2.2.4. Intro to Clinical Reasoning Low Back Pain

Question 1

Leading cause of disability in young people

Answer 1

Low back pain

Question 2

What does the designation “chronic” mean for low back pain

Answer 2

Persisting beyond 3 months and affects 15-45% of the population

Question 3

Spine ligaments

Answer 3

• Anterior longitudinal ligament - Posterior longitudinal ligament (weaker of these two) - Ligamentum flavum, which joins adjacent laminae - Supraspinous ligament

Question 4

Conus Medullaris

Answer 4

Tapered end of the spinal cord which occurs at about L1 to L2

Question 5

Cauda Equina

Answer 5

Has dorsal and ventral roots that join together in the intervertebral neuroforamen to become the spinal nerves

Question 6

Description of why/how flexing and extending the back can cause pain

Answer 6

Important portion of the disc is the nucleus pulposus, which becomes looser with conditions like rupture and herniation. Remember from Physical exam small group that when we have a problem with flexing the back (leaning forward), which involves an anterior vertebral compression, we are pushing the disc outward. In a compromised disc, the goop (nucleus pulposus) pushes back against the nerves, causing bad pain. With extension problems, we know the issue is boney. Why? Because we have a posterior compression, the vertebrae are crunching posteriorly, and if there is pain, we know there is arthritis, a fracture, something like that. These patients tend to want to be bent over.

Question 7

Annulus fibrosus

Answer 7

Problems with the nucleus pulposus is caused do to a break in integrity of the annulus fibrosus, the layer surrounding the nucleus pulposus that protects it from herniating and rupturing

Question 8

Flexion typically occurs where?

Answer 8

80-90% of flexion occurs at L5-S1 and L4-L5

Question 9

Weakest part of the spine?

Answer 9

The disc is the weak link. Slow degeneration and shrinkage of the disc leads to decreased tension of the anterior and posterior longitudinal ligaments (ALL & PLL) This produces segmental dysfunction and instability.

Question 10

What happens to the rest of the vertebrae once we have a weakened disc

Answer 10

Weight gets shifted from the anterior elements (disc/vertebral bodies) to the posterior elements (facets). The anterior instability leads to calcification (spur formation) of the ALL & PLL.

Question 11

What happens with increased shift to the posterior elements of the spine?

Answer 11

Increased weight shift to the posterior elements leads to osteoarthritic changes of the facets (as discussed above with the nucleus pulposus) with associated spur formation and stenotic changes. All this extra calcium deposition leads to ankylosis and thus, stabilization of the segmental instability.

Question 12

Can we get nerve pain even with no compression directly on the nerve?

Answer 12

aqueous contents (Phospholipase Alpha-2 being the most well known) of the disc are noxious to the nerve.

Question 13

When do we see an inflammatory response after the nerve is exposed to the nucleus pulposus?

Answer 13

Inflammatory changes occur within 5 days of exposure of the nerve to nucleus pulposus contents.

Question 14

Releationship between size of herniation and symptoms?

Answer 14

None

Question 15

What are the 7 points in retrieving a History for low back pain?

Answer 15

1. Onset of pain
2. Location of pain
3. Type/Character of pain (sharp, dull, etc)
4. Aggravating and relieving factors
5. Medical history that includes previous injuries
6. Psychosocial stressors at home or work
7. Evidence of systemic disease

Question 16

What are some indications of inflammatory low back pain?

There are 4

Answer 16

1. Alternating buttock pain
2. Morning stiffness lasting greater than 30 minutes
3. Alleviated with use, aggravated by rest
4. Pain in the second half of the night

Question 17

How long should back pain occur without red flags before imaging is indicated?

Answer 17

4-6 weeks

Question 18

What percentage of low back pain gets better on its own when red flags are absent and there is no sciatica?

Answer 18

90%

Question 19

How long is bed rest recommended for low back pain?

Answer 19

Only 24-48 hours, longer seems to be counterproductive

Question 20

What are some indications for surgical referral of low back pain?

There are 6

Answer 20

1. Progressive motor weakness
2. Bowel or bladder disturbance
3. Incapacitating nerve root pain despite conservative treatment for at least 4 weeks
4. Recurrent incapacitating pain despite conservative treatment
5. Suspected cord compression
6. Cauda Equina Syndrome signs

Question 21

What are some symptoms of umbar spinal stenosis?

Answer 21

Symptoms of significant lumbar spinal stenosis include back pain, transient tingling in the legs, and ambulation-induced pain localized to the calf and distal lower extremity, resolving with rest (especially sitting or spinal flexion). This pain with walking, referred to as “pseudoclaudication” or “neurogenic claudication”, is clinically distinguished from vascular claudication by the presence of normal arterial pulses.

Question 22

What are some symptoms consistent with cauda equina syndrome?

5 listed here

Answer 22

1. Severe back pain
2. Saddle Anesthesia
3. Incontinence
4. Lack of an Achilles reflex
5. Sexual dysfunction

Question 23

Sciatica with disc herniation is typically worsened by what?

What is one maneuver we can use to test this?

Answer 23

Worsened by sneezing or coughing

May have patients perform the Valsalva maneuver