Case 10 45-year-old male presenting with low back pain - Mr. Payne

Case 10
45-year-old male presenting with low back pain - Mr.
Payne
Author: Shou Ling Leong, M.D., Penn State College of Medicine
Learning Objectives:
1.
2.
3.
4.
Understand the differential diagnosis for low back pain.
Develop physical exam skills in evaluating low back pain.
Develop the skills in the diagnosis and treatment of low back pain.
Recognize the red flags or alarming symptoms for serious causes for low
back pain.
5. Know when imaging studies are indicated.
6. Be able to prescribe treatment for back pain.
7. Know when to refer for consultation and surgical intervention
Summary of Clinical Scenario:
Mr. Payne, a 45-year-old white male truck driver presents with two weeks of back
pain and a tingling sensation down his left leg after lifting a 10-pound box. After
a thorough history rules out potentially serious causes of lower back pain and a
physical exam reveals straight leg raising (SLR) is positive at 75 degrees on the
left, Mr. Payne is given a provisionary diagnosis of back pain with radiculopathy
and sent home for conservative treatment with physical therapy.
At follow up three weeks later, Mr. Payne’s pain is now radiating down the lateral
part of his left leg and side of his left foot. On physical exam, SLR is positive at
45 degrees on the left, and reflexes are absent at the left ankle and 1+ at the
right ankle.
An MRI is ordered, which depicts a large herniated disc at L5-S1. He is referred to
the pain clinic for consultation and possible selective S1 nerve root injections.
During a phone call two weeks later, Mr. Payne happily reports that the cortisone
injection was a big success. His pain is much improved and he has gone back to
work part-time.
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After a few months of improvement, Mr. Payne’s pain flares up again and he
develops weakness of his left foot. A repeat MRI shows progression of the disc
herniation. He elects for surgery, which relieves his pain.
Pain worse with movement and sitting,
improves while lying down
Pain radiates down the leg/numbness
Key Findings from History
No history of trauma
No problem with bowel or bladder control
No dysuria/frequency
No fever or chills
Tenderness on palpation on the left lumbar
paraspinous muscle with increased tone
Key Findings from Physical
Exam
Straight leg raising (SLR) is positive at 75
degrees on the left and negative on the
right.
Second exam: SLR is positive at 45
degrees on the left and reflexes are absent
at the ankle.
Lumbar strain, disc herniation, spinal
Differential Diagnosis
stenosis, spinal fracture, cauda equina
syndrome, & pyelonephritis.
MRI: herniated disc at L5-S1 with
Key findings from Testing
associated impingement on the S1 nerve
roots.
Final Diagnosis
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Back strain with herniated disk.
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Case Highlights:
This case contains a detailed explanation of performing a complete neurological
exam of lower extremities, illustrates the use of Evidence Based Medicine to
determine when imaging studies are warranted in lower back pain, and discusses
the use of conservative management for lower back pain while reserving surgery
as the treatment of last resort.
Key Teaching Points
Knowledge:
Low back pain (LBP) is the fifth most common reason for all doctor visits. In the
US, lifetime prevalence of LBP is 60-80%. 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.
Major systems approach to LBP:
A mnemonic such as CT MIND and V can serve as a reminder of the major
systems to include when considering a broad differential for the etiologies of back
pain.
Congenital:
Scoliosis/Kyphosis
Toxic or traumatic:
Lumbar strain, Compression fracture
Metabolic:
Osteoporosis, Hyperparathyroidism, Paget‘s disease, Osteomalacia
Infectious:
Pyelonephritis, Osteomyelitis, Discitis, Herpes zoster, Spinal or
epidural abscess
Inflammatory:
Ankylosing Spondylitis, sacroiliitis, Rheumatoid Arthritis
Neoplastic:
Multiple Myeloma, Metastatic Disease, Lymphoma/Leukemia,
Osteosarcoma
Degenerative:
Disc Herniation, Osteoarthritis , Facet arthropathy, spinal
stenosis, sacroiliitis
Vascular:
Aortic Aneurysm, Diabetic Neuropathy
Visceral:
Prostatitis, PID, Ovarian cyst, Endometriosis, Kidney stones,
Cholecystitis, Pancreatitis
Common causes of LBP:
1. Mechanical: no primary inflammatory or neoplastic cause (97%). There are
several common etiologies of mechanical LBP:
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Lumbar strain/sprain (70%)
Age related degenerative joint changes (10%)
Herniated disc (4%)
Osteoporotic fracture (4%)
Spinal stenosis (3%)
2.
3.
