PPT of Spondylolisthesis

1. Presented by :
Dr.Shankaragouda Patil
Post Graduate in M.S (Orthopedics)
Moderator:
Dr Mohan N S
Asso Professor in Orthopedics
SPONDYLOLISTHESIS

2. HISTORICAL ASPECTS
In 1782, Herbiniaux, a Belgian obstetrician, noted a
bone prominence in front of the sacrum that caused
problems in delivery.
In 1854, Kilian coined the term spondylolisthesis,
derived from the Greek spondylos, meaning “vertebra,”
and olisthenein, meaning “to slip.”

3. DEFINITION
• Spondylolisthesis is defined as the forward
slippage of one vertebra on its adjacent
caudal segment.
• Spondylolysis is a defect in pars
interarticularis (the part of neural arch just
caudal to the confluence of the pedicle, the
superior articular process and the most
cephalad part of the lamina)
• Spondyloptosis: used to describe as fall of
L5 vertebra into the pelvis and lie anterior
to sacrum.

4. RELEVANT ANATOMICAL STRUCTURES

6. • Pars interarticularis: portion of bone between superior and inferior
articulating processes and the thinnest part of the neural arch
• Neural arch: bridge of bone formed by the posterior elements of a vertebra
that surrounds the spinal cord
• Facet joint: the contact junction between the inferior articular process of
one vertebra and the superior articulating process of the vertebra below it
• Motion segment: functional unit of the spine, consisting of two adjacent
vertebrae and the intervening disc along with, facet joints, capsule and
ligaments.
• Pedicles: thick bony struts that connect the vertebral body with the posterior
elements
• Lamina: the portion of the neural arch between the articular processes and
the spinous process
• Spondylosis: degenerative changes of the spine(vertebral joints and disc)

7. Hook:
•Pedicle
•Pars inter-articularis
•Inferior process of the cephalad level
Catch:
•Superior process of the caudal level

8. CLASSIFICATION
• Wiltse, Newman and Macnab (Based on a mixture of
etiological and topographical criteria)
• Meyerding Classification( based on percentage of slip in
lateral radiograph)
• Marchetti and Bartolozzi ( emphasizes the developmental
and dysplastic aspects)
• Spinal Deformity Study Group/SDSG classification

9. Wiltse, Newmann, MacNab
Clin Orthop 1976
Type Name Description
I Congenital Dysplastic abnormalities
II Isthmic
A Lytic (stress fracture)
B Healed fracture (elongated, intact)
C Acute high energy fracture
III Degenerative Segmental instability
IV Traumatic Fracture of hook other than pars
V Pathologic Underlying pathology
VI Iatrogenic Surgical excision of posterior elements

10. WILTSE, NEWMAN, AND MACNAB'S CLASSIFICATION
Type I, Dysplastic (20%)
•Occurs only at L5-S1 level
•Primary congenital dysplasia of L5-S1 facet joints.
•Typically the inferior facet of L5 is dysplastic and
the sacral facet absent.
•No pars interarticularis defect
•Frequent assosciation with spina bifida
occulta of L5 and sacrum.
•More common in females.
•Increased incidence in first degree relatives of
patients: genetic

11. WILTSE, NEWMAN, AND MACNAB'S CLASSIFICATION
• Type II: Isthmic(50%) Defect in pars
interarticularis that allows forward slippage of L5
over S1
• Three Types:
Lytic:- stress fracture of pars interarticularis
Healed version of Lytic- pars interarticularis
intact but elongated
Acute fracture of pars interarticularis due high
energy injury.
The incidence tends to stabilize in adulthood.

12. WILTSE, NEWMAN, AND MACNAB'S CLASSIFICATION
• Type III: Degenerative(25%):
• Due to intersegmental instability of long duration and
subsequent remodelling of the articilar process.
• Often accompanied by spinal stenosis,
• older than 40 years
• Most common at L4-5 (six times more)
• Women ( four to six times )
• 2 theories: sagittal facet theory & disc degeneration
theory
• Studies shows progressive spondylolisthesis occurred in
34%, and further disc space narrowing continued in the
patients without further slip.
• Low back pain improved in patients with continued
disc space narrowing: autostabilization.

