10: 45-year-old man with low back pain

Question 1

Low Back Pain Prevalence, Cost, & Duration

Answer 1

Low back pain (LBP) is the fifth most common reason for all doctor visits. In the U.S., lifetime prevalence of LBP is 60% to 80%. The direct and indirect costs for treatment of LBP are estimated to be $100 billion annually. Fortunately, most LBP resolves in two to four weeks.

Question 2

MSK Causes of Back Pain

Answer 2

Axial:

• Degenerative disc disease
• Facet arthritis
• Sacroiliitis
• Ankylosing spondylitis
• Discitis
• Paraspinal muscular issues
• SI dysfunction

Radicular:

• Disc prolapse
• Spinal stenosis

Trauma:

• Lumbar strain
• Compression fracture

Question 3

Non-MSK Causes of Back Pain

Answer 3

Neoplastic:

• -Lymphoma/leukemia
• -Metastatic disease
• -Multiple myeloma
• -Osteosarcoma

Inflammatory:
–Rheumatoid Arthritis

Visceral:

• -Endometriosis
• -Prostatitis
• -Renal lithiasis

Infection:

• -Discitis
• -Herpes zoster
• -Osteomyelitis
• -Pyelonephritis
• -Spinal or epidural abscess

Vascular:
–Aortic aneurysm

Endocrine:

• -Hyperparathyroidism
• -Osteomalacia
• -Osteoporosis
• -Paget disease

Question 4

Most Common Causes of Back Pain

Answer 4

There are three major categories of back pain: mechanical, visceral, and non-mechanical.

Mechanical
97% of back pain
no primary inflammatory or neoplastic cause

Visceral
2% of back pain
no primary involvement of the spine, usually from internal organs

Non-mechanical
1% of back pain other

The three most common causes of back pain are all mechanical:
1. lumbar strain/sprain - 70%
2. age-related degenerative joint changes in the disks and facets - 10%.
3. herniated disc - 4%
Acute sciatica is lower back pain with radiculopathy below the knee and symptoms lasting up to six weeks. Sciatica is a common and costly problem, caused by a variety of conditions: disk herniation, lumbar spinal stenosis, facet joint osteoarthritis or other arthropathies, spinal cord infection or tumor, or spondylolisthesis.

Less common causes of mechanical back pain:

• -osteoporotic fracture - 4%
• -spinal stenosis - 3%

Uncommon causes of back pain:
Pyelonephritis, a visceral cause, accounts for 0.4% of back pain.

Question 5

Risk Factors for Low Back Pain

Answer 5

• -Prolonged sitting, with truck driving having the highest rate of LBP, followed by desk jobs –Deconditioning
• -Sub-optimal lifting and carrying habits
• -Repetitive bending and lifting
• -Spondylolysis, disc-space narrowing, spinal instability, and spina bifida occulta
• -Obesity
• -Education status: low education is associated with prolonged illness
• -Psycho-social factors: anxiety, depression stressors in life
• -Occupation: Job dissatisfaction, increased manual demands, and compensation claims

Question 6

Red Flags For Serious Illness or Neurologic Impairment with Back Pain

Answer 6

Fever
Unexplained weight loss
Pain at night
Bowel or bladder incontinence 
Neurologic symptoms
Saddle anesthesia

Question 7

Mechanical lower back pain generally involves one or more of the following:

Answer 7

1. bones of the spine
2. muscles and ligaments surrounding the spine
3. nerves (the nerves entering and exiting the spinal cord or problems with the cord itself)

Question 8

Symptoms of Disc Herniation

Answer 8

When disc herniation is suspected, a very important historical point is the position of comfort or worsening of symptoms.

Classically, disc herniation is associated with exacerbation when sitting or bending; and relief while lying or standing.

