> Table of Contents > Spinal Stenosis
Spinal Stenosis
N. Wilson Holland, MD, FACP, AGSF
Birju B. Patel, MD, FACP, AGSF
image BASICS
DESCRIPTION
Narrowing of the spinal canal and foramen:
  • Spondylosis or degenerative arthritis is the most common cause of spinal stenosis, resulting from compression of the spinal cord by disc degeneration, facet arthropathy, osteophyte formation, and ligamentum flavum hypertrophy.
  • The L4-L5 level is most commonly involved.
EPIDEMIOLOGY
The prevalence of spinal stenosis increases with age due to “wear and tear” on the normal spine.
Incidence
Symptomatic spinal stenosis affects up to 8% of the general population.
Prevalence
  • The prevalence of spinal stenosis can be very high if assessed solely by imaging in elderly patients. Not all patients with radiographic spinal stenosis are symptomatic. The degree of radiographic stenosis does not always correlate with patient symptoms. Lumbar MRI showed significant abnormalities in one study in 22% of asymptomatic patients <60 years and in 57% of patients >60 years. T2-weighted imaging showed a 98% prevalence of disc degeneration in asymptomatic patients >60 years (1)[C].
  • Predominant age: Symptoms develop in 5th to 6th decades (congenital stenosis is symptomatic earlier) (2)[A].
ETIOLOGY AND PATHOPHYSIOLOGY
  • Spinal stenosis can result from congenital or acquired causes. Degenerative spondylosis is the most common cause.
  • Disc dehydration leads to loss of height with bulging of the disc annulus and ligamentum flavum into the spinal canal, increasing facet joint loading.
  • Facet loading leads to reactive sclerosis and osteophytic bone growth, further compressing spinal canal and foraminal elements.
  • Other causes of acquired spinal stenosis include:
    • Trauma
    • Neoplasms
    • Neural cysts and lipomas
    • Postoperative changes
    • Rheumatoid arthritis
    • Diffuse idiopathic skeletal hyperostosis
    • Ankylosing spondylitis
    • Metabolic/endocrine causes-osteoporosis, renal osteodystrophy, and Paget disease (3)[A]
Genetics
No definitive genetic links
RISK FACTORS
Increasing age and degenerative spinal disease
GENERAL PREVENTION
There is proven prevention for spinal stenosis. Symptoms can be alleviated with flexion at the waist:
  • Leaning forward while walking
  • Pushing a shopping cart
  • Lying in flexed position
  • Sitting
  • Avoiding provocative maneuvers (back extension, ambulating long distances without resting)
image DIAGNOSIS
PHYSICAL EXAM
Neurologic exam may be normal. Key exam areas:
  • Examine gait (rule out cervical myelopathy or intracranial pathology).
  • Loss of lumbar lordosis
  • Evaluate range of motion of lumbar spine.
  • Pain with extension of the lumbar spine is typical.
  • Straight-leg raise test may be positive if nerve root entrapment is present.
  • Muscle weakness is usually mild and involves the L4, L5, and (rarely) S1 nerve roots.
  • About half of patients with symptomatic stenosis have a reduced or absent Achilles reflex. Some have reduced or absent patellar reflex.
DIFFERENTIAL DIAGNOSIS
  • Vascular claudication. Symptoms of vascular claudication do not improve with leaning forward and usually do not persist with standing or rest.
  • Disc herniation
  • Cervical myelopathy
DIAGNOSTIC TESTS & INTERPRETATION
Generally a clinical diagnosis. Imaging (MRI is best) is used to stage severity and plan treatment.
Initial Tests (lab, imaging)
  • CBC, ESR, C-reactive protein (if considering infection or malignancy)
  • New back pain lasting >2 weeks or back pain accompanied by neurologic findings in patients >50 years generally warrants neuroimaging.
  • MRI is the modality of choice for the diagnosis of spinal stenosis.
  • CT myelography is an alternative to MRI but is invasive and has higher risk of complications.
  • Plain radiography helps exclude other causes of new back pain (e.g., malignant lytic lesions) but does not reveal the underlying pathology.
  • Radiologic abnormalities in general do not correlate with the clinical severity (6)[C].
Diagnostic Procedures/Other
Surgical decompression is the definitive option for patients who are symptomatic after nonoperative treatment:
  • Spinal stenosis generally does not lead to neurologic damage.
  • Surgery may be required for pain relief, allowing patients to become more mobile and improving overall health and quality of life.
