Spinal canal stenosis

Lumbar spinal canal stenosis is one of the difficult topic of spine. All the information are taken from Campbell's operative orthopedics Thirteen edition and from internet. I also took help from the lectures of renowned orthopedics professors of Bangladesh.

1. Basics Of Spinal canal stenosis Prepared by Dr. Md. Ashiqur Rahman Resident,DMCH

2. Introduction: I t is the narrowing of the spinal canal and the consequent compression of cord and nerve roots. It may affect cervical, thoracic or lumbar spine. Common in lumbar vertebrae.

3. Diameter of spinal canal & foramen: AP 15mm and transverse diameter 20mm. AP<11mm and transverse diameter <16mm is abnormal.

4. Vascular symptoms typically are felt in the upper calf, are relieved after a short rest (5mins.) while still standing, do not require sitting or bending and worsen despite walking uphill or riding stationary bicycle. Neurogenic claudication improve improves with trunk flexion, stooping or lying but may require 20 minutes to improve.

5. Extension – occurs when standing Flexion – Occurs when sitting or bending forward Anatomy of the Spine Understanding your spine: Helpful Terms

6. Lateral canal Lateral to the dura is the lateral canal, which contains nerve roots. 1. Lateral recess also known as ‘lee’s entrance zone’. 2. Foraminal region also known as ‘lee’s midzone ’. 3. Extra- foraminal region also known as ‘Exit zone’

7. 1. Central spinal canal stenosis Denotes involvement of area between the facet joints. Which is occupied by the dura and it’s contents. Stenosis in this region caused by: Protrusion of a disc. Bulging annulus. Osteophyte Buckled or thickened ligamentum flavum .

8. 2.Lateral recess stenosis ( This is where the nerve roots exit the dura & courses distally & laterally under the superior articular facet) Boundary: Anteriorly: Disc and the posterior ligamentous complex. Posteriorly : The superior articular facet. Laterally : Medial border of Pedicle. Medially : The central canal. Stenosis in this region caused by : Facet arthritis Vertebral body spur Annulus pathology

9. 3.Foraminal stenosis Boundary : (Which lies ventral to the pars) Anteriorly : Posterior vertebral body & disc. Posteriorly : Pars interarticularis Medially : Lateral recess Laterally : Lateral border of the pedicle. Stenosis in this region: Pars fracture Lateral disc herniation Thickening of ligamentum flavum A spur from underlying surface of pars

10. 4. Extra- foraminal (Far-out) Boundary : The exit zone is identified as the area lateral to the facet joint. Stenosis in this region : A ‘far lateral’ disc. Spondylolisthesis Associated subluxation Facet arthritis

11. Stenotic Lumbar Vertebra Vertebrae provide body support Discs act as “shock absorbers” Vertebra protects spinal cord and nerves Nerves have space and are not pinched As we age, ligaments and bone can thicken Narrowing is called “stenosis” Narrowing squeezes nerves in spinal canal and nerve roots exiting spine to legs Result - pain & numbness in back and legs Nerve Root Spinal Canal Bone (Facet Joint) Healthy Intervertebral Disc Thickened Ligament Flavum Pinched Nerve Root Narrowed Spinal Canal

12. Spinal Pain Axial Pain – Back Pain From bones, joints, muscles, discs Neurogenic Pain – Leg Pain +/- Tingles From nerve irritation

13. Classification of spinal canal stenosis: A) Anatomic: Anatomic Area Anatomical Region (Local segment) 1. Cervical ( i )Central (ii) Foraminal 2. Thoracic ( i )Central (ii)Lateral recess (iii) Foraminal (iv)Extra- foraminal (Far-out)

14. B) Pathologic: Congenital: Achondroplastic (Dwarfism) Congenital forms of spondylolisthesis Scoliosis Kyphosis 2. Idiopathic

15. 3. Degenerative & inflammatory: Osteoarthritis Inflammatory arthritis Diffuse idiopathic skeletal hyperostosis Scoliosis Kyphosis Degenerative forms of spondylolisthesis 4. Metabolic: Paget disease fluorosis

16. Difference between neurogenic claudication & vascular claudication Evaluation Vascular neurogenic Walking distance Fixed Variable Palliative factors Standing Sitting/Bending Provocative factors Walking Walking /Standing Walking uphill painful Painless Bicycle test Positive (painful) Negative Pulses Absent Present Weakness Rarely Occasionally Back pain Occasionally Commonly Back motion Normal Limited Pain character Cramping -distal to proximal Numbness , aching-proximal to distal Atrophy Uncommon Occasional

17. Sitting or bending forward relieves symptoms Standing provokes symptoms Pain/weakness in the legs Patients lean forward while walking to relieve symptoms Symptoms of Lumbar Spinal Stenosis (Elevator Syndrome)

18. Symptoms of Lumbar Spinal Stenosis Classic Presentation: Dull or aching back pain spreading to your legs Numbness and “pins and needles” in your legs, calves or buttocks Weakness, or a loss of balance A decreased endurance for physical activities

19. Clinical features: Male>50 years Low backache Cauda equina claudication (Most common symptom) Stoop test : Positive---walking---increased pain---stooped---decreased pain(due to canal length increased by 2.2mm). Bicycle test : Positive Walking test: Positive.

