Low back pain (LBP) is extremely

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1 An Evidence-Based Approach to Low Back Pain in Primary Care Thomas M. DeFer, MD ABSTRACT Low back pain (LBP) is a prevalent condition resulting in many office visits and billions of dollars of medical and social costs per year. While there are multiple potential serious causes, a specific diagnosis cannot be made in up to 85% of patients. Approximately 1% of patients have LBP caused by a serious nonmechanical spinal condition, and about 2% have LBP referred from visceral disease. A directed history and physical examination focusing on the red flags of LBP identified by the Agency for Healthcare Research and Quality are still very relevant. Psychosocial factors including job dissatisfaction, insufficient social support in the workplace, and psychologic distress are very influential in the development and persistence of LBP. The yellow flags of LBP can identify those at risk for chronicity and disability. This review presents the evidence for established evaluation strategies and treatments for acute and chronic LBP, as well as new information on the impact of cognitive behavioral therapy in the management of LBP. (Adv Stud Med. 2004;4(3): ) MUSCULOSKELETAL MEDICINE Low back pain (LBP) is extremely common, with a lifetime incidence estimated to be greater than 70%. 1 The point prevalence is approximately 7.5%, and about 15% of adults report having had back pain in the previous 2 weeks. 2 As many as 40% of people experience LBP each year; the highest prevalence rates are in people 45 to 64 years of age. 1,2 LBP is the fifth most common reason for physician visits, ranking just below upper respiratory infections, and is the most common cause of disability for persons under 45 years of age. 3 About 2% of workers submit claims for LBP-related disability each year. 1 The medical and social costs of LBP are enormous, ranging from $38 billion to more than $50 billion. 4 Most of these costs are related to those very few patients with temporary or permanent disability. 4,5 LBP has been likened to a 20th century healthcare disaster. 6 To date, there has been no perceivable change in the pathology or prevalence of LBP. There have been many advances in our knowledge; yet, resounding treatment successes are elusive and disability rates rise exponentially. Clearly, an evidence-based, patient-centered approach to the diagnosis and management of LBP in primary care is warranted. ETIOLOGY MECHANICAL CAUSES Approximately 97% of acute LBP is mechanical in origin, including musculoligamentous strain, spondylosis, disc herniation with or without sciatica, and spinal stenosis. Only about 1% of patients have LBP caused by serious nonmechanical spinal conditions, and 2% have back pain referred from visceral disease (Table 1). 7-9 In up to 85% of patients with LBP, a specific diagnosis cannot be made. 7,9,10 Their condition is often referred to as nonspecific or Dr DeFer is Director, Internal Medicine Clerkship; Director, Ambulatory Care Experience for Students; Assistant Professor of Medicine, Division of Medical Education, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri. Dr DeFer reports he receives honoraria for a Pfizer Inc. speakers bureau. Off-Label Product Discussion: The author does not include information on off-label use of specific products. Correspondence to: Thomas M. DeFer, MD, Campus Box 8121, 660 S Euclid Avenue, St. Louis, MO Advanced Studies in Medicine 135

2 MUSCULOSKELETAL MEDICINE idiopathic mechanical back pain. In most cases it is presumed to be attributable to some form of musculoligamentous strain or sprain. Such an imprecise diagnostic term is certainly less than satisfying. Specific and directly causative pathologic abnormalities, however, are not demonstrable in most patients. 10 Spondylosis is the generalized degenerative changes of the spine, including disc degeneration with disc-space narrowing and osteoarthritic changes of the facet joints. These changes are generally thought to be age related. Spondylosis is just as common in asymptomatic individuals as in symptomatic ones. 11 Nonetheless, in some patients, approximately 10%, spondylosis may be the primary cause of LBP. 7 Patients with LBP and Table 1. Causes of Acute and Chronic Low Back Pain* Condition Approximate Frequency Mechanical or Activity Related 97% Myofascial or soft-tissue injury, strain, or sprain; more appropriately termed nonspecific/idiopathic mechanical low back pain 70% Spondylosis: degenerative changes of the vertebrae, facet joints, and discs, usually age related 10% Disc herniation 4% Osteoporotic vertebral fracture 4% Spinal stenosis 3% Spondylolisthesis 2% Traumatic vertebral fracture <1% Congenital structural disease <1% Spondylolysis Discogenic (internal disc disruption) low back pain Facet joint syndrome Presumed spinal instability Nonmechanical Spinal Conditions 1% Primary or metastatic neoplasm 0.7% Bone, disc, or epidural infection 0.01% Spondyloarthropathies 0.3% Myofascial pain syndrome/fibromyalgia Metabolic bone diseases Referred Pain from Visceral Disease 2% Gastrointestinal Ulcer disease, pancreatitis, cholecystitis Genitourinary Pyelonephritis, nephrolithiasis, prostatitis Pelvic inflammatory disease, ectopic pregnancy, endometriosis Abdominal aortic aneurysm Hip problems Adapted from Deyo RA, Weinstein JN. Low back pain. N Engl J Med. 2001;344: *Percentages represent the approximate frequencies of these conditions in all patients with low back pain seen in primary care practice. Often associated with neurogenic leg pain. Data not provided in original source. spondylosis generally have the same prognosis as those with LBP without spondylosis. Lumbar disc herniation is common, and the peak incidence occurs between ages 30 to 55 years. Approximately 95% of disc herniations occur at the L4-L5 and L5-S1 levels. 8,9 Disc herniation may result in LBP, sciatica, or both. However, disc herniations may also be totally asymptomatic. 