What is it? Why did I get it? What can I do about it?

The spine consists of a combination of structures that surround and protect the spinal cord and nerve roots in the spine. In the front of the spine there are rectangular blocks of bone called vertebrae that are separated by Intervertebral Discs. There are 24 vertebrae and 23 discs. There is no disc between the 1st and 2nd vertebrae in the neck. Discs have two components and are often compared to a jelly donut. The outer part of the disc is called the annulus and is formed of rings of fibrous tissue like a tire. The inner part of the disc is called the nucleus. Protein molecules in the nucleus attract fluid that acts as a cushion or shock absorber between the vertebrae. As we age the nucleus loses its water content and the cushioning function. The disc also loses height by 1-2 mm at each level. That is why we get shorter as we get older.

We used to think that the disc was the major source of back pain due to degeneration. However, our view of back pain has changed over the years. We now know that the disc does not have many nerves and therefore, is probably not a major source of back pain. However, degeneration of the discs with loss of height causes stress on other structures like the facet joints, which are located at the back of the spine. This results in degeneration of the cartilage and the development of osteoarthritis, which is probably the major source of back pain.

Degenerative disc disease is a bad term because it is really not a disease. It is a fact of life and is mostly a genetic condition. We are all pre-programmed to get grey hair, wrinkles and disc degeneration to a variable degree. There is no good evidence that factors such as the type of work we do, the type of recreational activity we do, or how big we are causes disc degeneration. It affects people of all shapes, sizes, occupations and activity levels. Everyone gets it to some degree. There is also no correlation between how bad your back looks on CT or MRI imaging and how much back pain you have. Some people with terrible looking spines have little or no pain. Other people with perfectly normal looking spines have terrible back pain.

There are no known ways to prevent the discs from degenerating and no way to repair them. Artificial disc replacements were developed in the hope of curing back pain. Unfortunately, that has not proved to be a viable option. There are a small number of people who benefit from disc replacement surgery but there are risks associated with the procedure. It is often difficult to prove that the disc is the source of a person’s pain. Discography is a procedure that involves injecting dye into the degenerative disc under x-ray guidance to see if it reproduces the person’s pain. However there is a risk of infection and the results of the test are not that reliable. If the disc is the source of pain, then doing a disc replacement or fusing the disc may relieve the pain. However the improvement results are often not much greater than 50%, and surgery can sometimes make the pain worse. They used to inject an enzyme into the disc to cause it to degenerate but that procedure is no longer performed which infers that it was not that effective. At the moment there is no good treatment for disc degeneration. There have been some studies on stem cell injections into the discs but it is too early to say if that will produce any long term benefits. The best treatment for degeneration of the spine is regular exercise to maintain strong core muscles. Physiotherapists can provide a personalized exercise program that can be done on a regular basis.

 Degenerative Disc Disease