2. References
Campbell’s Operative Orthopaedics,13th ed
Apley and Solomon’s System of Orthopaedics and Fractures,10th
edition
Chapman’s Orthopaedic Surgery
Turek’s orthopaedics principles and their applications, 7th ed
2
4. Introduction
• Spinal stenosis is used to describe abnormal
narrowing of central canal ,the lateral recess or
intervertebral foramena to the point where
neural elements are compromised
• Spinal canal may be round, oval or trefoil in
cross section
• Patient experiences neurological symptoms and
signs in lower limbs
4
5. Introduction
• Verbiest (1954) described classic findings of middle
aged and older adults with back and lower
extremity pain precipitated by standing , walking
and aggravated by hyperextension
• Progressive disorder , involves entire spinal motion
segment
• Results in initial relative instability and
hypermobility of facet joints
5
6. Pathogenesis
• Increased pressure on facet joints with disc space
narrowing and increasing angles of extension
• Hypertrophy of facet joints ( sup articular process)
• Hypertrophic process results in local ankylosis
• Calcification and hypertrophy of ligamentum flavum
• Reduced spinal canal dimensions and compression of
neural elements 6
12. Pathology
• Degeneration of disc occurs with disc narrowing and
ligamentous redundancy
• Central spinal stenosis :involvement of area
between facet joints which is occupied by dura and
its contents
• Symptomatic stenosis results in neurologic
claudication
• Stenosis caused by :
– Protruded disc
– Bulging annulus
– Osteophyte
– Buckled / thickened ligamentum flavum 12
13. Anatomy
Zones of lateral canal as
described by Lee.
Entrance zone (1) is comprised
of cephalad and medial aspects
of lateral recess, which begins at
lateral aspect of thecal sac and
runs obliquely down and
laterally toward intervertebral
foramen.
Midzone (2) is located beneath
pars interarticularis and just
inferior to pedicle and is
bounded anteriorly by posterior
aspect of vertebral body and
posteriorly by pars; medial
boundary is open to central
spinal canal.
Exit zone (3) is formed by
intervertebral foramen.
13
14. Pathology
• Lateral recess : Lee’s entrance zone : begins at
lateral border of dura , extends to medial border
of pedicle
• Site where nerve root exits the dura
• Facet arthritis more commonly causes stenosis in
this zone 14
15. Pathology
• Foraminal area : Lee’s midzone : lies ventral to pars
• Dorsal root ganglion and ventral motor root occupy
> 30% of space
• Point where dura becomes confluent with nerve
root
• Causes : pars fracture , proliferative fibrocartilage ,
lateral disc herniation , thickened lig. flavum 15
16. Pathology
• Lee’s exit zone : area lateral to facet joint
• Nerve root present here
• Likely compresses by :
– “Far lateral” disc
– Spondylolysthesis
– Facet arthritis
16
17. Pathology
• Most common type
– Degenerative arthritis of spine
– Forestier’s disease
• Other causes :
– Paget’s disease
– Fluorosis
– Kyphosis
– Scoliosis
– Fracture with canal narrowing
17
18. Natural History
• Not all patients with narrowing develop symptoms
• Many asymptomatic patients have significant
radiologic findings
• Conservative treatment sufficient in >50 % of
cases , time of treatment may be needed upto 3-5
years
18
19. Clinical Evaluation
• Patient profile : Man > 50 years
• Complaints :
– Aching , heaviness , numbness , paraesthesia in thighs
and legs
– Comes on standing upright or walking for 5 -10 mins
– Relieved by sitting ,squatting , leaning against wall
– Grocery cart sign
– Patient prefers walking uphill
• Examination :
– On asking patient to walk , symptoms /neurological
symptoms revealed 19
20. Clinical Evaluation
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
Skin Loss of hair; shiny Normal
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 20
21. Imaging
• Xrays :
– Short pedicles on lateral view
– Narrowing between pedicles on AP view
– Ligament ossification
– Foraminal narrowing
– Hypertrophy of posterior articular facets
• Methods of identifying central canal stenosis
– AP canal measurement by CT ( Normal : 11 – 15mm)
– Measurement of transverse dural sac area with
myelography (Normal : >100mm2)
21
22. Imaging
• Flexion and extension views – identify
instability hence need of fusion
• Translation of >4mm or rotation of >10-15°
indicates instability
• A reversal of normal trapezoidal disc geometry
with widening posteriorly and narrow
anteriorly also indicates instability
22
29. Imaging
• CT Myelography :
– CT + Myelography Dx accuracy in 90% cases
– More useful in surgical planning
– Best suited for patients with dynamic stenosis ,
postoperative leg pain , severe scoliosis ,
spondylolysthesis
• Other studies :
– Electro diagnostic studies :
• Used if diagnosis of neuropathies esp. diabetes is uncertain
• Differential diagnosis aided by exercise testing
29
31. Imaging
This axial CT image
from a CT
myelogram of the
cervical spine
demonstrates left-
sided spondylosis
(black arrow)
resulting in lateral
recess stenosis
(double yellow
arrow) and lateral
neuroforaminal
stenosis (white
arrow) 31
33. Non Operative treatment
• Conservative management successful in most
patients
• Includes :
– Rest upto 2 days
– Pain management
– Trunk stabilization exercises
• Epidural steroids :