12,13 Rarely, large midline disc herniations may cause the cauda equina syndrome. Spinal stenosis is usually caused by hypertrophy of the ligamentum flavum and facet joints, resulting in narrowing of the spinal canal, often at multiple levels. This narrowing may result in entrapment of nerve roots as they traverse the spinal canal. So-called discogenic back pain is said to originate from internal disc disruption and is characterized by a provocative discography that reproduces the patient s typical back pain. [See Other Imaging Studies on page 139 for an explanation of discography.] Such patients are distinct from those with the syndrome of sciatica caused by disc herniation. 14,15 In a similar manner, the facet joint syndrome may be a specific source of LBP in a few patients. The syndrome is diagnosed clinically in patients with lumbar pain that improves following the injection of corticosteroid or local anesthetic into or near the facet joints. NONMECHANICAL CAUSES There are many serious causes of LBP, but overall they are very uncommon. The most common nonmechanical causes are primary or metastatic malignancy and infection. Osteoporotic compression fractures should always be considered in older patients with LBP. The spondyloarthropathies may affect the spine; however, affected individuals will usually have other signs and symptoms attributable to these diseases. Abdominal aortic aneurysms should be considered in older patients with a history of or risk factors for coronary artery disease. Referred pain may present as LBP, including pain caused by hip problems and gastrointestinal, genitourinary, or gynecologic disorders. EVALUATION STRATEGY The first step in the management of acute LBP is to classify the pain to 1 of 3 diagnostic categories: (1) LBP possibly secondary to a serious underlying condition, (2) LBP with sciatica, or (3) nonspecific mechanical LBP. 16 The primary diagnostic tool is a careful but focused history and physical examination during which the primary care physician searches for findings that suggest a serious underlying condition or a neuro- 136 Vol. 4, No. 3 March 2004

3 LOW BACK PAIN logic urgency. In the absence of such findings, diagnostic tests are rarely indicated during the first 4 to 6 weeks of pain. 7-10,16-18 The concept of the red flags of back pain, first promoted in 1994 by the Agency for Healthcare Research and Quality, is still very relevant. As is most often the case, when no red flags are found, further diagnostic testing is unwarranted and conservative therapy is appropriate. HISTORY Other than painful decreased range of motion, most patients with acute LBP have no specific clinical signs or symptoms. Approximately 2% of individuals present predominantly with sciatica. 7 Sciatica typically increases with coughing, sneezing, sitting, or doing the Valsalva maneuver. The sensitivity of the symptom of sciatica, defined as pain radiating into the buttocks and down the leg below the knee, is sufficiently high (0.95) that its absence makes a clinically significant disc herniation unlikely. 16,17 Fewer than 1% of patients will present with the cauda equina syndrome, and those who do usually present with LBP, bladder retention, saddle anesthesia, bilateral lower extremity pain, and neurologic deficits. 7 A large midline disc herniation is the most common cause, but malignancy or infection are other possible causes. These patients require emergency neurosurgical evaluation and imaging. Individuals with symptomatic spinal stenosis often present with pseudoclaudication (or neurogenic claudication), which is characterized by LBP along with lower-extremity pain and numbness that worsen with walking, standing, and extension of the spine. True vascular claudication is generally not provoked by standing without walking. When associated with radiculopathy, focal sensory loss and weakness may occur. Flexion of the spine and sitting typically improve the symptoms. The discomfort of pseudoclaudication usually lasts longer after walking than with the discomfort of true vascular claudication. Though not very specific (0.60), a clear history of pseudoclaudication and age older than 50 years suggest spinal stenosis. 16,17 The very few patients with more serious or systemic causes of LBP may present with signs and symptoms associated with those diseases. An occupational history should be obtained from all patients. Multiple physical factors in the workplace have been associated with an increase in the occurrence of LBP. The most well established of these are manual materials handling (lifting, carrying, pulling, pushing), bending and twisting, and wholebody vibration Most investigators, however, did not control for possible confounding psychosocial factors. Low Back Pain: Red Flags General Pain duration >1 month Pain unresponsive to treatment for 1 month Pain unrelieved or worsened by rest Cancer Age >50 years History of cancer Unexplained weight loss Infection Chronic steroid use Intravenous drug use Urinary tract or other infection Fever Fracture Age >70 years Chronic steroid use Bladder dysfunction Significant trauma relative to age Cauda Equina Syndrome Saddle anesthesia Unilateral or bilateral major motor weakness Bowel or bladder dysfunction Reduced anal sphincter tone Rapidly progressive, severe radiculopathy Figure. A Cognitive Behavioral Model of Pain-Related Fear If pain, possibly from an injury, is interpreted as threatening (pain catastrophizing), pain-related fear evolves. This leads to muscular reactivity, hypervigilance, and avoidance behavior. Long-term avoidance subsequently may increase levels of disability, disuse, and depression. The latter will maintain the pain experiences, thereby exacerbating the increasing fear and avoidance. In noncatastrophizing patients, no pain-related fear is present and rapid confrontation with daily activities is likely to occur, leading to recovery. Reproduced from Pincus T, Vlaeyen JW, Kendall NA, Van Korff MR, Kalauokalani DA, Reis S. Cognitive-behavioral therapy and psychosocial factors in low back pain: directions for the future. Spine. 2002;27:E133-E Advanced Studies in Medicine 137

