Annular Tears

Frequently asked questions about annular tears:

1. What is the disk?

- The intervertebral disk is a structure that provides mobility  between the bones of your spine.
- It is best to think of the disk as a gasket or ball-bearing that aids in motion.

2. What are the parts of the intervertebral disk?
- Outer fibrous layer, called the annulus fibrosis (annulus)
- Inner gel layer, called the nucleus pulposus (nucleus)

3. How does a normal healthy disk work?
- The disk is a pressurized system which allows motion. 
- The nucleus contains gel that allows for motion
- The annular fibers provide structural support for the nucleus

4. What is a herniated disk?
- A herniated disk (sometimes called disk protrusion or disk extrusion) is when the gel in the nucleus pushes outward, stretching or breaking through the annular fibers
- A herniated disk can be painful if it pushes on a nerve root. This may cause pain that shoots down your limb (often called radiculopathy or "sciatica")

5. What is an annular tear?
- An annular tear is a tear in the annular fibers
- It can be identified on an MRI as a "high intensity zone." This is a bright area that is seen in the otherwise dark disk as shown in the picture below.  (The annular tear is in the white dot in the back aspect of the second disk from the bottom as indicated by the black arrow)

The MRI image above is called a sagittal slice, which is a slice through the middle of your body (separating the left and right side of the body).  The left side of the screen represents the front of the body, and the right side represents the back of the body.

The image below is from what is called an axial slice, which is a cut through the body separating the top and bottom of the body.  This image is specifically through the L4-L5 disk.   In the center of the screen is an oval structure with a whitish center and black outer rim- that is the disk.  The whitish center is the nucleus, and the black outer rim is the annulus.  Within the annulus, there is a thin white line toward the lower part of the annulus- that is the annular tear (indicated by the white arrow).

6. Are a herniated disk and an annular tear the same thing?

- No
- They can co-exist, but they can also occur separately
- A simple (and mostly true) way to think about it is that annular tears cause low back pain, herniated disks cause pain that shoots down the limb when it pushes on a nerve root

7. What are the symptoms of an annular tear?
- Stiffness in the low back when waking in the morning
- Vague pain that is difficult to localize
- Pain putting on shoes and socks in the morning
- Pain with prolonged sitting
- Shifting positions while sitting
- Tendency to axially off-load while sitting (e.g., using straight arms with a fist to push yourself off the table)
- Improvement in symptoms when walking following prolonged sitting (e.g., when first stepping out of the car after a long car ride, once you have straightened out)
- Pain with Valsalva maneuvers (e.g., coughing, laughing, sneezing, sexual intercourse, and bowel movements)

8. What about muscle spasms?
- Muscle spasms are sometimes experienced along with annular tears and herniated disks. However, they can be seen in the absence of a herniated disk or annular tear.
- Muscle spasms are often not the primary source of pain.

9. What is the treatment for an annular tear?
- Physical therapy
- Injections, such as epidural steroid injections can be a useful complement for physical therapy.  One particular approach, called a transforaminal approach, may be more effective than other alternative approaches that are more commonly used.
- Medications, such as oral steroids can be used early on in treatment course.  We find that transforaminal epidural steroid injections below the level of the disk injury, however, tend to work better than oral medications.