– Used commonly if symptoms persist
– No scientifically long term outcomes validated till date
– Technique of placement : caudal , translaminar or
transforaminal is also debatable
33
34. Non Operative treatment
• Epidural steroids : Rationale :
– Edema and venous congestion of nerve roots leads to
compression and ischemic neuritis
– Leakage of neurotoxins ,phospholipase , leukotriene B
– Corticosteroids decrease inflammation , leukocyte
migration , inhibition of cytokines and membrane
stabilization
• Complications :
– Headache
– Dural puncture
– Hypercorticism
– Epidural hematoma 34
35. Non Operative treatment
• Complications :
– Retinal hemorrhage
– Epidural abscess
– Chemical meningitis
– Intracranial air
– Temporary paralysis
• Ideal candidate :
– Acute radicular symptoms or neurogenic claudication
unresponsive to traditional analgesics and rest with
significant impairment of activities of daily living
35
36. Operative treatment
• Reserved for patients with increasing pain
completely unresponsive to conservative
management
• Better results seen with :
– Disc herniation
– Single level
– Weakness of less than 6 weeks duration
– Monoradiculopathy
– Age < 65 years
• Neurologic symptoms more readily resolved than
pain 36
37. Operative treatment
• Principles of Surgery :
– Decompression by laminectomy or fenestration is the
procedure of choice
– If excess bone resection creates instability , fusion
indicated
– Other indications for fusion :
• Spondylolysthesis , scoliosis or Kyphosis
• Adjacent segment degeneration
• Recurrent stenosis or herniated disc after degeneration
– Proceed from area of less stenosis to more stenosis so
as to free the neural structures
37
38. Operative treatment
• Adjacent segment degeneration :
– Disc degeneration occurs adjacent to a fusion because
of the ensuing hypermobility of the unfused joint
– Adjacent segment breakdown may cause symptoms
that require surgery in 30%
– Fusion is more difficult as the number of levels fused
increases, with L4-5 being the most frequent site of
pseudarthrosis
– Sx should attempt to maintain normal segment
lordosis & global sagittal balance , in addition to
fusing fewest segment possible
38
39. Operative treatment
• Decompression
– “Ideal patient” : with pronounced constriction of the
spinal canal, significant lower back pain, no
concomitant disease affecting walking ability, and a
symptom duration of less than 4 years
– Traditional : Removal of the spinous processes,
laminae, variable portions of the facets and pars,
supraspinous and interspinous ligaments, ligamentum
flavum, and portions of facet capsules
– minimally invasive technique : decompression of the
significant compressing anatomy, while preserving
paraspinal muscles, the spinous processes, and
intervening supraspinous and interspinous ligaments39
40. Operative treatment
• Bilateral laminectomy :
• Bilateral laminectomies for all affected levels
• Attempt made to spare pars
• If discectomy performed, consider arthrodesis
– Complications
• Facet fracture
• Post op spondylolisthesis : Usually L4-5
40
41. Operative treatment
• Hemilaminectomy
– Patients with unilateral surgery
– Better preserves post op stability
– Difficulty in accessing
• Contralateral side
• Neural foramen
– Risk for dural tear
– Increased stability, decreased exposure
– Removes ligamentum flavum, sup aspect of inferior
lamina, inferior aspect of superior lamina
– Partial facetectomy 41
42. Operative treatment
Spinous process osteotomy
Spinous process osteotomy. A, Muscle is taken down on only one side
and only to medial facet border. B, Decompression is performed under
microscopic magnification. C, After closure, spine returns to normal
position
42
43. Operative treatment
Midline decompression ( neural arch resection)
Typical midline
decompression for spinal
stenosis. Medial
facetectomy and
foraminotomy with
preservation of the pars.
Decompression is from
inferior border of L3
pedicle to superior border
of L5 pedicle, exposing
both lateral borders of
dura in lateral recess
43
44. Operative treatment
• Decompression with Spinal fusion
– Generalized spinal stenosis that requires extensive
decompression with the loss of multiple articular
processes may require fusion
– Fusion should be considered after decompression and
excision of synovial cysts in patients with spinal
stenosis with or without preoperative instability as
cysts reflect derangement of facet joint
– Types of fusion :
• Anterior lumbar interbody fusion
• Posterior lumbar interbody fusion
• Posterior or posterolateral fusion 44
45. Operative treatment
Lateral view of a
lumbar myelogram
performed in a
patient who has
been fused across
the L4-L5 and the
L5-S1 vertebral
interspaces using
transpedicular
screws
45
46. Interspinous distraction
• A spacer is inserted into interspinous space as
far anteriorly and as close to posterior aspect
of lamina
• Requires no ligamentous or bony resecion
• Spinal canal is not breached, eliminating risk
of neural damage.
46
49. summary
• Spinal stenosis: narrowing in the spine that
results in nerve compression
• Results in pain,numbness, and weakness
• Treated with non-surgical and surgical options
• The goals of surgery are to alleviate the nerve
compression to relieve pain, improve function
and restore quality of life.
49