4 MUSCULOSKELETAL MEDICINE PSYCHOSOCIAL FACTORS A complete discussion of psychosocial factors and LBP is beyond the scope of this review; however, they have become an important area of research. Psychologic factors include attitudes (eg, catastrophizing), beliefs (eg, fear avoidance), and mood (eg, anxiety and depression) (Figure). 23 Social factors include the quality of relationships with family, friends, and coworkers (eg, social support). Low Back Pain: Yellow Flags Factors That Predict Poor Outcome Belief that back pain is harmful or potentially severely disabling Fear-avoidance behavior (avoiding a movement or activity due to misplaced anticipation of pain) and reduced activity levels Tendency to low mood and withdrawal from social interaction Expectation that passive treatments rather than active participation will help Suggested Interview Questions Have you taken time off work in the past with back pain? What do you understand is the cause of your back pain? What are you expecting will help you? How is your employer responding to your back pain? Your coworkers? Your family? What are you doing to cope with your back pain? Do you think that you will return to work? When? Investigators have reported that the psychosocial risk factors for new-onset LBP include hardly ever enjoying work, job dissatisfaction, psychologic distress, depression, low control over work, low-level employment, low social status, perceived inadequacy of income, lack of recognition and respect, frequent problems at work, limited decision-making authority, insufficient management and coworker support, and stressful and monotonous work A systematic review of prospective studies through 1997 concluded that there is strong evidence to support the effects of low job satisfaction and insufficient social support in the workplace on LBP. 38 When any of these factors influences the patient, disadvantageous behaviors may result, such as reduced activity level, excessive care seeking, and frequent disability claims. The question is not whether psychosocial factors have an important impact on the development and continuance of LBP but what can be done about them when they are identified. A clear answer relevant to primary care is still being formulated. Referral to other appropriate clinicians may be required if psychosocial factors appear to be playing a significant role. RISK FACTORS FOR CHRONIC LBP Being able to predict which patients are at risk for developing chronic disabling pain would have obvious potential advantages. Psychosocial factors appear to be particularly important in this regard. Many have been associated with the development of chronic LBP, including level of self-reported pain and disability, a personality disorder, job dissatisfaction, poor coping strategies, poor self-reported health, and lower educational attainment; other risk factors include low levels of physical activity, and widespread pain A systematic review of psychologic factors as predictors of chronicity and disability in prospective cohorts through 1999 indicated there is strong evidence that psychologic distress and depressed mood play a role in the development of chronic LBP. Moderate evidence was found to support the role of somatization. 48 The yellow flags of acute LBP were developed to assist physicians with identifying on first presentation patients at risk for chronicity. 49 These yellow flags most often represent less advantageous, albeit normal, reactions to pain as opposed to psychopathology. 50 Patients with persistent pain at 2 to 4 weeks can be more thoroughly screened with a specific 24-item questionnaire. 51,52 Hazard et al have also developed a questionnaire that may identify individuals at risk. 53 PHYSICAL EXAMINATION The back should be inspected for anatomic abnormalities, such as kyphosis and scoliosis. Although tests measuring reduced forward flexion of the spine are relatively reproducible, they are of limited diagnostic value. Tests for sacroiliac joint tenderness are poorly reproducible and inaccurate for distinguishing ankylosing spondylitis from nonspecific mechanical LBP. 16,17,54 A summary of the neurologic findings in sciatica is presented in Table 2. 16,17 In patients with a herniated disc causing sciatica, straight leg raising from the supine position stretches the affected nerve root and reproduces the patient s sciatic pain the straight leg raising sign. The test may be done with the patient lying supine or sitting. Hamstring extensibility may also be important. 55 A typical positive straight leg raising sign reproduces or worsens the patient s sciatica when the leg is elevated to between 30 and 60 degrees. The ipsilateral straight leg raise is only moderately sensitive (0.80) and is nonspecific (0.40). When the contralateral leg is raised and pain is elicited in the leg with sciatica, this is the crossed straight leg raising sign. The crossed straight leg raising sign is less sensitive (0.25) but quite specific (0.90). 16,17 Combining the 2 tests could lead to a more accurate diagnosis. 54 When neurologic symptoms other than sciatica are present, a complete neurologic examination 138 Vol. 4, No. 3 March 2004

