Intervertebral disc conditions
In this section, we talk exclusively about intervertebral discs (also just called ‘discs’) and the many things that can go wrong with them. We have written specific articles on the degeneration (wear and tear), infection and acute (traumatic) injuries to discs.
Degenerative discs (technical)
Degenerative disc is a term that typically describes wear and tear in discs. These changes may occur during the normal ageing process or be sped up with lifestyle, sporting, occupations and hereditary factors. Inflammatory diseases, chronic wear and tear, and infections that affect discs could speed this degeneration up.
Degenerative discs (non-technical)
The term degenerative disc implies that the disc has lost some of its structural integrity due to wear and tear. Changes can be normal or pathological. Normal wear and tear occurs during the ageing process and happens to everyone. Pathological changes occur from disease, infection or injury. Degenerative discs usually have tears (fissures), herniations (slipped discs) and other signs of degeneration such as extreme dryness (lost moisture within). Degenerative discs may or may not be painful.
Normal Vs. pathological disc changes
In this section, we will try to remove some myths about spinal degeneration and what is considered normal and abnormal in regards to changes that occur in the spine and intervertebral discs.
A disc bulge refers to a general extension of the whole circumference of a disc beyond the border in which it usually sits. This border is called the apophyseal ring. A bulging disc is just a squashed disc that bulges out in all directions, and a good analogy would be to imagine a flat tyre.
Intervertebral disc herniation (disc herniation) describes the displacement of disc material beyond where it normally sits. That is, a part of the disc is pocking out. A disc herniation may complicate other pre-existing abnormalities such as degenerative vertebrae changes and fractures. Herniations are subcategorised as either a protrusion (prolapse), extrusion or sequestration.
A disc protrusion is a type of disc herniation. It is a common type of disc herniation and is the smallest of the disc herniations. Disc protrusions may be painful or non-painful depending on several factors.
An extruded disc is a type of herniated disc. Just like disc protrusions, disc extrusion describes disc material pocking out from where it normally sits. More disc material has come out compared to a disc protrusion.
A disc sequestration is a subcategory of disc extrusion. Disc sequestration occurs when a portion of a disc extrusion (herniation) breaks off and lodges in the spinal column. When a fragment breaks of the herniated disc, this is sometimes called a ‘free fragment’.
Contained and uncontained discs
There is an increasing reference to intervertebral disc herniations as contained or uncontained. A contained herniated disc is a herniated disc where the displaced portion disc material is covered by one of the surrounding ligaments. An uncontained herniated disc is a herniated disc where the displaced portion of the disc does not have a covering.
Disc (intervertebral disc) fissures are also called disc tears. Disc fissures are tears within a disc. The majority occur as a result of disc degeneration. Disc degeneration implies that the disc has slowly broken down over time. Disc degeneration occurs as a result of mechanical factors (heavy lifting occupations), nutritional factors (disc not getting nutrients for repair), and hereditary factors (genetically not a tough disc).
Disc tears occur due to wear and tear in an intervertebral disc. They are associated with the normal ageing process or may occur as the result of an injury. Disc tears may be painful or non-painful depending on several factors
Intervertebral discs can become infected. A disc is infected and is a severe condition. We describe this infective process in the following article.
Traumatic disc injury
Traumatic disc injury describes a disc injury that has occurred physical trauma. Traumatic disc injury may occur during sport, falls and motor vehicle accidents. Traumatic disc injury doesn’t include injuries to a disc that have already been broken down by degeneration or previous herniation.