Chiropractic for Low Back Pain
By Felise Milan, MD. Dr. Milan is Associate Professor of Clinical Medicine at the Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY; she reports no consultant, stockholder, speaker's bureau, research, or other financial relationships with companies having ties to this field of study.
The lifetime prevalence of low back pain in industrialized nations is 70%1 and more than one-third of those afflicted with low back pain seek care from a health care provider.2 Low back pain is the second most common reason for office visits to primary care providers and the most common reason for visits to orthopedists, neurosurgeons, and occupational medicine physicians.3 This results in 17.4 million visits to physicians per year with an estimated cost of $190 million per year.4
Chiropractic: Background Information
Spinal manipulation as a technique for treating musculoskeletal pain has been documented as far back as ancient China and Greece. The profession of chiropractic was developed in 1895 by Daniel David Palmer, a grocer and magnetic healer in Davenport, Iowa. Chiropractic (Greek for "done by hand") was founded on the principle that joint dysfunction and misalignment of the spine may play a significant role in heath and disease. Spinal manipulation therapy (SMT), therefore, can correct these problems and facilitate the return of health and equilibrium. Early in its history, the profession experienced a philosophical split between two factions. The "straight" chiropractors insisted on remaining true to the original theories proposed by Palmer, while the "mixers" felt that it was more realistic to incorporate other theories of health and disease, such as infection, which were being adopted by the scientific community of the time. This lack of uniformity within the field continues today.5
There are 17 accredited colleges of chiropractic in the United States with a total of 2,000 graduates per year. Two years of college is required for admission and the five-year curriculum requires 4,000 hours of basic science instruction and 1,000 hours of clinical internship for graduation. The National Board of Chiropractic Examiners administers a three-part licensing exam. Most states also require a practical exam for state licensure6 and all 50 require licensure, but individual states vary with regard to their permitted scope of practice. All states allow a spine-focused history and physical exam, X-rays, and spinal manipulation, and 90% also permit a more general history and physical, health advice, and ordering tests (ranging from blood work to CT scans). It is advisable for any physician to find out from his/her own state's licensing body what his/her state allows.
Chiropractic: Efficacy Data for Low Back Pain
The literature for chiropractic undoubtedly has been the most scrutinized of all the complementary and alternative medicine fields. Chiropractic research has faced the same challenge as other therapies that involve strong doctor-patient interactions and hands-on and individualized therapy with criticism of its methodology. An expert panel assembled for the RAND Corporation critically reviewed the literature on the efficacy of spinal manipulation for acute and chronic low back pain, neck pain, and headache. Although several of the studies had poor research design, the consensus of the panel was that for acute, uncomplicated low back pain, spinal manipulation hastens recovery and decreases work-time lost. Its long-term effect either in preventing chronic low back pain or preventing recurrence of acute low back pain is unknown at present.7
Two more recent reviews concluded that there was limited evidence to suggest that spinal manipulation is better than placebo, physical therapy, and exercise in the treatment of acute low back pain.8,9 These same authors, however, felt that there was strong evidence of efficacy in the treatment of chronic low back pain.
The U.S. Agency for Health Care Policy and Research10 and its British equivalent, the Clinical Standards Advisory Group,11 both have suggested that spinal manipulation is better documented as an effective treatment for acute mechanical low back pain than any other treatment except nonsteroidal anti-inflammatory drugs (NSAIDs).
A meta-analysis of 39 randomized controlled trials (n = 5,486) compared SMT to sham therapy, therapies considered ineffective (traction, bed rest, corset, home care, topical gel, and diathermy), and therapies conventionally advocated (physical therapy, exercise, back school, care by general practitioners, and analgesics).12 The authors found that SMT was more effective than either sham or ineffective therapies in relieving short-term pain for both acute and chronic low back pain. For chronic low back pain, SMT was more effective for relieving long-term pain as well as improving short-term function. (See Tables 1 and 2.) SMT was equally as effective as all therapies conventionally advocated on all outcome measures.12
|Table 1. Spinal manipulative therapy for acute low back pain compared to sham, ineffective therapies|
|Table 2. Spinal manipulative therapy for chronic low back pain compared to sham, ineffective therapies|
A more recent systematic review used best evidence synthesis on 43 randomized controlled trials that met selection criteria.13 The authors concluded that there is limited to moderate evidence that SMT is better than physical therapy and home back exercise for chronic low back pain in both the long and short term.
