EARLY OUT COME OF FUSION SURGERY FOR SPONDYLOLISTHESIS

INTRODUCTION
Spondylolisthesis is subluxation of one vertebra
over the other in sagittal plane. The reported incidence
is about 6 %. This may be anterior or posterior subluxation.
Anterior slip is the most common type and
lower lumbar spine is the common location of slip to
occur1. There are different types; isthmic, degenerative,
dysplastic and rarely traumatic or pathological. Isthmic
is the most common type and slip is due to the defect
in pars interarticularis. Degenerative is also quite common
and is due to the degeneration of facet joints with
or without disc degeneration. In the isthmic type, as
there is defect in the neural arch, the width of the canal
increases with slip and they may remain asymptomatic
for long time with out neurology. In contrast, degenerative
type due to intact neural ring rapidly gives rise to
stenosis like symptoms2.
The clinical presentations may be different.
There may be an episode of back pain, radiculopathy
and stenosis like symptoms in degenerative type. The
natural history of isthmic Spondylolisthesis is still unclear3.
This is why the treatment of Spondylolisthesis
is still controversial. It should be clear that nonsurgical
treatment should be the initial treatment in all cases of
isthmic and degenerative Spondylolisthesis4. Surgical
intervention is required in patients with backpain or
claudication compromising daily life, persistent back
pain with failed conservative treatment, neurology or
cuada equina5.
There are a variety of surgical procedures ranging
from simple decompression to various kinds of instrumentation
with fusion. Usually fusion with stabilization
is performed. These are basically posteriolateral fusion
(PLF) or interbody fusion done from the posterior or
anterior. PLF with instrumentation and without reduction
is being a standard surgical treatment for long time with
consistently good results6. Surgical reduction of the
high-grade slip is another controversial issue. According
to many authors it carries a great risk of neuronal injury
while in situ fusion is simple with out complications and
has good results7. With pedical screws fixation and
interbody fusion, slip can be reduced fully or partially
without major complications and increasing the chances
of fusion. It also addresses basic pathology and theoratically
improve biomechanics of the spine8,9. In this study
we present our early results of surgical interventions in
terms of functional outcome, slip reduction and complication
rate. Functional outcome was assessed with
Oswestry Disability Index ODI preoperatively and post
operatively10.