13. • Type IV :- Traumatic
• fracture in the area of the bony hook other than pars, ie
pedicle, laminas or facets.
• Type V :- Pathological :
• Due to generalized or localized bone disease,
osteogenic imperfecta, multiple myeloma, infection.
• Type VI Post surgical :
Due to loss of posterior elements secondary to surgery.
Wiltse, Newman, and Macnab's classification

14. MEYERDING CLASSIFICATION
• Based on the ratio of
[overhanging part of the
superior vertebral body] to
[anteroposterior length of the
adjacent inferior vertebral
body]:
• grade I: 0-25%
• grade II: 26-50%
• grade III: 51-75%
• grade IV: 76-100%
• grade V (spondyloptosis):
>100%

15. SPINAL
DEFORMITY
STUDY
GROUP(SDSG)
CLASSIFICATION

16. EPIDEMIOLOGY
• Incidence: 6% in general population
• Male:female ratio: 2:1, slippage more in females.
• Incidence in children <6years: 2.6%
• Ethnicity: more common in Caucasians than Blacks;
eskimos of Alaska reported incidence upto 50%.
• Exact etiology: obscure
• Degenerative spondylolisthesis(>40years) more
common in females.
• Genetic and familial assosciation: 26% of
patients with isthmic spondylolisthesis had first
degree relatives with same disease.

17. ETIOLOGY: DEVELOPMENTAL SPONDYLOLISTHESIS
WITH LYSIS
It is due to stress fracture in children with
genetic predisposition for the defect.
•Wiltse et al: normal flexon contracture of the
hip in childhood causes increased lumbar
lordosis leading to increased force at Pars
interarticularis.
•Lett et al: shear stress greater at pars when
lumbar spine is extended.
•Cryon and Hutton: Pars is thinner and vertebral
disc is less resistant to shear in children and
adolescents than in adults

18. Etiology: Isthmic
spondylolisthesis :Due to upright walking and wt . bearing.
M=F: 2:1
Risk factors: Gymnastics / Football/wt. lifting, dancing and
others with excessive lordosis or hyperflexion of the lumbar
spine.
Etiology of degenerative spondylolisthesis:
•TWO THEORIES
a)Sagital facet theory: Facet oriented in such a way that it
doesn’t resist Intratranslation forces over time and it leads to
Spondylolisthesis
b) Disc degeneration theory: Disc narrows first leading to
overloading of facets, Accelerated arthritic changes , Secondary
remodelling and Anterolisthesis

19. ETIOLOGY:
• TRAUMATIC: Acute fracture other than Pars
• POST SURGICAL : Laminectomy, Intervertebral
fusion.

20. PATHOPHYSIOLOGY
• TRAUMATIC PATHWAY
• DYSPLASTIC PATHWAY
• DEGENERATIVE PATHWAY

21. TRAUMATIC PATHWAY
In Erect posture-Center of Gravity is anterior to LS joint
Lumbar spine-forward force and rotate anteriorly into flexion about
the sacral dome.
Initiated by the repetitive cyclic loading
Sup. and inf. articular process impingement creates a bending moment
that is resisted by the Pars.
Repetitive impingement- fatigue

22. Stress fracture of Pars and post. neural arc separates from body
Gap occupied by the fibrous tissue
Non union
Increased shear load to disc though axial load remains unchanged
Premature disc degeneration
Vertebral subluxation

23. DYSPLASTIC PATHWAY
Initiated by the cong. defect (dysplasia) in the bony hook or
its catch.
Repeated loading unopposed by bony constraints
Plastic deformation of soft tissue restrains: IV Disc,
Anterior and Posterior Ligament complex
Subluxation of
vertebra

24. DYSPLASTIC PATHWAY
With continuous growth
Slippage and abnormal growth in the involved vertebral bodies
or sacrum
Changes seen:
-Trapezoid shape of L5
-Rounding of supero anterior aspect of sacrum
-Vertical orientation of the sacrum
-Junctional kyphosis at involved segments
- Compensatory hyperlordosis at the adjacent levels

25. DEGENERATIVE SPONDYLOLISTHESIS
Sagital facets degeneration
No resistance for anterior translation force
Predilection for slippage
Anterolisthesis
• Boden et al - sagital facet angles of > 45 degree at L4-L5 - 25 times greater
likelihood of degenerative spondylolisthesis.