Test Interpretation
Common radiographic findings include decreased disc height, facet hypertrophy, and spinal canal and/or foraminal narrowing.
image TREATMENT
  • In general, nonoperative interventions are preferred unless there are progressive or debilitating neurologic symptoms:
    • Physical therapy, exercise, weight management, lumbar epidural steroid injections, and medications are all options. There is not enough evidence in the current literature to guide definitive clinical practice.
    • Patients considering surgery should understand that the benefits of surgery may diminish over time (7)[A].
    • Rule out other neuropathies and peripheral vascular disease.
  • Spinal decompression and physical therapy yield similar effects (8)[A].
  • There is some controversy about whether a fusion should be performed with the decompression because of risk of future spondylolisthesis (7)[A],(9) [C],(10)[A].
MEDICATION
First Line
  • Acetaminophen: caution in those with preexisting liver disease; increased warnings for hepatotoxicity; limit daily dosing in the elderly.
  • NSAIDs: Consider potential for GI side effects, fluid retention, and renal failure.
Second Line
  • Tramadol—currently a schedule IV controlled substance. Has the potential to cause confusion, dizziness, lower seizure threshold, and increase fall risk in the elderly; should be used with caution
  • There is limited evidence for long-term efficacy of lumbar epidural steroid and/or anesthetic injections. Injections maybe less effective in those with more severe stenosis and those with stenosis involving >3 lumbar levels.
  • Use opioids judiciously and only when other treatments have failed to control severe pain.
Geriatric Considerations
  • Anti-inflammatory medications should be used with caution in the elderly due to the risks of GI bleeding, fluid retention, renal failure, and cardiovascular risks.
  • P.981

  • Side effects of opioids, include constipation, confusion, urinary retention, drowsiness, nausea, vomiting, and the potential for dependence.
  • >10% of elderly lack Achilles reflexes.
ISSUES FOR REFERRAL
Refer to a spine surgeon when patients are in unremitting pain or have a neurologic deficit.
ADDITIONAL THERAPIES
  • Patients with spinal stenosis are typically able to ride a bicycle because leaning forward tends to relieve symptoms.
  • Aquatic therapy (helpful for muscle training and general conditioning)
  • Strengthening of abdominal and back extensor muscles
  • Gait training
  • A brace or corset may help in the short term but is not recommended for prolonged periods due to development of paraspinal muscle weakness.
  • Encourage physical activity to prevent deconditioning.
SURGERY/OTHER PROCEDURES
  • Surgery is indicated when symptoms persist despite conservative measures (7)[A].
  • Age alone should not be an exclusion factor for surgical intervention. Cognitive impairment, multiple comorbidities, and osteoporosis may increase the risk of perioperative complications in the elderly.
  • Lumbar decompressive laminectomy is the mainstay of treatment. The traditional approach is laminectomy and partial facetectomy.
  • Controversy exists about whether the decompression should be supplemented by a fusion procedure:
    • There is evidence that fusion (simple or complex), as opposed to decompression procedure alone, may be associated with higher risk of major complications, increased mortality, and increased resource use in the elderly.
  • A less-invasive alternative, known as interspinous distraction (X STOP implant), is an option (11)[B].
  • The evidence for use of the Aperius interspinous implant device is inconclusive (12, 13)[C].
  • A unilateral partial hemilaminectomy combined with transmedial decompression may adequately treat stenosis with less morbidity in the elderly (14)[C].
  • Transforaminal balloon treatment may be a viable option for resistant spinal stenosis pain and functional impairment (15)[B].
INPATIENT CONSIDERATIONS
Admission Criteria/Initial Stabilization
Acute or progressive neurologic deficit
Discharge Criteria
Improved pain or after neurologic deficit has been addressed.
image ONGOING CARE
FOLLOW-UP RECOMMENDATIONS
  • Follow up based on progression of symptoms.
  • No limitations to activity; patients may be as active as tolerated. Exercise should be encouraged.
Patient Monitoring
Patients are monitored for improvement of symptoms and development of any complications.
DIET
Optimize nutrition for weight management and surgery.
PATIENT EDUCATION
  • Activity as tolerated, if no other pathology is present (e.g., fractures).
  • Patients should present for care if they develop progressive motor weakness and/or bladder/bowel dysfunction.
  • Patients should know the natural history of the condition and how best to relieve symptoms.
