Radiologic evaluation of degeneration in isthmic and degenerative spondylolisthesis

Abstract

Study Design: A cross-sectional imaging study. Purpose: The objective was to assess the degree of degeneration and the associated factors through imaging studies of the lesion segment and the adjacent superior and inferior segments of isthmic and degenerative spondylolisthesis. Overview of Literature: Few articles existed for degeneration and related factors in isthmic and degenerative spondylolisthesis. Methods: The subjects were 95 patients diagnosed with spondylolisthesis. Simple plain radiographs including flexion and extension and magnetic resonance imaging were used to investigate the degree of translation, disc degeneration, high intensity zone (HIZ) lesion, Schmorl's node (SN) and Modic changes. Results: Advanced disc degeneration, grade 5, was shown to be significant in the index segment of the isthmic type (p =0.034). Overall, type 2 Modic change was most common in both groups and also, it was observed more in the isthmus group, specifically, the index segment compared to the degenerative group (p =0.03). For the SN, compared to the degenerative type, the isthmus type had a significantly high occurrence in the index segment (p =0.04). For the HIZ lesions, the isthmus type had a higher occurrence than the degenerative type, especially in the upper segment (p =0.03). Conclusions: Most advanced disc degeneration, fifth degree, SN and Modic change occurred more frequently in the lesions of the isthmus type. HIZ lesions were observed more in the isthmus type, especially in the segment superior to the lesion. © 2013 by Korean Society of Spine Surgery.