Low Back Pain:
Approach to the patient in the E.D.
Lala M. Dunbar, M.D., Ph.D.
Clinical Professor of Medicine
LSU HSC
Epidemiology
• 60 – 90% of adults experience back pain at
some point in their life.
-  incidence age 35- 55 y.o.
- 90% resolve in 6 weeks
- 7% become chronic
- M/ F equally affected
• 85% never given precise pathoanatomical dx
• 5th Leading reason for medical office visits
• 2nd to respiratory illness as reason for
symptom-related MD visits
Epidemiology (cont.)
• #1 Cause and #1 Cost of work related
disability
• Healthcare expenditures $90 Billion (1998)
- $26.3 Billion attributable to back pain
Important Questions
1. Is systemic disease the cause?
2. Is there social or psycological distress
that prolongs or amplifies symptoms?
3. Is there neurologic compromise that
requires surgical intervention?
To Answer These Important
Questions
1. Careful History and Physical Exam
2. Imaging and Labs WHEN indicated
Differential Diagnosis of Low Back Pain
Evaluation in older adults
• Probabilities change
• Cancer, compression fractures, spinal
stenosis, aortic aneurysms more common
• Osteoporotic fractures without trauma
• Spinal Stenosis secondary to
degenerative processes and
spondylolisthesis more common
• Increased AAA associated with CAD
• Early radiography recommended
Clues To Systemic Disease
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Age
History of Cancer
Fever
Unexplained Weight Loss
Injection Drug Use
Chronic Infection Elsewhere
Duration and Quality of Pain
-Infection and Cancer not relieved supine
• Response to previous therapy
• h/o inflammatory arthritis elsewhere
Imaging
• Plain Radiography limited to patients with:
-findings suggestive of systemic disease
-trauma
• Failure to improve after 4 to 6 weeks
• CT and MRI more sensitive for cancer and
infections – also reveal herniation and stenosis
• Reserve for suspected malignancy,infection or
persistent neurologic defecit
MRI
• Shows tumors and soft tissues (e.g.,
herniated discs) much better than CT scan
• Almost never an emergency
– Exception: Cauda equina syndrome
CT Scan
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Shows bone (e.g., fractures) very well
Good in acute situations (trauma)
Sagittal reconstruction is mandatory
Soft tissues (discs, spinal cord) are poorly
visualized
• CT-myelogram adds contrast in the CSF
and shows the spinal cord and nerves
contour better
Abdomen, X-ray, Anteroposterior
View
1. 1st Lumbar vertebra
2. 2nd Lumbar vertebra
3. 3rd Lumbar vertebra
4. 4th Lumbar vertebra
5. 5th Lumbar vertebra
6. T12
7. Twelfth rib
8. Sacroiliac joint
9. Sacrum
10. Sacral foramen
11. Ilium
12. Pelvic brim
13.Superior ramus of
pubic bone
14. Pubic symphysis
Lower Third of Spinal Cord, MRI
1. Vertebral body
2. Spinal cord
3. Conus medullaris
4. Intervertebral disc
5. Filum terminale
(internum)
6. Subarachnoid
space
Sagittal Section through the
Spinal Cord
1. Intervertebral disc
2. Vertebral body
3. Dura mater
4. Extradural or epidural
space
5. Spinal cord
6. Subarachnoid space
Lumbrosacral Dermatones
Common Pathoanatomical Conditions of the Lumbar Spine
Disc Herniation – Physiology
• Tears in the annulus
• Herniation of nucleus
pulposus
Disc Herniation – Physiology
• Compression of the
nerve root in the
foramen leads to pain
Lumbar Disc Herniation –
Treatment
Conservative Tx.
– Moderate bed rest
– Spinal
manipulation
– Physical therapy
– Medication
• NSAIDs
• Muscle relaxants
• Rarely narcotics
Surgical Tx.
• “Microdiscectomy”
• Less than half of an
inch incision
• Go home the same or
next day
• Good results in up to
90% of cases
Results of Surgical Treatment
• Good outcome in 80-90% of cases
• Residual pain may last up to 6 months postop
• Results are worse if pain was present for over 8
months before the operation (permanent nerve
damage?)
Low Back Pain
• Second most common
cause of missed work
days
• Leading cause of disability
between ages of 19-45
• Number one impairment in
occupational injuries
Low Back Pain
• Most episodes of LBP are
self limited
• These episodes become
more frequent with age
• LBP is usually due to
repeated stress on the
lumbar spine over many
years (“degeneration”),
although an acute injury may
cause the initiation of pain
Disc Degeneration – Physiology
• With age and
repeated efforts,
the lower lumbar
discs lose their
height and water
content (“bone on
bone”)
• Abnormal motion
between the bones
leads to pain
Disc Degeneration – Treatment
Conservative Tx.
