SpineUniverse Case Study Library

Lumbar Spinal Stenosis with Grade I Spondylolisthesis

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What is this?


The patient is a 75-year-old female homemaker. She is 4'-9.5" and weighs 111 pounds. She presents with persistent severe low back pain for many years.

Her symptoms now include bilateral leg pain that has worsened; it has continued to worsen in the last 12 months. She has very little relief from pain, and the severity and consistency of her symptoms have limited all her activities of daily living.

The patient does not smoke and drinks alcohol socially.


  • Symptomatic low back pain for > 10 years
  • The patient rates her low back and bilateral leg pain as severe; 9 on a 10-point scale
  • Bilateral pain radiates downward into the posterior thighs and partially into the knees; left  > right
  • Paresthesias are greater in the left than right foot
  • The patient is unable to walk more than one city block
  • The patient trips over her feet
  • Lumbar range of motion is limited in flexion and extension
  • Range of motion in her hips is abnormal; pain with internal rotation
  • Bilateral muscle strength is 4+/5 in ankle dorsi and plantar flexors
  • Bilateral negative straight leg raise
  • Reflexes muted bilaterally
  • Sensory diminished to pinprick on the left side; L4-S1
  • Baseline Oswestry Disability Index score is 74%

Prior Treatment

  • A trial of epidural steroid injections did not reduce the patient's pain
  • A six-week course of physical therapy had a transient benefit
  • The patient refuses NSAIDs or narcotics for pain

Pre-treatment Imaging

post-operative posteroanterior thoracolumbar CT scan

Figure 1. Posteroanterior

Figure 2. Lateral

pre-operative neutral thoracolumbar CT scan

Figure 3. Neutral

pre-operative flexion thoracolumbar CT scan

Figure 4. Flexion

pre-operative extension lumbar CT scan

Figure 5. Extension


  • Severe spinal stenosis and Grade I spondylolisthesis at L4-L5
  • Severe degenerative disc disease at L2-L3, L3-L4, and L5-S1

Suggest Treatment

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Selected Treatment

The patient underwent a partial laminectomy, foraminotomy, and facetectomy (< 25%) bilaterally at L4-L5 with placement of the coflex® implant; size 8 mm (coflex® Interlaminar Stabilization™, Paradigm Spine, LLC, New York, NY).

Estimated blood loss was 100 cc. The patient was discharged home on post-operative day 3.

Post-operative Imaging

post-operative posteroanterior thoracolumbar CT scan

Figure 6. Posteroanterior

post-operative lateral lumbar CT scan, coflex device

Figure 7. Lateral

post-operative neutral lumbar CT scan, coflex device

Figure 8. Neutral

post-operative flexion lumbar CT scan, coflex device

Figure 9. Flexion

post-operative flexion lumbar CT scan, coflex device

Figure 10. Extension

Outcome: 5 Years Post-Op

The patient continues to do well 5 years after surgery. Her health-related quality of life improvements are 100% post-op versus pre-op.

  • No pain in her lower back or legs
  • She is able to walk unlimited distances
  • Oswestry Disability Index score is 0%

Exam Outcome

  • Bilateral EHL are 4+/5, and others are 5/5
  • Reflexes are symmetric
  • Sensory is intact

5 Years Post-Op Imaging

5 years status post posteroanterior lumbar CT scan, coflex device

Figure 11. Posteroanterior

5 years status post lateral thoracolumbar CT scan, coflex device

Figure 12. Lateral

5 years status post flexion thoracolumbar CT scan, coflex device

Figure 13. Flexion

5 years status post extension thoracolumbar CT scan, coflex device

Figure 14. Extension

Indications for Use – The coflex® Interlaminar Stabilization™ Device
"This device is indicated for use in one- or two-level lumbar stenosis from L1–L5 in skeletally mature patients with at least moderate impairment in function, who experience relief in flexion from their symptoms of leg/buttocks/groin pain, with or without back pain, and who have undergone at least 6 months of non-operative treatment. The coflex is intended to be implanted midline between adjacent lamina of 1 or 2 contiguous lumbar motion segments. Interlaminar stabilization is performed after decompression of stenosis at the affected level(s)."