Visceral: no primary involvement of the spine (2%)
Non-mechanical: others (1%)
Risk factors for mechanical LBP:
Prolonged sitting, with truck driving having the highest rate of LBP, followed
by desk jobs.
Deconditioning.
Suboptimal lifting and carrying habits.
Some radiologic findings are associated with LBP including spondylolysis,
disc-space narrowing, spinal instability, and spina bifida occulta.
Obesity is a possible risk factor, but the evidence is limited and inconsistent.
Prognosis:
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 3 months. For
patients who are out of work greater than 6 months, there is only 50% chance of
them returning to work; this drops to almost zero chance if greater than 2 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%.
SKILLS
History:
1. To get a good picture of the pain, determine:
If the pain radiates
Is the pain constant or remitting
Exacerbating circumstances (active vs. passive motion, day vs. night)
Palliative circumstances (medication, positioning-sitting, lying, standing)
What has the patient tried to relieve the problem (what worked, what didn't)
Intensity of the pain
History of similar problem
2. Review of Systems:
Neurologic problems (numbness, tingling, muscle weakness, incontinence)
Urinary symptoms (frequency, dysuria)
Fever, nausea, vomiting
Unexplained weight loss
Fatigue
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3. Pertinent history:
Recent illness
History of trauma
Patient's occupation
History of back injury, cancer, diabetes, etc.
4. Relevant Past Medical History
5. Current medications and allergies
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, parasthesias, and
muscle weakness, such as foot drop.
Physical Exam:
Perform the back exam with the patient first standing, then sitting, and finally
lying down. This should be done systematically, so as not to miss any step.
Physical Exam: Standing
1. 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. Have 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.
2. 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.
3. 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
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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.
4. 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.
5. Stoop Test: Have the patient go from 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.
Physical Exam: Sitting
1. Check for costovertebral angle (CVA) tenderness, a sign suggesting
pyelonephritis.
2. Straight leg raise (SLR) test: Raise each leg by extending the knee from 90
degrees to straight. If the pain is functional, the action is possible without
difficulty. If the pain is due to structural disease, the patient will instinctively
exhibit the "tripod sign" by leaning backward and supporting himself with his
outstretched arms on the exam table.
3. Neurological exam: check reflexes, muscle strength, and sensation of the lower
extremities. Most neuropathic back pain is due to impingement of L4, L5, and S1
nerve roots. Therefore, check the patellar and achilles reflexes. 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 dermatonal distribution of the great toe (L5), lateral malleolus and
posteriolateral foot (S1).
Nerve Root Impingement Associated Findings; Reflex; Pin-Prick Sensation;
Motor Examination; Functional Test
L3 - Patellar tendon, Lateral thigh and medial femoral condyle, Extend
quadriceps, Squat down and rise
L4 - Patellar tendon; 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; Posterior calf, sole of foot, and lateral ankle; Stand
on toes; Walk on toes (plantarflex ankle)
Physical Exam: Supine
1. Abdominal Exam
Auscultation: Check for abdominal bruit, looking for abdominal aortic
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aneurysm.
Palpitation: 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.
2. Rectal Exam
To be done only on patients with red flags or alarm symptoms.
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.
3. Passive Straight Leg Raise (SLR or Lasegue’s sign)
The normal leg can be raised 80 degrees. If a patient raises their leg <80
degrees, they have tight hamstrings or a sciatic nerve problem. To
differentiate, 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. This
radiation indicates stretching of the nerve roots (specifically S1 or L5) over a
herniated disc and will most likely occur between 40 and 70 degrees. Pain
will not occur until the leg is lifted at least 30 degrees. Pain earlier than 30
degrees is suggestive of malingering.
Pain in the opposite leg during a straight leg raise is suggestive of root
compression due to complete disc herniation.
The ipsilateral straight leg raise test has a sensitivity of 0.80 and a
specificity of about 0.40. Thus, a negative test makes a herniated disc
unlikely, but a positive test is nonspecific.
4. Crossed Leg Raise:
Asymptomatic leg is raised.
Test is positive if pain is increased in the contralateral leg; this correlates
with the degree of disc 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.
5. FABER Test: Flexion, ABduction, and External Rotation
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 can
not lower to the point of being parallel to the opposite leg.
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The FABER test should done on all patients suspected of having sacroiliac
pain, not just in the elderly patients. Sacroiliitis can occur in the young
population as well.
6. Pelvic Compression Test
Performed by forcibly pressing together the hips
A positive test elicits pain in the sacroiliac joint.
7. Muscle Atrophy: of quadriceps and calf muscles.
Lack of atrophy, despite patient's complaints of long-term weakness,
suggests malingering.
