spondylolisthesis

1. SPONDYLOLISTHESIS
Dr. Mohammad Masoom Parwez
PG student

2. DEFINITION
• Spondylolisthesis is a condition in which one of
the vertebra slips over the vertebra below it.
• A crack in a vertebra, without slippage, is called
spondylolysis.
• Defect in pars articularis called spondylosis
• Spondylolisthesis a greek word means –
Spondylos – bone
Olisthos – Sliding down

3. History
• Herbinuax ( 1782) – Described it as a prominence in
front of serum
• Killian ( 1854) – Coned term spondylolisthesis
• Robert ( 1855) – First to assert that spondylosis was
due to defect in pars articularis
• Neugbauer ( 1881) – Slippage may be due to
elongation of pars without any defects.
• Newman ( 1963) – Showed that spondylolisthesis
caused by advancing age to the degenerative
disease.

4. Anatomy
Facet joint in coronal plane -
– Inferior articular process (upper vertebra) located
posteriorly
– Superior articular process (lower body) located
anteriorly.
• Prevents forward movement
• Locks in the superior vertebra relative to the
inferior vertebra

5. Anatomy
• Orientation of articular
processes is critical for spinal
motion
• Lumbar facets are biplanar
– General orientation is 45 deg
from sagittal or frontal plane
– 90 deg from transverse plane
• Anterior aspect in frontal plane
– Resists anterior shear
• Posterior aspect in sagittal
plane
– Resists rotation

6. Anatomy
• Center of gravity of the human body
is anterior to the spine -
• It exerts a forward slipping force on the
spine, especially at L5-S1 level
• Anteriorly located center of gravity
causes a rotating movement, with the
axis of rotation oriented transversely at
the L5-S1 level
• In severe spondylolisthesis, a kyphotic
deformity also develops

7. Anatomy
• Forward slip of the fifth vertebra is resisted by:
– bony locking of posterior facets,
– intact neural arch and pedicle,
– normal bone plasticity preventing stretch of the
pedicle, and
– intervertebral discs bonding vertebral bodies together
• Breakdown of this normal locking mechanism
occurs with articular defects and defects in the
neural arch.

8. ETIOLOGY
• Multifactorial
• Congenital predisposition
• Biomechanical factors
• Gravitational and postural forces causes stress at
pars interarticularis
• Lumbar lordosis and rotational forces also play role
• High levels of activity during childhood
• Genetic factors

9. Classification :Newman in 1963
but Wiltse published in 1976
• I. Dysplastic (congenital)
• II. Isthmic
– A. Lytic- fatigue fracture of the pars.
– B. Elongated but intact pars.
– C. Acute fracture of pars (not to be confused
with "traumatic").
• III. Degenerative
• IV. Post Traumatic ( fracture of the bony hooks
other then pars)
• V. Pathologic
• VI. Iatrogenic

10. TYPE 1- DYSPLASTIC
• Also called congenital
• Represents a defect in the upper sacrum or neural arch
of L5, posterior elements & facet joints.
• High rate of nerve root compression at S1 foramen
• Normally the L5 S1 joint is coronally oriented
• Change in axial orientation lead to instability
1.Type Ia Hyposagittal (  coronal orientation )
2.Ib Hypersagittal ( Exaggerated coronal
orientation)

11. TYPE 2- ISTHMIC
• Occurs early in life
• Defect in pars interarticularis
• Orientation of articular process is normal
• abnormality of pars interarticularis separates the inferior
facet from L5 body, allowing forward slippage.
• 3 types
Type A – Defect in pars interarticularis
Type B – Pars elongated but intact
Type C – fractured pars

12. ISTHMIC SPONDYLOLISTHESIS
• Characterised by bilateral defect
• Hereditary tendency
• Isthmic spondylolisthesis most commonly affects L5-S1
• The stress fracture most often occurs in early childhood
but the slippage often occurs later - during periods of
rapid growth. Slippage is uncommon after adolescence
• It is a common cause of back pain in children. While one
of 20 children may have this condition, only 1/1000 ever
requires surgery

13. TYPE 3- DEGENERATIVE
• Occurs late in life
• Acquired condition resulting from disc
degeneration and facet incompetence
• Leads to segmental instability and gradual
slippage usually at L4-L5
• Seen more at L4-5 as L5-S1 is protected by
transverse alar ligament.
• L5-S1 lie below iliac crest (so protected from
motion)

