Sequestrated Disc

A sequestrated disc is the result of a herniated disc, where the nucleus of the disc becomes lodged in the spinal canal, where the nerve root exits the spinal cord.

A sequestrated disc is an event that occurs occasionally as a result of a herniated disc. A herniated disc occurs when one of the intervertebral disc in the human spine become worn out at its outer envelope (annulus fibrosus) to the point that its contents ooze through tears in the discs. Not all herniated discs are the cause of back pain. Patients may experience back pain as a result of a herniated disc if the inner materials of the disc (nucleus fibrosus) move into the space of the nerve that exits the spinal cord. If a bulging disc presses against the nerve, or if the material from the disc makes contact with the nerve, the results may be severe pain or disability.

Herniated disc actually have the ability to heal themselves, as the concentric tears of the intervertebral discs have the ability to path themselves up. Discs that have sealed themselves up at their outer envelope may then reabsorb water and other nutrients to re-inflate to their original height.

There are some cases, though, where patients may still experience back pain after the herniated discs have healed themselves. In these cases, the discs may have healed themselves, but the material that was ejected while the wall of the discs was torn still remains in the spinal canal where the nerve root is. This rare type of herniation is called a sequestrated disc.

Spinal surgeons may treat sequestrated discs in the same way that they treat herniated discs, by removal through surgery.

There are other types of back problems that are related to herniated discs, that may cause patients to experience back pain even after herniated discs or parts of discs that have become sequestrated in the spinal canal have been removed. There are spinal problems related to "adhesions" that were removed along with the discs during surgery. Adhesions are special materials that were created where swelling occurred near the site of disc herniation or injury, that have remained attached to certain anatomical structures (especially the nerves) after the disc has healed itself, or has been removed.

The theory is that at the time of the injury, that there was a buildup of swelling at the site of injury. Due to poor circulation, or muscle tension, the fluid that built up due to the swelling, was not reabsorbed by the lymphatic vessels or blood vessels after the original cause of the injury healed itself. Because this fluid was not able to be reabsorbed by the body, it began to dry out, and the fluid that remained was a viscous, sticky mass of material. This left over viscous material eventually lodged and stuck to the parts of the spine that was closest to it. These adhesions remain stuck to these spinal parts, causing their functioning to be repaired. Adhesions that lodge onto the nerve roots of the spine may cause pain or other neurologic dysfunction.

The intervertebral discs that are most likely to become herniated, and cause secondary medical problems such as sequestrated discs and adhesions are the L4-L5 and L5-S1 discs. These discs are the most vulnerable because they bear the most weight.