Back Pain Explained - What is Spinal Stenosis?

OK, here we go. Spinal stenosis involves the spinal column and the word stenosis actually means narrowing.

Basic Anatomy Lesson!

If you took the spine and chopped it in half across-ways and then looked down from the top you would see the following...

The hole in the middle forms the spinal canal and is where the spinal cord travels through from top to bottom of your spine. Now, the spinal canal is plenty wide enough for the spinal cord to pass through but in spinal stenosis, there is a narrowing of the canal. This means less space for the spinal cord (which is the central nerve). Less space means more chance of the nerve being squashed and so causing you problems. The narrowing tends to be localised to a certain level in your back.

Narrowing can be caused by a variety of things and not all bony!

Narrowing!

1) The first could be the disc itself. The disc is a jelly like substance that can move. The most common direction, is for it to move backwards as in a slipped disc.

In this case, the disc actually bulges out into the spinal canal and if bad enough can push onto the spinal cord giving symptoms.

Please note that many people do have minor disc bulges present. They are not significant in the sense that it never causes any problems and they may never have had any back pain in their lives.

So just because a disc bulge is present, does not mean it is causing your problem, it depends how bad it is!

2) Osteophytes (pronounced ost-eeo-fight) are extra bits of bony outgrowths from the bone adapting to forces placed upon it. Bone is a living tissue and continuously changing. If you place too much pressure on a bony area, the body will try and adapt by putting down new bone to support the area. These extra bony bits are called osteophytes. If an osteophyte develops and extends into the spinal canal, you may get narrowing and therefore spinal stenosis.

3) Tumour! In uncommon cases, such as cancer, a growth can occur within the spinal canal that narrows it and pushes onto the spinal cord.

These are sometimes called 'space occupying lesions' because they take up space! If they stick out into the spinal canal enough, then it can narrow the hole through which the spinal cord travels and cause symptoms.

Spinal stenosis is usually diagnosed from taking the individuals history and having a scan. Individuals frequently have symptoms on both sides (sciatica), affecting both legs. They may or may not have lower back pain. The symptoms tend to occur from walking a certain distance or for a certain length of time. The time before onset is often quite consistent. On resting the symptoms usually go away fairly quickly. Exercises that tend to help involve low back flexion. This provides a little more room within the spinal canal.