By Melissa Quick, DO, and David Kiefer, MD
Dr. Quick is PGY-2 Family Medicine Resident, Beth Israel Medical Center, New York, NY
Dr. Quick reports no financial relationships relevant to this field of study.
SYNOPSIS: Osteopathic manual treatment (OMT) resulted in statistically and clinically significant improvement in adults with chronic low back pain (CLBP) compared to those receiving sham OMT. Ultrasound therapy (UST) had no effect on CLBP. There was no interaction between OMT and UST.
SOURCE: Licciardone JC, et al. Osteopathic manual treatment and ultrasound therapy for chronic low back pain: A randomized controlled trial. Ann Fam Med 2013;11:122-129.
Researchers in Texas performed a study to explore the efficacy of osteopathic manual
treatment (OMT) and ultrasound therapy (UST) on 455 non-pregnant adults suffering from chronic low back pain (CLBP). This study, known as "The OSTEOPAThic Health outcomes In Chronic low back pain (OSTEOPATHIC) Trial," involved a randomized, double-blind, sham-controlled, 2 × 2 factorial format designed to independently assess OMT and UST for chronic back pain.
Candidates were excluded if they had "red flag conditions" (cancer, spinal osteomyelitis, spinal fracture, herniated disc, ankylosing spondylitis, or cauda equine syndrome); low back surgery in the past year; workers’ compensation benefits in the preceding 3 months; ongoing litigation involving back problems; angina or congestive heart failure; bleeding or infection in the lower back; use of corticosteroids in the past month; or used any sort of manual treatment (OMT or otherwise) or UST in the past 3 months or more than three times in the past year.
Once enrolled in the study, patients were randomized into four groups: OMT + UST; OMT + sham UST; sham OMT + UST; or sham OMT + sham UST. (See Figure 1.) Patients were then assigned secondarily via stratified randomization to a type of physician (faculty physician, pre-doctoral fellow, or resident). Fifteen different physicians provided six treatment sessions (at week 0, 1, 2, 4, 6, and 8) over the course of the study and the same treatment physician was maintained peer patient during recurrent sessions when possible, for continuity. The same physician performed both OMT and UST interventions during a treatment session.
|Osteopathic Manual Treatment (OMT)|
After a standard diagnostic evaluation at the beginning of each treatment session, patients then received two treatments: OMT or sham OMT (delivered for 15 minutes) followed by either UST or sham UST (delivered for 10 minutes). For the OMT group, the physicians implemented common OMT techniques (high-velocity, low amplitude thrusts; moderate-velocity, moderate amplitude thrusts; soft tissue stretching, kneading, and pressure; myofascial stretching and release; positional treatment of myofascial tender points; and isometric muscle contractions) focusing on the lumbosacral, iliac, and pubic regions. Sham OMT was also targeted to these same regions and involved hand contact, active and passive range of motion, and techniques that simulated OMT but used lighter touch, improper patient positioning, misdirected movements, and diminished physician force.
The UST intervention was performed after the OMT intervention, primarily to avoid any complications that the ultrasonic conductivity gel may have caused — presumably decreased skin friction or improper evaluation of chronic skin and muscle changes secondary to gel residue. The UST used a Sonicator 730 with a 10 cm2 applicator at an intensity of 1.2 W/cm2 and frequency of 1 MHz in continuous mode. For reference, most ultrasound machines are set between 1-3 MHz with 1 MHz sound waves absorbed at a depth of 3-5 cm and 3 MHz used more commonly for more superficial lesions at depths 1-2 cm.1 Conductivity gel was applied to enhance absorption and to produce deep muscle thermal effects. A surface area of 150-200 cm2 of the lower back was treated at each session. Sham UST was provided with a similar technique except with a sub-therapeutic intensity of 0.1
The primary outcome of the OSTEOPATHIC study was to assess the effect of the above interventions on reducing chronic back pain. A 100 mm visual analog scale assessed the "current" level of low back pain before each treatment session and, additionally, at week 12, 4 weeks after the last treatment. Back pain was rated "moderately" improved (30% or greater pain reduction) and "substantially" improved (50% or greater pain reduction) based on the 2008 Initiative on the Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) consensus statement recommendations.2
Overall, the results showed significant reductions in pain scores on the visual analog scale over time with OMT compared with sham OMT (P = 0.002), despite no significance with UST compared with sham UST (P = 0.99). Significant and clinically relevant improvements in CLBP were discovered at week 12: 145 (63%) OMT patients vs 103 (46%) sham OMT patients reported moderate improvements (relative risk [RR] = 1.38; 95% confidence interval [CI], 1.16-1.64; P < 0.001) and 114 (50%) OMT patients vs 79 (35%) sham OMT patients reported substantial improvement (RR = 1.41; 95% CI, 1.13-1.76; P = 0.002). These OMT treatment effects were clinically relevant because they met or exceeded the Cochrane Back Review group criterion.
Secondary outcomes focused on patient experiences with disability (Roland-Morris Disability Questionnaire = RMDQ); general health (Medical Outcomes Study Short Form-36 Health Survey = SF-36 GH); number of lost work days (over the past 4 weeks, secondary to low back pain); and general satisfaction with their back care (5-point Likert scale). Neither OMT nor UST affected RMDQ or SF-36 GH scores. Overall, OMT patients reported being "very satisfied" with their back care at all endpoints compared to sham OMT patients (P < 0.01). Additionally, prescription drugs were used by fewer OMT patients (13%) than by sham OMT patients (20%).
