What is a Posterior Cervical Foraminotomy?

We spent the past several posts talking about the various symptoms that can result from cervical degenerative disc disease (DDD) and cervical spondylosis.  I also reviewed some of the non-surgical treatments of neck pain.  Recall that surgery should typically only be performed in cases of radiculopathy (pinched nerve) that has not responded to conservative management, or in cases of myelopathy (spinal cord compression and injury.)   In the next few posts I will discuss various surgical interventions that address the DDD, spondylosis and stenosis that causes cervical radiculopathy or myelopathy.  In this first post I’ll discuss the posterior cervical foraminotomy (PCF).

The PCF has been performed for cervical radiculopathy for decades (the first large series of patients was published in the 1960s). Initially it was performed via a long midline incision (which as you know from my previous posts can very destructive.)  This resulted in significant post-operative pain and other problems so many surgeons abandoned the procedure in favor of the anterior cervical discectomy and fusion (ACDF), which I’ll discuss in a later post.  With the advent of minimally-invasive surgical techniques much of the morbidity associated with posterior approaches (i.e. from the back of the neck) is no longer seen.  Thus, there has a renaissance, so to speak, of the PCF as a viable treatment option for cervical radiculopathy.  

The benefits of the PCF include that it allows for immediate access to the area where the nerve root is being compressed (the neural foramen) by a herniated disc or bone spur (see figure 1.)  Once the bony roof the foramen is drilled away by the surgeon, the nerve root is immediately seen and complete decompression of the nerve root can be confirmed.  Another benefit of the PCF is that the motion of the affected level of the spine is preserved (versus being immobilized in the fusion of an ACDF.)  I think that this is particularly valuable in young patients and athletes where a fusion should be avoided if possible.

 Spinal  con Fusion | neurosurgery explainedReichow Karen M MR MRI CERVICAL SPINE WITHOUT CONTRAST  Wind 1

Figure 1: The image on the left (source: Carette et al, 2005) shows a herniated disc fragment (red arrow) compressing the exiting nerve root as it passes through the neural foramen (the bony tunnel outlined in blue lines.)  The image on the on the right is an axial MRI demonstrating the same pathology (the herniated fragment is indicated by the red arrow.)  

In a minimally-invasive PCF a small incision is made at the back of the neck just off midline and the spine is accessed via a small tubular retractor (see how this retractor is docked on the spine here: http://www.youtube.com/watch?v=qPlNUOyuKmI ).  A small amount of the lamina and facet joint (see figure 2) overlying the neural foramen is drilled away to expose and decompress the exiting nerve root.  Once the nerve root is exposed it can be gently retracted out of the way and any herniated disc material or bone spurs in front of the nerve can be removed.  Typically this is done on an outpatient basis and recovery is quite rapid. Peyton Manning aside (based on his scar, a PCF was tried before he ultimately underwent an ACDF), the PCF is associated with excellent outcomes with symptomatic relief seen in over 95% of patients.   

Cervical Lamina 1 3

Figure 2: a model showing the posterior bony anatomy of the cervical spine.  The laminae and facet joints are seen.  The red circle indicates where the tubular retractor is docked and the blue line indicates the course of the nerve root as it exits the spine.

You can watch a video of a PCF that I performed recently here: 

 

Happy New Year everyone!

J. Alex Thomas, M.D.

Carette S, Fehlings MG. Clinical practice. Cervical radiculopathy. N Engl J Med. Jul 28 2005; 353(4): 393-399.



 

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The Benefits of Minimally-invasive Spinal Surgery: Part 2

Traditional spinal surgery is done via long, open incisions in the middle of the back.  Once these incisions are made the skin and muscles are held out of the way using large, sharp metal retractors (see image 1). 

 Open incision with retractors

Image 1: Large metal retractors used in traditional spinal surgery. (courtesy of Deukmedjian et al, http://www.practicalpainmanagement.com, July 2012.)

Multiple studies have shown real, long-lasting muscle injury when these retractors are used for prolonged periods of time.  That’s right, these retractors have actually been shown to destroy surrounding muscle if they’re in place long enough.  Look at image 2: the image on the left is a normal MRI of the lumbar spine.  The red arrow points to the normal paraspinal muscles that run along your spine.  The image on the right demonstrates what can happen after a long traditional spinal surgery: the muscle has died and has been replaced with fat (red arrow.)

Normal axial MRI 1Paraspinal atrophy MRI

Image 2: Normal MRI of lumbar spine, left; MRI showing paraspinal muscle injury, right.

Why is this so bad?  These paraspinal muscles act much like the cables of a suspension bridge: they provide critical support to the spine, especially with movement.  If the muscles are injured this can have serious long-term consequences to the structural stability of the spine (more on this in the next post.)    

IMG 0953

Image 3: A tubular retractor in place over the lumbar spine.  

Minimally-invasive techniques in spinal surgery often use small tubular retractors (see image 3 and video below) to gently spread the muscles out the way so that they are not injured during surgery.  By avoiding muscle injury, minimally-invasive techniques lead to the benefits we’ve already discussed (decreased pain, decreased blood loss, shorter hospital stays, etc.) AND may also prevent future spinal problems after surgery.

The Benefits of Minimally-invasive Spinal Surgery, Part I

Minimally-invasive techniques in spinal surgery were developed over the past several years to reduce the many of the complications and bad outcomes of traditional open spinal surgery.  Open spinal surgery typically relies on long incisions in the middle of the back.  After the incision is made the surgeon then must “strip” or cut the muscles off of the spine to expose the bones of the spinal column (see image 1).

Open incision

(Image 1: long, open incision in spinal surgery)

The muscles are then held out of the way, often for hours at a time with big, sharp metal retractors.  Several studies have shown real, long-lasting damage to the muscles of the spine caused by these large retractors.  Minimally-invasive techniques in spinal surgery, on the other hand, use very small incisions (see image 2 and 3), tubes not retractors, and innovative approaches (be sure to check back later for a blog entry on lateral spinal surgery) to spare the normal structures of the spine.

Large and Small Incision

(Image 2: Skin marking for a minimally-invasive incision to remove a herniated disc in the lumbar spine.  The patient had the exact same surgery a few years ago for the same problem via an open surgery; notice how much longer the scar is.)

Open Fusion IncisionPedicle Screw Incisions

(Image 3: On the left you see a patient who had a lumbar fusion via an open approach.  On the right is a patient who had the SAME surgery using minimally-invasive techniques.)

When compared to open spinal surgery, minimally-invasive spinal surgery results in:

  • decreased pain levels
  • decreased risk of infection
  • less blood loss and need for transfusions
  • shorter hospital stays
  • faster return to work and LIFE

To sum it up: minimally-invasive spinal surgery, in my opinion, is better and safer for the patient.

Dr. T