1. TS Fong
12.3.2012

2. SPONDYLOLISTHESIS
 Forward translation of one
vertebra on another in the
sagittal plane of the spine
 Spondylolysis
 defect in the pars interarticularis
of lumbar vertebra
 most commonly due to repeated
and increased stress on the pars
interarticularis

3. ANATOMY
 Pars
 region between the superior and inferior articulating
facet of the vertebra
 weakest area in the neural arch
 susceptible to stress fracture

4.  Pars defects
 not observed in newborns or nonambulatory
patients
 lysis or elongation does not occur in primates
that do not have an upright bipedal gait
 presence of lumbar lordosis (unique in humans)
is necessary for spondylolisthesis to occur

5. EMBRYOLOGY AND OSSIFICATION CENTRES
SAGI ET AL SPINE 1998
 pars ossify at 12-13 weeks gestation
via endochondral ossification
Lumbar Vertebrae
 ossification centre in the region of
the pars
 uneven trabeculation and cortication
 ossification centre that arises at the
upper end of pedicle
 uniform trabeculation throughout the
pars
 potential stress riser which could be
susceptible to fatigue fracture

6. CLASSIFICATION

7. CLASSIFICATION
WILTSE, NEWMAN AND MACNAB 1976
 Type I: Dysplastic (child)
 Type II: Isthmic (5-50 yrs)
 Type III: Degenerative (older)
 Type IV: Traumatic
 Type V: Pathologic

8. DYSPLASTIC SPONDYLOLISTHESIS
 dysplasia/aplasia of posterior facet joints of
the L5/S1 levels
 constant spina bifida occulta at the L5 level
– congenital nature
 concomitant elongation of the pars
interarticularis --- frank lysis
 condition is strongly familial, with as many
as a third of first-degree relatives affected
with the dysplastic form (Wynne-Davis et al)

9. Lateral radiograph
• rounding of the top of the sacrum as
L5 has rolled round anteriorly due to
poorly formed posterior facet joints
AP view
• 'Napoleon's hat' appearance of L5
superimposed through the sacrum

10. ISTHMIC SPONDYLOLISTHESIS
 repetitive cyclical extension/torsion of the spine
 repetitive infraction fatigue failure of the pars
 high prevalence rate
 highest biomechanical forces on the pars at
L5/S1 level
 commonest site of a lytic spondylolysis

11. Lateral radiograph of a lytic
spondylolisthesis
Oblique radiograph of a lytic
spondylolisthesis

12. DEGENERATIVE SPONDYLOLISTHESIS
 incompetence of the posterior facet joints
 10x more common at the L4/5 than the L5/S1
 not encountered in the under 50-year-old
 the degree of slippage in the sagittal plane is
no good guide to the amount of neural
compression
 fourth dimension, time, is important
 degenerative process going on for years and years
 patients are much more readily able to adapt to neural
compression than for example with a rapidly growing tumour

13. CT scan
• level of a degenerative
spondylolisthesis
• facets have come forward to
contact the back of the
vertebral body and completely
close off the epidural space
DEGENERATIVE SPONDYLOLISTHESIS

14. Traumatic spondylolisthesis
 acute vertebral fractures do not occur through the
pars, but through pedicles, bodies, discs
 so-called 'traumatic spondylolistheses' are not
discrete entities
 should not be part of the generic spondylolisthesis
classification
Pathological spondylolisthesis
 metastasis and rheumatoid disease are the more
common causes
 disease of the whole motion segment rather than
the pars in particular

15. CLASSIFICATION
MARCHETTI AND BARTOLOZZI 1997
 etiology-based system
 importance of high and low grade developmental spondylolisthesis
 permitting early recognition and treatment

16. LOW GRADE SPONDYLOLISTHESIS
 low grade variety present in young adults
 frequently associated with spina bifida
 slip is characterized by translation without any angulatory or
kyphotic component

17. HIGH GRADE SPONDYLOLISTHESIS
 Usually at L5-S1 and become symptomatic in adolescents
 wedge shaped L5 and a domed vertical sacrum
 anterior translation of L5 associated with angulation --true
lumbosacral kyphosis
 potential to develop into spondyloptosis if untreated or
mismanaged

18. CLASSIFICATION BY MARCHETTI AND
BARTOLOZZI
SPINE/SRS SPONDYLOLISTHESIS SUMMARY STATEMENT 2005
 based on etiology
 clearly distinguishes between developmental and
acquired forms of this deformity
 highlights the pathogenesis of the different types of
spondylolisthesis
 potentially has the most relevance to natural
history, risk of progression, and implications for
treatment

19. NATURAL HISTORY
 wide spectrum of clinical presentation
 dysplastic and isthmic spondylolisthesis present during
childhood and adolescence
 dysplastic variety usually at a younger age than
isthmic
 early stages - low back pain is the only consistent clinical
feature
 immature patient - high index of suspicion should be
raised about the possibility of an underlying
spondylolisthesis

