Wednesday, May 5, 2010

So What Happened?

There are several types of Spondylolisthesis, and I'm going to focus on two. The first of of which is traumatic. While you would think that the motorcycle accident could have caused it, it seems unlikely that it did. Most likely it is of the isthmic variety. Approximately 4% of the population is born with a propensity for spondylolysis (not to be confused with spondylosis)--a fracture in the pars interarticularis usually caused by a genetic weakness in that particular segment. This is the bony part that connects your vertebrae to your spine. Think if it as outstretched arms that wrap around the actual spinal cord. When this is broken there is less to support the vertebrae and prevent anterior displacement. In the majority of those who are diagnosed with this, it usually an incidental finding and is not the source of pain. It is only when the vertebrae slips forward and pinches the nerve roots leading to the legs that it becomes an issue. While there are several grades, usually only grade II or above is symptomatic. When I initially had my supine lower back x-ray, it was graded as a Grade I. But there is a problem with this that later became apparent when I saw the specialist--when you stand, gravity pulls things down and forward. In my case a standing lower back lateral x-ray showed a significantly worsened listhesis, at Grade II/III. This of course correlates exactly with my symptoms as when I sit or lay down I am just fine, but when standing or walking....

So what likely happened in 2008 was that during the motorcycle wreck, landing on my left hip caused compression and further displacement of the L5/S1 junction (in my case L6) stretching whatever ligaments held the segment in place. It was this additional motion that was first responsible for the back pain, that later progressed to radiating back pain (left hip) and leg numbness (sciatic nerve root stenosis/irritation).

While I am not a radiologist (if you are correct me in the comments below if needed) here are my observations from the MRI I had done:

Here you can see that the L5/S1 disc is significantly damaged compared to the rest. This was likely the source of pain the first few months along with other nearby trauma.

As we continue to look you can see the forward slip. This is laying down on my back so it shows a Grade I (less than 25%)

Continuing down we look at it from another angle, and you can see in the enlarged crop exactly where the fracture is:

The results of this is the displacement of the nerve roots, and in the following you can see where those exiting at L5 are significantly different with accompanying stenosis causing the symptoms:

And this is when laying down...when upright this is significantly worse.

Physical therapy is a great option for many, and with the greater abdominal and back strength it is possible to prevent further slippage and maybe even to reduce the fracture. However in my case that is not enough. After seeing the surgeon he recommended to get some steroid injections and give that a 'shot'. Supposedly that can buy me some more time and put off the surgery as long as possible.

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