14. TYPE 3- DEGENERATIVE
•  in lumbar lordosis
 shear strain at facet joints

• Sets up a vicious cycle

• Degenerative lithiasis (This involves intervertiberal disc,
ligaments , facet joints complexes)
• Hence it may present as :
1. Spondolytic instability
2. Lumbar stenosis with potential lithiasis
3. lumbar stenosis with stable lithiasis

15. TYPE 4- TRAUMATIC
• Occurs at any age
• This include lithiasis
gradually occurring
after injury
• Acute fracture
dislocations are
excluded
• # of pedicle also falls in
this groups.
CERVICAL TRAUMATIC
SPONDYLOLSTHESIS

17. TYPE 5- PATHOLOGICAL
• Due to generalized or focal disease of bone
leading to instability and inability of the
spine to resist the forward thrust by weight
of trunk e.g. in
• Paget’s disease
• Achondroplasia
• Osteogenesis imperfecta
• Infectious & tumors of bone
• Marfan syndrome

18. Iatrogenic spondylolisthesis
Described by Unander scharin
• Follows spinal fusion
• Defect in pars appears usually in pars at level
and immediately adjacent to fusion
i. Attributed to devitalization of pars due to
subperiosteal dissection and decortication
ii. Related to facet joint orientation in
multiple level laminectomies

19. Clinical presentation
Isthmic and dysplastic type-
• Palpable step-off of lumbar spinous processes.
• In severe cases, bodies may be palpable through
abdominal wall.
• Exaggerated lumbar lordosis stance to compensate for
kyphosis with pelvic tilt (i.e. sacrum becomes vertical)
• Tight hamstring syndrome is seen in younger patients
– Stooped posture with flexion at hip and knees with
waddling gait.
• SLR may be positive

20. Clinical presentation
• LBA worse with activity and improved with rest (suggest
mechanical nature)
• (Maneuvers involving hyperextension and rotation, such as
standing on one leg while leaning backward worsens pain)
• Pain Localised to area of listhesis,
• Reduced lumbar mobility, paraspinal muscle spasms
• There is Higher incidences of pain when
– Listhesis >25%,
– Degeneration at level of slippage,
– listhesis of L3 or L4

21. Clinical presentation
• Symptoms may also be attributable to
secondary processes like Neurogenic
claudication ..
• Need to differentiate from vascular
claudication
– Forward flexion (‘shopping cart sign’),
– worsening of pain on extension,
– worsening of pain on bicycling- vascular
claudication

22. Clinical presentation
Remember :
• High grade spondylolisthesis may cause
increased pain with flexion and possibly
decreased by extension
(This is an evidence to support that slippage
rather than central stenosis is the primary
cause for symptoms)

23. Differential diagnosis
• Confounding findings on physical exam. may
be d/t osteoarthritis of hip
• Provocative hip motion test will not produce
pain in pure spondylolisthesis
• 11 - 17 % of patients with degenerative
listhesis have osteoarthritis of spine- therefore
variable symptoms
• Pure Osteoarthritis: normal strength &
sensation, & reflexes normal.

24. Differential diagnosis
Others are:
• Sacroiliac joint disease,
• diabetic neuropathy,
• vascular disease,
• spinal stenosis,
• disk disease,
• spondylosis, other sacropelvic pathology.

25. Imaging
X-rays:
• Lateral - flex./ext.
• Oblique – Integrity of the
pars “Scotty Dog”
• PARS IS SEEN AS NECK OF
SCOTTIE DOG AND DEFECT AS
COLLAR OF DOG

26. Scottie Dog

27. A spot lateral radiograph of L5/S1 demonstrates
clear evidence of spondylolysis.
The vertebral body, pedicles, and superior articular facets are separated
from the inferior articular facets and spinous process.

28. Anterior Displacement

29. Meyerding’s classification of slip
• Grade 1 = 25%,
• Grade 2 = 26% to 50%,
• Grade 3 = 51% to 75%,
• Grade 4 = 76% to 100% slip.
• Grade 5 = A complete
dislocation of L5 on S1 was
called a spondyloptosis.

30. Sagittal plane rotation or roll
• Angle between anterior
margin of L5 and posterior
margin of S1
• Measures rotational
listhesis.
• BEST predictor of
instability and progression
LL Wiltse and RB Winter, Terminology and measurement of
spondylolisthesis, J Bone Joint Surg Am. 1983;65:768-772.

