Chronic Low Back Pain: Evaluation and Management ALLEN R. LAST, MD, MPH, and KAREN HULBERT, MD, Racine Family Medicine Residency Program, Medical College of Wisconsin, Racine, Wisconsin Chronic low back pain is a common problem in primary care. A history and physical exami- nation should place patients into one of several categories: (1) nonspecific low back pain; (2) back pain associated with radiculopathy or spinal stenosis; (3) back pain referred from a nonspinal source; or (4) back pain associated with another specific spinal cause. For patients who have back pain associated with radiculopathy, spinal stenosis, or another specific spinal cause, magnetic resonance imaging or computed tomography may establish the diagnosis and guide management. Because evidence of improved outcomes is lacking, lumbar spine radiog- raphy should be delayed for at least one to two months in patients with nonspecific pain. Acet- aminophen and nonsteroidal anti-inflammatory drugs are first-line medications for chronic low back pain. Tramadol, opioids, and other adjunctive medications may benefit some patients who do not respond to nonsteroidal anti-inflammatory drugs. Acupuncture, exercise therapy, multidisciplinary rehabilitation programs, massage, behavior therapy, and spinal manipula- tion are effective in certain clinical situations. Patients with radicular symptoms may benefit from epidural steroid injections, but studies have produced mixed results. Most patients with chronic low back pain will not benefit from surgery. A surgical evaluation may be considered for select patients with functional disabilities or refractory pain despite multiple nonsurgical treatments. (Am Fam Physician. 2009;79(12):1067-1074. Copyright © 2009 American Academy of Family Physicians.) ▲ Patient information: ost primary care physicians into one of the following categories: (1) non- A handout on coping with can expect to see at least one specific low back pain; (2) back pain associ- chronic low back pain, patient with low back pain per ated with radiculopathy or spinal stenosis; written by the authors of this article, is avail- week. Acute episodes of back (3) back pain referred from a nonspinal source; able at http://www.aafp. Mpain are usually self-limited. Patients with or (4) back pain associated with another spe- org/afp/20090615/1067- persistent or fluctuating pain that lasts lon- cific spinal cause2 (Table 13). For patients who s1.html. ger than three months are defined as having have back pain associated with radiculopa- chronic low back pain. Patients with chronic thy, spinal stenosis, or another specific spinal This clinical content low back pain are more likely to see a fam- cause, magnetic resonance imaging (MRI) or conforms to AAFP criteria ily physician (65.0 percent) for their pain computed tomography (CT) may establish for evidence-based con- compared with orthopedists (55.9 percent), the diagnosis and guide management. tinuing medical education (EB CME). physical therapists (50.5 percent), and chi- The medical history should include ques- ropractors (46.7 percent).1 The economic tions about osteoporosis, osteoarthritis, and impact of chronic low back pain stems from cancer, and a review of any prior imaging prolonged loss of function, resulting in loss studies. Review of systems should focus on of work productivity, treatment costs, and unexplained fevers, weight loss, morning disability payments. Estimates of these costs stiffness, gynecologic symptoms, and uri- range from $12.2 to $90.6 billion annually.1 nary and gastrointestinal problems. The physical examination should include Evaluation the straight leg raise and a focused neuro- The initial evaluation, including a history and muscular examination. A positive straight physical examination, of patients with chronic leg raise test (pain with the leg fully extended low back pain should attempt to place patients at the knee and flexed at the hip between June 15, 2009 ◆ Volume 79, Number 12 www.aafp.org/afp American Family Physician 1067 Downloaded from the American Family Physician Web site at www.aafp.org/afp. Copyright © 2009 American Academy of Family Physicians. For the private, noncommercial use of one individual user of the Web site. All other rights reserved. Contact [email protected] for copyright questions and/or permission requests. Low Back Pain Table 1. Differential Diagnosis of Chronic Low Back Pain Nonspecific or Referred pain Nonmechanical idiopathic (2 percent) (1 percent) (70 percent) Aortic aneurysm Neoplasia rapidly progressive disease (Table 2 5,6) Lumbar sprain or strain Diseases of the Multiple myeloma or radicular symptoms that do not spon- Mechanical pelvic organs Metastatic carcinoma taneously resolve after six weeks. Because (27 percent) Prostatitis