It’s been two years since I had a disc removed from my lumbar spine. I was fine after the surgery for the first two months. Then just like that my symptoms came back. A recent MRI showed another herniation of the same disc. But how is that possible if I had the disc removed?

You may have heard the expression a rose is a rose is a rose. The general suggestion is that there isn’t much difference from one rose to another — they are all the same type of flower with slightly different colors or sizes.

Well, the same expression doesn’t hold true for a disc herniation. Disc disorders have a wide range of differences that can’t be lumped all together. The three main types of disc herniation can actually be divided into disc prolapse, disc herniation, and disc sequestration.

In the case of a prolapse, the disc is bulging. The inner portion of the disc (the nucleus) is intact has migrated or moved into the outer covering called the annulus. The direction of the disc material is usually backwards toward the spinal canal. A bulge or prolapsed disc can be large enough to actually press against the nearby spinal nerve root causing back and/or leg pain.

If the nucleus breaks out of the annulus, you have a disc herniation or protrusion. To get a bit more technical, a protrusion of the disc material means the amount of tissue that is pressing backward is equal from one side to the other. The same bulge could be called an extrusion if the shape is more like a balloon with a narrow base and wider, rounder end-point.

Finally, there can be something called a sequestration. This means the disc has protruded and then a piece has actually broken off and is free to move in the spinal canal. This is a very dangerous situation as the disc fragment can press into the spinal cord causing paralysis.

Surgery to remove a disc can range from just removing any free floating fragments found during the operation to removing the entire disc. Recurrence of disc herniation or reherniation as it is sometimes called occurs when only the protruding, extruding, or sequestered part of the disc was taken out.

Some portion of the disc still remains sandwiched between the two vertebral bodies. Some surgeons leave as much of the disc behind to continue functioning as a cushion, dispersing the load and force through the spine. This helps reduce the degenerative processes in the spine at that segment but does increase the risk of a reherniation.