31. Sacral rounding
• percentage of superior
end plate of sacrum
deformed,
• usually at anterior margin
• It is sign of instability and
represents barrier to
reduction

32. Slip angle
• The “slip angle” or sagittal rotation
measures the degree of
lumbosacral kyphosis.
• Normal : 0 to 10 %
• This is calculated by measuring the
angle formed by the intersection of
two lines:
• 1) a tangent to a line drawn along
the posterior aspect of the sacrum
and
• 2) a line parallel to the inferior
endplate of L-5.
• In the normal situation, the angle
formed by the intersection of
these two lines measures zero.

33. SACRAL INCLINATION:
• The “tilt” or sacral inclination
refers to the vertical position
of the sacrum,
• measuring the angle formed
by the intersection of a line
perpendicular to the floor
with
• second one drawn parallel to
the posterior aspect of the
sacrum (S1).
• Usually this angle should be
greater than 30°;
• as the sacrum obtains a more
vertical position, this angle
becomes progressively
smaller.

34. • LUMBAR INDEX as %
(Wedging of the
listhetic Vertebra) –
ratio of posterior height
of body /anterior height

35. Imaging
CT scan
• Evaluate bony pathology
• Spondylolysis diagnosed by “incomplete ring”
sign (ring of cortical bone should be present
on at least one axial cut in normal vertebra
with intact arch)
• Best test to diagnose pseudoarthrosis after
failed fusion

36. • Axial CT bone window of
L5: progressively caudal
slices
• ARROWS shows:
lucencies representing
bilateral spondylolytic
defects
• If what appears to be an
apophyseal joint is seen
• Then , at the level of the
pedicles, it may
represent a pars defect.

37. CT myelography:
• Good quality dynamic
scans can be obtained.
• Bony anatomy and
thecal compression is
better defined
• useful in already
instrumented cases

38. MRI:
• evaluate soft tissue
pathology
• Nerve compression
• Spinal compression
• Sagittal image
demonstrate pars defect.
• Assess disc herniation

39. SPECT:
• Useful when Inconclusive x-rays despite high
clinical suspicion
• May be positive for pars injury that is
radiographically inapparent.
• Acute vs. chronic
• Bone scanning may be helpful in determining the
age of a lysis,
• Acute lesions demonstrate increased contrast
uptake on examination

40. Coronal SPECT scan of the lumbar spine. Note
the solitary area of high radionuclide uptake. This corresponds
to a unilateral L4 spondylolysis (an unusual level).
On standard radiography and conventional planar scintigraphy,
this finding was occult.

41. PRINCIPLES OF MANAGEMENT
Symptoms are very important as management
depends upon these
• Compressive symptoms- decompression +/-
fusion
• Mechanical symptoms – stabilization & fusion

42. Conservative management
Offered to:
• Asymptomatic patients
• young patients with spondylolysis
• low grade listhesis
• older patients with non-disabling DSO

43. Conservative management
• Conservative measures:
– NSAIDS
– Selective nerve/pars/facetal/ epidural injections,
– brace therapy,
– restriction of athletic activities,
– Physical therapy to augment muscle strength
– bed rest (3-5days of rest till acute episode of pain
subsides)

44. Conservative management
• Patients are classified into one of the
following categories
– 1) known spondylolysis without LBA regardless of
age
– 2) young patient with LBA with suspected or
known spondylolysis;
– 3) adult patient with LBA with suspected or known
spondylolysis
(Daniel W. Haun,DCa,NormanW. Kettner,DC , Department of
Radiology, Logan College of Chiropractic, Chesterfield,
Missouri: J Chiropr Med 2005)

45. • In one study, 82 adolescents with symptomatic
spondylolysis or spondylolisthesis were treated
nonoperatively.
• In a follow-up period of 1 to 14.3 years, only 25
patients required surgical treatment for pain.
• Of those with Meyerding Grade I or II
subluxation, resolution of pain occurred in
approximately 70% after conservative therapies
(Pizzutillo PD, Hummer CD III: Nonoperative treatment for
painful adolescent spondylolysis or spondylolisthesis. J Pediatr
Orthop 9:538–540, 1989)

46. Surgical options
Depends on
1.Type
2.Degree of spondylolithesis
• Grade I spondylolisthesis
Fusion & fixation is controversial
• G II – Benefited with surgery
• III & IV – Greatly alleviates symptoms by Sx.
• Unstable spine :
Some patients has only symptoms of unstable spine but no
evidence of spondylolisthesis
Flexion : Extension X-rays are done
• Any > 4 mm movement
• 10 degree angulation
• Benefit with external brace
Spine is considered to be unstable and benefited with
surgery