Lymphoma and leukemia evidence of improved outcomes is lacking, Degenerative processes Endometriosis Spinal cord tumors imaging, such as lumbar spine radiogra- of disks and facets Chronic pelvic Retroperitoneal tumors phy, should be delayed at least one to two Herniated disk inflammatory Primary vertebral tumors months in patients with nonspecific pain Osteoporotic fracture* disease Inflammatory arthritis, often without red flags for serious disease.6 Spinal stenosis Gastrointestinal associated with human disease Psychosocial issues play an important Traumatic fracture* leukocyte antigen-B27 Pancreatitis role in guiding the treatment of patients Congenital disease Ankylosing spondylitis Cholecystitis with chronic low back pain. One study Severe kyphosis Psoriatic spondylitis Penetrating found that patients with chronic low back Severe scoliosis Reiter syndrome ulcer pain who have a reduced sense of life con- Transitional vertebrae Inflammatory bowel disease Renal disease trol, disturbed mood, negative self-efficacy, Spondylosis Infection* Nephrolithiasis high anxiety levels, and mental health dis- Internal disk disruption Osteomyelitis or discogenic pain Pyelonephritis* orders, and who engage in catastrophiz- Septic diskitis Presumed instability Perinephric ing tend to not respond well to treatments Paraspinous abscess abscess* such as epidural steroid injections.8 “Yellow Epidural abscess flags” are psychosocial risk factors for long- Shingles term disability9 (Table 39-11). Evaluation of Scheuermann disease psychosocial problems and “yellow flags” (osteochondrosis) are useful in identifying patients with a Paget disease of bone poor prognosis.8,9 *—Indicates conditions more likely to present as acute low back pain. Management Adapted with permission from Deyo RA, Weinstein JN. Low back pain. N Engl J Med. 2001;344(5):365. GENERAL PRINCIPLES The goals of treating chronic low back pain often change over time, shifting from the 30 and 70 degrees) can suggest lumbar disk herniation, initial intent to cure to improving pain and function. with ipsilateral pain being more sensitive (i.e., better Patients often have unrealistic expectations of complete at ruling out disk herniation if negative) and contra- pain relief and full return to their previous level of activ- lateral pain being more specific (i.e., better at ruling in ity. There is often a large gap between a patient’s desired herniation if positive).4 Testing deep tendon reflexes, amount of pain reduction and the minimum percentage strength, and sensation can help identify which nerve of improvement that would make a treatment worth- roots are involved. while.12 Documenting goals and expectations and revis- Laboratory assessment, including erythrocyte sedi- iting them on follow-up visits may be helpful. mentation rate, complete blood count, and C-reactive Patients should receive information about effec- protein level, should be considered when red flags indi- tive self-care options and should be advised to remain cating the possibility of a serious underlying condition active (because muscles that do not move can eventually are present (Table 2 5,6). Urinalysis may be useful when become hypersensitive to pain).13 Assessing the response urinary tract infections are suspected, and alkaline to therapy should focus on improvements in pain, mood, phosphatase and calcium levels can help identify con- and function. ditions, such as Paget disease of bone, that affect bone Treatment should begin with maximal recom- metabolism; however, these tests are not needed in all mended doses of nonsteroidal anti-inflammatory drugs patients with chronic low back pain. (NSAIDs) and acetaminophen, followed by adjunctive Imaging has limited utility because most patients medications. Nonpharmacologic therapies are effective with chronic low back pain have nonspecific find- in certain clinical situations and can be added to the ings on imaging studies,7 and asymptomatic patients treatment program at any time. For those with severe often have abnormal findings.6 Initial imaging with functional disabilities, radicular symptoms, or refrac- MRI, which is the preferred study, or CT is only rec- tory pain, referral for epidural steroid injection or surgi- ommended for patients with red flags for serious or cal evaluation may be reasonable (Figure 12). 1068 American Family Physician www.aafp.org/afp Volume 79, Number 12 ◆ June 15, 2009 Low Back Pain Table 2. Red Flags Indicating Serious Causes of Chronic Low Back Pain and Evaluation Strategies Diagnosis of concern Evaluation strategy Cauda equina CBC/ESR/ Plain Finding syndrome Fracture Cancer Infection CRP level radiography MRI Age older than 50 years X X 1* 1 2 Fever; chills; recent urinary tract or skin X 1 1 1 infection; penetrating wound