Spondylolisthesis may be associated with degenerative disease of the spine and occurs even in the absence of spondylolysis.
In the presence of degenerative joint disease, the smooth pattern of spinal movement is transformed in to one that is irregular and either excessive or restricted. Consequently traction between opposing articular facets occurs, allowing a vacuum phenomenon to develop.
We report CT scans demonstration of a vacuum between lumbar facets due to their separation in degenerative spondylolisthesis.