5 LOW BACK PAIN is warranted. Patients with the cauda equina syndrome typically have saddle anesthesia (sensitivity, 0.75) and bilateral radicular findings (sensitivity, >0.80). Decreased anal sphincter tone is found in 60% to 80% of patients with this syndrome. 17 Often referred to as nonorganic signs, the presence of 3 or more behavioral responses to being examined suggests that the patient does not have a straightforward physical problem. 56 Psychosocial issues must be carefully explored in these patients, who have poorer treatment outcomes and more disability. Isolated behavioral signs should not be overinterpreted, and the presence of these signs does not negate organic findings or confirm malingering. They are not recommended as useful indicators in elderly patients. DIAGNOSTIC TESTING PLAIN RADIOGRAPHS Most plain films in individuals with nonspecific LBP ultimately are nondiagnostic. Such films are costly and expose patients to gonadal irradiation. In general, plain radiographs of the lumbar spine are overused. 11,16,57,58 Lumbar spine plain radiograph findings correlate poorly with the presence of LBP. Many patients without back pain have degenerative changes, whereas individuals with LBP may have completely normal films. Therefore, when degenerative changes are seen, it is very difficult to determine their actual significance. Plain films cannot detect nerve root impingement or spinal stenosis. When there are no red flags, plain radiographs of the lumbar spine are not recommended during the first month of acute LBP. 7,8,16,59 POTENTIAL INDICATIONS Significant changes in clinical findings in the acute phase (particularly severe or progressive neurologic symptoms or signs) may indicate the need for plain radiography. They are also potentially indicated for any patient with chronic LBP who develops clinical findings suggestive of tumor, infection, or fracture. When plain radiographs of the lumbar spine are nondiagnostic in patients with red flags, additional imaging studies such as computed tomography (CT) or magnetic resonance imaging (MRI) should be strongly considered. 16,60 CT AND MRI Degenerative changes are even more common in individuals undergoing CT and MRI than in those undergoing plain radiography. 12,13,16,61 CT or MRI is recommended when tumor, infection, fracture, or other space-occupying lesion is strongly suggested by the clinical findings. 8,16 In the absence of severe or progressive neurologic symptoms, it is generally not necessary to do a CT or MRI for patients with sciatica, as many patients with sciatica substantially improve in 4 to 6 weeks. If symptoms have not improved in that time and the patient is an appropriate potential surgical candidate, CT or MRI may be useful. 16 Urgent CT or MRI is recommended for patients with symptoms suggestive of the cauda equina syndrome or progressive major motor weakness. 16 OTHER IMAGING STUDIES Bone scans are rarely indicated. They have relatively poor spatial resolution and do not provide a specific diagnosis. They may have a high yield for spinal metastases in patients with a known history of cancer. However, when they are positive, other diagnostic tests are often required such as CT or MRI. Table 2. Neurologic Examination for Sciatica Test Knee reflex Ankle reflex Ankle dorsiflexion Great toe dorsiflexion Ankle plantar flexion Pinprick medial foot Pinprick dorsal foot Pinprick lateral foot Behavioral Response to Examination Superficial tenderness Nonanatomic tenderness Pain on axial loading of skull Pain on passive rotation of shoulders and pelvis Sitting and supine straight leg raising discrepancy Regional weakness Regional sensory change Overreaction to examination: tremor, sweating, collapse, exaggerated verbalizing; inappropriate sighing, guarding, bracing, and rubbing; insistence on standing or changing position; questionable use of walking aids or equipment Comment Upper lumbar disc herniation Disc herniation, usually L5-S1 Disc herniation, usually L4-L5 Disc herniation, either L4-L5 or L5-S1 Suggests S1 compression (only severe impairments are readily detectable) Suggests L4 compression Suggests L5 compression Suggests S1 compression Straight leg raise Positive if leg pain at <60 degrees (sensitivity, 0.80; specificity, 0.40) Crossed straight leg Positive if pain in contralateral leg (sensitivity, 0.25; raise specificity, 0.90) Advanced Studies in Medicine 139

6 MUSCULOSKELETAL MEDICINE Discography consists of injecting water-soluble contrast material into the nucleus pulposus. An abnormal contrast pattern along with reproduction of the patient s typical back pain and a nonpainful control disc injection constitute a positive test. 16 The interpretation of discography is difficult. If or how these patients should be treated differently is not known. 14,15,62 Discography is an invasive procedure with potential risks. There is no good evidence to recommend this test over CT or MRI. 16 ELECTROPHYSIOLOGIC TESTS Electrophysiologic tests are not a substitute for a thorough neurologic examination. Such testing is usually not indicated in individuals with obvious radiculopathy or in those with isolated LBP. They appear to be most useful in patients with leg pain when the cause is unclear. 9,63 TREATMENT In the absence of red flags, treatment for the vast majority of patients with acute nonspecific LBP can be simple and conservative (Table 3). Most patients improve in about a month with or without treatment. Patients with pain that has persisted without improvement for over 1 month should be re-evaluated. A large number of treatment alternatives are available. In the relatively recent past, multiple systematic reviews and metaanalyses have been published clarifying the efficacy of some of these treatments. EDUCATION Patients with LBP who do not receive sufficient information about their condition tend to be dissatisfied with their care. 9,16 The physician should discuss the rarity of serious or permanent damage and should explain why not being able to give a specific diagnosis is typical and not a cause for alarm. The very good prognosis overall for patients with acute LBP should be stressed but not oversold. The possibility of recurrences ought to be mentioned, along with the fact that very few people develop chronic disabling pain. In addition, the physician needs to explain that staying physically active and taking an active role in treatment is critically important and that pain with movement does not mean serious harm is occurring. Specific recommendations for activity level, work restrictions, and symptom management should be offered. 