26. DEGENERATIVE SPONDYLOLISTHESIS
•Disc degeneration
• Disc narrowing and subsequent overloading of
facets
Accelerated arthritic changes
Secondary remodelling
Anterolisthesis

27. PATHOLOGICAL SPONDYLOLISTHESIS
Due to local or systemic pathological process causing a defect
in the neural arch
Vertebral
Subluxation

28. TRAUMATIC SPONDYLOLISTHESIS
High energy trauma
Translational deformity
Fracture of bony hook other than Pars ie: Pedicle,
Superior and Inferior articular facets Associated multiple
bony and STI
Subluxation

29. POST SURGICAL
• Laminectomy
• Removal of >1/2 or entire
articular process
• Destabilize the spine
• subluxation

30. POST SURGICAL
Fusion of segments
Resection of capsular, Supraspinous and Interspinous
ligaments
•Increasing motion demand
• subluxation

31. NATURAL HISTORY
• Risk factors for the progression :
1)Young age at presentation
2)Female gender
3)A slip angle of > 10 degree.
4)A high grade slip
5)Dome shaped or significantly inclined sacrum

32. NATURAL HISTORY IS PREDOMINANTLY DETERMINED BY
• Developmental or acquired spondylolisthesis
• Low or high dysplasia
• Quality of pedicle , pars and facets
• Age when diagnosis is made
• Degree of lordosis and position of gravity line
• Degree of secondary or remodeled deformity
• Competency, hydration and height of the disc

33. NATURAL HISTORY
1)Dysplastic spondylolisthesis :
Early age; usually asymptomatic
Severe slip(9-15,seldom after 20)
Risk of neurological complications
Higher risk of slip progression-cauda equina syndrome as
the neural arc is intact.

34. NATURAL HISTORY OF ISHTHMIC
SPONDYLOLISTHESIS
No progression of slip
:
•
•
•
•
•
•
Progression of slip
>25% slip symptomatic
Risk of slip progression
.Backache in later life
< 10% displacement Asymptomatic
No progression after adulthood
No backache later
Increases with agein life

35. -Rare before 50.
-Matsunaga et al 10 yrs prospective study--34% showed progression of
the slippage-though no significant effect in the clinical outcome
-further disc space narrowing continued in those without slip
-However back pain improved (Autostabilisation)
-83% of the pts with neurological signs and symptoms deteriorated
Natural history of Degenerative Spondylolisthesis
:

36. CLINICAL EVALUATION
-Usually asymptomatic – Incidental finding in X ray.
-Symptoms depend on the severity of slip and is caused by :
•Chronic muscle spasm : Body limits motion around a painful pseudo-
arthrosis of facet and its Pars .
•Tears in the Annulus Fibrosus of the degenerated discs.
•Compression of the nerve roots.

37. CLINICAL EVALUATION
When symptomatic :
In Children and Young adults :
•Back fatigue and back pain-on movement (Hyperextension) due to
instability of the affected segment.
•Hamstring fatigue and pain due to irritation of L5 nerve root.
•Sciatica – may occur in one or both legs

38. In patients > 50 yrs:
•Backache
•Sciatica
•Pseudoclaudication d/t spinal stenosis when subluxation is severe.
•
•Other signs of nerve root compression- motor weakness, reflex
changes and sensory deficits.
CLINICAL EVALUATION

39. CLINICAL EVALUATION
Compression of central canal :
Features:
1.Bladder and bowel dysfunction
2.Bilateral leg symptoms
3. +ve SLRT B/L
4. +ve crossed SLRT

