What is the difference between Disc Bulges, Herniations, Protrusions and Extrusions? By: Dr. Peter Le
Anyone who has had back pain has spent enough time searching the internet looking for answers. How many of you have done Google searches or combed through WebMD to come across the term disc bulges, disc herniations, or disc extrusions? Aren't they all the same thing? The answer is yes and no.
So, what really is the difference between all these disc problems?
To really get to the bottom of this, you must look at the general anatomy of the lower back. There are a few important things to pay attention to. The first would be the skeletal structure. This is comprised of the vertebras and the sacrum. Next, will be the disc in between each vertebra. These discs are cartilaginous, and they allow the back to flex and extend. They also act like glue to hold the spine together. In addition, the discs are designed to act like a cushion between each vertebra. The healthier the disc, the greater the distance between each vertebral. As a result, a tunnel is form between a top vertebra, a disc, and a bottom vertebra. These tunnels allow a singular nerve to pass through and innervate specific body parts. These tunnels are typically 2 to 3 times larger than the nerve’s diameter. This design allows for some degeneration of the disc without compression.
What is a Disc Bulge?
Now, when you look at the anatomy of the disc, you will see two distinctive regions. There is a very fibrous outer ring called your annulus and a jelly like core called your nucleus. Now imagine a disc that is nice and plump, that acts like a pillow in between your vertebra. If this disc goes through degeneration, then that disc can start to lose its structural integrity. This is like a balloon being compressed from top and bottom. The height of the disc decreases, while the sides of the disc start to “bulges” out the sides. This is a Disc Bulge.
What is a Disc Herniation, Disc Protrusion?
Similar to a disc bulge, a disc herniation or protrusion can also extend into a tunnel and compress a nerve. However, unlike a disc bulge, a disc herniation involves tearing of the disc. The fibrous outer ring of the disc tears creating a fissure from the edge of the disc to the nucleus (the jelly-like inner core). This allows the core to protrude, creating an out pouching. This is a Disc Herniation or sometimes called a Disc Protrusion.
What is a Disc Extrusion?
A Disc Extrusion is typically used to describe a large disc herniation. When the herniation is so large that the edge of the herniation extends up and/or down covering portions of the upper and/or lower vertebra.