Spinopelvic parameters in degenerative spondylolisthesis.

The purpose of this study was to compare various sagittal spinopelvic parameters between patients with and without degenerative lumbar spondylolisthesis (DLS). A total of 165 patients who underwent surgery for low back and/or radicular pain were divided into two groups: those without DLS (non-DLS group; n = 85) and those with DLS (DLS group; n = 80). In all sagittal spinopelvic parameters, no significant difference was found between the non-DLS and DLS groups. The mean pelvic incidence (PI) value of the DLS group (56.4°) was almost similar to that of the non-DLS group (57.5°). The cross-sectional ratio of lumbar musculature was significantly smaller in the DLS group than in thenon-DLS group (p = 0.046). Contrary to the results of previous studies, a high PI may not be a predisposing factor for DLS development. Atrophy of back extensor muscles may play a role in the pathogenesis of DLS.