40. ON INSPECTION:
•Buttocks
– Flat
- Heart shaped in high grade slip d/t sacral
prominence.
•Sacrum – more vertical
- appears to extend to the waist
•Lumbar hyperlordosis above the level of the slip
to compensate for the displacement.
•Transverse loin crease
•With severity- absence of waist line
•Peculiar spastic gait -due to hamstring tightness
and lumbosacral kyphosis.
CLINICAL EVALUATION

41. INSPECTION FINDINGS
absence of waist lineTransverse loin
crease
Lumbar hyperlordosis

42. PALPATION :
Palpable step
Tenderness over Pars defect
Hamstring tightness on leg raising.
MOVEMENTS :
Usually normal in young pts.
May be – Hamstring + Paraspinal muscle tightness-
limiting forward bending and hip flexon.
Degenerative type: spine-often stiff.
Positive nerve root tests if root compression.
CLINICAL EVALUATION

43. IMAGING
Radiographs:
•AP view
•Standing Lateral view including the hips.(15% of deformities
spontaneously reduce on supine imaging.)
•Oblique view: help in viewing pars interarticularis defect( decapitated
scotty dog)
•Lateral flexion and extension views: determination of translational
instability.
•Flexion-extension lateral views may reveal instability, which is considered
to be present when 4 mm of translation or 10 degrees of sagittal rotation
greater than the adjacent level is identified
•Fegurson view depicts the L5 pedicles, transverse processes and
sacral ala more clearly

44. FEGURSON VIEW(20 DEGREES CAUDO
CEPHALIC AP VIEW)

45. RADIOGRAPHS

46. FLEXION EXTENSION X RAYS

47. Demonstrates
a bilateral break in the pars interarticularis or
spondylolysis (lucency shown by black arrow)
that allows the L5 vertebral body (red arrow) to
slip orward on the S1 vertebral body (blue
arrow).
The normal pars interarticularis is shown by the
white arrow.

53. INVERTED
NAPOLEON’S HAT
SIGN
indicates the presence
of bilateral spondylosis and
significant spondylolisthesis. The
dome of the hat is formed by the
overlying body of L5 vertebra
and the brim is formed
by downward rotation of the
transverse processes.

54. SCOTTY DOG SIGN ON OBLIQUE VIEWS

56. OTHER INVESTIGATIONS
CT myelography and MRI are used as indicated
for the evaluation of spinal stenosis and may show
facet overgrowth, hypertrophy of the ligamentum
flavum, and, rarely, disc herniation, tumors, etc.
SPECT: most senstive for impending spondylolysis.,
Can determine the chronicity of lytic defect.
NCV, EMG: to rule out peripheral neuropathy
Arterial doppler/ CT angiography: to rule out
vascular causes of claudication

57. ROLE OF SPECT
• A Single-photon Emission Computed Tomography
bone scan is necessary to show whether uptake is
increased in the pars. A SPECT scan is helpful in
determining whether the process is acute or chronic.
• If increased uptake is confirmed, a CT scan can
be obtained to evaluate whether there are thickened
cortices consistent with a stress reaction or
whether there is an acute stress fracture.

58. MAGNETIC RESONANCE IMAGING
• Allows for additional visualization of soft tissue and neural structures
and is recommended in all cases associated with neurologic findings.
• In the early course of the disease, MRI helps in identifying the stress
reaction at the pars interarticularis before the end-stage bony defect.
• MRI may show the degree of impingement of neural elements by
fibrous scar tissue at the spondylolytic defect.
• Status of disc

59. DISC DEGENERATION: MRI
Pfirrmann et al Spine
Grade I Grade II Grade III Grade IV Grade V

63. IMPORTANT RADIOLOGICAL
PARAMETERS
• SLIP ANGLE(by Boxall et.al):
• The slip angle is measured from the
superior border of L5 and a
perpendicular line from the posterior
edge of the sacrum
• Angle greater than 45 to 50
degrees associated with greater risk
of slip progression,
instability, and development of
postoperative pseudoarthrosis.
• It is the best predictor of progression
os slip.
• A slip angle greater than 55 degrees is
associated with a high probability and
increased rate of progression

65. PELVIC INCIDENCE (PI)• Pelvic incidence: A line
perpendicular to the midpoint of
the sacral end plate is drawn. A
second line connecting the same
sacral midpoint and the center of
the femoral heads is drawn. The
angle subtended by these lines is
the pelvic incidence
• Pelvic incidence: Pelvic tilt +
sacral slope
• normal, ≈50 degrees)
• Unaffected by posture
• Increased PI may predispose
to spondylolisthesis.