47. GOAL OF SURGERY
• Stabilize the segment with listhesis
• Decompress neural elements under pressure
• Restoration of normal sagittal alignment to be
achieved
• Each patients algorithm to be individualized
for optimal outcome

48. INDICATIONS FOR SURGERY
• Failure of conservative treatment progression of
listhesis inspite of conservative treatment
• Neurological signs-unresponsive to conservative
measures
• Evidence of instability, progression of listhesis
• Traumatic listhesis
• Iatrogenic listhesis
• Degenerative listhesis with instability
• Postural deformity

49. Surgical management
• Decompression
• Reduction
• Fusion
• Instrumentation

50. Decompression
• “Gill’s procedure” (1955) : removal of loose
posterior elements and cartilaginous
• Its drawback is the potential for increasing the
subluxation postoperatively
• In children, decompressive surgery is rarely
indicated
• in situ stabilization (fusion) has been shown to
be effective in resolving neural symptoms
(Osterman K : Late results of Gill’s operation, Clin Orthop.
1976)

51. Reduction
• It is seldom required in low grade ISO or DSO.
• Rarely achieved in high grade listhesis
• Appropriate positioning in OT table is vital (eg.
extension)
• Instrumentation help in reduction(eg.- distraction force
applied to pedicle screw)
• Precontouring the vertical rod or plate will also help
• It acceptable to fuse in situ without making heroic
attempts at reduction as long as decompression is
adequate
(Rengachary SS, Balabhandra R. Reduction of
spondylolisthesis. Neurosurg. Focus 2002: Article 2)

52. GENERAL INDICATIONS FOR FUSION
Fusion for three main reasons:
• 1) intractable pain positively correlated with
spondylolisthesis in which conservative have
failed (pain is due to dynamic instability)
• 2) following decompressive laminectomy for
lumbar stenosis associated with the subluxated
segments;
• 3) radiographically documented subluxation
progression or severe high-grade subluxation
greater than 50%
R. F. Heary and C. M. Bono: Neurosurg. Focus / Volume 13 / July, 2002

53. Fusion (with or without instrumentation)
Fusion procedures are :
– Intertransverse fusion (ITF)
– Posterior lumbar interbody fusion(PLIF)
– Transforaminal lumbar interbody fusion (TLIF)
– Anterior lumbar interbody fusion (ALIF)
– Circumferential (270 or 360 degree)
• Autografts, allografts (cadaveric bone or commercially
available femoral rings) or xenografts (bovine bone)
• Cages (titanium, carbon fibre, ceramic, or polyethyl
ether ketone(PEEK))

54. Posterior approach
transpedicular screw fixation
Indications
1.When direct decompression needed
2. In multiple level, bone graft placement and fusion
• Preoperative planning
1. Plain lateral X-rays
2. Axial CT scan to ascertain suitability and pedicles to be
instrumented.
3. In lumbar region pedicular diameter should be atleast 5
mm for screw placement
4. MRI and myelography ( dynamic ) should be done.

55. Transpedicular screw fixation
Rule of thirds
• Diameter of pedicle screw should not be > 2/3
of width of pedicle.
• Pedicle screw should extend no further than
2/3 of length of body

56. PROCEDURE
Position of patients ,anaesthesia and monitoring
• Prone position
• Knees slightly bent
• Pressure points padded
• Somatosensory evoked potential monitoring
placed (? Relaxant)
• ‘C” Arm used to confirm the location and plan
the incision

57. Exposure
• Dorsal mid line incisions

• By cautery reach facial planes

• Dissection extended laterally on either side of iliac crest to
obtain graft material (Separate incision better)

• Dissection continued in midline and paraspinal muscle
dissected from the spinous process and lamina.

• Expose 1-2 levels above and below the proposed level of
decompression for sufficient lateral exposure over transverse
process.

• Dissection continued over transverse process and facets
.Other transverse process are not exposed.

58. Decompression
Bone cutter used to remove spinous process sharp cutters
used for lig flavum

Laminectomy performed

Facitectomy done for hypertrophied facets laterally

• Lateral recess decompressed by using kerrison’s punch

• Medial aspects of pedicle is flush with decompression

Nerve roots follows under each pedicle through their
respective foramina
• Foramenotomy done in case of stenosis
• Buldging discs are inspected
Not treated until compress thecal sac

59. Nerve Root
Inter v.Disc
Thecal Sac
Exposure after facet resection

60. Transpedicular screw
• Available for thoracolumbar & sacral spine
• Various screw system available with their own
advantages and disadvantages. None of implant is
ideal
• Identification of pedicle ( By Tactile , radiologically or
visual)
• Imaginary line from transverse process and line in
sagital plane from superior articular facet gives
centre of pedicle.
• In sacrum first dorsal sacral foramina and sacral
recession are identified. Pedicle is identified
inferolateral to S1 facet.
• By Drill and T Handle AWL placed in center of pedicle
and body of vertebra.

