Download Principles of Back Pain - UNC School of Medicine

Principles of Back Pain
Outpatient Internal Medicine
Cases:
• Mr. A
• 43y/o male, works for
a lumber company,
strained his back
loading his truck 2
wks ago.
• Had to take off work
2/2 pain, muscle
spasm. Hurts to
move.
• Mrs. B
• 68y/o female, retired,
known OA in knees &
hands, now feeling
low back pain
x2months. No h/o
trauma.
• Paraspinal muscles
tight & sore. Hurts to
move.
What could be causing their pain?
•
•
•
•
•
Nerve impingement (roots, nerves)
Muscle trauma
Disc pain
Facet joint pain
Bony pain
How do you differentiate?
• History: age, red flag signs
– Incontinence, bladder retention, saddle anesthesia –
think cord compression or cauda equina syndrome
– sudden, excruciating pain with minimal trauma –
think insufficiency fracture 2/2 osteoporosis or tumor
– Fever, IV drugs – infection
• Physical exam:
– Straight leg raise – think disc herniation
– Piriformis tenderness – think sciatic entrapment in the
piriformis muscle
– Muscle pain/tightness – raises suspicion for muscle
injury, although pain from any source can cause
reactive muscle spasm
– Tenderness over bony prominence – think fracture
A word on sciatica
• Sciatica is a symptom, not a diagnosis
• Inflammation of the sciatic nerve can
happen at many places, including:
– L4/L5 nerve roots (most common!)
– Piriformis or other muscle entrapment of
sciatic nerve
– Spinal cord itself (spinal stenosis)
When do you image?
– Most low back pain resolves in 6 weeks, so
no imaging is needed
– Consider imaging if:
•
•
•
•
•
•
•
Young (<20)
Old (>50)
Hx of tumor
Trauma
Night/rest pain
Systemic symptoms
Red flag symptoms
How do you image?
• X-rays:
– Good for detecting fracture
– Can document presence or absence of
arthritic changes, but won’t assess nerve
involvement
• MRI:
– Delineates disc disease, nerve impingement
– Detects tumors
– Use contrast if there is a history of back
surgery or tumors
Examples
L3 endplates
should be
parallel, like L4.
Collapse implies
fracture.
L3
L4
White circle shows
disc herniation in
above sagittal view
of MRI
Red arrow shows
nerve impingement
by disc/osteophyte
in axial view of
MRI
Treatment
• For most back pain, NSAIDs, heat, early return
to normal activity as tolerated x 6 weeks.
• Other options:
– Narcotics – patches for constant pain, prn pills for
intermittent pain
– Muscle relaxers if significant spasm is causing
problems
– Injections (steroid/lidocaine) – epidural, facet joint,
disc, piriformis
– Surgery – spinal fusion
Cases:
• Mr. A
• Negative straight leg
raise, significant
paraspinal tightness and
tenderness. Exquisite
pain with turning.
• Dx: likely muscle tear.
• Tx: NSAIDs, heat, muscle
relaxers, mild activity.
• Mrs. B
• Positive straight leg raise,
moderate paraspinal
tenderness on palpation.
Pain in back and leg on
arising from seated
position
• Dx: likely herniated disc
• Tx: NSAIDs, heat, mild
activity, consider imaging
since 2+ months.
Consider referral to
anesthesia for injections.
References:
• Skyrme, A. Common Spinal Disorders.
Remedica, 2003.
• Stone, R. Harrison’s Principles of Internal
Medicine. McGraw-Hill, 2001.
• Wheeler, S. et al. “Approach to the
diagnosis and evaluation of low back pain
in adults”. UpToDate. 2008.