PROGNOSIS
  • Spinal stenosis is generally benign, but the pain can lead to limitation in ADLs and progressive disability.
  • Surgery usually improves pain and symptoms in patients who fail nonoperative treatment.
  • Surgical outcomes are similar in terms of pain relief and functional improvement for patients of all ages.
REFERENCES
1. Baker ADL. Abnormal magnetic resonance scans of the lumbar spine in asymptomatic subjects. A prospective investigation. In: Banaszkiewicz P, Kader DF, eds. Classic Papers in Orthopedics. London, England: Springer London; 2014: 245-247.
2. Ammendolia C, Stuber K, de Bruin LK, et al. Nonoperative treatment of lumbar spinal stenosis with neurogenic claudication: a systematic review. Spine Spine (Phila Pa 1976). 2012;37(10):E609-E616.
3. Katz JN, Harris MB. Clinical practice. Lumbar spinal stenosis. N Engl J Med. 2008;358(8): 818-825.
4. Suri P, Rainville J, Kalichman L, et al. Does this older adult with lower extremity pain have the clinical syndrome of lumbar spinal stenosis? JAMA. 2010;304(23):2628-2636.
5. Ohtori S, Yamashita M, Murata Y, et al. Incidence of nocturnal leg cramps in patients with lumbar spinal stenosis before and after conservative and surgical treatment. Yonsei Med J. 2014:55(3):779-784.
6. Li AL, Yen D. Effect of increased MRI and CT scan utilization on clinical decision-making in patients referred a surgical clinic for back pain. Can J Surg. 2011;54(2):128-132.
7. Weinstein JN, Tosteson TD, Lurie JD, et al. Surgical versus nonsurgical therapy for lumbar spinal stenosis. N Engl J Med. 2008;358(8):794-810.
8. Delitto A, Piva SR, Moore CG, et al. Surgery versus nonsurgical treatment of lumbar spinal stenosis: a randomized trial. Ann Intern Med. 2015:162(7):465-473.
9. Deyo RA, Ching A, Matsen L, et al. Use of bone morphogenetic proteins in spinal fusion surgery for older adults with lumbar stenosis: trends, complications, repeat surgery, and charges. Spine (Phila Pa 1976). 2012;37(3):222-230.
10. Deyo RA, Mirza SK, Martin BI, et al. Trends, major medical complications, and charges associated with surgery for lumbar spinal stenosis in older adults. JAMA. 2010;303(13):1259-1265.
11. Miller LE, Block JE. Interspinous spacer implant in patients with lumbar spinal stenosis: preliminary results of a multicenter, randomized, controlled trial. Pain Res Treat. 2012;2012:823509.
12. Postacchini R, Ferrari E, Cinotti G, et al. Aperius interspinous implant versus open surgical decompression in lumbar spinal stenosis. Spine J. 2011;11(10):933-939.
13. Surace MF, Fagetti A, Fozzato S, et al. Lumbar spinal stenosis treatment with Aperius perclid interspinous system. Eur Spine J. 2012; 21(Suppl 1):S69-S74.
14. Morgalla MH, Noak N, Merkle M, et al. Lumbar spinal stenosis in elderly patients: is a unilateral microsurgical approach sufficient for decompression? J Neurosurg Spine. 2011;14(3):305-312.
15. Kim SH, Choi WJ, Suh JH, et al. Effects of transforaminal balloon treatment in patients with lumbar foraminal stenosis: a randomized, controlled, double-blind trial. Pain Physician. 2013;16(3):213-224.
See Also
&NA;
Algorithm: Low Back Pain, Acute
Codes
&NA;
ICD10
  • M48.00 Spinal stenosis, site unspecified
  • M48.06 Spinal stenosis, lumbar region
  • M48.04 Spinal stenosis, thoracic region
Clinical Pearls
&NA;
  • Spinal stenosis often presents as neurogenic claudication (pain, tightness, numbness, and subjective weakness of lower extremities). This can mimic vascular claudication.
  • Neurogenic claudication (as opposed to vascular claudication) is improved by uphill ambulation and lumbar flexion.
  • Flexion of the spine generally relieves symptoms associated with spinal stenosis.
  • Spinal extension (prolonged standing, walking downhill, and walking downstairs) can worsen symptoms of spinal stenosis.
  • Urgent surgery should be considered for patients with cauda equina/conus medullaris syndrome or progressive bladder dysfunction. Most other patients with lumbar spinal stenosis can begin with conservative management.