SpineUniverse Case Study Library

Grade II Isthmic Spondylolisthesis Revision


This 27-year-old female, with a grade 2 isthmic spondylolisthesis, with low back pain and bilateral lower extremity radicular pain was treated with a L4-S1 instrumented posterior lumbar fusion with iliac crest bone graft.

She did very well for 9 months without almost no low back or leg pain. While lifting a 75-pound box at a Wal-Mart warehouse, she heard a "pop" with marked increase in low back pain and bilateral lower extremity radicular pain.


The patient had a normal neurological examination, but back tenderness was noted.


Posterior / anterior (Figure 1A) and lateral (figure 1B) x-rays demonstrate previous instrumentation and fusion.

posterior anterior x-ray; instrumentation and fusionFigure 1A

lateral lumbar x-ray; instrumentation and fusionFigure 1B

The images below (Figures 2A-2C) are axial myelography.

axial myelography; L4Figure 2A: L4

axial myelography; L5Figure 2B: L5

axial myelography; L5-S1 showing broken screw at S1Figure 2C: L5-S1 showing broken screw at S1

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Grade II isthmic spondylolisthesis revision

Selected Treatment

The patient underwent an L4-L5, L5-S1 ALIF followed by posterior instrumentation and fusion. The broken screws were removed with broken screw removal set.

Standing postoperative anterior / posterior and lateral x-rays (Figs. 5A, 5B)

standing postoperative anterior posterior lumbar x-rayFigure 3A

standing postoperative lateral lumbar x-rayFigure 3B


The patient returned to work, where her tasks include lifting packages. She has also returned to a fully active lifestyle. The patient reports a 2/10 low back pain score.

The initial fixation failed because of lack of anterior column support following a wide-Gill laminectomy at L5. Dr. Shaffrey addressed the lack of anterior column support with an ALIF at L4-L5 and L5-S1, which will appropriately load share the posterior construct. I commend him on being able to remove all of the broken screw fragments and performing the required posterior revision. Extra distal fixation could have been achieved with iliac wing fixation that may have required removal at a later date.

My preference for these revisions is to perform an all-posterior procedure, obtaining interbody support through TLIFs or PLIFs at both levels with iliac fixation, especially if there is difficulty in obtaining good S1 fixation.

Community Case Discussion (2 comments)

SpineUniverse invites spine professionals to share their thoughts on this case.

I agree that revision surgery for a situation like this must address the anterior column support. In my opinion, First I would approach L4/5 through a lateral transpsoas interbody fusion, followed by an L5/S1 ALIF using a graft with integrated screws. My rational is to minimize the potential vascular injury of a L4/5 ALIF. In our experience, the L4/5 lateral transpsoas interbody fusion incidence of transient nerve injury is much lower now than a year ago. I would then revise the posterior instrumentation, as done by Dr. Shaffrey

In this case I try to do all my surgery posterior with Pedicular transvertebral screw fixation of the lumbosacral spine with take out the previous screw and inserted pedicle srews obliquely through the pedicles of S1 and using a fluoroscopic guidance , the pedicle screw are the directed across the L5-S1 intervertebral disc space and into the anterior aspect of L5 vertebral body(Abdu Technique spine 1993)and two additional pedicle srews in L4. I think this is a easy and simpler way to resolve a pseudarthosis and we Do not necesitate anterior aproach and do no necesitate interbody fusion(tlif or Plif)


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