Pedical screws used for pat with significant instability
Dr. M. M. Prabhakar
Director Govt. Spine Institute
Prof. & Head Department of
B. J. Medical college
Definition: Ant. or post. translational displacement
of one vertebral body over another.
2. Degenerative changes
3. Defects in the bony architecture
congenital or pathological
Dysplastic Spondylolisthesis: secondary to a congenital
defect of either the superior sacral or inferior L5 facets
or both with gradual slipping of the L5 vertebra
Isthmic or spondylolytic:
the lesion is in the
isthmus or pars interarticularis,
If a defect in: the pars interarticularis & no slipping
If one vertebra has slipped forward: Spondylolisthesis.
Type II A: Lytic or stress spondylolisthesis and is
most likely caused by recurrent micro-fractures
caused by hyperextension. It is also called a "stress
fracture" of the pars interarticularii and is much more
common in males
Type II B probably also occurs from micro-fractures
in the pars. However, in contrast to Type II A, the
pars interarticularii remain intact but stretched out as
the fracture fill in with new bone
Type II C is very rare in occurrence and is caused by
an acute fracture of the pars. Nuclear imaging may be
needed to establish diagnosis
Type III is a degenerative
occurs as a result of the
degeneration of the lumbar
facet joints. The alteration
in these joints can allow
forward or backward
Most often seen in older
There is no pars defect and
the vertebral slippage is
never greater than 30%
Type IV, traumatic spondylolisthesis, is associated
with acute fracture of a posterior element (pedicle,
lamina or facets) other than the pars interarticularis
Type V, pathologic spondylolisthesis, occurs because
of a structural weakness of the bone secondary to a
disease process such as a tumor or other bone
Traumatic listhesis is rare condition.
Results from Acute fracture of the posterior element
other then pars…
It is fracture dislocation of the spine…involving all
It is the shear forces which cause break in the
posterior stabilizers and the force is transmitted at
the level of Intervertebral disc resulting in anterior or
posterior displacement of the vertebral body.
Commonly occurs at cervical spine with axis
fractures…resulting in displacement at c2 c3 level
Rare in lumbar spine usually associated with high
Above L2 level it is fracture dislocation of the spine
involving all three columns.
1. Bone graft, chronic pain 5% pts.
2. Fusion, pseudoarthrosis, bleeding, infection
3. Instrumentation, loss of fixation, loosening and
bone screw interface, implant breakage
4. Decompression (neural elements), nerve damage,
dural tears, arachnoiditis, surgical scars
Decompression with Posterior Lateral Fusion:
Younger pts (30 y.o.)
Intact vertebral disk
McGuire and Anderson:
27 pts, military recruits
Stable, low grade slips
No difference in fusion rate with in situ vs pedicle screws
Smokers less effective outcomes (40% nonunion)
Fusion did not determine success 67% went back to military
service, decrease leg and back pain
Ant. Column support and Posterior Stabilization:
Interbody Graft techniques:
Requires separate incision
Post. Trans-foraminal approach
Post lateral fusion with pedicle screws
Post. Trans-foraminal approach:
Decompression and stabilization 1 approach
Decreased risk of neural compromise
Ant. Column support and Posterior Stabilization:
Spruit et alt.
21% pre-op slips 7 % post op
100% fusion rates
75% returned to pre injury activity
Reduction of High Grade
Advocated by some authors
Correct slip angle
No need to perform in adults
HIGH rate of neural compromise
Don’t do it!!!!!
Younger age group (Avg 38 yrs)
Usually due to hyperextension-axial compression
forces (windshield strike)
Neurologic injury seen in only 5-10 %
(acutely decompresses canal)
Traditional treatment has been Halo-vest
Collar adequate if < 6 mm displaced
Coric et al JNS 1996
Traumatic spondylolisthesis of
The fracture line passes through
the neural arch.
It may or may not result in ant.
displacement of C2 on C3.
Most commonly caused by a
Motor Vehicle accident and a
Current classification (Levine &
Edwards) is based on
radiological findings: 4 types are
described and each category has
different mechanism of trauma.
Mechanism: hyperextension – axial loading
Integrity of ALL, PLL, and Disc
Displacement < 3 mm
Stable fracture: Collar.
Significant angulation and translation.
Extension – axial loading followed by flexion.
Most common type
Unstable: halo vest.
Flexion – distraction
Unstable: Halo vest
Severe angulation and translation + unilateral or bilateral C2-3 facet dislocations.
Flexion – compression.
Unstable fractures: Surgical reduction and fixation.
Low grades like type I and Type II are treated
Skull traction (contra indicated in IIA causing
distraction and further damage)
Cervical collar/ SOMI brace
Halo traction device
High grade type II facture require surgical
Open reduction, fixation and fusion
Trans pedicular screw fixation for motion preservation
in type II fracture
Direct pars screw:
the C2 pedicle should be
palpated using a fine
dissector after removal of
Conservative treatment is mainstay
Progression of slip rarely occurs
Decompression and fusion give excellent results
for radiculopathy and back pain
4. Fusion 360 degrees increases fusion rates but
does not correlate with better outcomes
5. Poor outcomes in high grade of cervical