What Is an Annular Tear?

top view of a spinal disc that is leaking annulus pulposus

The discs found between each of the vertebrae in the spine are made up of two components, and the outer of these is known as the annulus. The annulus is tough and durable, and it is critical for providing stability for the spine. However, this portion of the spinal disc can wear down and become torn or cracked. If this does occur, it can lead to a number of other back problems.

What is an Intervertebral Disc Made Of?

Intervertebral discs are composed of the nucleus pulposus and the annulus fibrosis. The nucleus pulposus is a jelly-like substance that is found on the inside of the disc. The composition of this portion allows it to serve as a cushion for the spine. It helps to make certain motions possible, like bending, twisting, or compressing.

The outer layer is called the annulus fibrosis. This layer is tougher and is connected to the vertebrae above and below the disc. It composed of fibers that allow it to withstand large amounts of pressure and works to contain the inner layer, preventing it from leaking out.

These two layers work in tandem to evenly distribute the forces that the spine must endure, helping to prevent the vertebrae from rubbing against one another, ensuring that the spinal nerves running through the vertebrae do not become pinched, and eliminate pain in the spine.

How do Annular Tears Occur?

disc explaining how an annular tears affects backpainThe annulus fibrosis is composed of between 15 and 20 layers of fibrous tissue. The direction of the fibers in these layers alternate, which further increases the stability and strength of the annulus. However, injury to the annulus can still occur for various reasons.


One of the most common causes of annular tears is age. As the body gets older, the fibers can begin to break down due to daily wear and tear. This is known as disc degeneration, and its effects can be seen as early as 30 years old in many cases. As these discs wear down, certain motions can stress the discs and cause them to become torn if they are repeated over and over. 

Annular tears can also occur due to a traumatic injury. In these cases, a certain movement places so much strain on the intervertebral disc that it is torn immediately. This is commonly seen in high impact sports, such as gymnastics and football, but can also occur from weight lifting and other activities like golf.

How to Detect an Annular Tear

In most cases, annular tears are detected through the use of imaging technology. The MRI is the most commonly used technique. MRI stands for magnetic resonance imaging, and this technology allows physicians to see the various components of the spine and compare them with one another.

If an annular tear has occurred, the MRI will most likely show it because of the increased water content in the area of the tear. This varied composition will show up differently than the normal fibrous tissue. 

CT, or computed tomography, myelograms can also be used to detect annular tears if your physician believes that the pain is stemming from an issue relating to nerve or spinal cord compression. These tests use dyes in conjunction with imaging to scan the spinal canal to locate any anatomical changes that may have occurred due to an annular tear.

What are the Side Effects of a Disc Tear?

In many cases, annular tears go unnoticed and are not associated with any symptoms at all. However, if these tears become more serious, they can lead to other spine issues that can cause severe pain and other problems.

If a spinal disc tear does occur, pain is usually either localized and concentrated in the area directly surrounding the tear or radicular in nature and affecting various areas innervated by the affected nerve root. 

Localized pain is generally a deeper pain that can become worse with certain movements that irritate or stress the affected disc. Radiating pain stems from irritation of the spinal nerve. Nerves running through the spinal canal and out of the vertebral foramen can become irritated from the inflammation surrounding the tear. In other cases, if the inner layer of the disc begins to leak out, it can place pressure on the nerve, causing it to become pinched.

One of the potential complications of annular tears is leaky disc syndrome. This occurs when the nucleus pulposus slowly leaks out of a small crack in the annulus. This causes the discs to become flatter, limiting their ability to withstand compression and other strenuous forces. The leakage can also cause inflammation to occur around the spinal nerves, leading to increased pain levels.

Annular tears are a common injury, especially as the body ages. These tears can arise due to a specific traumatic injury or from degenerative disc disease. While these tears may not seem like a major problem initially, if they are left untreated and become worse, their negative effects can increase substantially.

https://www.ncbi.nlm.nih.gov/books/NBK459235/
https://www.spinemd.com/symptoms-conditions/annular-tear