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| Low back pain |
 | 15% to 20% incidence in the population |
| Majority of acute and chronic back pain are benign |
| Lifetime prevalence 80%; most last less than 6 weeks |
| Each year 3% to 4% of the population is temporarily disabled, and 1% of
the working-age population is totally disabled from low back problem. |
| Natural history of the benign self limited low back pain
 | 90% recover spontaneously in 4-6 weeks |
| Tendency to recur |
| Factors promoting transition to chronic pain not clear. |
| Imaging: disc degeneration and protrusion can be seen in over 60% of
asymptomatic adults. |
|
| Back pain in a primary care setting, causes other than a benign self
limited back pain
| 4% compression fracture |
| 3% from spondylolisthesis |
| 0.7% from malignancy |
| 0.3% from ankylosing spondylitis |
| 0.1% from vertebral osteomyelitis |
|
|
| Potential Red Flags In Low Back Pain:
Diagnostic tests may be indicated early on |
| Past History:
| Cancer, unexplained weight loss |
| Immunosuppression, including prolonged steroid use |
| IV drug use |
| History of recent urinary infection |
| Fever or constitutional symptoms |
| Coagulopathy: Low platelet, anticoagulant |
| Older patient with new onset of back pain |
| Metabolic bone disorder |
|
| Present history
| Significant trauma
 | Fall from height or severe injury in young adult |
| Minor injury or lifting in osteoporotic patient |
|
| Pain worse at night, supine position or not relieved by any position.
|
| Suspect cauda equina syndrome or spinal cord
compression:
| bladder dysfunction |
| saddle anesthesia or sensory level |
| major limb motor weakness |
|
| Progressive neurologic deficit |
|
| Physical examination and laboratory findings
| Pulsatile abdominal mass |
| Fever |
| Neurologic deficit not explained by a single radiculopathy |
| Elevated sedimentation rate, C reactive protein, unexplained anemia. |
|
| Pattern not compatible with benign mechanical back pain |
| Lack of response to conservative measures
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| Causes Of Low Back Pain |
| Mechanical causes: 98% of low back pain. Sitting produces the highest
load on the spine, typically worsens the pain.
| Intervertebral disc Herniations |
| Facet: commonly described as lateralized pain, referring to the
gluteal region and the thigh. Extension, with lateral flexion or rotation toward the
painful side, may increase the pain. |
| Lumbar spinal stenosis:
| Sometimes known as pseudoclaudication. |
| Aching pain, paresthesias & heaviness in the legs that progresses
with walking. |
| Relieved by trunk flexion, stooping, or sitting. |
|
| Paraspinal muscles |
| Sacroiliac joint:
| Pain is worsened by extensive use of the leg, such as walking. |
| May be reproduced by stressing the joint, such as forced flexion of one
lower extremity coupled with extension and abduction of the other. |
|
| Spondylolysis/Spondylolisthesis
|
| Nonspecific back pain |
|
| Rheumatologic: pain is frequently worst in the morning with
constitutional symptoms.
| Seronegative spondyloarthropathies:
| Ankylosing spondylitis: affects 1% of Caucasian, 3-5 times more common in
males. |
| Psoriatic arthritis, Reactive spondyloarthropathy,
|
| Reiter's syndrome:
| affects young men, 10:1 male: female. |
| Involves the lumbar spine and the lower extremities.
|
| Urethritis in 93% of cases. |
| Constitutional symptoms, mucocutaneous lesions of the mouth, genitals,
palms, soles, and nails. |
|
|
| Rheumatoid arthritis |
| Polymyalgia rheumatica |
| Nonarticular rheumatic disorders: Myofascial pain, Fibromyalgia syndrome
|
|
| Neoplastic Disease
| Primary tumors of the spine:
| Multiple myeloma: rare < 40 yo, back pain is the presenting symptom in
35% of cases. |
| Bone or cartilage tumor: Osteoid osteoma
|
|
| Metastatic spinal disease:
| Most common mets: breast, lung, prostate, kidney, lymphoma, melanoma, and
GI tract. |
| Back pain is the presenting symptom in 90% of patients who have spinal
metastasis. |
| Early mets is not visualized on plain radiographs, bone scans positive in
85%. |
| MRI may identify spinal metastasis in patients who have normal
radiographs and bone scans. |
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|
| Infections: acute or chronic
| Osteomyelitis |
| Discitis |
| Epidural abscess |
|
| Vascular or Hematologic
| Abdominal aortic aneurysm (atherosclerotic or inflammatory) rupture,
erosion of adjacent structures or Dissection. |
| Epidural hematoma |
| Retroperitoneal hematoma while on anticoagulant therapy: severe pain on
extension of the hip. |
| Hemoglobinopathy: painful bone infarcts, becomes susceptible to
osteomyelitis. |
|
| Endocrine/Metabolic
| Osteoporosis: Primary or secondary
|
| Pagets disease |
|
| Referred pain
| Pelvic disorders:
| Endometriosis: pain associated with periods |
| Torsion of a mass, cyst, or fibroid
|
| Pelvic inflammatory disease
|
| Prostatitis, Cystitis |
|
| Abdominal disorders
| Pancreas: pain worst with supine position. |
| Posterior duodenal ulcers
|
| Renal |
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| Other nonmechanical causes
| Hip joint or trochanteric bursa
|
| Guillain-Barre syndrome |
| Meningeal irritation |
|
| Psychological factors: Signs suggestive of nonorganic back pain
