Although classification systems exist,
- Grade I: 0-25%
- Grade II: 25- 50%
- Grade III: 50-75%
- Grade IV: 75-100%
- Grade V: greater than 100%
</ref> the most important parameter is the percentage of slippage as compared to the depth of the vertebral body.
- For a full list of contributors, see article Radlines:Authorship for details. . Creators of images are attributed at the image description pages, seen by clicking on the images. See
- Spondylolisthesis is sometimes defined as anterior displacement specifically, see for example Spondylolisthesis terminology in Wikipedia for details.
- . Spondylolysis and Spondylolisthesis of the Lumbar Spine. Massachusetts General Hospital. Retrieved on 2016-12-14.