In this video Dr. Graham, an east end Louisville Chiropractor explains the term Stenosis. Dr. Graham states that stenosis is derived from the greek word which means narrow. Spinal stenosis means that the spinal canal which contains the spinal cord is too narrow for the cord and puts pressure on it. Dr. Graham illustrates the common causes of spinal stenosis below.
#1. Bone spurs may cause the canal to narrow because the spur is taking residence in the canal. Bone spurs are the result of abnormal stress on a bone. Often times they are found on the heal of the feet, but more often they are found on vertabrae of the spine. Bones spurs form in response to abnormal forces usually caused from misalignments to the spine. Misalignments may occur form such events as car accidents, slips and falls, just to name a few. When the spine misaligns or jams up the center of gravity can change and this puts that portion of the spine under undue stress. In response to this the body lays down more bone in that area. Unfortunately, that additional growth on the spinal bone many times is in the back of the bone just in front of the canal. So when the bone spur forms, often times it grows right into the canal where the nerve roots are.
Facet joints that have enlarged will take space up in the canal. Facet joints are formed from the back portion of the spinal bones. Facet joints allow the spine to better be able to bend and twist without damaging our spine. However, when there is stress on the spinal bones these facet joints can grow in response to the stress. And just like the vertabra, they can grow into the canal and cause havic to the nerve roots.
#2. Disc degeneration can cause the diameter of the canal to narrow. The disc rests in between 23 of the 24 spinal bones. One of the many functions they serve is a spacer so that the spinal nerve root has an adequate amount of space to pass through. If the disc is traumatized or the spinal bones are misaligned causing the spine to compress and jam the spinal joints, the disc will not always get the proper nutrition as blood flow may be compromised. This lack of nutrition most often leads to degenerative changes which causes the disc to thin. This thinning is what makes the diameter of the canal to reduce in size.
It is not surprising that many people that are elderly have spinal stenosis. This is usually because most elderly people have degenerated discs in their spines, and of course bone spurs which is talked about in the previous segment.
#3. The ligaments that attach the spinal bones together hypertrophy (enlarge) which can change the diameter of the canal. When the disc degenerates the ligament (ligamentum flavum) often times will buckle causing it to push into the canal. This will cause stenosis as well. Often times on the MRI report this ligament is one of the culprits.
#4. Finally, spondylolisthesis (a slippage of a spinal bone) can make the diameter change and cause stress on the spinal nerve roots. This is an uncommon finding, but more common in the elderly population. This is because the ligaments and supporting soft tissue has stretched allowing the bone to slide forward. When this occurs it clogs up the canal.
#5. Genetic. Some people are born with smaller canals. I don’t see this very often, but it can cause the very same problems that the other four causes mentioned above do. Again, this is a very small percentage of the population.