Low Back Pain

Passive straight leg raise

(SLR or Lasegue's sign) 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

Red flags for serious illness or neurologic impairment with back pain

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

Low Back Pain Prevalence

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.

step wise approach to looking at lateral view

1) Check for height loss in the vertebral bodies. This height loss may be due to trauma, metabolic disease, or metastatic disease. 2) Look at the configuration of the end plates. Are the end plates crisp? Irregular endplates could reflect degeneration or infectious disease. 3) Look at the disc space thickness. The disc space thickness should diminish as you go down the spine, but this should be subtly and uniformly. 4) Check for alignment in the AP direction. Are the anterior and posterior spinal lines intact? 5) Look to see if there any osteophytes projecting from the vertebral bodies. Are there any calcifications in discs? 6) Check that the spinous processes are present. Did the patient have previous spine surgery? 7) Last but not least, look for other abdomen and pelvic pathology. AP and lateral films can show calcifications in the kidney, vascular calcifications, or foreign bodies.

Step wise approach to looking at an AP film of the spine

1) Count the lumbar vertebral bodies (these are the non-rib bearing vertebra). An individual with classic anatomy will have 5 lumbar vertebral bodies, but there is quite a bit of normal variation. 2) Look to see that each vertebral body has 2 "eyes" (pedicles) and 1 "nose" (spinous process). 3) Look for vertical alignment of the spinous processes. Misalignment suggests a rotational injury such as unilateral facet dislocation 4) Look for smooth undulating borders. 5) Look for uniformity among the disc spaces. 6) Compare the pedicles with the spinous processes. Widening of the pedicles may represent a compression fracture. Comparison of these will also show rotation of the spine. 7) Look at the lateral curvature, which may reveal scoliosis. 8) Look at the sacroiliac joints to ensure the white margin is intact. Is the joint sclerotic, ankylosed (fused), or destroyed

Physical exam for Back pain in the standing position

1) inspection: -look at posure, contour, and symmetry 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 - 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

Three most common causes of back pain

1. lumbar strain/sprain - 70% 2. age-related degenerative joint changes in the disks and facets - 10%. 3. herniated disc - 4% other less common causes of mechanical low back pain are osteoporotic fracture and spinal stenosis

More physical exam in the standing position

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 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.

Supine Exam

Abdominal Exam: -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. Rectal Exam: -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.

Acute sciatica

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.

Guidlines for low back X-Ray

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

Low Back MRI indications

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.

Spondylolistheisis

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.

Seated back exam

Asses -CVA tenderness (suggestive of pyelonephritis) -positioning -reflexes and strength in the lower extremity 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).

Prostatitis

Can cause referred LBP in men. (Pelvic inflammatory disease and endometriosis in women can cause referred LBP). Expect to find evidence of infection in the history.

Ankylosing spondylitis

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.

EMG Considerations

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.

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 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.

Treatment after adequate trial of conservative theapy

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.

Malignancy

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.

Assessment of acute back pain

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.

Lower back pain differential

Infection: -Discitis -Herpes zoster -Osteomyelitis -Pyelonephritis -Spinal or epidural abscess Vascular: -Aortic aneurysm Endocrine: -Hyperparathyroidism -Osteomalacia -Osteoporosis -Paget disease

Common causes of Back Pain

MSK causes: -Degenerative disc disease -Facet arthritis -Sacroiliitis -Ankylosing spondylitis -Discitis -Paraspinal muscular issues -SI dysfunction -Disc prolapse -Spinal stenosis Trauma: -Lumbar Strain -Compression fracture Neoplastic: -Lymphoma/leukemia -Metastatic disease -Multiple myeloma -Osteosarcoma Inflammatory: -Rheumatoid Arthritis Visceral: -Endometriosis -Prostatitis -Renal Litiasis

Acute low back pain 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 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%.

Conservative therapy for acute low back pain

Pharmacologic therapy: Aspirin/NSAID and/or muscle relaxants Local therapy: Local therapy (heat/cold). Learn more about local therapy here. Activity: Advice to stay active or sending patient to physical therapy may help prevent recurrence.

Cauda equina syndrome

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.

Symptoms of Disc Herniation

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

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. 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.