16,88 Many patients will request, or even insist on, X-rays just to be sure. The general lack of usefulness of these films should be explained. Physicians also should encourage patients to notify them if symptoms change significantly and should discuss the possibility of diagnostic testing if symptoms change or persist beyond 1 month. The Back Book pamphlet by Roland et al (available from has been shown to have a positive effect on patients beliefs and clinical outcomes. 64 This excellent resource focuses less on the biomedical aspects of LBP and more on positive coping strategies and patient activity. Table 3. Nonsurgical Treatments for Acute Nonspecific Low Back Pain Recommended Unclear Not Recommended Patient education 64 Continuation of usual activities 65,66 Moderate, low-stress aerobic activity Acetaminophen NSAIDs or selective COX-2 inhibitors 67 Muscle relaxants* 68,69 Local heat or ice 70 Cognitive-behavioral treatments 71,72 Back school 73,74 Narcotic analgesics* Lumbar corsets and back belts 75 Multidisciplinary biopsychosocial rehabilitation 76 Spinal manipulation Massage 79,80 Bed rest 65,66,81,82 Trunk strengthening exercises 77,83 Systemic steroids Antidepressants Transcutaneous electrical nerve stimulation Traction 84,85 Trigger point injections 86 Facet joint injections 86 Epidural steroids 86 Acupuncture 79,87 NSAIDs = nonsteroidal anti-inflammatory drugs. *Risk of known side effects must be carefully considered. High cost may not justify use in acute or subacute low back pain. Cannot be recommended for acute LBP but may be considered in selected patients with chronic LBP for whom conservative treatment has not been effective. 140 Vol. 4, No. 3 March 2004

7 LOW BACK PAIN BACK SCHOOL Traditional back schools consist of educational group sessions focusing on spinal anatomy and function, biomechanics and ergonomics, lifting techniques, posture, and activity suggestions. Home back and abdominal strengthening exercises may also be included. There is some evidence that back school is better than placebo for short-term relief of acute LBP; however, it does not appear to be more effective than other conservative treatments. There is moderate evidence that attending back school results in better short-term outcomes than other conservative treatments for chronic LBP, but these effects are not sustained in the long term. 73,74,88-90 BED REST Mounting evidence has demonstrated that bed rest may actually delay recovery and potentially contribute to the development of chronic back pain (Table 4). Patients with acute nonspecific LBP should be advised to continue ordinary activities as much as possible. 7-9,16,65,66,81,88,90 Patients with sciatica also should also be encouraged to go on with daily activities as tolerable. 82 ACTIVITY RESTRICTION Although patients with acute nonspecific LBP should be encouraged to continue usual daily activities, it is reasonable to advise temporarily limiting activities known to increase mechanical stress on the spine, including prolonged unsupported standing or sitting, heavy lifting, and bending or twisting the back while lifting. 7-9,17 However, this strategy may not shorten the duration of nonspecific LBP-related absence from work. 97 EXERCISE The available data suggest that specific exercise therapy is not more effective than other therapies for acute nonspecific LBP. 7-9,16,77,83,88,90 Low-stress aerobic exercises (eg, walking, biking, swimming) and conditioning exercises for the trunk muscles can be performed safely during the first month of symptoms and may decrease pain, reduce recurrences, and improve functional outcomes. 8,9,16 For chronic LBP there is good evidence that exercise therapy is effective. 83,89,90 It is unclear exactly which specific conditioning exercises for the trunk muscles should be recommended. All patients with chronic LBP should be seen by a physical therapist. Recommending lowstress aerobic exercise is important for all patients. In addition to many health benefits, this type of exercise encourages the patient s active role in the healing process. Intensity should gradually increase in a timecontingent, not pain-contingent, manner. MEDICATIONS ACETAMINOPHEN There are no studies that compare acetaminophen to placebo for the treatment of LBP. In appropriate doses it can be effective, safe, and inexpensive for mild-to-moderate pain. Acetaminophen is a reasonable first-line choice for the treatment of acute and chronic LBP. 8,9,16,88-90 NONSTEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS) There is strong evidence that NSAIDs are more effective than placebo in patients with acute nonspecific LBP. There is moderate evidence that NSAIDs are effective for chronic LBP. There are no convinc- Table 4. Nonsurgical Treatments for Chronic Low Back Pain Recommended Unclear Not Recommended Patient education Back school 73,74 Continuation of usual activities Moderate, low-stress aerobic activity Trunk strengthening exercises 83 Acetaminophen NSAIDs or selective COX-2 inhibitors Local heat or ice Cognitive-behavioral treatments 91,92 Multidisciplinary biopsychosocial rehabilitation, intensive with functional restoration 93 Muscle relaxants* Narcotic analgesics* Antidepressants* 94 Lumbar corsets and back belts 75 Trigger point injections 86 Facet joint injections 86 Epidural steroids 86 Spinal manipulation 78,79 Massage 79,80,95 Bed rest Systemic steroids Transcutaneous electrical nerve stimulation 96 Traction 84,85 Acupuncture 79,87,95 *Risk of known side effects must be carefully considered. NSAIDs = nonsteroidal anti-inflammatory drugs. Advanced Studies in Medicine 141