20. NATURAL HISTORY
 hamstring tightness, spinal deformity, gait
abnormality
 frank neurology
 severe degrees of spondylolisthesis
 usually dysplastic variety - lower lumbosacral nerve
roots can be compressed behind the upper back of the
sacrum
 isthmic spondylolisthesis
 some degree of L5 radicular pain is not uncommon
 hypertrophic callus around the lysis
 degenerative spondylolisthesis
 spinal claudication in association with low back pain

21. PHALEN-DIXON SIGN
 sciatic crisis typically seen in high
grade adolescent
spondylolisthesis
 sign includes
 sciatic pain
 vertical sacrum and pelvis
 lumbosacral kyphosis
 tight hamstrings
 hyperlordotic lumbar spine
 waddling gait

22. BACK PAIN AND SPONDYLOLISTHESIS
 The cause of back pain is unclear and is
multifactorial
 The pain may be due to
 disc degeneration
 facet degeneration
 chronic nerve root irritation from compression or
traction
 patient may have accompanying spinal stenosis

23. RADIOGRAPHY

24. Defect in the pars interarticularis –
‘collar’ around the ‘neck’ of an illusory
‘dog’- oblique xray

25. THE BENDING FILMS
 demonstrate persistent
motion and instability
 especially in the presence of
degenerated disc disease at
the level of spondylisthesis
 disc degeneration and
collapse of the disc space is
an attempt to stabilize the
motion segment

26. RADIOLOGICAL EXAMINATION
 large number of suggested and preferred radiological parameters to
assess spondylolisthesis
 Only 2 are of any great importance (Wiltse LL et al )
1. The amount of displacement
2. The slip angle (the angular relationship between L5 and S1 in the
dysplastic form of spondylolisthesis)
Percentage slip (x/y(x 100)
slip angle or angle of sagittal rotation

27. RADIOGRAPHIC INDEX
Slip angle of Boxall
superior border is chosen
 more constant
 not affected by adaptive changes
commonly occur in the inferior end
plate
represent local kyphosis across
the L5-S1 motion segment

29. RADIOGRAPHIC INDEX
 the degree of slips or transitional displacement (Meyerding)

30. RADIOLOGICAL EXAMINATION
CT scan
 helpful in preoperative planning especially in cases with
severe dysplasia
MRI
 assess neural foramen on the sagittal views
 determine extent of associated disc disease
 disc herniation is common
 25% cases occur at the level above the slip
 15% occur at the level of the slip itself
 rule out tumor or infection

31. MANAGEMENT

32. PREDICTORS OF SLIP PROGRESSION
 female gender
 prepubescence
 trapezoidal L5
 domed and vertical sacrum and
sagital rotation
 slip angle > -10o
 high grade slip (>50% slip
progression)
 inclined sacrum (>30o beyond
vertical)

33. INDICATIONS FOR SURGERY
AGABEGI ET AL (THE SPINE JOURNAL 2010)
 Slip progression
 more common in skeletally immature patients who have
not reached the adolescent growth spurt
 the higher the grade of slip, the more likely it is to
progress
 slip progression rarely occurs in adults
 High-grade slip with significant lumbosacral
kyphotic deformity causing sagittal imbalance

34. INDICATIONS FOR SURGERY
AGABEGI ET AL (THE SPINE JOURNAL 2010)
 Neurological deficit
 In most cases, the L5 nerve root is involved
 Low back pain unresponsive to a prolonged course
of conservative treatment
 Radicular pain with associated nerve root
compression on imaging studies that is not
responsive to conservative treatment

35. CONSERVATIVE TREATMENT
 Directed at symptomatic relief
 Rest
 anti-inflammatory agents
 lumbar corset
 Physical therapy
 abdominal strengthening exercises
 hamstring stretching
 avoidance of extension exercises which will
exacerbate the symptoms
 Sinaki et al showed 3-year outcomes were significantly better in
patients who followed the flexion exercise program compared to
extension exercise

36. SURGICAL TREATMENT
 directed towards symptoms and etiology
 radiculopathy
 neurologic deficit from spinal stenosis
 instability pain
 discogenic pain
 the mainstay of treatment is
 Decompression
 Fusion
 Instrumented
 Non instrumented

37. ISTHMIC SPONDYLOLISTHESIS
TREATMENT
VACCARO ET AL
Findings Treatmennt
Grade I observation
Grade II Asymptomatic: Observe
Symptomatic: Activity modification
Failed: Surgery
Grade III-IV Surgery

