Disc Prolapse / Herniated Disc

This handout was written to help better understand a disc prolapse.

While this may seem like a major injury to the spine it is not altogether uncommon and the vast majority of people recover and return to their normal activities and sports. Time is a key part of recovery, and there are things people can do to get the best outcome for themselves.

What Is The Disc?

disc prolapseThe spine is made up of individual bones that are stacked one above the next to form a column. The disc sits between the main blocks of bone and acts as a shock absorber while still allowing movement in the spine.

The disc is made up of 2 parts. In the centre there is a softer, semi fluid tissue called the nucleus. This is surrounded and contained by a wall named the annulus. The wall is layered like the rings of an onion.

When we move we cause pressure to build up on one side of the disc and the soft nucleus is forced to move away from the pressure (like a bar of soap between wet hands). The longer we stay in one position the more the nucleus moves. The surrounding wall limits the amount the nucleus moves.

The structure of the disc changes during our life. These changes are normal but at a certain point in this wear process the chance of the disc prolapsing becomes greater.

How The Disc Changes.

Inside the disc wall fissures or cracks gradually develop. As this occurs the soft nucleus starts to loose water and gradually dries out making it less mobile. During this process there is a risk that some of the nucleus will be pushed into a crack in the disc wall causing the outer wall to bulge. Where the disruption inside the disc is smaller and the outer wall remains strong the displaced nucleus can be returned to its normal position (learn more) . If the pressure on the outer wall becomes too much the wall fails and this is what we term a disc prolapse.

The diagrams above are a view from the side and in cross section to show the inside of the disc.

Why Does The Pain Go Down The Leg?

As the disc prolapses a bulge appears in the disc wall. This bulging of the disc will often push into the space normally occupied by a nerve. The disc bulge places pressure on the nerve and causes it to become inflamed. The result is what we call sciatica, which is a referred pain into the leg. During assessment of the problem there are tests designed to show when the nerve is involved.

disc prolapse diagram

The diagrams are a view of the gradual disc bulge and its pressure on the nerve. The view is from above.

Are Xrays Or Scans Needed?

The majority of the diagnostic process comes from looking closely at the symptoms produced by the problem, the limitation of function, and a thorough examination. In most cases x-rays and scans are used to “fill in parts of the puzzle”. When the diagnosis is quite clear then it is better to avoid unnecessary tests as it has been shown that their results don’t significantly influence the treatment.

Most often further imaging studies are required when the problem is not responding as expected, when a surgical solution is being investigated, or when the symptom behaviour of the problem is atypical. In these cases the information we gain is very important.

What are the options?

In most cases the problem resolves over a 3 – 6 month period. The worst of the pain usually starts reducing in the first 2 – 3 weeks. Normally it is possible to self manage the problem, minimising the recovery time and the chance of recurrence. It is important to get a good understanding of the problem and the specific exercises to use.

In a minority of cases surgery is required. This is normally to relieve extreme pressure on the nerve, or where the normal improvement of severe symptoms hasn’t occurred. When surgery is the preferred option, full details of the procedure and expected recovery will be supplied by the surgical team.

Each problem is different and unfortunately this means there is no recipe of exercises that are right for everyone. It is important to remain as active as symptoms allow. The rule to follow is that it is all right to cause some pain during movement or activity as long as the pain settles within 1 hour of changing position or stopping the activity. It is also important to note that it is not necessarily the most vigorous activity that does the most damage, in a lot of cases it is in fact the most commonly adopted position we get into on a daily basis (eg. sitting). Guidance is usually required to set up a problem specific and effective self-management programme.

Author Cameron Green

  • Spine Care Clinic
  • Epsom, Akl.
  • Ph. (09) 6306400