Other symptoms of disc herniation include:

• -increased pain with coughing and sneezing
• -pain radiating down the leg and sometimes the foot
• -paresthesias
• -muscle weakness, such as foot drop

Question 9

Red Flags for Serious Underlying Causes of Back Pain

Answer 9

Cancer

1. History of cancer
2. Unexplained weight loss >10 kg within 6 months
3. Age over 50 years or under 17 years old
4. Failure to improve with therapy
5. Pain persists for more than 4 to 6 weeks
6. Night pain or pain at rest

Infection

1. Persistent fever (temperature over 100.4 F)
2. History of intravenous drug abuse
3. Recent bacterial infection, particularly bacteremia (UTI, cellulitis, pneumonia)
4. Immunocompromised states (chronic steroid use, diabetes, HIV)

Cauda Equina Syndrome

1. Urinary incontinence or retention
2. Saddle anesthesia
3. Anal sphincter tone decreased or fecal incontinence
4. Bilateral lower extremity weakness or numbness
5. Progressive neurologic deficits

Significant Herniated Nucleus Pulposus

1. Major muscle weakness (strength 3 of 5 or less)
2. Foot drop

Vertebral Fracture

1. Prolonged use of corticosteroids
2. Mild trauma over age 50 years
3. Age greater than 70 years
4. History of osteoporosis
5. Recent significant trauma at any age (car accident, fall from substantial height)
6. Previous vertebral fracture

Question 10

Acute Low Back Pain Prognosis

Answer 10

Most cases of low back pain are acute in onset and resolution, with 90% resolving within one month and only 5% remain disabled longer than three months.

For patients who are out of work greater than six months, there is only 50% chance of them returning to work; this drops to almost zero chance if greater than two years.

Patients who are older (>45) and patients who have psychosocial stress take longer to recover.

Recurrence rate for back pain is high at 35 to 75%.

Question 11

Recommended Low Back Pain History

Answer 11

1. History of present illness.
   - -What is the location of the pain? Is it upper, middle or lower back?
   - -What is the duration of the pain or how long ago did it start? Is it getting worse or better? Does the pain radiates? Pain that radiates below the knee- more consistent with sciatica; pain around the buttock- more consistent with lumbar strain.
   - -What is the severity of the pain? Use a pain scale of 1-10 to make the severity somewhat more objective. Intensity of the pain
   - -What is the quality of the pain? Is it achy, or sharp, or dull, or throbbing?
   - -Is the pain constant or remitting? Is it present at night or at rest?
   - -Are there associated symptoms? Does the patient have weakness or numbness or tingling?
   - -Are there aggravating or alleviating factors? Aggravating circumstances (active vs. passive motion, day vs. night). Valsalva can increase pain from a herniated disk.
   - -Alleviating circumstances (medication, positioning-sitting, lying, standing) What has the patient tried to relieve the problem (what worked, what didn’t)
   - -Any history of similar problems?
2. Pertinent past history. Recent illnesses, history of recent trauma or injury, patient’s occupation, previous history of back injury, cancer, or DM. (Fatigue is a nonspecific finding which may not help you to narrow your differential diagnosis.)
3. Review of systems. In order to narrow your differential diagnosis for the patient’s problem, a review of systems, focused on pertinent positives and negatives is important.
   –Neurologic symptoms
   (saddle anesthesia, lower extremity numbness, tingling, muscle weakness particularly in the lower extremities, fecal incontinence)
   –Urinary symptoms
   (urinary incontinence, hesitancy, frequency, dysuria)
   –Gastrointestinal symptoms (nausea, vomiting)
   Constitutional symptoms
   (fever, unexplained weight loss)
4. Current medications and allergies

Question 12

Perform the back exam systematically in sequential order with the patient:

Answer 12

1. Standing
2. Sitting
3. Supine

Question 13

Physical Exam for Back Pain - Standing

Answer 13

I. Inspection: Look at posture, contour and symmetry
–Check for lordosis
–Check for kyphosis
–Check for scoliosis
Slight scoliosis may be more easily visualized during lumbar flexion. This is performed by having the patient stand with their feet and hands together, like they are about to dive off a diving board, bending forward toward their toes. Look out across the back to see if the shoulders are level.

II. Palpation: Check for any tenderness, tightness, rope-like tension, or inflammation in the paraspinous muscles or tenderness over bony prominences. This procedure checks for muscle spasm, vertebral fracture, or infection.

III. Range of Motion (ROM):

• -Lumbar Flexion (normal is 90 degrees): This is the best measure of spine mobility. Restriction and pain during flexion are suggestive of herniation, osteoarthritis, or muscle spasm.
• -Lumbar Extension (normal is 15 degrees): Pain with extension is suggestive of degenerative disease or spinal stenosis.
• -Lateral motion (normal is 45 degrees): Most patients should be able to touch the proximal fibular head of the knee. Pain on the same side as bending is suggestive of bone pathology, such as osteoarthritis or neural compression. Pain on the opposite side of bending is suggestive of a muscle strain.
• -Range of motion may be varied due to the patient’s age and body habitus

IV. Gait: Ask the patient to walk on heels and toes. Expect normal gait, even with disc herniation.

• -Difficulty with heel walk is associated with L5 disc herniation
• -Difficulty with toe walk is associated with S1 disc herniation

V. Stoop Test: Have the patient go from a standing to squatting position.
In patients with central spinal stenosis, squatting will reduce the pain. However, asking the patient to run is not part of a back exam and may cause discomfort to the patient who is already in pain.