Chronic non-specific low back pain (CNSLBP) is a common, complex, and costly condition. CNSLBP is defined as pain that occurs between the bottom of the rib cage and the buttock crease3 that lasts for more than 3 months4 (though this time frame is not set in stone — some argue LBP to be chronic if the pain "lasts beyond the time of expected healing")5,6 and can lead to progressive physical and psychological effects. Currently in the United States, low back pain is responsible for more than 20 million ambulatory medical care visits and more than $100 billion in costs annually — one-third of which are indirect, stemming from lost wages and reduced productivity.7 Previous research by Licciardone highlights the concept of shared physician care for CLBP as family (general) medicine, internal medicine, neurology, and orthopedic surgeons often overlap in their services for this population.8
Despite the myriad of options that exist for the treatment of low back pain — increased activity, medications, surgery, etc. — the potential for non-pharmacologic and non-invasive interventions (such as OMT and UST) to relieve symptoms is a promising yet hotly debated field. Treatment for chronic back pain management is further complicated by the limited — and conflicting — guidelines that currently exist. Most guidelines tend to focus on brief educational interventions (specifically including supervised exercise therapy), cognitive behavioral therapy, and short-term use of nonsteroidal anti-inflammatory drugs or weak narcotic analgesics for pain relief.9,10
In 2007, the American College of Physicians and the American Pain Society listed spinal manipulation as a valid therapy (albeit a "weak recommendation with moderate-quality evidence") for chronic or sub-acute low back pain.10 Additionally, the most recent European guidelines on CLBP agree that, "a short course of spinal manipulation/mobilization as a treatment option for CLBP [should be considered]."9 The Agency for Healthcare Research and Quality performed a meta-analysis of studies on OMT and back pain and provided the following statement guideline in 2009: "[the meta-analysis] clearly demonstrate[s] a statistically significant reduction in low back pain with osteopathic manipulative treatment."11 An updated Cochrane Collaboration review in 2011, however, found that spinal manipulation is not more effective than sham interventions for short-term pain relief or functional status.12 The above limited discussion represents a mere fraction of the debate on CLBP. The OSTEOPATHIC trial is in part a response to the limitations above and critiques of previous studies evaluating the efficacy of OMT on CLBP.
Spinal manipulation — specifically OMT performed by trained osteopathic physicians — remains a controversial intervention for low back pain.13 Osteopathic medicine as a whole is a medical system consisting of a holistic, integrative, whole-body approach. Due to this holistic diagnostic model, the broad range of manual techniques that exist, and the varying degrees and comfort level that practicing osteopathic physicians have to perform such techniques, it would seem difficult to characterize OMT as a single intervention. Additionally, many osteopathic physicians do not practice OMT due to a number of obstacles, ranging from limited office visit time, to decreased confidence and skill level over time, and inadequate office space and equipment.11 Another barrier that has been cited by osteopathic physicians has been poor reimbursement for OMT for CLBP.
The author developed this study in response to a lack of evidence in assessing UST for chronic low back pain and the fact that no previous studies have evaluated the combination of OMT and UST together.14 UST for low back pain is a less established modality. The scientific basis for UST is that ultrasound may induce thermal and non-thermal physical effects in soft tissue such as increased blood flow, reduction in muscles spasm, and a pro-inflammatory response.1,15 Previous research suggested, however, that there was no efficacy or effectiveness of UST for CLBP, and one guideline specifically recommends against using this modality.15,16
Additionally, these researchers sought to create a study with a larger sample size and a lower risk of bias than previous analyses. Indeed, the OSTEOPATHIC trial is an impressive example of a quality study with a low risk of bias.17 However, there are several aspects of this study that, if rectified, could increase the validity of the study’s findings. There was randomization, allocation concealment, and blinding in his study, all of which coincide with a low risk of bias. Despite these techniques, there is no final assessment of the success of blinding. If, for example, the question had been asked if participants believed they were receiving the "real" intervention vs the "sham" intervention, these additional data would arguably provide more clarity and greater validity to the study’s findings. The placebo effect — or worse, the leakage of information from the treatment provider — surely could influence the outcome of the study.
Another discrepancy in this study is the lack of reporting specific OMT techniques used during the treatment sessions. There was an attempt to maintain the same treating physician per participant throughout the study (which demonstrates the attempt for homogeneity among treatment subjects), yet documentation is lacking on exactly which osteopathic techniques were utilized. As discussed above, OMT cannot be simplified as "one single therapeutic intervention." Therapeutic interventions vary in intensity, duration, and of course operator-dependent variability. Soft tissue stretching, which can be considered less aggressive, for example, arguably would have a much different effect than a physician who tended to only provide high-velocity, low amplitude thrusts. As an osteopathic physician myself, I can attest to the variability of OMT between practitioners. This study does not account for individual differences that surely exist between the different levels of providers — resident, fellow, and attending — nor does the study discuss which specific techniques each physician used. A table that documented exactly which techniques were used and how often surely would provide added transparency to the general concept of OMT.
Unfortunately, it seems the appropriate treatment for CNSLBP is as uncertain as the pathology itself. The National Institute for Health and Clinical Evidence makes perhaps the most self-evident yet valid statement with regard to treatment strategies for CLBP: "Take into account the person’s expectations and preferences when considering recommended treatments, but do not use their expectations and preferences to predict their response to treatments."3 Using multiple therapies that complement each other — such as physical therapy, increased activity, and spinal manipulation — in addition to imaging and pharmacological interventions when necessary, may be the best approach to treating CLBP. Overall, OMT can be recommended as a safe, non-invasive, palatable treatment option for patients suffering from CLBP and can reduce the need for pharmacologic adjunctive therapy that may cause adverse effects. n