8 MUSCULOSKELETAL MEDICINE ing data to suggest that one NSAID is more effective than another. The known side effects should be considered. There is very limited and conflicting evidence as to whether NSAIDs are more effective than paracetamol (similar to acetaminophen). 7-9,16,67,88-90,98 For most patients, (nonselective or selective) NSAIDs will be the analgesic of choice. MUSCLE RELAXANTS Most muscle relaxants used for LBP are central nervous system depressants with minimal if any direct skeletal muscle relaxing properties. Their precise mechanism of action is not known but may be related to sedative effects. The concept of skeletalmuscle spasm as a cause of LBP is not universally accepted. There is moderate evidence that muscle relaxants are more effective than placebo for reducing the symptoms of acute nonspecific LBP and that different types of muscle relaxants are probably equally effective. 7,68,69,88,90 The potential for side effects must be carefully considered, particularly drowsiness, dry mouth, and dizziness. These medications may be particularly useful at night when side effects will be less troublesome or even desirable (eg, drowsiness). There is very little information available regarding the use of muscle relaxants in chronic LBP. Trials are needed to determine whether muscle relaxants are more effective than analgesics or NSAIDs. OPIOIDS The use of opioids for many forms of acute pain and chronic pain caused by terminal illnesses is well accepted. To the contrary, their use in LBP remains controversial. It is not completely clear that opioids are always more effective than nonopioids for controlling pain. Side effects can occur, such as drowsiness, dizziness, nausea, and constipation, but can be more serious. (For a review of using opioids to treat pain caused by nonmalignant disease, see Potter MB. Adv Stud Med. 2004;4:31-40.) Advocates argue that patients who have chronic nonterminal pain can achieve adequate analgesia and improved functioning with stable doses of opioids and a minimal risk of addiction. However, prescribing opioids for the patient with chronic pain may be challenging and time-consuming in the primary care setting. 99 A protocol for chronic opioid therapy was recently published by Ballantyne and Mao. 99 Prior to prescribing opioids for chronic LBP, the physician should be relatively certain that other nonopioid and medical treatments have been ineffective. If the potential benefits outweigh the risks, both should be clearly explained to the patient and treatment goals negotiated. A cross-sectional study of patients seeking care at specialty spine care centers showed that opioids were recommended, prescribed, or continued for 3.4% of patients. 100 More than 75% of opioidtreated patients had pain for longer than 3 months. There was no significant difference in therapeutic efficacy between the opioid and non-opioid groups, but the study did not control for duration or severity of pain or for opioid type or dose. Of note, more than 80% of the physicians involved were surgeons, physiatrists, and neurologists. 100 Primary care physicians may be more likely to prescribe narcotics. 101 There are no randomized controlled trials comparing an opioid analgesic to placebo for acute LBP and only a few small studies comparing opioid analgesics to other medications. In addition, there is no convincing evidence that narcotics are more effective than NSAIDs for promoting a return to full activity. However, opioid analgesics may be an effective time-limited option for patients with acute severe LBP or sciatica not relieved by other medications. 7-9,16,88,98 Patients should understand that only shortterm use is expected. ANTIDEPRESSANT MEDICATIONS The few small, randomized controlled trials evaluating the efficacy of antidepressant medications specifically for chronic LBP are of generally low-to-moderate methodologic quality, and several had high dropout rates. The types and doses of antidepressants studied varied and included selective serotonin reuptake inhibitors and heterocyclic and tricyclic antidepressants. Some of the studies included patients with depression while others excluded them. The research shows that antidepressants may have a small but beneficial effect on pain severity but not on functional status. As expected, patients treated with antidepressants had significantly more side effects. 94 While not Food and Drug Administration approved for this indication, they may be considered as possible adjunctive therapy to routine care, but only in patients for whom the potential benefits seem to outweigh the known adverse effects. 7-9,89 OTHER MODALITIES For symptomatic relief, patients may apply ice or heat locally for short periods of time several times a day (Tables 3 and 4). 16,70,88,89 There is insufficient evidence to recommend the use of transcutaneous electrical nerve stimulation (TENS), and traction appears to be ineffective. 7-9,16,84,85,88-90,96 The data suggest that lumbar supports are not more effective for reducing pain than other types of treatment. 75,88, Vol. 4, No. 3 March 2004

9 LOW BACK PAIN INJECTION THERAPY The theory of trigger points as a cause or perpetuator of LBP is not universally accepted and quality scientific data is severely limited. A systematic review concluded that there is insufficient evidence to prove the effectiveness of local injection therapy in subacute and chronic LBP; they may be considered in selected patients with chronic LBP who have failed more conservative treatment. 9,16,86,89 From the very limited data available, facet joint injections do not appear to be effective, but they have not conclusively been shown to be ineffective. 7-9,16,86 They may be considered in selected patients with chronic LBP who have failed more conservative treatment. 86 Epidural injections have been recommended for subacute or chronic LBP with or without sciatica. Results from multiple studies have been conflicting. A large systematic review of injection therapies found that no conclusion regarding the use of epidural steroids could be made, though an insignificant positive result was noted. 86 Epidural steroids may be an option for patients with subacute sciatica (ie, greater than 1 month) who have not responded to conservative therapy in an effort to avoid surgery. 