Question 14

Physical Exam for Back Pain - Seated Position

Answer 14

1. DTR
2. Muscle Strength
3. Sensation

Question 15

Nerve Impingement Syndromes

Answer 15

Nerve Root
Reflex
Pin-Prick Sensation
Motor Examination
Functional Test

L3
Patellar tendon reflex
Lateral thigh and medial femoral condyle
Extend quadriceps
Squat down and rise

L4
Patellar tendon reflex
Medial leg and medial ankle
Dorsiflex ankle
Walk on heels

L5
Medial hamstring
Lateral leg and dorsum of foot
Dorsiflex great toe
Walk on heels

S1
Achilles tendon reflex
Posterior calf, Sole of foot, and lateral ankle
Stand on toes
Walk on toes (plantarflex ankle)

Question 16

Neurological exam

Answer 16

Check reflexes, muscle strength, and sensation of the lower extremities. Focus on the L4, L5, and S1 nerve roots because most neuropathic back pain is due to impingement of these. Therefore, check the patellar reflex (L2-4) and Achilles reflex (S1). Check muscle strength for hip flexion, abduction, and adduction; knee extension and flexion; as well as ankle dorsiflexion and plantar flexion. Also, test for sharp and light touch along the dermatomal distribution of the great toe (L5), lateral malleolus and posterolateral foot (S1).

Question 17

I. Abdominal Exam

Answer 17

Auscultation: Check for abdominal bruit, looking for abdominal aortic aneurysm.

Palpation: Check for abdominal tenderness (on all patients, not just female patients), pelvic tenderness (PID), pulsatile mass, unequal femoral/brachial pulses (abdominal aortic aneurysm), or any general tenderness indicating visceral pathology.

Question 18

II. Rectal Exam

Answer 18

To be done only on patients with red flags or alarm symptoms, which we will discuss later!

Check for masses, bleeding, or abnormal rectal tone. Bleeding or rectal mass can be signs of cancer with metastasis to the spine causing back pain. Decreased tone can indicate disc herniation and/or cauda equina syndrome.

Question 19

III. Passive Straight Leg Raise (SLR or Lasegue’s sign)

Answer 19

The normal leg can be raised 80 degrees.

If a patient only raises their leg <80 degrees, they have tight hamstrings or a sciatic nerve problem.

To differentiate between tight hamstrings and a sciatic nerve problem, raise the leg to the point of pain, lower slightly, then dorsiflex the foot. If there is no pain with dorsiflexion, the patient’s hamstrings are tight.

The test is positive if pain radiates down the posterior/lateral thigh past the knee. This radiation indicates stretching of the nerve roots (specifically S1 or L5) over a herniated disc.

This pain will most likely occur between 40 and 70 degrees. Pain earlier than 30 degrees is suggestive of malingering.

Pain less than 30 degrees is not a sign of disc herniation.

Question 20

IV. Crossed Leg Raise : asymptomatic leg is raised

Answer 20

Test is positive if pain is increased in the contralateral leg; this correlates with the degree of disc herniation. Such
results imply a large central herniation.

Cross SLR test is much less sensitive (0.25) but is highly specific (about 0.90). Thus, a negative test is nonspecific, but a positive test is virtually diagnostic of disc herniation.

Question 21

V. FABER Test: Flexion, Abduction, and External Rotation

Answer 21

The Faber test looks for pathology of the hip joint or sacrum (sacroiliac pain from sacroiliitis).

The test is performed by flexing the hip and placing the foot of the tested leg on the opposite knee. Pressure is then placed on the tested knee while stabilizing the opposite hip.

The test is positive if there is pain at the hip or sacral joint or if the leg cannot lower to the point of being parallel to the opposite leg from pathology of the hip, sacrum or sacroiliac joint.

The FABER test should be done on all patients suspected of having sacroiliac pain, not just in the elderly patients. Sacroiliitis can occur in the young population as well.