66. PELVIC TILT (PT)
• Pelvic tilt:. A line from the
midpoint of the sacral end
plate is drawn to the center
of the femoral heads. The
angle subtended between
this line and the vertical
reference line is the pelvic
tilt.
• Higher pelvic tilt
predisposes to
spondylolisthesis.

67. SACRAL SLOPE(SS)
• Sacral slope: A line parallel to
the sacral end plate is drawn.
The angle subtended
between this line and the
horizontal reference line is
the sacral slope.
• Vertical sacrum (SS<100
degrees) is
causes progression in slippage.

68. ALPHA ANGLE L5 INCIDENCE
• Alpha angle L5 incidence: A line
from the midpoint of the upper end
plate of L5 is connected to the
center of the femoral heads. A
second line perpendicular to the
upper L5 end plate is drawn from
the midpoint of the end plate. The
angle subtended by these two lines
(α) is the L5 incidence.
• Higher values are associated with
spondylolisthesis/unbalanced pelvis

69. CONCEPT OF BALANCED VS UNBALANCED
PELVIS
• The balanced pelvis is one in which compensatory
increased lumbar lordosis and decreased thoracic
kyphosis of the spine are adequate to maintain an
adequate C7 plumbline or normal sagittal balance.
• In the unbalanced, or retroverted, pelvis, there is
high PI because of increased pelvic tilt (visualized
as an anterior position of the femoral heads
relative to the sacrum) that the spine cannot
accommodate the associated high L5 incidence
angle, leading to positive forward balance.
• unbalanced spine, occurs when the C7 plumbline
falls anterior to the femoral heads on the standing
lateral radiograph.
• The spine is balanced when the plumbline falls on
or posterior to the femoral heads.

70. BALANCED VS UNBALANCED PELVIS

72. MEYERDING XRAY GRADING OF
SPONDYLOLISTHESIS
• Percentage of slipping calculated by measurement
of distance from line parallel to posterior portion of
first sacral vertebral body to line parallel to posterior
portion of body of L5; anteroposterior dimension of
L5 inferiorly is used to calculate percentage of
slipping.
• Grade I: displacement of 25% or less;
• Grade II: between 25% and 50%;
• Grade III: between 50% and 75%; and
• Grade IV: more than 75%. A
• Grade V represents the position of L5 completely
below the top of the sacrum -SPONDYLOPTOSIS.

73. DE WALD MODIFIED NEWMAN
SPONDYLOLISTHESIS GRADING SYSTEM
• Better define the amount of anterior roll of L5.
• The dome and the anterior surface of the sacrum is divided into
10 equal parts.
• The scoring is based on the position of the posterior inferior
corner of the body of the L5 with respect to the dome of
the sacrum.
• The second number indicates the position of the anterior inferior
corner of the body of the L5 vertebra with respect to the anterior
surface of the first sacral segment.

74. Modified Newman spondylolisthesis grading system. Degree of slip is measured by two numbers—
one along sacral endplate and second along anterior portion of sacrum:A = 3 + 0; B = 8 + 6; and C
= 10 + 10.
Modified Newman Spondylolisthesis
Grading
System.

