Canal Stenosis

Extension – occurs when standing

Flexion – Occurs when sitting or bending forward

Anatomy of the SpineUnderstanding your spine: Helpful Terms

CANAL SHAPE

• Round• Triangular• Trefoiled

(15%)• Trefoiled &

asymmetric

STENOSIS

• Narrowing of the spinal canal or neuroforamina

• causing a symptomatic compression of the neural element.

PATHOPHYSIOLOGY

• “Three-joint Complex”– a large tripod with the

disc as the front support and two facet joints as the back supports

– Any alteration in one of these joints can lead to damage to the others

• Vertebrae provide support for your head and body

• Discs act as “shock absorbers”• Vertebra protects spinal cord• Nerves have space and are not

pinched

• As we age, ligaments and bone can thicken

• Narrowing is called “stenosis”• Narrowing impinges on nerves in

spinal canal and nerve roots exiting to the legs

• Result - pain & numbness in back and legs

Nerve Root

Spinal Canal

Vertebra

“Trapped” Nerve Root

Bone (Facet Joint)

Ligament Flavum

Healthy Stenotic

Intervertebral Disc

STENOSIS

PREVALENCE

• Most common indication for spinal surgery in patients over 60 y.o.

• 400,000 Americans are estimated to have spinal stenosis

SYMPTOMS

• Neurogenic claudication• Radicular pain• Weakness• Sensory abnormalities• Back pain

PHYSICAL FINDINGSPhysical Finding Literature

Review

• Limited lumbar extension 66-100%• Muscle weakness 18-52%• Sensory deficit 32-58%

• Katz JN, et al: Diagnosis of lumbar spinal stenosis. Rheum. Dis. Clin. North Am. 20:471-483, 1994

NEUROGENIC CLAUDICATION

• Cardinal symptom of lumbar stenosis• Progressive pain and/or paresthesia in the

back, buttock, thigh and calves brought on by walking or standing, and relieved by sitting or lying down with hip flexion

POSTURE & AMBULATION

DIFFERENTIAL DIAGNOSIS

• Vascular claudication• Osteoarthritis of hip or knee• Lumbar disc protrusion• Intraspinal tumor• Unrecognized neurologic disease• Peripheral neuropathy

NONOPERATIVE TREATMENT

• Rest• Analgesic• Oral steroid• Physical therapy• Bracing• Spinal injection

REST

• Short term activity modification for acute pain

• Long term activity modification is not recommended

Lack of activity may lead to: • Obesity• General physical deterioration• Depression/other psychological problems• Worsening of co-morbidities

Treatment of Degenerative Lumbar Spinal Stenosis, Agency for Health and Quality 2004

Disease Burden of LSS

ANALGESIC

• NSAIDS• Tylenol• Narcotics• Neurontin

Oral Steroid

• Effective for acute pain• Short duration therapy• ? Chronic or repeat tapering dose

PHYSICAL THERAPY

• Avoid extension exercises acutely

• William Flexion Exercises

• Water aerobics• Strengthening of weak

muscle groups

SPINAL INJECTIONS

• Epidural steroid• Transforaminal root block• Facet joint injection

EPIDURAL STEROID

• Commonly prescribed• 50% short-term efficacy• Not as selective• May not require

fluroscope

SPINAL INJECTION

• Most effective for acute pain• May not be indicated in cases of acute

denervation or progressive motor loss

OPERATIVE TREATMENT

• Decompression of neural element

• Stabilization of unstable segment

“LAMINECTOMY”

DECOMPRESSION OF LATERAL RECESS

• Undercutting the ventral aspect of the facet joints and the associated ligamentum flavum.

• Medial facetectomy if necessary

• The traversing nerve root underneath the facet joint must be visualized

FUSION

• Sagittal instability• Scoliosis• Iatrogenic pars defect• Greater than 50%

facet joint resection

INSTRUMENTATION

References

• Jung U. Yoo, M.D. Spinal Stenosis. Department of Orthopedics and Rehabiliatation: Oregon Health and Science University.

• Hazem Eltahawy. Lumbar Spinal Stenosis:Symptoms and Treatment. University Neuologic Surgeons