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.
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.
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.