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| Nonoperative treatment for acute low back pain |
| Nonoperative treatment sufficient in most patients:
| Resorption of disc material can occur over time (MRI and autopsy proven) |
| Uncontrolled studies show 90% good to excellent results with conservative
treatment in patients who are operative candidates |
| Random longitudinal study shows surgery better at one year but no
difference at four to ten years |
|
| Bed rest
| Appropriate for acute low back pain |
| Two days as effective as seven |
| Prolonged bedrest has deleterious effects on physical and psychological
condition |
| Not recommended for chronic pain |
|
| Activities and Exercise
| Temporary avoidance of activities that increase mechanical stress on
spine |
| Gradual return to normal activities |
| Low-stress aerobic exercise |
| Conditioning exercises for trunk muscles after 2 weeks |
|
| Medications: useful in both acute and chronic pain
| NSAID:
| Anti-inflammatory & analgesic effect |
| Side effects: GI, renal, more profound in elderly, history of GI events,
concomitant steroids, diuretics. |
| Regular dosing needed |
| Individual variation in response to different agents: switch families |
| Ketorolac and bromfenac particularly efficacious for acute events. |
| Misoprostol (Cytotec), a prostaglandin derivative, may be more GI
protective than H2 blockers or antacids. |
| COX2 inhibitors may prove safer |
|
| Acetaminophen
| Lacks anti-inflammatory effect |
| Good analgesic without GI toxicity |
| May potentiate analgesic effect of concomitant agents |
|
| Corticosteroids
| Short course of PO steroids may be helpful when radicular symptoms
predominate (controversial) |
|
| Epidural injection may be useful for acute management of radicular pain |
| Muscle relaxants
| Mainly used in acute pain |
| Sedative side effects limit daytime use, may help with sleep |
|
| Narcotics
| May be necessary for moderate to severe acute pain, especially with
radiculopathy or pre-operatively |
| Adjust dose according to analgesic effect, limited by side effects |
| Concomitant NSAID or acetaminophen may allow lower dose |
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|
| Early aggressive treatment of pain may prevent peripherally induced CNS
changes that may intensify or prolong pain. |
|
| Chronic back pain |
| Tricyclic antidepressants
| Enhance endogenous pain suppression, especially dysesthetic pain |
| Alleviate symptoms associates with chronic pain: insomnia, dysesthesias,
and perhaps fatigue, anxiety, and depression. |
| May exhibit a "therapeutic window" of efficacy where pain
recurs with increasing doses. Start low and go slow. |
|
| Neuropathic and sympathetically maintained pain:
| Anticonvulsants (carbamazepine, gabapentin)may reduce paroxysmal
lancinating pain |
| Alpha blockers (phenoxybenzamine, clonidine, prazosin) may reduce
sympathetically maintained pain |
|
| Narcotics
| If needed in chronic pain: regularly scheduled doses rather than prn |
| Functional achievement (vocational, recreational, social) rather than
subjective pain relief as a the measure of efficacy. |
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| Other treatment methods |
| Trigger point injections into painful paravertebral soft tissues:
| Unproven in double blind comparison of steroid plus local anesthetic
versus saline, dry needle, or vapo-coolant spray and acupressure |
|
| Facet joint injections
| Injecting saline may reproduce symptoms; anesthetic may alleviate pain |
| Several studies show no long term benefit |
| Costly, invasive, of dubious therapeutic value |
|
| Epidural steroid injections
| May be useful in radicular pain to avoid surgery |
| Not recommended for back pain without radiculopathy |
|
| Manipulation: safe and effective in first month of non-radicular low back
pain |
| Traction: not helpful for low back problems |
| Physical modalities: no proven efficacy in acute low back symptoms. |
| Back schools: helpful. |
| Functional Restoration Programs:
| Sports medicine approach. |
| Highly structured, interdisciplinary, intensive.
|
| Some studies show up to twice the return to work rates. Expensive. |
|
| Pain Rehabilitation programs: Behavior oriented, multidisciplinary. |
| Prevention:
| Morbid obesity and smoking increase the risk of low back problems. |
| Isometric lifting strength and cardiovascular fitness are not predictive |
| Training, education, and ergonomic intervention not proven to reduce risk |
| Job dissatisfaction has a great impact on low back disability. |
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References & further reading
|
Musculoskeletal pain - BMJ Sept 2002 |
| Swenson R: Lower Back Pain. Differential diagnosis . A reasonable
clinical approach. Neurologic clin. Vol 17. No 1. Feb 1999. |
| Deyo RA: Back pain revisited. Newer thinking on diagnosis and therapy.
Consultant 33:88-100, 1993. |
| Jensen MC, Brant-Zawadzki MN, Obuchowski N, et al: Magnetic resonance
imaging of the lumbar spine in people without back pain. N Engl J Med 331:69-73, 1994
|
| Deyo RA, Rainville J, Kent OL: What can the history and physical
examination tell us about low back pain? JAMA 268:760-765, 1992 |
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