MediVisuals, Inc.


Call NOW! 800.899.2153




Tell MediVisuals About YOUR

Case or Needs



Richmond Office

2008 Libbie Ave, Suite 200

Richmond, VA 23226



How a Disc "Bulge" is Different From a "Herniation"

(Intervertebral Disc Pathology, Part 1 of 3)

By: Robert Shepherd MS, Certified Medical Illustrator, President & CEO, MediVisuals Inc.

It is difficult to appreciate the subtle differences between the various types or severities of intervertebral disc injuries that result in them being defined as bulges, herniations, protrusions, extrusions, etc.  The way disc pathology is defined may even vary from physician to physician—perhaps primarily due to the fact that, prior to 1995, many physicians’ professional societies used different criteria to define the various classifications of disc injuries.  In 1995, a joint undertaking by representatives from the North American Spine Society, the American Society of Spine Radiology, and the American Society of Neuroradiology worked together to develop a more widely accepted and used system to define disc pathology as published in "Nomenclature and Classification of Lumbar Disc Pathology”.


This will be the first of three blogs dedicated to helping explain the definitions of disc pathology as recommended by the 1995 combined task force.  This blog will focus on the difference between "bulges" and "herniations".  Topics to be discussed in future articles are differences between a "Herniated Disc" and an "Annular Tear" and the difference between "Protrusions" and  "Extrusions".


In the image below, a normal disc is shown in comparison to the two types of intervertebral disc injuries covered in this article: "Bulges" and "Herniations."  Disc "Bulges", in general, are defined by the presence of disc material beyond the normal margins around at least 50% of the disc's circumference.  A "Herniation" is defined as displacement of disc material beyond the limits of the intervertebral disc space that extends less than 50% around the circumference of the disc.  The displacement material can consist of the nucleus, the annulus, or parts of both.  This is significant in personal injury litigation because the defense often places a great deal of emphasis on whether disc pathology is defined as a "bulge" or "herniation" when determining the severity of an injury.  However, a "bulge" can actually impinge nerve roots or the spinal cord to a more severe degree than a "herniation".
























The next image compares the normal disc to two different types of disc "Bulges."  A "Bulge" is defined as "Symmetrical" when the right and left sides of the herniation more or less mirror each other.  A bulge is "Asymmetrical" when the bulge is more severe on one side when compared to the other.
























Finally, the below image shows a normal disc as compared to two types of "Herniations."  A "Broad-Based" herniation is defined as disc material extending beyond its normal limits in an area between 25 and 50% of the disc's circumference.  A "Focal" herniation is one involving extension of disc material beyond its normal limits in less than 25% of its circumference.

Medical Legal Educational Blog for Personal Injury Attorneys

The Medical Legal Expert Blog is your source for some of the most helpful and useful medical and demonstrative evidence facts and information.


Originally Posted by MediVisuals at 8/20/2014

© MediVisuals, Inc. - Permission to use any image (or parts thereof) posted on this blog in depositions, demand packages, settlement hearings, mediation, trial, and/or any other litigation or non-litigation use can be obtained by contacting MediVisuals at – otherwise copyright laws prohibit their use for those or other purposes.

Bob Shepherd, MS, CMI, FAMI 

Bob Shepherd is a Certified Medical Illustrator, having graduated from one of only four accredited medical illustration graduate programs in North America.


President  | CEO

Chief Medical Illustrator

Visual Consultant

About the Author

Mailing List

Stay up to date on NEW Products, Case Outcomes and Educational Blogs by submitting your email below.

Educational Blog Archives

Click on blog icon or More>> below to view full article.

3D Reconstructions of CT and MRI Data (Volume Renderings) Complimented by Medical Illustration

Computer generated 3D reconstructions from a person's actual CT or MRI data (a.k.a. 3D volume renderings) as well as medical illustrations are powerful tools that can be used separately to demonstrate a plaintiff's injuries ......


Understanding the Osteophyte/Disc Complex in

Spinal Trauma

A traumatic event causing injury to an intervertebral disc may also cause subtle injuries to the bones around the disc.  During an extreme lateral flexion injury, the edges of the bone are driven together, injuring.......


Cervical Connective Tissue Injury (a.k.a. “Whiplash,” “Cervical Soft Tissue Injury,” and “Cervical Strain and/or Sprain”)

"Cervical Connective Tissue Injury," "Cervical Soft Tissue Injury," "Cervical Strain," and "Cervical  ......


Breaking Down Traumatic Arthritis

Fractures can result in several long term or permanent complications that can necessitate additional surgical procedures. One of the most common long term debilitating complications is traumatic arthritis.Traumatic ......

TUESDAY, MAY 14, 2014


It is difficult to appreciate the subtle differences between the various types or severities of intervertebral disc injuries that result in them being defined as bulges ......

How a Disc "Bulge" is Different From a "Herniation" (Intervertebral Disc Pathology,

Part 1 of 3)  


Brain injuries are classified into two basic categories; those that are associated with obvious, incontestable evidence of intracranial injury and those that are ......

Understanding Traumatic Brain Injuries:

Mild (less severe) to Severe - Part 1

 Send Clear
Wrong password.