75. Clinical
•Growth yrs (9 – 15)
•Girls > Boys
•symptomatic
•Postural or gait
abnormality
Radiographic
•Type 1 (dysplastic)
•Vertical sacrum
•>50 % slip
•Increasing slip angle
•Instability on flex/ext
views
RISK FACTORS FOR SLIP PROGRESSION IN
SPONDYOLISTHESIS (HENSINGER 1989)

76. MANAGEMENT
• Nonoperative Treatment
• Operative Treatment

77. • Includes complete cessation of activity, rehabilitation with strengthening of
the abdominal and paraspinal musculature, minimization of pelvic tilt, and
antilordotic bracing.
• The brace is worn for 24 hours/day for minimum of 3 to 6 months.
If clinical symptoms improve, the brace can be gradually weaned through a
period of part-time wear.
Conservative Management

78. • Vigorous activities are restricted and back, abdominal and core
strengthening exercises are prescribed.
• If the symptoms are more severe, a brief period of bed rest or brace
immobilization may be required. Once the pain has improved and the
hamstring tightness has lessened, the child is allowed progressive
activities.
• Yearly examinations with standing spot lateral radiographs of the
are advised to rule out the development oflumbosacral spine
spondylolisthesis.
•If the patient remains asymptomatic, limitation of activities or contact sports
is not necessary.
Conservative Management

79. • If the SPECT scan reveals metabolic activity and a CT scan shows
thickening of the pars, avoidance of aggravating activity and core
strengthening exercises are recommended.
• If the SPECT scan is metabolically active and CT indicates an acute
stress fracture, a 3-month trial of orthotic treatment is warranted.
• If the defect has not healed in 3 months, continued orthotic wear is not
indicated. The CT scan is the most helpful radiographic technique to
determine the presence or absence of healing.
Conservative Management

80. • Have excellent relief of symptoms or only minimal discomfort at
long-term follow-up.
• If a child does not respond to conservative measures, other
causes of back pain should be ruled out.
• Special attention should be paid to children whose symptoms do not
respond to bed rest or who have objective neurological
findings.
• A very small percentage of children with spondylolysis who do
not respond to conservative measures and in whom the other
possible causes of back pain have been eliminated may require
OPERATIVE TREATMENT.
Conservative Management.

81. OPERATIVE TREATMENT:
INDICATIONS:
•Persistent symptoms despite 9 months to 1 year of conservative
treatment,
•Persistent tight hamstrings, abnormal gait, and pelvic-trunk deformity.
•Development of a neurological deficit .
•In a skeletally immature patient with slippage greater than 50% or a
mature adolescent with a slip greater than 75%, even if the patient is
asymptomatic.

82. SURGICAL GOALS
•Address the pars defect
•Decompress the foraminal stenosis
•Address the degenerate disc/s
•Address the dynamic instability

83. OPERATIVE OPTIONS
• Direct repair of pars defect
• Decompression and fusion without fixation
• Decompression and fusion with pedicle screw fixation
• Posterolateral insitu fixation
• Partial reduction and fixation
• Complete reduction, fusion and fixation
• Posterolateral interbody fusion and fixation/PLIF
• Trans foraminal interbody fusion/TLIF
• Anterior interbody fusion/ALIF
• Note:
• repair preserves motion segment
• Fusion removes motion segment

84. DECOMPRESSION: ABSOLUTE INDICATIONS
• Neurological deficit
• Non relieving Leg pain
• Sphincter dysfunction
• Claudication

85. DECOMPRESSION:
• The Gill procedure: Removal of the loose laminar arch
• Foraminotomy + facetectomy
• Associated with ↑ pseudarthrosis rate
Carragee JBJS Am 1997

86. DECOMPRESSION AND INTERBODY
FIBULAR GRAFT FIXATION

87. IN-SITU POSTERO-LATERAL FUSION
• L5 S1 only adequate
• Improvement in leg pain even when
not decompressed
Burkus JBJS Am 1992
Frennerd Spine 1991
Ishikawa Spine 1994
deLobrresse Clin Orthop 1996

88. POSTERIOR INSTRUMENTATION
• Better fusion rate, better clinical
outcomes
• Un-instrumented better for
osteoporortic bones
Moller Spine 2000
Zdeblick Spine 1993
Yuan Spine 1994
Bjarke Spine 2002 Deguchi
J Spinal Dis 1998 Ricciardi
Spine 1995

89. LEVELS TO INSTRUMENT
•Look at the changes at the levels
above
•Higher slip angle: retro-listhesis
above the slip

90. REPAIR OF SPONDYLOLYTIC DEFECT
• Principles:
• Debridement,
• Grafting of the site with autogenous bone graft, and
• Compression across the fracture.
• If a direct repair of the spondylolysis is considered, the disc status should be
evaluated with MRI. If disc degeneration is significant, an arthrodesis at that
level may be a better choice
• Procedures :
• Buck technique,
• Scott wiring and Modified Scott Technique
• Kakiuchi procedure (repair with an ipsilateral pedicle screw and hook).

