Chapter 99. Back Pain

A 60-year-old woman presents with chronic low back pain that began many years ago. Her back pain waxes and wanes and she has taken acetaminophen and ibuprofen with some relief. About 3 months ago, she began to have daily pain. She recalls no trauma. Her examination is unremarkable other than some decreased flexion. Straight leg raise test is negative. As the patient is older than 55 years of age, radiographs are ordered and they demonstrate degenerative changes in her lumbar spine (Figure 99-1). She is started on scheduled acetaminophen and ibuprofen along with an exercise program.

Back pain is one of the most common reasons that adults see their physician. Most acute back pain is a result of mechanical causes. Serious pathology can be recognized by the presence of red flags. Acute back pain is treated with reassurance, returning to activities, and acetaminophen with or without an NSAID. Psychological factors increase the risk of development of chronic pain. Chronic back pain is difficult to treat and the best outcomes are typically achieved by an interprofessional team.

• Six percent of visits to primary care physicians are for back pain.1
• Low back pain 1-year incidence is 20% and 1-year prevalence is 40% in adults.2
• Thoracic back pain 1-year prevalence is 15% to 27% in adults.3
• Treatment for back and neck problems accounted for approximately $86 billion in health care expenditures in the United States in 2005.4
• Prevalence of malignancy in patients with LBP presenting to a primary care office or emergency room is 0.1% to 1.5%.5

• LBP can be caused by pain in the muscles, ligaments, joints, bones, discs, nerves, or blood vessels.2
• In 90% of cases, the specific cause of LBP is unclear.2
• In 10% of cases, a specific cause such as an infection, fracture, or cancer is identified.

• Older age—Prevalence of LBP increases with age into the sixth decade.2
• Low educational status.2
• Occupational factors—Manual labor, bending, twisting, and whole-body vibration.2
• Psychosocial factors increase the risk of transition from acute to chronic pain.2
• Risk factors for cancer—Previous history of cancer (positive likelihood ratio [LR+] 23.7), elevated erythrocyte sedimentation rate (ESR) (LR+ 18.0), reduced hematocrit (LR+ 18.3).5

The diagnosis can be classified into three categories:

1. Nonspecific back pain—Pain for less than 6 weeks (acute), 6 to 12 weeks (subacute), or more than 12 weeks (chronic); negative straight-leg raise test; absence of red flags.

2. Radicular syndrome—LBP with radiation down leg; positive straight-leg raise test; absence of red flags.

3. Serious pathology—Further work-up required for presence of red flags, including age younger than 20 or older than 55 years; significant trauma; fever; unexplained weight loss; neurologic signs of cauda equina; progressive neurologic deficit.

Typical Distribution

Lumbar pain is about twice as common as thoracic pain.

Laboratory Testing

Helpful in the presence of red flags:

• Complete blood count (CBC) to evaluate for anemia (malignancy) or leukocytosis (infection).
• Consider human leukocyte antigen (HLA)-B27 in younger patients with inflammatory symptoms.

Imaging

• In acute back pain without red flags, imaging can be delayed for 6 weeks.
• Radiographs may show degenerative joint disease changes in osteoarthritis; vertebral fractures; malignancies; and findings of ankylosing spondylitis including erosions, sclerosis, syndesmophytes (see Chapter 98, Ankylosing Spondylitis).
• MRI is the best imaging test for disc herniation and imaging of the spinal cord. Emergent MRI is indicated in patients with suspected spinal cord compromise or cauda equina syndrome.
• CT myelogram is a useful alternative to evaluate disc herniation in patients who cannot undergo MRI.

• Osteoporotic vertebral fracture—Acute onset of pain, typically seen in older patients or those at risk for osteoporosis, point tenderness at the level of the fracture, confirmation by plain radiographs demonstrating compression or burst fracture (Figure 99-2).
• Spinal stenosis—Pain worse with extension, presence of unilateral or bilateral leg symptoms worse with walking and better with sitting, confirmation by CT or MRI.
• Herniated disc—Radicular pain that is worse with flexion or sitting, may be accompanied by numbness or weakness of foot plantar flexion (L5/S1) or dorsiflexion (L4/L5), MRI confirms the level and shows the type of herniation (Figures 99-3 and 99-4).
• Spinal infection/abscess—Most commonly seen in patients who use IV drugs, have diabetes mellitus, have cancer, or have a transplant; symptoms include fever, night pain, night sweats, and elevated ESR. MRI is the study of choice. If neurologic deficit is present, obtain an urgent MRI to evaluate for an abscess, which would require hospitalization and consultation with a spinal surgeon.
• Ankylosing spondylitis (see Chapter 98, Ankylosing Spondylitis)—Pain, most commonly in the low back or sacroiliac joints, usually begins in late adolescence or early adulthood. Pain and stiffness worsen with immobility and improve with motion. HLA-B27 may be positive. Radiographic findings confirm the diagnosis, but occur years after symptoms.
• Malignancy—Typically seen in an older patient; symptoms of weight loss and night pain; significant anemia; history of cancer; nonresponse to therapy. Often seen on plain radiographs. Bone scan is the most sensitive test.
• Abdominal pathology such as pancreatitis, pyelonephritis, and cholecystitis can present as back pain or pain radiating to the back.