A group in Oregon has done a much larger, prospective, non-randomized study following 2,870 patients with acute and chronic low back pain for four years. They compared patients followed by MDs and DCs for their back pain.14 A clinically and statistically significant improvement in pain (> 10 VAS points) and disability was seen in chiropractic patients with both acute and chronic low back pain in the short term (P < 0.001) and was sustained for up to 12 months. Chiropractic and medical costs were not significantly different when referrals and imaging costs were included.15
The same group in Oregon followed patients (n = 72) with chronic low back pain who were randomized to one, two, three, or four chiropractic visits a week for three weeks. They found a positive and clinically important effect on pain intensity and disability at four weeks with a greater number of chiropractic visits.16
An important multicenter randomized controlled trial with rigorous methodologythe U.K. BEAM (U.K. Back pain Exercise And Manipulation) trialadds important information on both the relative efficacy and cost effectiveness of SMT for low back pain. Patients with low back pain, recruited from general practices (GPs) across the U.K. (n = 1,334) were randomized to general practice, exercise, manipulation, and manipulation and exercise for 12 weeks.17 The participating GPs were trained in the U.K. national acute back pain guidelines and these patients received educational materials (The Back Book). The exercise program and spinal manipulation "package" were standardized protocols developed by multidisciplinary groups of experts for use in this study. Based on the Roland disability questionnaire and the modified Von Korff scale for pain and disability, the study found that spinal manipulation with or without exercise provided the greatest benefit at three and 12 months follow-up. Exercise and GP care was better than GP care alone. Spinal manipulation was the most cost-effective therapy.18
There has been some work recently to develop19 and validate20 a clinical prediction rule to identify which patients with low back pain are the most likely to benefit from spinal manipulation. Although having a clinical prediction rule potentially would be useful, it has only been studied in a military population with physical therapists administering a standardized manipulation therapy,20 making it difficult to generalize the results to the broader population receiving individualized SMT from various practitioners.
One of the more widespread concerns about chiropractic care is that spinal manipulation, especially cervical, is actually dangerous. In fact, the estimated risk of a major complication from cervical spine manipulation is 6.39 per 10 million manipulations and one per 100 million manipulations for lumbar spine manipulation.21 This compares quite favorably to other forms of therapy for some of the same conditions. The rate of serious complications for spinal surgeries is 15.6 per 1,000 surgeries and 3.2 per 1,000 subjects for NSAIDs.21 Although serious complications from manipulation of the lumbar spine are exceedingly rare, there has been much concern about case reports of vertebral artery stroke attributed to cervical spine manipulation. The incidence of this has been estimated to be anywhere from one in 0.5 million to one in 5.85 million cervical manipulations.22,23 The rarity of vertebral artery stroke makes this association very difficult to study.
A case-control study tried to determine whether SMT is an independent risk factor for vertebral artery dissection.24 Cases of TIA/stroke and cervical artery dissection in patients age 60 and younger were identified from the databases of two academic stroke centers with controls being patients with TIA or stroke from other causes. After a review of the hospital records and imaging data, two neurologists classified neurovascular events due to arterial dissections. Dissection of both carotid and vertebral arteries were included as cases even though carotid artery dissections have not previously been associated with SMT. Of 51 cervical artery dissections (25 vertebral and 26 carotid) found, seven patients reported visiting a chiropractor 30 days prior to the TIA or stroke. In multivariate analysis, vertebral artery dissection was independently associated with visit to a chiropractor within 30 days (odds ratio 6.62, 95% confidence interval 14-30). However, the controls were older and sicker and less than one-third of the cases identified were enrolled in the study. Analyses are based only on patient reports of a visit to a chiropractor and there is no information on whether there was actually manipulation of the cervical spine during those visits. An editorial in the same journal recommended caution in interpreting the results due to concerns about selection and recall bias.25
Contraindications to manipulative therapy include severe rheumatoid arthritis with ligamentous laxity, bleeding disorders or anticoagulation therapy, and conditions that render the bony structures susceptible to additional trauma such as acute fractures, bone tumors, and severe osteoporosis. It is not unusual for patients to experience mild untoward effects from manipulation that turn out to be benign in nature, such as an increase in symptoms, myalgias, and fatigue. These effects usually are transient and need not prohibit further manipulation treatments provided that careful repeat assessment is done regularly to exclude worsening of the patient's condition.
As mentioned above, the field of chiropractic is not unified in the philosophies that it promotes. This manifests in varying practice styles and practices among different chiropractors. Before making a chiropractic referral, it is useful to find out what you and your patient can expect from the practitioner. (See Table 3.) Some chiropractors limit their practice to spinal manipulation, and others may use any variety of other therapeutic interventions including exercise, dietary changes, and dietary and nutritional supplements. Some promote the idea of routine spinal manipulation on an ongoing basis (maintenance therapy), while others believe it inappropriate and focus on successfully treating the presenting problem. Some tout the use of chiropractic for any and all physical problems, but others use it almost exclusively for musculoskeletal problems.
Spinal manipulative therapy is safe and as effective as any of the more conventional therapies that routinely are recommended for the treatment of uncomplicated low back pain. Patient satisfaction with chiropractic for the treatment of low back pain is consistently higher than for patients who visit physicians. This may be explained by the reported relative inadequacy of explanation that physicians often provide with respect to diagnosis and cause/effect, the relative paucity of self-care advice provided compared to chiropractors, as well as the fact that chiropractors regularly touch their patients in an appropriate manner. It also may be due, in many patients, to an actual improvement in their pain and function. In the future, it may be clearer which patients are likely to benefit from chiropractic. As fears of additional adverse effects from analgesics (NSAIDs and COX-2 inhibitors) commonly used for uncomplicated low back pain increase, chiropractic can be considered an attractive alternative for select patients with this very common complaint.
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