High-Grade Spondylolisthesis (Part 5)

This is Part 5 on Spondylolistheses and we have gone from
the mild deformities and progressing to the severe grades.

In this post we will present a Type 5 High Grade
deformity.  This means the patient is
compensating for the spondylolisthesis slippage, by rolling the pelvis
backwards.  In the Type 5 deformities it
means the patients successfully compensate and stay globally balanced, so they
are not leaning forward or backwards.

The case we will present is one of a 16-year old female, who
was having low back pain for 2-3 years which was shooting down both of her
legs, right more than left leg.  In
addition she was tripping frequently, as she was having difficulty lifting her
foot up.  This happens in High-Grade
slips, as the nerve root which permits us to lift our foot up gets pinched and
may not work normally.

The below figure focuses on the radiographic deformity.  The numbers on the slide are very technical,
but are important when we diagnosis, classify and plan surgery for this
problem.  For this blog post we will not
discuss these numbers.

Rather look at the middle 2 x-rays, especially the one third
from the left with the red arrow.  The L5
vertebra should be sitting on top of the S1 vertebra, but it has slid forward
and down.

Below is the MRI of the deformity.

The yellow arrow is pointing at the nerve roots which can be
pinched as the L5 vertebra slips forward and down on S1.

Since this is an unbalanced patient, we needed to partially
reduce L5 on S1.  We don’t want to fully
reduce the slip, as the nerve roots (yellow arrow above) can be stretched too
much and not work normally.  If this happens
the patient may not be able to lift her foot up, making walking difficult and
need to wear a brace on her foot/ankle long-term.  By partially reducing the deformity, we can
balance the spine and not cause a nerve root problem (or muscle weakness).

Again we place a cage between L5 and S1 to give support
after we removed the disc, and to permit a fusion to happen between L5 and S1
in the front of the spine.

Since there are huge forces to reduce and hold the spine in
its new position, the use of iliac screws (green arrow) is necessary.

After surgery this patient did not have any nerve root
problems (no muscle weakness) and her back and leg pain has resolved.  The below figure is now 1 year after surgery
and the red arrow shows a robust, thick fusion mass between L5 and S1 (which
incorporates the cage).

This is the last post on spondylolisthesis, for now.

If you have questions let me know!  This is a complicated problem which is
infrequently cared for by most pediatric spine surgeons.

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