Biomechanics:
Anteriorly directed vector
Contraction of Erector Spinae
muscle
Coupled with the force of
gravity
Act on upper body mass
through lordoticspine
Anatomic structures that resist
anteriorly directed force are:
•Facets
•Annulus fibrosis
•Posterior bony arch
•Pedicles
Hook & catch concept:
•Hook:
Pedicles
Pars-interarticularis
Inferior process of cephalad level
•Catch:
Superior process of caudal level
EPIDEMOLOGY :
•Incidence : 7 % by age of 18 years
•L5/S1-82% , L4/L5-11%
•Degenerative spondylolisthesis: Common in women
> 50 years
•Isthmic spondylolisthesis-Familial association:
26% in first degree relatives
Source:https://pubmed.ncbi.nlm.nih.gov/31078236/
Classifications:
Wiltse, Newmann, Macnab classification
(Aetiological & topographical)
Meyerding classification(% of slip in lateral
radiograph)
Marchetti-bartolozzi classification(based on
developmental & acqired)
I) Wiltse Classification:
•Type –I : Dysplastic 20 %(congenital abnormalities
of upper sacral facet or inferior facet of L5)
•Type-II : Isthmic 50%(defect in pars
interarticularis)
•Type III :Degenerative25 %(intersegmental
instability)
•Type IV : Traumatic(# in bony hook)
•Type V :Pathologic(eg: osteogenesis imperfect)
•Type VI : Iatrogenic (added later)
ISTHEMIC SPONDYLOLISTHESIS
Hallmark : defect in pars interarticularis
Defect : lytic(stress fracture) or microfracture
Most common type with Common : L5-S1
Age: 5-50 years
First occur during or just before adolescence
May progress until skeletal maturity
IIA : disruption of pars due to stress #
IIB : Elongation of pars without disruption due
to healed micrfractures
IIC: Acute # through pars
DEGENERATIVE
SPONDYLOLISTHESIS
2
nd
most common type
Common : L4-L5 level
Results from segmental instability as a result
of disc degeneration & facet remodeling
Female =5 times Male
Age > 50 yrs
Risk factors for the progression:
1)Youngageatpresentation
2)Femalegender
3)Slipangle>30degree
4)Highgradeslip
5)Domeshapedorsignificantlyinclinedsacrum
6)Increasedpelvicincidence
7)Discdegeneration
CLINICAL FEATURES :
Usually asymptomatic : Incidental finding in X ray
Symptoms depend on the severity of slip
Due to :
1) Chronic muscle spasm
2) Tears in the Annulus Fibrosus
3) Compression of the nerve roots
C/F (according to age):
InChildren
Asymptomaticusually
Parentnoticedundulyprotrudingabdomen
Pecularstance
InYoungadults:
Low back pain-on movement (Hyperextension),
Intermittent
Hamstring pain due to irritation of L5 nerve root
Radiculopathy –may occur in one or both legs.
C/F :
In patients > 50 yrs:
•Backache –episodes of backache
•Sciatica
•Pseudoclaudicationd/t spinal stenosis
•Other signs of nerve root compression-motor
weakness, reflex changes and sensory deficits.
