uncertainty of evidence and change in practice 5 September 2007
Nurudeen T Amusat, Physical Therapist Two Hills Health Centre, Two Hills, Alberta. Canada Send rapid response to journal: Re: Uncertainty of evidence and change in practice sepet69{at}hotmail.com Nurudeen T Amusat	There seemed to be a disagreement between Wong and associates(2) and the invited commentator on the status of ultrasound effectiveness. Although Robertson(1) in her commentary might have referred to ultrasound therapy as being ineffective, the evidence provided by Wong et al that 11 of 15 reviews could not conclude on the effectiveness of ultrasound therapy showed that there might still be some uncertainty.(1,2) Based on the definition of an Established Effective Treatment (EET), ultrasound therapy is certainly not an EET.(3) However, going by the fact that most systematic reviews could not draw a definite conclusion on the effectiveness of ultrasound therapy and there is evidence of emerging potential for clinical use of ultrasound in physical therapy,(1) I would think that there is a state of “equipoise” on this issue.(4) Equipoise is the situation where honest ambivalence, uncertainty, or indifference exists. Until the uncertainty is disturbed somehow and conclusive evidence is provided, there will continue to be a disconnection between the clinical and the scientific (research) physical therapy communities on the issue of ultrasound therapy. What if clinicians using ultrasound have anecdotal evidence that patients are benefiting? The fact that some randomized trials do not have adequate sample sizes and hence [do not have adequate] power has been pointed out. Altman and Bland(5) contended that to describe the intervention being investigated as “ineffective” may be wrong. Similar danger of misinterpretation was shown to exist in meta-analyses of published trials too.(5) The inconclusive reviews certainly raised methodological concern as one of the issues in ultrasound studies.(6,7) On the issue of how long ultrasound should be applied, are we also out to lunch on this too? The animal studies discussed by Robertson used way more time on small animals than we used on humans. Overall, we have so many questions in need of answers, which certainly might have contributed to the difficulty in the integration of current evidence to practice. Absence of “proof of effectiveness” may not be proof of “absence of effectiveness.”(5) References 1. Robertson VJ. Invited commentary. [RE: A survey of therapeutic ultrasound use by physical therapists who are orthopaedic certified specialists.] Phys Ther. 2007;87:995-999. 2. Wong RA, Schumann B, Townsend R, Phelps CA. A survey of therapeutic ultrasound use by physical therapists who are orthopaedic certified specialists. Phys Ther. 2007;87:986-994. 3. National Placebo Initiative. Final report of the National Placebo Working Committee. 2004. Available at http://www.cihr- irsc.gc.ca.login.ezproxy.library.ualberta.ca/e/25139.html. Accessed on August 31, 2007. 4. Freedman B. Equipoise and the ethics of clinical research. New Engl J Med. 1987;317:141-145. 5. Altman DG, Bland JM. Absence of evidence is not evidence of absence. BMJ. 1995;311:485. 6. Brosseau L, Casimiro L, Robinson V, et al. Therapeutic ultrasound for treating patellofemoral pain syndrome. Cochrane Database Syst Rev. 2001;(4):CD003375. 7. Welch V, Brosseau L, Peterson J, et al. Therapeutic ultrasound for osteoarthritis of the knee. Cochrane Database Syst Rev. 2001;(3):CD003132.
We Are Still Not Listening 7 August 2007
John D Childs, Physical Therapist US Army-Baylor Send rapid response to journal: Re: We Are Still Not Listening john{at}evidenceinmotion.com John D Childs	Wong and colleagues make the case that clinical expertise is useful for guiding decision-making in the absence of higher levels of evidence. Although this is certainly true, it doesn't readily apply in the case of therapeutic ultrasound as traditionally used by physical therapists. Repeated studies (including Cochrane reviews on using ultrasound for virtually every musculoskeletal condition managed by physical therapists) have failed to find a benefit for therapeutic ultrasound. These papers have not offered a glimmer of a hope that even a small subgroup may exist for whom therapeutic ultrasound is beneficial. The fact that physical therapists still widely use therapeutic ultrasound for patients with musculoskeletal conditions is much more likely attributable to the 15- to 20-year "evidence gap" that exists in health care and that third-party payers continue to reimburse for mostly worthless interventions such as therapeutic ultrasound. In our fee-for-service health care system that rewards doing procedures absent of any regard for whether the patient benefitted, I am not an optimist that much will change. Surveys like this remind me that we are still not listening (http://www.ptjournal.org/cgi/reprint/78/7/705.pdf).