61. Orientation angles : ( Zindrick et al)
In general trajectory of awl is 5 degree medial
• L1 -5
• L2 – 10
• L3 - 15
• L5 – 25
• S1 – 25
• S2 – 40 medial

62. Cont
• Rostrocaudal orientation is determined by lateral fluoroscopic
image tragectory is maintained parallel to end plate .
• During advancement of T handle trajectory is maintained
parallel to end plate
• pedicle should not give away during the procedure ( Palpated
throughout)
• once tapped, confirm cortex not breached threading of cavity
done
• appropriate size screw placed , screw should be advanced at
least ½ way, not more than 2/3 of vertebral body.
• Rod is measured and cut and connected with pedicle screws
and connectors.
• Distracter may be used and screws are tightened.
• Cross linkage added if > 1 segment fixed or there is rotational
instability.

63. Pedical Screw
with Cross linkage

64. Bone graft harvesting for posterior
approach
• instrumentation only provides stabilization for bony
fusion.
• Lateral exposure proformed for posterior iliac crest
for bone graft
• Not more than 8 cm exposure made
• Gluteus muscle reflected.
• Unicortical chips of bone graft is harvested.
• Haemostasis attained by gelfoam, wax.
• When possible separate incision made for graft.

65. Fusion technique
• Posterolateral fusion
• transverse process exposed and decorticated
• bone placed, bone from decompression of
spine also placed.
• Facet joint fusion also made by exposing
bone and packing chips of cancellous bone.

66. Posterior lumbar interbody fusion [PLIF]-
Principles
• Posterior lumbar interbody fusion (PLIF)
surgery involves adding bone graft to an area
of the spine to set up a biological response
that causes the bone to grow between the
two vertebral elements and thereby stop the
motion at that segment.

67. Post lumbar interbody fusion(PLIF)
Cloward ( 1940)
• Done for degenerative spondylolisthesis , TB ,
trauma , tumor
• Many times limited procedures needed like
discordectomy for disc rupture or herniation
and decompression for canal stenosis causes
some lumbar spinal instability.

68. Instability
1.Pathological
2.Iatrogenic ( Wide decompression )
Advantages of PLIF
• Clinical instability : Episodic severe pain with
hypertrophied paraspinal musculature.
• Complete decompression i.e. wide laminectomy.
Medial facetectomy and foraminotomy.
• Interbody fusion give greater surface area beween
bone graft and host bed than on lay technique
• mechanically sound fusion for weight bearing.

69. Principles :
• Discoidectomy + fusion with bone graft
• Recently : Interbody implants used for immediate stability
across the segment.
• Motion segment :
1. consecutive vertebrae
2.Disc
3.Posterior elements
• Degeneration of Disc, facets and vertebral elements

• Spur formation , hypertrophy of facets, ligaments causing
spinal canal stenosis.
• Degenerative segment with degeneration is considered a
“Dysfunctonal motion segment’ ( Unstable segement)
• Lumbar region if decompression done without fusion lead to
slip progression

70. • PLIF :
• Prevent 2 ary degenerative changes and
instability
• Separates 2 vertibera, reestablish disc height
and normal physiology.
• Restores foramina diameter indirectly
decompress nerve roots.

71. Procedure
Anaesthesia :  GA, May avoid muscle relaxant
for somatosensory evaluation
• Positions :
• Prone in spinal operating frame
• Some prefer flexion of hip by 90degree
( Complication – flat back syndrome)

72. Exposure : Lower back prepared including both iliac
Crest
• Exposure by midline incision ,1 level above and 1
level below made.
• Intraop radiographs guide dissection

• In cases redo surgery PLIF is complicated due to
scarring
prior surgery defect should be exposed in full extent
scar excised from dura ( 10% laceration)

73. Decompression :
• Wide decompression vs preservation of dorsal element
• Cloward pioneer of procedure advocated wide
decompression by laminotomy and medial facetectomy.
• Lin et al advocated conservation of dorsal elements
• Recent bio mech evaluation showed sig. destabilizing effect of
extensive posterior element removal.
• When pedicle screw fixation supplemented with PLIF we can
do extensive decompression without compromising stability.
Lead to superior decompression, pedicles can easily
identified.

