Spondylolysis and Spondylolisthesis

Diagram of a human spine showing the grades of SpondylolysisA spondylolysis is a type of broken bone in the spine.  Both struts holding the front and back parts of the bone together break. The back part of the vertebral bone (the lamina) separates from the front part (the body).  Because of the broken bone, the spine can become unstable and the body can slip forward.  The slippage is called a spondylolisthesis. 

Spondylolisthesis is graded.  Higher numbers indicate a more severe problem.  There are five grades, or levels, of severity. 

To determine the grade of spondylolisthesis, or slippage, the disc is divided in quarters.  The grade is equal to the number of quarters of slippage.  If there is no slippage, the grade is zero.  If the slippage is equal to one quarter of the total width of the disc, the slippage is grade one.  If the slippage is three quarters of the width of a disc, it is a grade three spondylolisthesis.  If the slippage is more than four quarters (the whole disc space) then it is called a grade 5.  In a grade 5 spondylolisthesis, the spine is completely dislocated.

 
Diagram showing spondylolysis grade zero (0) Diagram showing spondylolysis grade one (1) Diagram showing spondylolysis grade two (2)  
  Diagram showing spondylolysis grade three (3) Diagram showing spondylolysis grade four (4) Diagram showing spondylolysis grade five (5)

Go to the next chapter on symptoms, starting with back pain.






The information in this site briefly describes issues related to medical treatments, and has been licensed by from Northern California Neurosurgery Medical Group, Inc., who is solely responsible for said content.  This web site is not a substitute for good medical care or for a consultation with a spine specialist. It should not be used to plan your treatment. The well considered advice of a specialist who has personally examined you is always superior to even the best internet pages.


Copyright 2007, Northern California Neurosurgery Medical Group. All rights are reserved.  No part of this web site may be reproduced, transmitted, or stored, electronically or on paper, without the written permission of the Northern California Neurosurgery Medical Group, Inc.
Last modified: 07/27/08