Question 22

VI. Muscle Atrophy: of quadriceps and calf muscles.

Answer 22

do it

Question 23

Conservative therapy for acute low back pain includes:

Answer 23

Pharmacologic therapy: Aspirin/NSAID and/or muscle relaxants

Local therapy: Local therapy (heat/cold).

Activity: Advice to stay active or sending patient to physical therapy may help prevent recurrence.

Question 24

Conservative Therapy for Acute Low Back Pain: Pharmacologic therapy:

Answer 24

The first line medications for the treatment of LBP are non-steroidal anti-inflammatory drugs (NSAIDs), acetaminophen, and muscle relaxants. A systematic review of randomized controlled studies found strong evidence that NSAIDs and muscle relaxant are helpful in the treatment of LBP. The various NSAIDs and muscle relaxants are equally effective, while some muscle relaxants are more sedating. There is conflicting evidence about the superiority of NSAIDs to acetaminophen. Opioids should be considered a second- or third-line option for treatment of back pain. There is little evidence regarding the benefits and harms of opioid use in LBP. No studies support the use of oral steroids in patients with LBP.

Strict bed rest has not been shown to be beneficial. Patients should be encouraged to resume normal activities as
soon as they are able to.

Referral to a surgeon or advanced imaging, such as MRI/CT scans, should be entertained if back pain is not better in four to six weeks or if progression of neurologic deficits is demonstrated.

Question 25

Effectiveness of Physical Therapy for Acute Back Pain

Answer 25

There is some data to show that tailored physical therapy is slightly more effective for acute back pain compared to patients who just stay active. At four weeks, patients who received physical therapy had 10-point improvement in a 100-point disability score compared to the control group. There is great variation in physical therapy because various interventions (exercises, traction, massage) and different modalities (heat, ice, ultrasound) may be used. There is also evidence that spinal manipulation is safe and can help in the short term.

Question 26

Treatment After Adequate Trial of Conservative Therapy

Answer 26

If a patient has been in pain for five weeks with progression of neurological deficit (such as absent reflex at the ankles) and poor pain control, it is reasonable to refer him to a spine surgeon for surgical consultation.

If the patient doesn’t have any red flags, continuation of conservative treatment is also an option. However, if the patient has already been getting PT, more PT is not likely to help.

There is some evidence that acupuncture can be helpful in low back pain.

Question 27

CBC

Answer 27

CBC and sedimentation rate should be ordered if tumor or infection is suspected.

Question 28

Agency for Health Care Policy and Research (AHCPR) guidelines for x-ray:

Answer 28

History of trauma
Strenuous lifting in patient with osteoporosis Prolonged steroid use
Osteoporosis
Age <20 and >70
History of cancer
Fever/chills/weight loss
Pain worse when supine or severe at night Spinal fracture, tumor, or infection

Question 29

Lumbar spine film

Answer 29

Lumbar spine films are commonly used, but lack specificity and have a high rate of false-positive findings. Patients with symptoms and pathology may have an apparently benign x-ray and asymptomatic patients may have abnormal x-rays.

Question 30

MRI

Answer 30

An MRI is indicated if the following are present:

• -Worsening or unremitting neurologic deficit or radiculopathy
• -Progressive major motor weakness
• -Cauda equina compression (sudden bowel/bladder disturbance)
• -Suspected systemic disorder (metastatic or infectious disease)
• -Failed six weeks of conservative care

However, 75% of herniated discs improve with six weeks of conservative therapy. MRI testing is not associated with clinical benefit in randomized trials. Early MRI is not associated with improved outcomes in patients with acute back pain or radiculopathy (Level 2/mid-level evidence). If surgery is being considered, some physicians recommend, in the absence of red flags, to obtain an imaging study after one month of symptoms.

Question 31

Electrodiagnostics-Electromyography

Answer 31

Electrodiagnostics-Electromyography (EMG) and nerve conduction studies can be used in the evaluation of patients with radicular pain and lumbar spinal stenosis.

Electrodiagnostic tests are useful to confirm the existence of radiculopathy (level of nerve involvement) and to exclude the presence of other peripheral nerve disorders. Electrodiagnostic tests are time sensitive because nerve root abnormalities may not be reliably detectable until three weeks after the onset of symptoms.They are particularly useful as an adjunct to clinical evaluation and Imaging in the following two clinical scenarios: physical examination does not correlate with imaging studies; and to clarify the functional significance of an imaging abnormality.