ON EXAMINATION:
A) LOOK:
Buttocks –Flat
-Heart shaped in high grade slip
-d/t sacral prominence
Sacrum –more vertical
-appears to extend to the waist
Lumbar hyperlordosisabove the level of the slip to
compensate for the displacement
Transverse loin crease
With severity-absence of waist line
Peculiar spastic gait -d/t hamstring tightness and
lumbosacral kyphosis (late stage)
Inspection:
Heart shaped Abdominal
crease
Absence of
waist line
Incresed
lumber
lordosis
Radiographic assessment ( X-ray)
•AP View:
Inverted Napoleon’s hat sign
(in severe Spondylolisthesis)
Standing lateral view: Vertebral
subluxation and pars defect
(15% deformities reduce on supine
imaging)
Ferguson coronal view:
By angling
(30°cephalad tilt & the x-
ray beam parallel to L5-
S1disc)
L5 pedicles, transverse
process and sacral ala is
more visible
X-RAY (upright lateral Flexion and
extension views):
Show excessive
movement across the
site of pseudoarthrosis
in pars
Subluxationof vertebral
body as patient moves
from extension to
flexion
For operative decision
X-RAY Oblique view:SCOTTYDOG SIGN:
“SCOTTY DOG SIGN” (decapitated dog )
Pars area is in relief apart from underlying bony
elements
Bone scintography/ SPECT:
•Detectsstressreaction
beforefracture
•Uses: Symptomatic
patient without
radiologicalcahnges
•Findings:Increasebone
metabolicactivityin
acutelyinjuredpars
interarticularis
Operative options:
•Direct repair of pars defect
•Decompression & fusion without fixation
•Decompression & fusion with pedicle screw
fixation
•Posterolateral insitu fixation
•PLIF (Posterolateral Interbody Fusion &
Fixation)
•TLIF (Trans Foraminal Interbody Fusion)
•ALIF(Anterior interbody fusion)
Directrepairofparsinteraticulais:
•Radiographic Criteria for direct
repair:
Absence of spondylolisthesis
Absence of degenerative change at involved
disc level
Absence of degenerative facet changes
Absence of dysplastic changes such as spina
bibida
Direct repair of pars interaticulais:
•TECHNIQUE:
Buck technique:
Indicated : gap < 3 mm
Fibrous tissue at pars defect
debrided
Stabilized with 4.5 mm cortical
screw
Direct repair of pars interaticulais:
•Other techniques are:
Scott wiring & modified scott
technique
Kakiuchi procedure( repair with
ipsilateral pedicle screw & hook
Repair of pars defect V-rod technique:
In situ posterolateral instrumented fusion
•Debride lytic defect
Exposure & bone harvest
•Pedicle screw
fixation(polyaxial pedicle)
•Approach: Wiltse & Spencer
Interbody fusion
•Interbodyfusion promote fusion between the
vertebral bodies by
a)Device( with instrumentation)
b)Bone graft
GOAL : Elimination of pathological segemnt
•Accto Surgical approach used during device:
Anterior lumbar interbodyfusion (ALIF)
Transforaminallumbar interbodyfusion (TLIF)
Posterior lumbar interbodyfusion (PLIF)
Transforaminallumbar interbody
fusion (TLIF):
•Ideal for grade I or II
spondylolisthesis with
unilateral symptoms
•Improved fusion rates d/t
circumferential support
•Single bone graft between
vertebra from side
Posterior lumbar interbody fusion
(PLIF)
3 surgical steps:
Laminectomy or laminotomy
with partial or complete
facetectomy
Removal of intervertebral disc
Fusion
Decompression (in degenerative
type)
•Gill procedure= removal of loose laminar
arch
•Foraminotomy
•Faectectomy
•Common : Decompression & fusion with or
without instrumentation
•Studied from Mubai India by Kulkarni et. al published in 2020
•In recent years, there is increasing trend towards minimal access surgery in spine,
which is associated with improvement in implants, navigation technology and use of
newer imaging modality. Although MIS techniques have historically been commonly
implemented for limited indications in spine with technological advancement and
increased surgeon experience, can adopt MISS for wide range of surgeries including
high grade spondyloisthesis and spondyloptosis.
Take Home Messages:
Isthimictypeism/ctypeofspondylolisthesiswith
hallmarksofparsdefect
Riskfactorsforprogressionareearlyageof
presentationwithfemalegender
Transverseloincrease,absencewaistlinewith
palpablestepinspineiskeytoclinicaldiagnosis
APviewalongwithFergusoncoronalview,upright
lateralFlexionandextensionviewsandoblique
viewsX-rayareneeded
Recentadvanceintreatmentforhighgrade
spondyloisthesisandspondyloptosisisMIS