20. Investigations: X-ray L/S spine – AP, Lateral & Oblique view. D ecrease inter-pedicle distance Hypertrophy & stenosis of the facet joint D ecreased intra-laminar distance S hort, stout spinous process Associated features : Presence of listhesis , prolapsed disc, osteophytes.

21. Myelography : Waist like narrowing of the dural sac. Identation of dural sac due to disc prolapse. MRI

22. Treatment Options

23. Lumbar Spinal Stenosis Treatment Standard of Care: Mild to Moderate Symptoms Non-operative care: Avoid activities that bring on pain (24 Hour Thermostat) Impact aerobics Frequent bending, twisting, lifting Non-Steroidal Anti-Inflammatory Drugs (NSAIDs), Herbals Physical Therapy, Chiropractic, Exercise & Weight Reduction To help stabilize the spine Lessen the burden on the spine Reduce irritation of pain sensitive structures

24. Lumbar Spinal Stenosis Treatment Standard of Care: Mild to Moderate Symptoms Epidural Steroid Injection Reduce swelling and inflammation of nerves May or may not be effective (24-48 Hours) Can break a pain cycle but will not correct underlying problem Typically limited to 3-4 injections every 12 months

25. Principles of spinal stenosis surgery Decompression by laminectomy or a fenestration procedure is the treatment of choice for lumbar spinal stenosis. Laminectomy may be required is older patients and severe multilevel stenosis. Whereas fenestration procedure, consisting of bilateral laminotomies and partial facetectomies , that preserve midline structures, are an alternative in younger patients with intact disc.

26. Principles of spinal stenosis surgery If radical decompression of only one root is necessary, additional stabilization by fusion with or without instrumentation is usually unnecessary. The removal of more than one complete facet joint may require instrumented fusion.

27. Fenestration : Making a hole in the ligamentum flavum .

28. Lumbar Spinal Stenosis Treatment Standard of Care: More Severe Symptoms Laminectomy Un-roofing the spine, Opening the “pipe” Removal of parts of the vertebra, including: Lamina (bone) Attached ligaments Facets (bone) Goal: relieve pressure on nerves by increasing size of spinal canal and nerve exit openings Most common surgery for stenosis, may require a fusion General anesthesia In-patient procedure 6-12 week recovery .

29. Lumbar Spinal Stenosis Treatment Options Surgical Care Laminectomy Laminectomy with Fusion Non Operative Care Lifestyle modification NSAIDs & other drugs Exercise & weight reduction PT, Chiropractic Epidural injections Spinal Stenosis Symptoms: Continuum of Care Mild Severe Moderate Atlas - Clin Orth Rel Res 2006 .

30. Lumbar Spinal Stenosis Treatment Options Surgical Care Laminectomy Laminectomy with Fusion Non Operative Care Lifestyle modification NSAIDs & other drugs PT, Chiropractic Epidural injections X-STOP ® Spacer Spinal Stenosis Symptoms: Continuum of Care Mild Severe Moderate .

31. The X-STOP ® Spacer Spacer only limits extension Wings prevent side-to-side and upward migration Preserves your supraspinous ligament, which prevents backward migration Preserves anatomy Treats LSS symptoms, not “anatomy” Supraspinous ligament Spinous process

32. X-STOP ® Superior to Non-operative Care Differences between X-STOP and Control groups statistically significant (p < 0.001) at all follow-up intervals. (all 3 criteria) SOURCE: X-STOP ® IPD ® System Summary of Safety and Effectiveness (SSE); Includes all study sites.

33. The X-STOP Spacer Compared to traditional LSS surgery, X-STOP benefits include: Can be done under local anesthesia Can be done as an outpatient procedure No removal of the lamina (vertebral bone) or ligaments that protect and stabilize the spine Potential of a shorter recovery

34. Are you a candidate? The X-STOP Spacer is indicated for: People aged 50 or older Pain or weakness in the legs Confirmed diagnosis of lumbar spinal stenosis Moderately impaired physical function Experience symptom relief in flexion (sitting) Completed 6 months of non-operative treatment Operative treatment indicated at one or two lumbar levels (but no more than 2 levels)

35. X-STOP ® IPD ® System Instructions For Use (IFU) Contraindications The X STOP is contraindicated in patients with: an allergy to titanium or titanium alloy; spinal anatomy or disease that would prevent implantation of the device or cause the device to be unstable in situ, such as: significant instability of the lumbar spine, e.g., isthmic spondylolisthesis or degenerative spondylolisthesis greater than grade 1.0 (on a scale of 1 to 4); an ankylosed segment at the affected level(s); acute fracture of the spinous process or pars interarticularis significant scoliosis (Cobb angle greater than 25 degrees); cauda equina syndrome defined as neural compression causing neurogenic bowel or bladder dysfunction; diagnosis of severe osteoporosis, defined as bone mineral density (from DEXA scan or some comparable study) in the spine or hip that is more than 2.5 SD below the mean of adult normals in the presence of one or more fragility fractures; active systemic infection or infection localized to the site of implantation.

36. X-STOP® Interspinous Process Decompression (IPD®) System 16000805 Rev 1

37. Thank you