Question 32

Assessment of Acute Back Pain

Answer 32

In the absence of red flags or findings suggestive of systemic disease, diagnostic testing, especially imaging, is not indicated until after four to six weeks of conservative treatment. Ordering tests too early is not only cost ineffective, but can also cause harm to the patient.

Spine x-rays expose patient to radiation. This is particularly concerning in younger women because the radiation exposure to the ovaries in a single plain radiograph of the lumbar spine is equal to getting a daily chest x-ray (CXR) for more than a year.

CT scans expose patients to contrast materials that have renal toxicity, and even higher doses of radiation. Routine imaging of the back using CT or MRI is not associated with improved outcomes, and may identify abnormalities that are unrelated to the patient’s back pain. This can cause anxiety and could lead to more testing and possibly unnecessary intervention.

Question 33

Differential for Low Back Pain

Answer 33

The most appropriate diagnoses on your differential include:
Lumbar strain, disc herniation, spinal stenosis, and degenerative arthritis .

Pain worse with movement and sitting is suggestive of a mechanical cause of back pain, such as a lumbar strain, disc herniation,or degenerative arthritis.

Pain radiating down the leg and numbness indicate nerve involvement, such as in disc herniation.

Pain that improves with the supine position suggests spinal stenosis and disc herniation.

Question 34

Spinal fracture

Answer 34

Not likely without history of trauma.

Question 35

Cauda equina syndrome

Answer 35

Should always be considered due to the seriousness of the consequences.

Occurs when a large mass effect (such as an acute disc herniation or a tumor) compresses the cauda equina, causing pain radiating down the leg and can be accompanied by weakness and numbness of the leg.

True emergency. Decompression should be performed within 72 hours to avoid permanent neurologic deficits.

Low on the differential if the patient denies problem with bowel or bladder control.

Question 36

Pyelonephritis

Answer 36

Unlikely with lack of fever and urinary symptoms.

Question 37

Malignancy

Answer 37

Important consideration. A very serious, although uncommon, cause of back pain.

Unlikely without a history of cancer.

Back pain due to malignancy is localized to the affected bones, it is a dull, throbbing pain that progresses slowly, and it increases with recumbency or cough .

More commonly seen in patients over 50.

Question 38

Ankylosing spondylitis

Answer 38

Chronic, painful, inflammatory arthritis primarily affecting the spine and sacroiliac joints, causing eventual fusion of the spine.

Often seen in patients 15-40 years old, associated with morning stiffness and achiness over the sacroiliac joint and lumbar spine.

Question 39

Spondylolisthesis

Answer 39

Anterior displacement of a vertebra or the vertebral column in relation to the vertebrae below.

Can occur at any age.

Causes aching back and posterior thigh discomfort that increases with activity or bending.

Question 40

Prostatitis

Answer 40

Can cause referred LBP in men.

Question 41

Pancreatitis

Answer 41

Pancreatitis and other gastrointestinal diseases such as cholecystitis and ulcers can cause LBP via visceral pain.

Usually associated with other abdominal symptoms.

Question 42

nerve root impingement at the level of L5

Answer 42

The clinical signs presented by this patient-difficulty with heel walk and the abnormal strength of ankle plantar flexion-is consistent with nerve root impingement at the level of L5.

A hypoactive ankle tendon reflex is also consistent with a nerve root impingement at this level.

Pain with lumbar extension suggests degenerative disease or spinal stenosis, and spinal stenosis is similarly suggested by a positive stoop test.

Diminished hip flexor strength suggests a lesion at the L2, L3, or L4 level and decreased rectal tone suggests a cauda equina lesion

Question 43

prostatitis

Answer 43

In an older male patient, prostatitis may present with low back pain. This patient’s symptoms-general malaise, chills, hesitancy and pain on urination-and signs (fever) suggest acute bacterial prostatitis. Patients with acute bacterial prostatitis will often have exquisite tenderness over the prostate on rectal exam. This patient could also have pyelonephritis, which often goes along with costovertebral angle tenderness.

Question 44

“red flag”

Answer 44

The “red flag” in this history is that of chronic steroid use, and the concomitant risk of osteoporotic vertebral fracture. A vertebral fracture is best diagnosed with a plain x-ray. A CBC will not help with the diagnosis, and referral to a spine specialist is unnecessary. Conservative management and/or reassessment in four weeks demonstrate a failure to recognize the “red flag.”