SPINAL STENOSIS Jung U. Yoo, M.D. Professor and Chairman Department of Orthopedics and Rehabiliatation Oregon Health and Science University

STABILITY ORDINARY ACTIVITIES MAY GENERATE OVER 1000LB OF FORCE

MOTION

NEUROPROTECTION SPINAL CORD NERVE ROOTS

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

STENOSIS

Compresses the exiting nerve root FORAMINAL STENOSIS

CANAL SHAPE Round Triangular Trefoiled (15%) Trefoiled & asymmetric

DEGENERATION & STENOSIS

PREVALENCE Most common indication for spinal surgery in patients over 60 y.o. 400,000 Americans are estimated to have spinal stenosis

STENOSIS Narrowing of the spinal canal or neuroforamina causing a symptomatic compression of the neural element.

SYMPTOMS Neurogenic claudication Radicular pain Weakness Sensory abnormalities Back pain

PHYSICAL FINDINGS Physical Finding Literature Review Limited lumbar extension66-100% Muscle weakness18-52% Sensory deficit32-58% Katz JN, et al: Diagnosis of lumbar spinal stenosis. Rheum. Dis. Clin. North Am. 20: , 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

Root symptoms Unilateral No claudication Acute or chronic FORAMINAL STENOSIS

Claudication Radicular pain Weakness is rare Acute or chronic LATERAL RECESS STENOSIS

CENTRAL STENOSIS Varied presentation Classically with neurogenic claudication Some may only have back pain Rarely painless progressive weakness

DIAGNOSTIC TESTS

X-RAY Screening exam Stenosis cannot be diagnosed

X-RAY Instability such as scoliosis or listhesis

CT SCAN Difficult to diagnose stenosis Replaced by MRI May be useful for those who cannot have an MRI

CT SCAN Excellent bony detail

MRI Non-invasive Soft tissue visualization Gold standard

MRI Sagittal images Visualization of foramen

Excellent for intra-canal pathology Poor for foraminal pathology Replaced by MRI MYELOGRAPHY

Invasive 1% spinal headache Recurrent stenosis Inability to obtain MRI MYELOGRAPHY

MYELOGRAPHY

Excellent visualization of spinal canal CT-MYELOGRAPHY

Excellent for recurrent stenosis Invaluable in surgical planning CT-MYELOGRAPHY

MRI Expensive Patient cooperation Claustrophobia Open MRI

EMG-NCS Differentiation between neuropathy and radiculopathy Acute active denervation vs. chronic denervation

TREATMENT

NONOPERATIVE RX Rest Analgesic Oral steroid Physical therapy Bracing Spinal injection

REST Short term activity modification for acute pain Long term activity modification is not recommended

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

TRANSFORAMINAL ROOT BLOCK Highly selective Diagnostic as well as therapeutic Delivers medicine to the floor of spinal canal

FACET INJECTION Facet for back pain Not for radicular pain May act as epidural in 40% of cases

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

Thank you