1	Lumbar Spinal Stenosis D. Scott Kreiner, MD
2	Spinal Stenosis Low back pain is the second most common reason that patients seek medical care More health care dollars are spent on back pain than any other condition 3-6 million patients in US with chronic back pain Of patients who see a specialist for back pain, 13-14% have spinal stenosis Other causes include more disc injuries, posterior element pain, instability, fracture, etc
3	Lumbar Spine Five vertebral bodies Sacrum Five intervertebral discs Five lumbar nerve roots exit through the intervertebral foramen Five sacral nerve roots exit through the sacral foramen
4	Spinal Canal Bordered anteriorly by the vertebral body or intervertebral disc Bordered laterally by the pedicles Z-joints posterolateral Posteriorly bordered by lamina and ligamentum flavum
5	Intervertebral Disc Nucleus Pulposus - Semifluid mass with consistency similar to toothpaste Anulus fibrosis - 10-20 sheets (average 17) of collagen fibers called lamellae arranged in concentric rings surrounding the nucleus
6	Vertebae Layer of cartilage 0.6-1mm thick Covers the area on the vertebral body encircled by the ring apophysis Made of hyaline cartilage (near vertebral body) and fibrocartilage (near anulus) Deficient subchondral bone over about 10% of the vertebral end-plate allows nutrients from the marrow to diffuse into the nucleus
7	Innervation Outer 1/3 of anulus and PLL innervated by sinuvertebral nerves Anterior disc has some sensory input through sympathetic trunk Posterior spinal elements carry nociception through medial branch nerves
8	Dermatomes May be described as numbness, an “ache”, or less commonly paresthesias Dermatomes suggestive but not absolute
9	Myotomes T12, L1, L2, L3 Iliopsoas L2, L3, L4 Quadriceps Hip adductor group L4 Tibialis anterior Knee Jerk reflex L5 Extensor hallucis longus Gluteus medius Extensor digitorum longus & brevis S1 Peroneus longus & brevis Gastrocnemius-Soleus Gluteus maximus Ankle Jerk reflex
10	Lumbar Stenosis Congenital (Developmental) Acquired (Degenerative) Herniated Disc Spondylolisthesis Osseous
11	Congenital Lumbar Stenosis Normally the spinal canal reaches “adult size” by age 4 If it does not reach this size by that age, it will not catch up Radiographs reveal shortened pedicles (10-12mm in length) Stenosis is uniform throughout the spine
12	Other Conditions that May Contribute to Spinal Stenosis Bone dysplasia Calcium pyrophosphate deposition Congenitally short pedicles Achondroplastic dwarfism Diffuse idiopathic skeletal hyperostosis Infection Metabolic bone disease Hypoparathyroidism Renal osteodystrophy Ossification of the posterior longitudinal ligament Paget's disease of bone Previous lumbar surgery Senile ankylosing hyperostosis of the spine Vertebral osteomyelitis Discitis Tumors Epidural lipoma Intraspinal tumors or cysts
13	Degenerative Stenosis Hypertrophic Z-joints Ligamentum flavum hypertrophy Diffuse disc bulging usually present
14	Multifactoral Lumbar Stenosis
15	Spondylolisthesis A common cause of spinal stenosis May be a result of degenerative or isthmic listhesis Segmental instability more concerning that a “fixed” listhesis
16	Diagnosis History Examination Imaging Electrodiagnostic Studies Provacative Discography
17	Complaints (Historic Features) Frequently present with diffuse low back pain, may be chronic or recently started Have difficulty standing or walking for prolonged period of time Pain increases with extension Patients may assume a simian posture, stooped with flattening of normal lumbar lordosis Classically, symptoms reduce when pushing a shopping cart Degenertive stenosis is most common in patients 55-64 years in age Lumbar instability is more common in patients under 45 years of age Most common presenting complants¹: Back pain (95%) Claudication (91%) Leg pain (71%) Weakness (33%) Bladder disturbances (12%)
18	Claudication
19	Physical Examination Back pain is the most common complaint in patients with stenosis Patients typically demostrate a symian posture (stooped with flattening of normal lumbar lordosis) Peripheral vascular signs absent Focal weakness is not typically present, may demonstrate weakness in myotomes below the level of weakness
20	Electrodiagnostic Studies Sensitivity is very low in patient’s with lumbar radicular pain; about 77% sensitive if radiculopathy present¹ Few indications: Exclusion of more distal nerve damage Verification of subjective muscle weakness in patients presenting pain inhibition or lack of cooperation Recurrent surgical decompression if difficult surgery is expected No trials looking at the sensitivity of EMG to diagnose stenosis Electrophysiological evaluation does not directly evaluate neurologic mechanisms associated with pain generation Can not accurately determine the precise spinal nerve level
21	Radiographs Shows bones only Helpful in older patients where cause of stenosis is likely to be a result of degenerative changes or listhesis If spondylolisthesis is present, need flexion and extension views to evaluate for segmental instability Scoliosis evaluation may be beneficial in some cases
22	CT Scan Preferred method for bony evaluation of spine May diagnose disc pathology though sensitivity very low compared with MRI Helpful in fractures or other bony abnormalities, 3D reconstruction sometimes useful Role in disc pathology limited to post-discography scanning or post myelography scan
23	MRI
