Does this 21-year-old need a spinal fusion?

History

A 21-year-old male, with a previous history of low back pain, reported a marked increase in leg pain and related symptoms in the 3-month period prior to evaluation in our practice. He came to us through referral for an open reduction and internal fixation (ORIF) vs fusion at L5-S1.

At this time, he has significant right leg pain in the L5-S1 distribution with minimal low back pain. There is no history of bowel or bladder dysfunction, rash, lesion or known trauma.

The patient is gainfully employed in the construction industry and reports leg pain makes working difficult. He has no secondary gains and his family is very supportive.

Examination

The patient’s gait is slightly antalgic and he sits unloading his right buttock.

• Very positive straight-leg-raise on the right at 45-degrees. Left side is negative.
• No muscle wasting or atrophy.
• No long track signs (eg, hyperreflexia)
• No reflex asymmetry.
• Weakness only with right extensor hallucis longus.

Current and Prior Treatment

The patient completed months of physical therapy and uses non-steroidal anti-inflammatory medications off and on.

About 6 months ago, he completed 2 midline epidural steroid injections with equivocal results. An L5-S1 facet joint block improved his low back pain but right pain development and has not resolved in more than 6 months.

Pre-treatment Imaging

Figure 1. Lateral lumbar x-ray shows a pars fracture at L5-S1. Image courtesy of Christopher R. Hemmer, DNP, ANP, Terence Piper, MD, and SpineUniverse.com.

Figure 2. Posteroanterior lumbar x-ray. Image courtesy of Christopher R. Hemmer, DNP, ANP, Terence Piper, MD, and SpineUniverse.com.

Figure 3. Sagittal lumbar MRI from 6 months ago. Image courtesy of Christopher R. Hemmer, DNP, ANP, Terence Piper, MD, and SpineUniverse.com.

Figure 4. Axial lumbar MRI from 6 months ago shows the L5-S1 disk space. Image courtesy of Christopher R. Hemmer, DNP, ANP, Terence Piper, MD, and SpineUniverse.com.

Question/Answer: What would you do next with this patient?

1. Discuss ORIF of the L5 pars fracture
2. Discuss posterior instrumented fusion of L5-S1
3. Re-image given the significant changes in presentation
4. Continue to recommend further non-operative treatments

Answer: We elected to repeat imaging given the patient’s significant change in presentation. The family was very hesitant, as they were told he has a pars fracture and it must be the cause of his symptoms.

Keep in mind, the patient’s complaint was back pain up until several months ago when his back pain eased and leg pain significantly worsened.

The patient stated he can live with the low back ache, but not the right leg pain.

Figure 5. Repeat sagittal lumbar MRI. Image courtesy of Christopher R. Hemmer, DNP, ANP, Terence Piper, MD, and SpineUniverse.com.

Figure 6. Repeat sagittal lumbar MRI. Image courtesy of Christopher R. Hemmer, DNP, ANP, Terence Piper, MD, and SpineUniverse.com.

Figure 7. Repeat axial lumbar MRI shows the L5-S1 disc space. Image courtesy of Christopher R. Hemmer, DNP, ANP, Terence Piper, MD, and SpineUniverse.com.

Figure 8. Lateral lumbar CT/myelogram. Image courtesy of Christopher R. Hemmer, DNP, ANP, Terence Piper, MD, and SpineUniverse.com.

Figure 9. Posteroanterior lumbar CT/myelogram. Image courtesy of Christopher R. Hemmer, DNP, ANP, Terence Piper, MD, and SpineUniverse.com.

Figure 10. Lateral lumbar CT scan. Image courtesy of Christopher R. Hemmer, DNP, ANP, Terence Piper, MD, and SpineUniverse.com.

Figure 11. Axial lumbar CT scan. Image courtesy of Christopher R. Hemmer, DNP, ANP, Terence Piper, MD, and SpineUniverse.com.

Question/Answer: What is the large structure now noted at L5-S1 on the right?

1. Large synovial cyst
2. Large herniated disc
3. Meningocele
4. MRI artifact

Selected Treatment

After a lengthy discussion, the patient underwent decompression of the right L5 and S1 nerve roots. The history of the pars fracture and low back pain was discussed vs the acute radiculopathy and new study findings.

Intraoperative findings demonstrated a large cystic structure impaling the right L5, S1 and cauda equina. The cystic structure was mostly comprised of viscous light bloody synovial-type fluid.

Immediately post-op, the patient reported resolution of his leg pain.

Outcome

At 4 weeks post-op, the patient had returned to normal activities with minimal complaints of low back pain and no recurrent radicular leg pain or related symptoms.

Peer Case Discussion

Joshua M. Ammerman, MD

Neurosurgeon

Washington Neurosurgical Associates

This is an interesting case that illustrates the conundrum of how to manage a bilateral spondylolysis in a young adult. I agree with the authors that the synovial cyst was the offending pathology in this case and indeed surgical correction of that abnormality, without addressing the pars defects, resulted in the expected good clinical outcome.

The question is now, what does the future hold for this patient, specifically will a symptomatic spondylolisthesis develop? A few risk factors have been identified to help predict those patients who may progress, including a high sacral slope, early disc degeneration, a concomitant scoliosis, and more than 2mm of bony separation across the defect. For those patients at risk, a direct pars repair, augmented with hooks or screws, has been shown to result in bony healing in 70-100% of patients. Based upon the above, the surgeons appear to have chosen a wise course for this patient.