Practice Essentials
Lumbar (intervertebral) disk disease is a frequent source of low back pain. Bulging, protruding, extruding, or sequestered disks can result in lumbar disc disease. The normal aging process of the musculoskeletal system aggravates acute events. [1] Risk factors include age, activity, smoking. obesity, vibration (eg, driving a car), sedentary lifestyle, and psychosocial factors. Low back pain accounts for approximately 4% of emergency department visits. The lifetime prevalence of back pain is 70-85%. [2, 3, 4]
Signs and symptoms
Signs and symptoms of lumbar disc disease include the following:
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Sharp (rather than dull) pain
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Typically, bilateral pain located at the posterior belt line
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Referred pain rather than radicular
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Usually preceded by multiple episodes of less severe low back pain
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Localized to the lower back and gluteal area
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Pain with flexion, rotation, or prolonged sitting or standing
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Pain relieved in a recumbent position
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Pain of sudden onset [5] or gradual onset after injury
Diagnosis
Examination in a patient with suspected lumbar (intervertebral) disc disease may feature the following:
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Abnormal gait
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Abnormal postures
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Decreased lumbar range of motion
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Positive straight leg raising test: Indicative of nerve root involvement
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Usually negative nerve root stretch test results
Perform the usual motor, sensory, and reflex examinations (including perianal sensation and anal sphincter tone when appropriate). It is also mandatory to perform a careful abdominal and vascular examination.
Testing
Laboratory tests are generally not helpful in the diagnosis of lumbar disc disease. For an otherwise healthy individual, unless the patient is immobilized completely by the pain and requires admission or the pain has been present for more than 6 weeks, diagnostic studies are not recommended.
Indications for screening laboratory tests such as the following include pain of a nonmechanical nature, atypical pain pattern, persistent symptoms, and age greater than 50 years:
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Complete blood count with differential
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Erythrocyte sedimentation rate
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Alkaline and acid phosphatase levels
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Serum calcium level
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Serum protein electrophoresis
Imaging studies
The following radiologic studies may be used to evaluate lumbar disc disease:
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Magnetic resonance imaging: Imaging modality of choice [6]
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Computed tomography scanning: Useful but less sensitive than MRI
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Myelography: May provide definitive diagnosis itself, but technique is invasive
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Plain lumbar films: Generally not helpful in the diagnosis, except to rule out other diseases and to evaluate for possible skeletal etiology as the cause of the patient's symptoms
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Bone scanning: To rule out tumors, trauma, or infection
Management
Most patients with pain from lumbar disc disease have resolution of their symptoms with conservative treatment.
A cohort study of 600 patients with acute low back pain treated in an emergency department reported the following outcomes at 12-month follow-up [7] :
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70% had a complete recovery in a median of 70 days
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73% recovered from pain in a median of 67 days
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86% recovered from disability in a median of 37 days
Pharmacotherapy
Salicylates, acetaminophen, and nonsteroidal anti-inflammatory drugs appear to be about equally effective for the treatment of pain from lumbar disc disease. Opioids provide very effective acute pain relief, but they should not be used in patients with chronic pain. Muscle relaxants such as benzodiazepines, methocarbamol, and cyclobenzaprine are not only of limited use but also sedating.
NSAIDs such as the following may be used in patients with lumbar (intervertebral) disc disorders to reduce pain and inflammation:
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Ibuprofen
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Ketoprofen
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Flurbiprofen
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Naproxen
Surgical option
Patients with lumbar disc disorders who have not had a response after 6 weeks of conservative therapy may consider surgical intervention, such as the following:
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Discectomy
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Spinal fusion
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Injection of chymopapain
For excellent patient education resources, see eMedicineHealth's patient education article Low Back Pain.
Pathophysiology
The intervertebral discs act as shock absorbers and are found between the bodies of the vertebrae. They have a central area composed of a colloidal gel, called the nucleus pulposus, which is surrounded by a fibrous capsule, the annulus fibrosis. This structure is held together by the anterior longitudinal ligament, which is anterior to the vertebral bodies, and the posterior longitudinal ligament, which is posterior to the vertebral bodies and anterior to the spinal cord. The muscles of the trunk provide additional support.
The most common site of disc herniation is at the L5-S1 interspace in the lumbosacral region. This is believed to be due to the thinning of the posterior longitudinal ligament as it extends caudally.
Nomenclature specific to lumbar disc disease is as follows:
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Disc bulge - Annular fibers intact
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Disc protrusion - Localized bulging with damage of some annular fibers
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Disc extrusion - Extended bulge with loss of annular fibers, but disk remains intact
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Disc sequestration - Fragment of disk broken off from the nucleus pulposus