• Unlimited access to disc space to be fused as wide
facetectomy provide access to post laeral disc space. Leading
to minimal retraction in PLIF and grafting.

• Easy haemostasis of dural vessels.

74. Discoidectomy
• Radical discoidectomy is made with disc
rangers and curdle.
• After removal of disc material osteotome used
to remove additional disc material and
cartilage from end plates.
• Recently drill like reamers are used for same
space created for interbody grafting.
• Important to decompress medial space and
removal of residual disc material.

75. Incising Annulus
To Create Window
in Disc Space

77. Difficult Removal Part

78. Graft preparation and insertion
Grafts
• Use tricortical bone graft from iliac crest OR
subchondral graft
• Graft cut flat and put from lateral to medial with help
of chisel ( Cloward’s)
Other modifications
• Rectangular autograft pegs
• Morcelised bone chips ( posterior elements)
• Cortical bone dowels ( Femur)

79. Fusion Technique
• Distraction of disc space by distractor rotated to 90
degree on both sides ( Biannular).
• Reaming sleeve guide inserted into the disc space.
• Reaming sleeve slide and impact on reaming guide
take care to avoid root damage.
• Times of sleeve maintain distraction
• Reamer introduced to ream bone ( Fluroscopic
control)
• Threads are cut into disc space.
• Cortical allograft bone dowel tightened into the
space through sleeve
• Process repeated on other side.

80. Posterior lumbar interbody fusion [PLIF]-
Disadvantages
• Not much disc space can be removed with a
posterior approach
• Decreased surface area available for a fusion.
• larger bone graft cannot be inserted
• In cases of spinal deformity (e.g. isthmic
spondylolisthesis) a posterior approach alone is more
difficult to reduce the deformity
• There is a small risk of bone graft or cage
retropulsing into the canal and causing neural
compression

81. Posterior lumbar interbody fusion [PLIF]-
Complications
• Main risk is nonunion and further surgery may be
necessary. Fusion rates are as high as 90-95%.
• Nonunion rates are higher for patients who have had
prior spine surgery, patients who smoke or are
obese, patients who have multiple level fusion
surgery, and for patients who have been treated with
radiation for cancer.
• Infection
• Bleeding.
• Pain relief not adequate

82. Interbody fixation
• Fixation without pedicle screw fixation or further
instrumetnations
• Interbody system used
BAK cage
Ray adhered fusion cage
brantingan carbon fibre cage
( BAK cage is FDA approved. )
• Preop and Xray gives diameter of cage used
• Distraction carried out
• Disoidectomy done
• Bone dowels placed as in PLIF
• Implant placed in distracted verlibera , and cage firmly grips
end plates of vertibers lead to a firm interbody fixations.

83. Post op care
• Usually drain needed for 1-2 days as there is
ooze from bone
• ileus
• semi rigid lumbar orthosis is worn at least for
3 months to 6 months ( depend on callus
appearance)
• immediate post op times and every 6 weeks to
see fusion.
• CT may be needed to see graft.

84. Complications
• Early post op complications
Wound infection ( 0-6%) – Haematoma
Dural tears ( 0.5- 5.5%) & CSF leak
Prevention :
• Meticulus tech
• Local antibodies, PMMA , antibiotic
impregnated beads.

85. Late complications
1.graft dislodgement – avoided by end plate preparation and
graft shaping does not occur in internal fixation and in cage
fixation.
2. persistent pain
3. failed fusion
Treatment
• Rigid bracing
• Restrict activity , re surgery and internal fixation
• implant migration
• Post op radicular pain
– Injury
– Epidural scarring
– Compression due to migration of implant
• BAK cage post op weakness ( 3.9% ) and radicular pain 1.4%
• 6. In redosurgery pain may become worsen or same
intensity.

86. Instrumentation in lumbar fusion
Advantages
• Immediate stabilization
• Quicker ambulation and return to work
• Reduction of spondylolisthesis
• Correction of kyphosis or scoliosis
• Maximise chances of fusion
• Osteoporosis, smokers
• Minimise chances of recurrence of spondylolisthesis or
stenosis
• Better clinical outcome
(Easwaran R et al.: Progress in clinical Neurosciences Vol. 23 , 2009)

87. References
• Youmans Neurological surgery, 6th edition
• Ramamurthi & Tandon’s textbook of
Neurosurgery: 3rd edition
• Macnab’s backache: David A Wong and Ensor
Transfeldt, 4th edition.
• Various articles.

88. Thank You