J Korean Radiol Soc.  1996 Jan;34(1):111-116.

CT Findings of Isthmic Spondylolisthesis and Degenerative Spondylolisthesis

• Chang SK
• Chung GH
• Cho SI
• Lee SY
• Han YM
• Sohn MH
• Kim CS
• Choi KC

Abstract

PURPOSE
To evaluate the finding useful for differential diagnosis and associated abnormalities of isthmic spondylolisthesis and degenerative spondylolisthesis on CT.
MATERIALS AND METHODS
We reviewed retrospectively the CT images of 164 patients who were diagnosed spondylolisthesis. One hundred twelve patients had isthmic spondylolisthesis and 52 patients had degenerative spondylolisthesis.
RESULTS
Isthmic spondylolisthesis mostfrequently occurred at L5. The degree of anterior displacement was grade I and II. The defect had a horizontal plane, an irregular surface, a sclerotic margin, and protruding hypertrophic bony spur in the spinal canal. The most frequently associated structural abnormality was a herniated nucleus pulposus at the upper level of the defect. Degenerative spondylolisthesis most frequently occurred at L4-5 and were grade I. The degenerative facet joint had a vertical plane, a hypertrophic bony spur, and a vacuum facet phenomenon. We frequently detected apseudobulging disk. The most frequently associated structural abnormality was a herniated nucleus pulposus at the level of the displacement.
CONCLUSION
In spondylolisthesis, the findings in CT were valuable for differential diagnosis of isthmic and degenerative types and the detection of associated symptomatic abnormalities.

Keyword

Spine, CT; Spine, dislocation

MeSH Terms

Diagnosis, Differential
Humans
Spinal Canal
Spondylolisthesis*
Vacuum