Herniated Disc

What is a Herniated disc?

Commonly referred to as a slipped disc, ruptured disc or pinched nerve, a herniated disc will cause severe pain in the lower back and in approximately 80 percent of patients, disc surgery is usually not necessary.

Other common names for herniation of a disc are; ruptured disc, torn disc or bulging disc.

Herniation of a disc occurs when the inner core (Nucleus Pulpous), gets squeezed out through the ligaments in the outer layer of the disc (Annulus Fibrosus). The resulting tear will cause back pain and if the bulging disc itself exerts pressure on a spinal nerve then pain may be felt in any part of the body served by that nerve. 

Equally, there's a pairs of spinal nerves in between each vertebrae of the spine which are linked to different parts of the body (Nerve Root). Therefore, not only will a slipped disc cause pain in the lower back but it can also affect other areas too.

Fig1. Diagram of an un-injured disc, vertebra and spinal cord.

Fig2.  A herniated disc. The necleus pulposus pinching a nerve root.

Studies show that most people get a ruptured disc in the morning and although this is not yet clearly understood it is likely due to changes that happen within the spine throughout the day, and a regime of simple stretching before getting up may reduce the likelihood of a slipped disc occurring.

Most people suffer a herniated disc in the same two discs of the lower back. These are the discs between the fourth and fifth lumbar vertebra and those between the fifth lumbar and the first sacral vertebra. Of course it possible for a ruptured disc to occur anywhere within the spine, but these are the most painful and most common.

Symptoms of a Herniated Disc

The pain from a slipped disc is normally felt as a sharp pain down the affected leg served by the spinal nerve that is under pressure from the ruptured disc. Often the first sign is a snapping or tearing sensation, along with sudden back pain, although the patient may have a history of back or leg pain.

It is important to remember that a slipped disc is different from disc pain, where the disc itself causes the back pain in a localised area. This is referred to as Degenerative disc disease.

Treatment of back pain caused by a herniated disc

It is here that a diagnosis of the root cause of the back pain, neck pain or leg pain is vital to correctly ascertain which course of action is required for the patient. This is particularly important if disc surgery is being considered. For example the cause of the back pain may have been triggered by a sports injury and may only be a soft tissue or muscle strain and not a ruptured or slipped disc.

Procedures such as a CT Scan, MRI Scan or Discogram along with a physical examination of nerve function in different areas of the arms or legs, muscle strength and pain in certain positions, are all tools available to decide if disc surgery is necessary.    

Surgery to the spine will only be considered if normal treatments such as chiropractic care, pain medications, injections, physical therapy and exercise regimes have not provided adequate pain relief. Spinal surgery will only provide relief of back pain if the herniated disc or degenerative disc as shown by the MRI scan is the cause of the pain.   

The most common surgical procedures are:
• Microdiscectomy – when a portion of the herniated disc that is pressing on the nerve is removed.
• Spinal fusion – when the disc space in between two vertebrae is fused into one solid long bone.