Vertebral Discs

The vertebral disc is an interesting and unique structure. Its primary purpose is to act as a shock absorber. Discs are actually composed of two parts: a tough outer core and a soft inner core and the configuration has been likened to a jelly doughnut

At birth, eighty percent of the disc is composed of water. With age, the discs dehydrate and become stiffer. This is a natural aging process, although in some individuals, as the disc degenerates it can become painful. The most likely reason for this is that the degeneration can produce micromotion instability and the inflammatory proteins (the soft inner core of the disc) probably leak out of the disc space and inflame the well innervated structures next to the disc (e.g. nerve roots).

Sometimes a twisting injury damages the disc and starts a cascade of events that leads to degeneration . The disc itself has very few nerve endings and no blood supply. Without a blood supply the disc does not have a way to repair itself, and pain created by the damaged disc can last for years. In general, as we age there are less inflammatory proteins in the disc space and discogenic pain rarely occurs after 6o years of age.