Cost of low back pain (LBP) in the United States is estimated at $177 billion annually. Back symptoms are the most common cause of disability in those <45 years; LBP is the second most common cause of visiting a physician in the United States; >80% of people will have LBP at some point in their lives.
- Local pain: caused by injury to pain-sensitive structures that compress or irritate sensory nerve endings; pain located near the affected part of the back.
- Pain referred to the back: abdominal or pelvic origin; back pain unaffected by posture.
- Pain of spine origin: restricted to the back or referred to lower limbs or buttock. Diseases of upper lumbar spine refer pain to upper lumbar region, groin, or anterior thighs. Diseases of lower lumbar spine refer pain to buttocks, posterior thighs, calves, or feet.
- Radicular back pain: radiates from spine to leg in specific nerve root territory. Coughing, sneezing, lifting heavy objects, or straining may elicit pain.
- Pain associated with muscle spasm: diverse causes; accompanied by tense paraspinal muscles, dull or aching pain in the paraspinal region, and abnormal posture.
Include abdomen and rectum to search for visceral sources of pain. Inspection may reveal scoliosis or muscle spasm. Palpation may elicit pain over a diseased spine segment. Pain from hip may be confused with spine pain; manual internal/external rotation of leg at hip (with knee and hip in flexion) reproduces the hip pain.
Straight leg raising (SLR) sign-elicited by passive flexion of leg at the hip with pt in supine position; maneuver stretches L5/S1 nerve roots and sciatic nerve passing posterior to the hip; SLR sign is positive if maneuver reproduces the pain. Crossed SLR sign-positive when SLR on one leg reproduces symptoms in opposite leg or buttocks; nerve/nerve root lesion is on the painful side. Reverse SLR sign-passive extension of leg backward with pt standing; maneuver stretches L2-L4 nerve roots, lumbosacral plexus, and femoral nerve passing anterior to the hip.
Neurologic examination-search for focal atrophy, weakness, reflex loss, diminished sensation in a dermatomal distribution. Findings with radiculopathy are summarized in Table 50-1 Lumbosacral Radiculopathy: Neurologic Features.
“Routine” laboratory studies and lumbar spine x-rays are rarely needed for nonspecific acute LBP (<3 months) but indicated when risk factors for serious underlying disease are present (Table 50-2 Acute Low Back Pain: Risk Factors for an Important Structural Cause). MRI and CT-myelography are tests of choice for anatomic definition of spine disease. Electromyography (EMG) and nerve conduction studies are useful for functional assessment of peripheral nervous system.
Common cause of low back and leg pain; usually at L4-L5 or L5-S1 levels. Dermatomal sensory loss, reduction or loss of deep tendon reflexes, or myotomal pattern of weakness more informative than pain pattern for localization. Usually unilateral; can be bilateral with large central disk herniations compressing multiple nerve roots and causing cauda equina syndrome (Chap. 191 Spinal Cord Diseases).
Indications for lumbar disk surgery:
- Progressive motor weakness on examination or progressive nerve root injury demonstrated on EMG.
- Cauda equina syndrome or spinal cord compression; usually indicated by urinary retention or abnormal bowel function.
- Incapacitating nerve root pain despite conservative treatment for at least 6-8 weeks: Trials indicate surgery leads to more rapid pain relief but no difference at 1-2 years compared with nonsurgical treatment.
A narrowed spinal canal producing neurogenic claudication, i.e., back, buttock, and/or leg pain induced by walking or standing and relieved by sitting. Symptoms are usually bilateral. Unlike vascular claudication, symptoms are provoked by standing without walking. Unlike lumbar disk disease, symptoms are relieved by sitting. Focal neurologic deficits common; severe neurologic deficits (paralysis, incontinence) rare. Stenosis results from acquired (75%), congenital, or mixed acquired/congenital factors.
- Symptomatic treatment adequate for mild disease
- Surgery indicated when medical therapy does not allow for activities of daily living or if focal neurologic signs are present. Most pts treated surgically experience relief of back and leg pain; 25% develop recurrent stenosis within 7-10 years.
Low back strain or sprain used to describe minor, self-limited injuries associated with LBP. Vertebral fractures from trauma result in anterior wedging or compression of vertebral bodies; burst fractures involving vertebral body and posterior spine elements can occur. Neurologic impairment common with vertebral fractures; early surgical intervention indicated. CT scans used to screen for spine disease in moderate to severe trauma; superior to routine x-rays for bony disease. Most common cause of nontraumatic fracture is osteoporosis; others include osteomalacia, hyperparathyroidism, hyperthyroidism, multiple myeloma, or metastatic carcinoma.
Slippage of anterior spine forward, leaving posterior elements behind; L4-L5 > L5-S1 levels; can produce LBP or radiculopathy/cauda equina syndrome (Chap. 191 Spinal Cord Diseases).
Back pain induced by spine movement and associated with stiffness. Increases with age; radiologic findings do not correlate with severity of pain. Osteophytes or combined disc-osteophytes may cause or contribute to central spinal canal stenosis, lateral recess stenosis, or neural foraminal narrowing.
Back pain most common neurologic symptom in pts with systemic cancer and may be presenting complaint (20%); pain typically not relieved by rest (Chap. 22 Spinal Cord Compression). Early diagnosis is crucial. MRI or CT-myelography demonstrates vertebral body metastasis; disk space is spared.
Back pain unrelieved by rest; focal spine tenderness, elevated ESR. Primary source of infection usually urinary tract, skin, or lung; IV drug abuse a risk factor. Destruction of the vertebral bodies and disk space common. Lumbar spinal epidural abscess presents as back pain and fever; examination may be normal or show radicular findings, spinal cord involvement, or cauda equina syndrome. Extent of abscess best defined by MRI.
May follow inflammation within subarachnoid space; fibrosis results in clumping of nerve roots, best seen by MRI; treatment is unsatisfactory.
Ankylosing spondylitis, rheumatoid arthritis, reactive arthritis, psoriatic arthritis, and inflammatory bowel disease.
Loss of bone substance resulting from immobilization, hyperparathyroidism, chronic glucocorticoid use, other medical disorders, or increasing age (particularly in females). Sole manifestation may be back pain exacerbated by movement. Can also occur in the upper back.
Pelvis refers pain to sacral region, lower abdomen to mid-lumbar region, upper abdomen to lower thoracic, or upper lumbar region. Local signs are absent; normal movements of the spine are painless. Rupture of an abdominal aortic aneurysm may produce isolated back pain.
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Low Back PainACUTE LOW BACK PAIN (ALBP)
CHRONIC LOW BACK PAIN (CLBP)
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