7-9,86 They may also be considered in selected patients with chronic LBP who have failed other more conservative treatments. 86,89,90 COGNITIVE-BEHAVIORAL TREATMENTS Cognitive-behavioral treatments have been developed in response to the importance of psychosocial risk factors in chronic LBP and the limited efficacy of many medically based therapies. These treatments attempt to alter pain-related attitudes, beliefs, and feelings (cognitive therapy); behaviors (operant therapy); and physiologic reactivity (respondent therapy). Cognitive therapies seek to restructure cognition and modify maladaptive thoughts, feelings, and beliefs. Operant conditioning therapies (eg, increasing exercise quotas) positively reinforce healthy behaviors and are time-contingent rather than pain-contingent. Respondent therapies attempt to replace muscle tension with tension-incompatible techniques such as biofeedback and progressive relaxation. Often, combinations of these modalities are used. Two systematic reviews have reached essentially the same conclusion regarding cognitive-behavioral therapies. 91,92 There is good evidence that in patients with chronic LBP cognitive-behavioral treatments offer small-to-moderate positive benefits compared with no treatment or placebo. However, the addition of cognitive-behavioral modalities to a standard treatment program may not provide further benefit. No overall difference has been demonstrated among different types of behavioral treatment. 9,89-92 Subsequent to these systematic reviews, one small study in patients with acute sciatic pain showed that cognitive-behavioral therapy based on known risk factors resulted in fewer patients developing chronic pain than did biofeedback therapy and usual medical care. 71 In patients with LBP who had a self-perceived risk of developing chronic pain, another study demonstrated significantly less use of healthcare services, as well as a reduction in the risk of taking longterm sick leave. 72 A third study, involving Dutch airline workers on sick leave because of subacute LBP, investigated the use of usual care vs graded physical activity following operant-conditioning principles. 102 Patients with LBP in the graded activity group missed 58 days of work and those in the usual care group missed 87 days. The difference became statistically significant on the 50th day of the study and remained so through 6 months of follow-up (hazard ratio, 1.9; confidence interval, 1.2 to 3.2; P =.009). The intervention did not appear to affect pain levels. This is not surprising given that the goal was to increase activity based on time, not on the level of pain. These treatments are clearly promising and additional research is needed to clarify their role in the primary care setting. MULTIDISCIPLINARY BIOPSYCHOSOCIAL REHABILITATION Multidisciplinary rehabilitation addresses the physical, psychologic, and social-occupational aspects of LBP. The patient undergoes a thorough medical assessment, and appropriate pharmacologic treatment and/or exercise and physical therapy are prescribed. Patients are also evaluated for psychologic factors that may be affecting the pain; counseling and cognitive-behavioral treatments are provided. The patients social and occupational environments are considered as well and appropriate interventions initiated. There is strong evidence that intensive, daily multidisciplinary biopsychosocial rehabilitation (>100 hours of therapy) that incorporates the principles of functional restoration improves function in patients with chronic LBP. 89,93 There is moderate evidence that it also reduces pain. 66,97 The evidence is contradictory with regard to improving rates of return to work and decreasing sick leave. 89,93 Less intensive multidisciplinary biopsychosocial rehabilitation (<30 hours of therapy) that does not stress functional restoration has been shown to be no more beneficial than nonmultidisciplinary rehabilitation or usual care. 93 Clinicians who refer patients with chronic LBP for multidisciplinary biopsychosocial rehabilitation must clearly understand the Advanced Studies in Medicine 143

10 MUSCULOSKELETAL MEDICINE intensity and content of the program. Whether the potential benefits of these programs justify the significant costs is unclear. SURGERY The subject of surgical treatment for LBP is especially divisive. 5 This is particularly true regarding surgery for lumbar spondylosis. The debate is significantly less controversial regarding surgery for lumbar disc herniation. SURGERY FOR LUMBAR DISC HERNIATION For patients who fail to improve with conservative therapy, there is good evidence that surgical discectomy provides effective relief of sciatica for properly selected patients. Whether there is a significant difference in long-term outcomes is less clear. 7,16,103,104 The outcomes of microdiscectomy (discectomy accomplished with the aid of an operating microscope) appear to be comparable to standard discectomy. 98 The expertise of the surgeon, with respect to having more experience with one technique over the other, is probably the deciding factor. SURGERY FOR LUMBAR SPONDYLOSIS Only a very small percentage of patients with spondylosis ever come to surgery, but given the large total number of patients affected, many procedures are performed. Unless there is evidence of cauda equina syndrome, severe nerve root compression, or significant spinal instability, this type of surgery should not be considered for acute LBP. For patients with chronic LBP as a result of lumbar spondylosis unresponsive to conservative treatment, the possibility of surgery should be considered with extreme caution. Of course, there are risks to any type of surgery, and these should be weighed against the lack of solid evidence for these procedures. 