– Moderate bed rest
– Spinal
manipulation
– Physical therapy
– Medication
• NSAIDs
• Muscle relaxants
• Rarely narcotics
Surgical Tx.
• Lumbar fusion
OR
• Replacement with
artificial disc
Indications for Surgical
Treatment
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Low back pain for at least 2 years
Incapacitating
Resistant to physical therapy and medication
Positive MRI findings (degenerative changes) at
L4-5 and/or L5-S1
• For selected cases:
• Concordant pain on discography
• Psychological evaluation
Natural History
• Recovery from nonspecific LBP generally
rapid – 90% within 2 weeks – some
studies less rapid (2/3 at 7 weeks)
• Herniated Discs – slower to improve – only
about 10% considered for surgery after 6
weeks
• With surgery, no earlier return to work –
symptomatic and functional outcome
sometimes better
Physical Examination
• Fever – possible infection
• Vertebral tenderness - not specific and not
reproducible between examiners
• Limited spinal mobility – not specific (may help in
planning P.T.
• If sciatica or pseudoclaudication present – do straight
leg raise
• Positive test reproduces the symptoms of sciatica –
pain that radiates below the knee (not just back or
hamstring)
• Ipsilateral test sensitive – not specific: crossed leg is
insensitive but highly specific
• L-5 / S-1 nerve roots involved in 95% lumbar disc
herniations
Assessment of Function
• 98% disc herniations: L4-5; L5-S1
• Impairment: Motor and Sensory L5-S1
– L5: Weakness of ankle and great toe
dorsaflexion
– S1: Decrease ankle reflex
– L5 & S1: Sensory loss in the feet
STRAIGHT
STRAIGHTLEG
LEGRAISE
RAISETEST
TEST
The straight leg
raise test is positive
if pain in the sciatic
distribution is
reproduced
between 30° and 70°
passive flexion of
the straight leg.
Dorsiflexion of the
foot exacerbates
the pain
Waddell Signs For Non-organic Pain
• Superficial non-anatomic tenderness
• Pain from maneuvers that should not
ellicit pain
• Distraction maneuvers that should ellicit
pain BUT don’t
• Disturbances not consistent with known
patterns of pain
• Over-reacting during the exam
• Not definitive to rule out organic disease
Imaging Studies
• Progressive Neurologic Defecits
• Failure to Improve
• Hx of Trauma
• Risk for Malignancy or infection
Nerve Root Pain
• Associated w/ Radiculopathy
• Sciatica
-herniated disk
-foramenal or spinal stenosis
-ligamentous hypertrophy
-other space filling lesions: cysts, tumor, abscess
-viral or immune inflammation
-can occur w/ peripheral nerve involvement
• Spinal stenosis
-neurogenic claudication (pseudo claudication)
1 or both legs
-radiation to buttocks, thighs, lower legs
-pain increase with extension (standing, walking)
-pain decrease with flexion (sitting, stooping forward)
Indications for Surgical Referral
Therapy: Non-specific LBP
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NSAIDS
Muscle relaxants
Use on schedule than p.r.n.
Spinal manipulation/ P.T. (effects limited)
Delay referral until pain persists >3 weeks
– 50% will improve b/f this time period
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Rapid return to normal activities
Avoid heavy lifting, trunk twisting, vibrations
Alternative Tx: acupuncture and massage
Surgery- ineffective unless:
– sciatica, pseudoclaudication, spondylolisthesis
Therapy: Herniated Disks
• If no evidence cauda equina or progressive
neurologic defecit:
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Treat non-surgically minimum one month
Treat similar to non-specific LBP
Limited narcotics
Epidural steroids (helps in some)
• If severe pain or neuro defecits persist:
– CT/ MRI / consider for surgery
• Diskectomy
– Improved relief vs. non-surgery at 4 yrs./ ? 10yrs.
– Percutaneous and laser less effective than std.
– Arhroscopic techniques techniques comparable to
std. surgery
Therapy: Spinal Stenosis
• Conservative management may be useful
• For severe persistant pain decompressive
laminectomy
• Surgery – better pain relief and functional
recovery
• 30% recurrent severe pain in 4 years
– 10% reoperated
Therapy: Chronic LBP
• Sx often difficult to explain
• Intensive exercises help (hard to maintain)
• Anti-depressant therapy useful if
depressed
• Long term opioids – not recommended
• Referral to pain center
• Massage therapy is promising
• Therapeutic goals – optimize daily function
Long Term Outcomes
• Herniated Discs w/o neurologic deficits
– Diskectomy - > relief at 4 yrs; ? Better at 10 yrs
• Microdiskectomy – similar to standard
• Laser Diskectomy – less effective
• Arthroscopic diskectomy - promising