SpineUniverse Case Study Library

Central Canal and Foraminal Spinal Stenosis at L3-L4

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The patient is a 67-year-old retired male who presents with back and bilateral buttock pain with bilateral posterior thigh pain. Back pain radiates into the back of both legs for about one-and-one-half years. Pain is significant while standing, and he experiences pain when walking. The patient denies any bowel or bladder changes.

His past medical history is significant for coronary artery disease; he underwent heart bypass surgery 10 years ago. He denies diabetes and any history of cancer. The patient is a non-smoker.

Current medications are atorvastatin calcium (Lipitor®), lisinopril, metoprolol, hydrocodone bitartrate and acetaminophen (Vicodin®), and daily aspirin.


Physical Examination
The patient is 5’11” tall, weighs 267, with a BMI of 37.2

  • Gait is within normal limit
  • He is able to heel/toe raise without difficulty
  • Lumbar flexion, and right/left lateral bending is within normal limits
  • Decreased lumbar spine extension
  • Tenderness to palpation in the lumbar paraspinal musculatures

Neurologic Examination

  • Lower extremity motor exam is grossly intact at 5/5, including iliopsoas, quadriceps, hamstrings, gastrocnemius, anterior tibialis, foot inversion/eversion, and extensor hallucis longus.
  • Reflexes are normal.
  • Sensation is intact to light touch in the lower extremities bilaterally. Straight leg raises is negative bilaterally.

Pre-treatment Pain Measurements:

  • Oswestry Disability Index (ODI): 44
  • Visual Analogue Score (VAS): Back:  82
  • VAS: Right leg: 69
  • VAS: Left leg: 65
  • Zurich Severity Scale (ZSS): 3.0

Pre-treatment Imaging



Sagittal MRI

Axial MRI

Prior Treatment

Six months of non-operative treatment included a series of 3 epidural injections and physical therapy, which were not effective.


L3, L4 central canal and foraminal spinal stenosis

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Selected Treatment

The patient underwent minimally invasive L3-L4 decompressive laminotomy, L3-L4 bilateral foraminotomies, followed by implantation of the coflex® implant (size 12 mm) between L3 and L4 spinous processes (coflex® Interlaminar Stabilization®, Paradigm Spine, LLC, New York, NY).

Surgeon's Treatment Rationale
With coflex® I was able to provide stability in a less invasive manner than fusion.

Outcome: 4-years Status Post

At the patient’s first post-op appointment following discharge, he reported his back and leg pain was resolved. His recovery was uneventful. Soon after surgery he no longer needed pain medication and he completed an organized physical therapy program. There have been no problems with the coflex® device. The patient continues to do remarkably well, remains neurologically intact, and pain free.

Imaging: 4-years Status Post

Anteroposterior x-ray; neutral spine

Lateral x-ray*




*Implant shown in above x-rays are from the clinical trial.

Indications for Use
The coflex® Interlaminar Technology is an interlaminar stabilization device 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).

Hyun Bae, MD did not receive any compensation for this case presentation.

Case Discussion

This 67-year-old male patient with cardiac comorbidities presents with a 1.5 year history of back pain, bilateral radicular pain and neurogenic claudication. The diagnosis per the report is stenosis L3-L4. The patient had failed conservative care and underwent a "Coflex decompression" and insertion of a titanium inter-laminar dynamic coflex® device.

This case represents the typical degenerative spinal stenosis patient. The clinical dilemma for me always, is successfully identifying the pain generator(s). This was successfully accomplished based on the long-term outcome scores. I would be interested to know how this level was chosen when the history, exam findings, and limited diagnostic imaging did not reveal the pain generators.

The IDE demonstrated how coflex® not only deals with the symptoms of radicular pain and neurogenic claudication, but also significantly reduces back pain. This, all in the setting of motion preservation, shorter OR times, reduced blood loss, reduced length of stay, and quicker return to work and normal activity.

Technically, we have learned that sizing of the implant is very important. As coflex® is an "inter-laminar" device, it does not create kyphosis. The post-operative imaging in this case does show a retrolisthesis not seen in the pre-op X-rays and MRI. This could have been a sizing issue. Having said this, the outcome obviously doesn't reflect the retrolisthesis as being a clinical problem.

Finally, I often find L3-L4 decompression particularly challenging when the facet joints are so close to midline. The contra-lateral coflex® decompression technique allows for excellent decompression and preservation of facet integrity. Insertion of the Coflex device restabilizes the decompression (four joints are better than three) when compared to a fusion.

The distraction by the coflex® device also indirectly enlarges the neural foramina, by moving the pathological pain generating superior articulate process caudally from the exiting nerve root.

Excellent direct and indirect decompression with the bonus of motion preservation is what makes this procedure so appealing.


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