Degenerative Disc Disease
I want to relate a story from a recent patient visit that I had, and the interesting thing is that the conversation I had was one that I have had hundreds of times though out my career. I was asked to consult on a 35-year-old patient with a history of chronic lower back pain. I asked him what brought him in and his response was that he chronic back pain from two discs that he was told were disintegrating. He was told that he would have to curtail a lot of his favorite activities for the rest of his life because of these discs or else he would end up with spine surgery and well he has never known anyone that did well with surgery. He was terrified to do anything physically active because the discs would fall apart even faster. He was very worried that he would not be able to take care of his family and that he would be permanently disabled. The diagnosis he was given was degenerative disc disease.
Normal Spinal Ageing
The term, degenerative disc disease is slightly inaccurate because it is technically not a disease, nor is it strictly degenerative. It is not considered a disease because degenerative changes in the spine are natural and common.
There is a disc between each of the vertebrae in the spine. A healthy, well-hydrated disc will contain a great deal of water in its center, known as the nucleus pulposus, which provides cushioning and flexibility for the spine. Much of the mechanical stress that is caused by everyday movements is transferred to the discs within the spine and the water content within them allows them to effectively absorb the shock. At birth, a typical human nucleus pulposus will contain about 80% water. However daily stresses and strains as well as and injuries can cause these discs to gradually lose water as the anulus fibrosus, or the rigid outer shell of a disc, weakens.
This water loss makes the discs less flexible and results in the gradual collapse and narrowing of the gap in the spinal column. As the space between vertebrae gets smaller, extra pressure can be placed on the discs causing tiny cracks or tears to appear in the anulus. If enough pressure is exerted, it’s possible for the nucleus pulposus material to seep out through the tears in the anulus and can cause what is known as a herniated disc.
As the two vertebrae above and below the affected disc begin to collapse upon each other, the facet joints at the back of the spine are forced to shift which can affect their function. The facet joints also end up taking more weight than they are designed to handle and with that they start to cause back pain for some people.
Additionally, the body can react to the closing gap between vertebrae by creating bone spurs around the disc space to stop excess motion. This can cause issues if the bone spurs start to grow into the spinal canal and put pressure on the spinal cord and surrounding nerve roots and with that it can cause pain and affect nerve function. This narrowing of the nerve spaces caused by the bone spurs is known as spinal stenosis.
So, as you can see there is really nothing to fear about degenerative disc disease because it is a normal part of the ageing process. While we can look into the mirror and see that our hair is turning gray or our skin wrinkling we cannot see into our spines to see the same type of thing happening. So, the next time your doctor tells you that your back pain is from degenerative disc disease you should say that everyone gets degenerative disc disease so what is really causing my back to hurt?