24	MRI Order urgently if Cauda Equina Syndrome red-flag condition exists If no red-flag: Refrain from imaging on first visit, especially if early in course; wait until symptoms have persisted for ~6-7 wks Attempt conservative management prior to MRI Need MRI if surgery or possibly epidurals considered
25	MRI
26	Myelogram Study of choice when MRI can not be done Can effectively identify the location of narrowing Frequently an uncomfortable procedure Post-myelogram CT can give additional information about canal contents
27	Treatment Options NSAIDs COX-II Inhibitors Oral Steroids Muscle Relaxants Narcotics TENs Physical Therapy Epidural Steroid Injections Laminectomy Multiple Laminotomy Fusion
28	NSAIDs Helpful in reducing acute and sub-acute pain May have therapeutic effect on decreasing epidural inflammatory response COX-II inhibitors equally as effective as non-selective NSAIDs, safety profile better Should be first line agent
29	Oral Steroids Can help decrease epidural inflammation Reserve for use in patients with severe pain Systemic effects greater than for epidural steroids Know safety profile
30	Muscle Relaxants Gaba Agonists Baclofen (lioresal) Alpha₂ Agonists Zanaflex (tizanidine) SR Calcium Channel Blockers Dantrium (dantrolene) CNS depressants Soma (carisoprodol) Robaxin (Methocarbamol) Skelaxin (Metaxalone) Flexeril (Cyclobenzaprine) Benzodiazepines
31	Narcotics Helpful for severe, acute pain Lay out timeline to get patient off Avoid long-term use Plan for constipation, stool softeners with script
32	Physical Therapy No large, or controlled studies on the effectiveness of physical therapy for spinal stenosis Small observational studies indicate that manual therapy, core strengthening, individualized exercise programs and a walking program are beneficial in reducing pain and walking ability^1,2,3 Should be used in conjunction with other treatment modalities (oral agents, injections, etc)
33	Chiropractic Care Lumbar stabilization is more effective than manipulation in long term pain relief¹ Modality care can be helpful in reducing inflammation and pain symptoms No trials to support chiropractic manipulation aids in reducing symptoms or pathology from spinal stenosis Can cause injury if mobilizes spine through an unstable spondylitic segment
34	Epidural Steroid Injections Have been shown to provide some patients with sustained relief and improve function in over ½ of patients¹ ESIs in patients with spinal stenosis are not as effective as ESIs in patients with herniated discs²
35	Epidural Steroid Injections Approaches: Caudal Interlaminar Transforaminal Blind vs Flouroscopically-guided
36	Caudal Epidural Steroid Injections Effective for multilevel pathology including spinal stenosis Uses most volume of any approach Non-selective May be performed under flouroscopic guidance or blind
37	Epidurogram
38	Interlaminar Epidural Steroid Injections May be done in office setting Does not require use of flouroscopy Covers a broader area than transforaminal injections since higher volume is used Solution placed in posterior epidural space In patients with spinal stenosis, access at the symptomatic level is difficult and can be dangerous
39	Transforaminal Epidural Steroid Injections Direct injectate to the anterior epidural space Diagnostic and therapeutic Lower volume of injectate Much lower risk of dural puncture and associated headache Decrease leg pain and increase standing and walking tolerance in LSS
40	Flouroscopic vs Blind Injections Flouroscopic guidance is the only way to ensure that solution travels to the target location Flouroscopy decreases risk of complications Flouroscopic guidance is more effective than blind injections Flouroscopy does have risks associated with radiation exposure, though exposure is very limited
41	Laminectomy Indicated when a stenosis symptoms exist for more than 8 weeks despite conservative care Patients with severe symptoms seem to benefit more from surgery than conservative treatment¹ More urgent if has progressive loss of motor, bladder, or bowel function or there is excruciating pain that can not be relieved by non-operative treatment Delay for longer than 6 months in face of persistent and severe symptoms may compromise best results
42	Fusion Major indication in stenosis is for patients with spondylolisthesis Usually done in addition to laminectomy in these cases A solid fusion increases success¹, while posterior instrumentation may not be necessary² Risk failure at levels surrounding fusion
43	Red Flags Cancer Related Red Flags History of cancer Unexplained weight loss >10 kg within 6 months Age over 50 years or under 17 years old Failure to improve with therapy Pain persists for more than 4 to 6 weeks Night pain or pain at rest Cauda Equina Syndrome Related Red Flags Urinary incontinence or retention Saddle anesthesia Anal sphincter tone decreased or fecal incontinence Bilateral lower extremity weakness or numbness Progressive neurologic deficit Infection Related Red Flags Persistant fever (temperature over 100.4 F) History of intravenous drug abuse Recent bacterial infection UTI or pyelonephritis Cellulitis Pneumonia Immunocompromised states Systemic corticosteroids Organ transplant Diabetes mellitus HIV Rest Pain Acute Abdominal Aneurysm Red Flags Abdominal pulsating mass Atherosclerotic vascular disease Pain at rest or nocturnal pain Age greater than 60 years
44	Scott Kreiner, MD skreiner@ahwatukeesportsandspine.com Office: (480) 763-5808 Cell: (602) 363-6180