Table 1. Initial Evaluation of LBP: Diagnostic Work-Up
Possible Cause
Key Features on History or
Physical Examination
Imaginga
Cancer
>> History of cancer with new
onset of LBP
MRI
>> Unexplained weight loss
>> Failure to improve after 1
month
>> Age > 50 years
Lumbosacral
plain
radiography
>> Multiple risk factors present
Plain
radiography or
MRI
Vertebral infection >> Fever
>> Intravenous drug use
>> Recent infection
Additional
Studiesa
ESR
MRI
ESR and/or
CRP
Cauda equina
syndrome
>> Urinary retention
>> Motor deficits at multiple levels
>> Fecal incontinence
>> Saddle anesthesia
MRI
None
Vertebral
compression
fracture
>> History of osteoporosis
>> Use of corticosteroids
>> Older age
Lumbosacral
plain
radiography
None
Ankylosing
spondylitis
>> Morning stiffness
>> Improvement with exercise
>> Alternating buttock pain
>> Awakening due to back pain
during the second part of the
night
>> Younger age
Anteriorposterior
pelvis plain
radiography
ESR and/
or CRP,
HLA-B27
MRI
Consider
EMG/
NCV
>> Back pain with leg pain in
an L4, L5, or S1 nerve root
distribution
>> Positive straight-leg-raise test or
crossed straight-leg-raise test
None
None
>> Symptoms present > 1 month
MRI
Consider
EMG/
NCV
>> Radiating leg pain
>> Older age (pseudoclaudication
a weak predictor)
None
None
>> Symptoms present > 1 month
MRI
Consider
EMG/
NCV
Severe/progressive >> Progressive motor weakness
neurologic deficits
Herniated disc
(Perform
diagnostic studies)
Spinal stenosis
(Perform
diagnostic studies)
a
Level of evidence for diagnostic evaluation is variable.
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