Acute Back Pain

Most national guidelines agree on the following:6

• Nonpharmacologic:
  • Reassure patients without red flags that they do not have a serious condition, advise them to remain active, discourage bed rest, and encourage an early return to work while back pain is still present.
  • Exercise is considered no more effective than return to normal activities for LBP within the first 4 to 6 weeks.6
• Medications:
  • Acetaminophen
  • Add NSAID if needed (ask about GI problems and protect against ulcers as needed).
  • Consider a short course of opiates or muscle relaxers if pain is severe and inadequately treated with acetaminophen and NSAIDs.
  • Consider antidepressants (such as amitriptyline) or anticonvulsants (such as gabapentin) for radicular pain.
• Complementary and alternative therapy:
  • National guidelines differ; some recommend and some do not recommend spinal manipulative therapy for acute back pain.
  • Spinal manipulative therapy has a similar effect on pain relief and functional status as other interventions.7
• Referral or hospitalization:
  • Patients with cauda equina syndrome should have expedient imaging and urgent referral to a spinal surgeon.
  • Refer patients with serious pathology such as infection, tumor, or fracture to appropriate consultants.

Subacute (6 to 12 Weeks) or Chronic (>12 Weeks) Back Pain

Most national guidelines agree on these recommendations:6

• Nonpharmacologic:
  • Encourage an exercise program.
  • Recommend cognitive-behavioral therapy.
  • Discourage ultrasound or electrotherapy.
• Medications:
  • National guidelines vary on medication recommendations.
  • Start with acetaminophen then add NSAIDs if needed.
  • Consider adding one of these medications: tramadol, an antidepressant, a benzodiazepine, or an opiate.
• Complementary and alternative therapy:
  • Yoga—There have been a number of randomized controlled trials (RCTs) and metaanalyses that have found yoga to be an excellent treatment for chronic and recurrent LBP.1-4 SOR A A 12-week yoga program for adults with chronic or recurrent LBP led to greater improvements in back function than did usual care.4 Yoga classes were more effective than a self-care book, but not more effective than stretching classes, in improving function and reducing symptoms caused by chronic LBP, with lasting benefits.3
• Referral or hospitalization:
  • Chronic pain is difficult to treat. Use an interdisciplinary team to maximize effectiveness if possible.
  • Consider referring patients who do not respond to conservative therapy to a pain management specialist or a spine surgeon.

Good posture, appropriate lifting techniques, maintaining a healthy weight, and enjoying an active lifestyle may help prevent back pain. Adding yoga to an active lifestyle has the potential to prevent recurrent back pain and diminish the pain of chronic back pain.1-4 SOR A

• Patients with nonradicular acute back pain—By 12 months, 40% recover fully.8
• Patients with acute back pain that have psychological factors at baseline are more likely to develop chronic LBP.9

Follow-up is determined by etiology. Patients with acute back pain, without red flags, especially those at risk to develop chronic pain, should be followed closely. Patients with chronic pain benefit from ongoing treatment by an interprofessional team.

• Reassure patients without red flags that most acute back pain is not a result of a serious cause and can be treated conservatively.
• Advise patients with chronic back pain that a comprehensive approach to pain management is more likely to result in pain improvement than medications alone.
• Yoga and stretching can be a valuable adjunct to other treatments.1-4

Patient Resources

• Written and auditory patient information is available in English and Spanish at Family Doctor.org—http://familydoctor.org/familydoctor/en/diseases-conditions/low-back-pain.html.
• Yoga therapy for back pain. Audio and visual instructions for patients wanting to use yoga—http://www.samata.com/video4.php.
• Gentle yoga routine for lower back relief on YouTube—http://www.youtube.com/watch?v=u0BLxSY2L3Y.

Provider Resources

• A comprehensive list of red flags for back pain can be found in family practice notebook—http://www.fpnotebook.com/Ortho/Sx/LwBckPnRdFlg.htm.
• WebMD Back Pain Health Center. Useful for patients and providers—http://www.webmd.com/back-pain/default.htm.