7,9,105 In 2001 the results of the Swedish Lumbar Spine Study were published. In this methodologically strong, randomized, controlled trial, back pain was reduced in the surgical group by 33% compared with 7% in the nonsurgical group (P =.0002). At 2 years, 63% of the surgical group rated themselves as better or much better compared with 29% of the nonsurgical group (P <.0001). In this highly select group of patients, who had severe chronic LBP presumably secondary to lumbar spondylosis, surgical treatment appeared to be more effective than commonly used nonsurgical treatments. 106 SURGERY FOR SPINAL STENOSIS A prospective cohort study of 119 patients with lumbar spinal stenosis from community-based practices has recently been published. 107 Surgical treatment was found to be associated with better outcomes than nonsurgical treatment over 4 years of follow-up. The difference in outcome remained significant after controlling for baseline differences between the surgical and nonsurgical groups. However, the differences did narrow over time. 107 COMPLEMENTARY/ALTERNATIVE MEDICINE Many patients seek alternative or complementary modalities for the treatment of LBP. Before seeking these therapies all patients should undergo a complete evaluation to identify serious causes of LBP that require a well-established management strategy. If there are significant changes in symptoms the patient should be re-evaluated. Limited data indicate that for some patients spinal manipulation may be an effective and safe treatment for uncomplicated acute or chronic LBP. However, there is no evidence that it is superior to other standard treatments ,88,89,108 The effectiveness of acupuncture remains unclear. 7-9,79,87-89,95 Massage may improve symptoms and function for patients with subacute and chronic nonspecific LBP. 7,9,80,88,89,95 PROGNOSIS It is frequently said that 90% of acute episodes of LBP resolve within 1 month. While it is true most patients will substantially improve fairly quickly, physicians should not mislead patients to believe that all people with acute LBP will be pain-free in a short amount of time. When the data were pooled in a systematic review of 15 studies on the course of acute LBP, there was a 58% mean decrease in pain at 1 month, with lesser reductions over the next 2 months. Two of the studies with long-term followup showed that pain levels remained nearly constant between 3 and 12 months. A similar trend was seen for disability, with a large majority of subjects returning to work within 1 month. The cumulative risk of recurrence was 26% within 3 months and 73% within 12 months. 109 Other long-term followup studies have shown that at 1 year, approximately 35% to 45% of patients have continued LBP and that relapses are common The concepts of acute and chronic pain may well need to be modified to reflect more accurately the natural history of LBP. It would seem that LBP typically runs a recurrent course characterized by variation and change. Levels of functioning rather than pain may be more important outcome measures. PREVENTIVE MEASURES Given the high prevalence and expense of LBP, successful prevention strategies are of utmost impor- 144 Vol. 4, No. 3 March 2004

11 LOW BACK PAIN tance. This is particularly true in the workplace, where LBP often becomes a possibly compensable injury. 114 Despite decades of effort, convincingly successful prevention measures have been elusive. There appears to be limited evidence that exercise to strengthen the trunk muscles and improve overall fitness can decrease the incidence of LBP episodes. While controversial, there is minimal evidence to support the use of structured education programs about biomechanics, ergonomics, proper posture, and lifting. 115,116 Several studies have failed to show a reduction in the incidence of LBP with lumbar supports Obesity has been linked to LBP in several studies, but there are insufficient data to assess if obesity is truly causative. 121,122 No studies have tested the hypothesis that weight loss will result in less back pain. Smoking also has also been associated with LBP Again, clear evidence of causality and reversibility is lacking. There are no studies testing the hypothesis that stopping smoking reduces the occurrence or severity of LBP. CONCLUSION Complete eradication of low back pain is an unrealistic goal. Instead, the focus should be on functional outcomes. Patient education is important for achieving a positive treatment outcome, and should emphasize the patient s active role and coping skills rather than the biomedical aspects of treatment. Psychosocial factors are very influential in the development and persistence of LBP and are frequently overlooked. The physician should strongly encourage all patients to engage in low-stress aerobic activity and explain that some increased discomfort with activity is expected. Patients with acute LBP should be reevaluated in about 1 month. While very few patients develop chronic disabling LBP, treating them can be substantially more challenging and costly. Education, physical therapy, and aerobic activity are clearly indicated. Long-term opioids can be used successfully, but this may be difficult to accomplish in the primary care setting. The usefulness of antidepressants, injection therapies, and spinal manipulation remains to be clarified. Treatments not recommended because of negative data or a lack of sufficient data of good quality include bed rest, systemic steroids, TENS, traction, and acupuncture. Research on treatment modalities that address the psychosocial aspects of LBP is emerging and important, but how these modalities would be employed in a primary care setting remains uncertain. REFERENCES 1. Borenstein DG. Epidemiology, etiology, diagnostic evaluation, and treatment of low back pain. Curr Opin Rheumatol. 1999;11: Loeser JD, Volinn E. Epidemiology of low back pain. Neurosurg Clin N Am. 1991;2: Hart LG, Deyo RA, Cherkin DC. Physician office visits for low back pain. Frequency, clinical evaluation, and treatment patterns from a U.S. national survey. Spine. 1995;20: Frymoyer JW, Durett CL. 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