38. ISTHMIC SPONDYLOLISTHESIS
OPERATIVE TREATMENT
procedure advantage/disadvantage results
Defect repairs Preserve motion
Technically difficult
Variable
60-90%
Laminectomy (Gills) Increase instability Poor long term outcome
abandoned
Posterolateral fusion (in
situ)
Improved symptoms Children
Adult: variable
Reduction and fusion Allow correction
Add stability
Slippage >60%
Slip angle >50 degree
Age 12 to 30
(Bradford 1988)
Anterior and posterior
fusion
Additional stability
360 degree fusion
Difficult surgery

39. ROLE OF REDUCTION
( AGABEGI ET AL, 2010 )
 high-grade spondylolisthesis causes lumbosacral
kyphosis --- sagittal imbalance
 reduction procedure controversial
 literature support both sides of the argument
 high rate of neurologic complications
 reserved for patients with loss of global sagittal
balance because of significant lumbosacral
kyphosis
 circumferential fusion and stable fixation with iliac
screws are strongly recommended to prevent slip
progression and pseudarthrosis

40. DEGENERATIVE SPONDYLOLISTHESIS
OPERATIVE TREATMENT OPTIONS
 Decompressive laminectomy
 Decompression with posterolateral fusion
 Decompression with instrumented fusion
 Long-term follow-up in patients with
degenerative spondylolisthesis reveals a
positive correlation between fusion and
improved clinical outcome

41. THE FUSION OPTIONS
achieve posterior column stability
 posterolateral intertransverse fusion (PLF)
achieve anterior column stability
 anterior lumbar interbody fusion (ALIF)
achieving a circumferential fusion
 posterior lumbar interbody fusion (PLIF)
 transforaminal interbody fusion (TLIF)
no consensus of what constitutes optimal
surgical treatment
surgical option must be individualized

42. POSTERIOR INTERTRANSVERSE FUSION
 historically most popular
way of performing fusion
 direct decompression of the
neural elements
 deformity correction
 stability with pedicle screw
instrumentation
 the disadvantages are
 less optimal fusion rate: graft
under tension
 as it does not address the
anterior column: persistent
discogenic low back pain is
common

43. ANTERIOR LUMBAR INTERBODY FUSION
 allows for complete discectomy
 permits placement of a large
interbody graft
 facilitate slip angle correction
 reconstructs the disc space height
 anterior graft
 biomechanically compressive
environment
 allowing optimal fusion

44. ANTERIOR LUMBAR INTERBODY FUSION
 The disadvantages
 related to the approach
 risk of injury to major vessels,
retroperitoneal and intraperitoneal
structures
 in males, the sympathetic plexus can
be damaged and cause retrograde
ejaculation
 does not allow direct nerve roots
decompression
 Suk et al.
anterior support would be helpful for
preventing reduction loss in cases of
spondylolytic spondy- lolisthesis of
the lumbar spine

45. CIRCUMFERENTIAL FUSION
 the benefits of anterior and posterior
surgery ( TLIF/PLIF)
 circumferential stability obviously
promotes high fusion rate
 Open or MIS

46. SPONDYLOPTOSIS
 severe symptoms of low back pain,
deformity, and neurologic symptoms or
deficits
 Surgical options
 in situ circumferential fusion technique described
by Smith and Bohlman
 Gaines procedure (resection of L5 and reduction of
L4 onto the sacrum through a combined anterior
and posterior approach)
 Gaines technique is associated with a
high rate of postoperative neurologic
deficits and is generally reserved for the
most severe deformities

47. Gaines Procedure
• resection of L5 and
reduction of L4
onto the sacrum
• combined anterior
and posterior
approach

48. THANK YOU

49. Operative Vs Non-operative

50.  multicenter, prospective study
 highest level of evidence
 guide decision-making on operative vs nonoperative
care for the specific disorder of degenerative
spondylolisthesis
 treatments compared were lumbar laminectomy
with a single level fusion vs nonoperative treatment
 treating surgeon determined type of fusion
(uninstrumented posterolateral fusion, instrumented
posterolateral fusion, circumferential fusion)

51. Conclusion
 patients with degenerative spondylolisthesis and
spinal stenosis treated surgically showed
substantially greater improvement in pain and
function during a period of 2 years than patients
treated nonsurgically

52. DEGENERATIVE SPONDYLOLISTHESIS
OPERATIVE TREATMENT OPTIONS
Decompression alone or decompression with
segmental arthrodesis ?
 higher proportion of patients with good or excellent
outcomes among patients who underwent
decompression and arthrodesis compared with
those underwent decompression alone (Herkowitz
et al)

53. DEGENERATIVE SPONDYLOLISTHESIS
OPERATIVE TREATMENT OPTIONS
Instrumentation or non-instrumented fusion in
degenerative spondylolisthesis
 Martin et al ( systematic review )
significantly higher rate of achieving a solid
fusion in patients treated with instrumentation
compared with those treated without
instrumentation
 Kornblum et al
solid arthrodesis is associated with less
segmental instability and better outcomes than
pseudarthrosis
supports the use of instrumentation for fusion
rates