91. BUCK TECHNIQUE : DIRECT
REPAIR OF PARS
INTERARTICULARIS
• Fibrous tissue at the pars defect is identified, thoroughly débrided, and
stabilized with a 4.5-mm stainless steel cortical screw in compression.
• This technique was indicated only in cases in which the gap was smaller
than 3 to 4 mm.
• The narrowness of the lamina, a minimal displacement or malposition of
the screw can lead to implant failure or complications Such as nerve root
irritation, injury to the posterior arch Or dura, or pseudarthrosis.
• Better clinical results have been obtained in patients younger than age 30
years, possibly because chronic instability leads to degenerative disc
disease in older patients, which causes continued symptoms despite
fusion of the defect

92. • (a) Preoperative
lateral radiograph
• (b) axial CT scan
showing unilateral
defect of the pars
interarticularis of the
L4 vertebra.
• (c) Sagittal T2
weighted MRI
demonstrating the
normal L4-L5 disc
without any
degeneration.
• Follow-up lateral
dynamic radiographs
in (d) flexion and (e)
extension, showing
complete healing of
the defect without
signs of instability
• . (f) Postoperative
axial CT scan
demonstrating
complete healing of
the spondylolytic
defect

93. SCOTT TECHNIQUE
• A stainless steel wire is looped from the transverse processes to
the spinous process of the level involved and tightened, in
conjunction with local iliac crest bone graft.
• This wire creates a tension band construct, placing the pars
defect under compression, and holds the bone graft in place.
• Bradford and Iza reported 80% good to excellent results and
90% radiographic healing of the defects.
• This technique requires greater surgical exposure, with
extensive stripping of the muscles to expose the transverse
process.
• Complications such as wire breakage are common with this
technique.

94. SCOTT WIRING TECHNIQUE

95. MODIFIED SCOTT TECHNIQUE
• Modified SCOTT TECHNIQUE in
which a wire is passed around the
cortical screws introduced into both
pedicles and tightening it beneath the
spinous process.
• Biomechanical tests show that
fixation of the wire to the pedicle
screw does not increase the stiffness
of the system.
• This techniques have defect healing
rates of 86% to 100%.

96. MODIFIED
SCOTT
TECHNIQUE

97. KAKIUCHI TECHNIQUE
• Kakiuchi reported successful union of
pars defects with the use of a pedicle
screw, laminar hook, and rod system.
• A pedicle screw is placed in the
pedicle above the pars defect.
• The pars defect is bone grafted.
• A rod is placed in the pedicle screw
and then into the caudal laminar hook,
and compression is applied.
• This gives a more stable construct
than that afforded by wire techniques

98. COMPARATIVE STUDIES

99. GROB’S TECHNIQUE: DIRECT PEDICULO-
BODY FIXATION

100. GROB TECHNIQUE
• In situ fusion is a relatively safe and reliable procedure
associated with a high rate of arthrodesis and at lower risk of
neurologic injury .
• Fixation of the segment is achieved by two cancellous bone
screws inserted bilaterally through the pedicles of the lower
vertebra into the body of the upper slipped, vertebra
• In advanced intervertebral disc degeneration

101. INTER-BODY FUSIONS: THEORETICAL
CONSIDERATIONS
• Anterior column support
• Bio-mecahnically superior:
• Large area for fusion
• Grafts under compressive loads
• Degenerate disc removed
• consider disc height
• Build in the lordosis

114. INTER-BODY FUSIONS
P LIF T LIF
A LIF

118. RADIOLOGICAL RESULT

122. PLIF WITH TITANIUM MESH CAGE AND
PEDICLE FIXATION