Physician's Disclosure
Thomas J. Errico, MD received no personal compensation for this case presentation. NYU Langone Medical Center received study support through its participation in the Clinical Trial.

Surgeon's Summary

This patient met the classic indications for decompression and fusion with the diagnosis of lumbar stenosis and degenerative spondylolisthesis. The history of long-standing back pain would discourage thoughts of a decompression alone. She had failed exhaustive conservative management and was showing evidence of early neurologic weakness. She was enrolled in the coflex® trial and had dramatic long-lasting clinical improvement with limited bilateral laminectomy, partial facetectomy, and insertion of the coflex® device.

Case Discussion

Degenerative disc disease (DDD) with degenerative spondylolisthesis is a growing problem in our aging population. Interspinous process devices have grown in popularity over the last ten years. However, as with all surgery, patient selection is paramount in obtaining good outcomes.

One risk factor not mentioned in this case is the age- and race-associated risks of osteoporosis. If this patient is of Asian descent, as her petite stature suggests, she is at a higher risk of osteoporosis than her Caucasian or African American counterparts. I recommend pre-operative bone density studies for patients undergoing procedures such as this.

Isolation of the symptomatic level is particularly challenging in patients with multi-level disease. I would not have expected a patient with dermatomal sensory loss in four levels to have responded so well to a single level therapy. This patient obtained impressive post-operative pain relief suggesting spondylolisthesis was a more significant source of back pain than her multi-level DDD.

The parent coflex® IDE study has shown promising data regarding healthcare costs. It was the first prospective, Level I Pre-Market Application (PMA) spine study to collect economic data for spinal stenosis. Contrary to other studies,1 this trial has demonstrated significant cost savings. This particular case may have been an outlier with the surprisingly long length of stay of four days total. Was she kept in the hospital for inpatient rehab approved by Medicare?

Unfortunately, the control group in the parent study was a posterolateral pedicle screw fusion, which most surgeons would consider a dated procedure. A minimally invasive Transforaminal Lumbar Interbody Fusion (TLIF) would be my procedure of choice for a Grade I spondylolisthesis such as this. While long-term superiority of that procedure has not been consistently demonstrated, most would agree that minimally invasive TLIF offers significant benefits. Whether lower blood loss and shorter stays are worth the added cost of an interbody cage remains to be seen.

While this patient demonstrated long-term efficacy at five years, the parent study has only released 24-month data. So far, this data has been more promising than other studies, which have noted high rates of subsidence and recurrent symptoms.2,3,4 We anxiously await more follow-up allowing better evaluation of the long-term efficacy of the coflex® device. In the interim, Dr. Errico is to be commended on an exemplary case using this technology.

1. Epstein NE. A review of interspinous fusion devices: High complication, reoperation rates, and costs with poor outcomes. Surg Neurol Int. 2012;3:7.
2. Park SC, Yoon SH, Hong YP, Kim KJ, Chung SK, Kim HL. Minimum 2-year follow-up result of degenerative spinal stenosis treated with interspinous u (coflex). J Korean Neurosug Soc. 2009. Oct;46(4):292-299.
3. Verhoof OJ, Bron JL, Wapstra FH, van Royen BJ. High failure rate of the interspinous distraction device (X-Stop) for the treatment of lumbar spinal stenosis caused by degenerative spondylolisthesis. Eur Spine J. 2008;17:188–192.
4. Barbagallo GM, Olindo G, Corbino L, Albanese V. Analysis of complications in patients treated with the X-Stop Interspinous Process Decompression System: Proposal for a novel anatomic scoring system for patient selection and review of the literature. Neurosurgery. 2009. Jul;65(1):111-119;discussion 119-120.


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