Differential Diagnosis:
While most often back pain is benign and self-limited, a small number of cases are
due to systemic diseases, such as cancer and infection. Furthermore, back pain
with neurological symptoms can be treated surgically and should be followed
carefully.
Therefore, the major task in treating back pain is to distinguish the common
causes for back pain (95% of cases) from the 5% with serious underlying diseases
or neurologic impairments.
Serious medical conditions:
1. Cauda equina syndrome:
Spinal cord compression of the cauda equina, resulting from a large mass
effect (such as an acute disc herniation or a tumor) causing pain radiating
down the leg and numbness of the leg.
Pain is usually worse with movement and sitting -- and improves with lying
down. (As opposed to pain due to spinal stenosis, which is usually worse
with walking and better with sitting and when the spine is flexed.)
This is a true emergency and decompression should be performed within 72
hours to avoid permanent neurologic deficits.
Red flags signaling cauda equina include:
Progression of neurological deficit
Difficulty urinating and fecal incontinence
2. Cancer: causes dull, throbbing back pain localized to the affected bones, that
progresses slowly, and it increases with recumbency or cough.
Red flags signaling cancer include:
Unrelenting night pain, pain at rest, unexplained weight loss
Patients over 50 or under 17 years old
History of cancer
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Failure to improve with therapy
3. Infection
Red flags signaling infection include:
Persistent fever (>100.4 F), fever/chills
Risk factors for spinal infection such as recent bacterial infection (e.g.,
urinary tract infection), IV drug abuse, or immune suppression (steroids,
transplant, or HIV).
4. Fractures: cause pain which may be aggravated with movement.
Red flags signaling fractures include:
Major trauma (such as vehicle accident or fall from height)
Minor trauma (even strenuous lifting) in older patients who are potentially
osteoporotic
History of chronic oral steroid use or substance abuse.
Studies:
1. In the absence of red flags or findings suggestive of systemic disease,
diagnostic testing, especially imaging, is not indicated until after 4 to 6 weeks of
conservative treatment.
Ordering tests too early is not only cost ineffective, but can also cause harm
to the patients. Spine film can expose a patient to radiation. This is
especially concerning in young women because radiation to the gonads in a
single plain radiograph of the lumbar spine is equal to getting daily CXR for
more than a year. CT scans expose patients to contrast materials that have
renal toxicity. Routine imaging with CT or MRI is not associated with
improved outcomes, but can 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.
After four to six weeks of conservative treatment, a plain radiograph is often
the first imaging test in the evaluation of LBP because it is relatively
inexpensive and easily accessible with a quick turnaround time for the
results.
2. CBC and sedimentation rate should be ordered if tumor or infection is
suspected.
3. Agency for Health Care Policy and Research (AHCPR) guidelines for x-ray:
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).
4. Lumbar spine films are commonly used, but lack specificity and have a high
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rate of false-positive. Deyo has suggested a series of high yield criteria for
obtaining lumbar films:
Age over 50
Significant trauma
Neuromotor defect
Weight loss of 10 pounds
Ankylosing spondylitis
Drug or alcohol abuse
History of malignancy
Fever of 100 degrees Fahrenheit
Revisit without improvement or financial compensation
5. MRI testing is not associated with clinical benefit in randomized trials.
Indications for MRI include:
Neurological deficit
Radiculopathy
Progressive major motor weakness
Cauda equina compression (sudden bowel/bladder disturbance)
Suspected systemic disorder (metastatic or infectious disease)
Failed 6 weeks of conservative care. (However, 75% of herniated discs
improve with 6 weeks of conservative therapy.)
Some recommend that in the absence of red flags, it is reasonable to obtain
an imaging study after one month of symptoms if surgery is being
considered.
Management:
1. Conservative therapy for acute low back pain (0-3 months):
Pharmacologic (aspirin/NSAID, muscle relaxants, combination drugs, some
recommend corticosteroids)
Activity level (avoid strenuous activities but to remain active)
Local therapy (heat/cold)
Maintain good posture and practice good lifting techniques at all time.
Give patients instructions to call if there is no relief or if the pain increases,
progression of neurologic deficits, development of problem with bowel or
bladder control.
Advanced imaging, such as MRI/CT scans, referral to a surgeon, or referral
to the pain clinic should be entertained if back pain is not better in 4 to 6
weeks or if progression of neurologic deficits is demonstrated.
2. Physical Therapy: Tailored physical therapy is slightly more effective for acute
back pain compared to patients who just stay active. Various interventions
(exercises, traction, massage) and different modalities (heat, ice, ultrasound) may
be used.
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