3D morphometric analysis of laminae and facet joints in patients with degenerative spondylolisthesis

Objective. To clarify the three-dimensional (3D) morphometric characteristics of the spine in patients with degenerative spondylolisthesis (DS). Methods. 3D morphometric analyses of laminae and facets were performed and compared for a DS group, an age-matched spinal canal stenosis (LCS) group, and a control group of young persons without spinal disease. 3D facet sagittal angles (3D-FSAs), 3D facet axial angle (3D-FAAs), and 3D-FAA tropism at L3 and at L4 were measured by extracting the 3D inferior articular process. The 3D lamina inclination angles (3D-LIAs) of L3 and L4 were also measured by extracting the ventral surface of the laminae. Results. The 3D-FSAs at L4 in the DS group were significantly higher than for the other groups, but the difference in 3D-FSAs at L3 was not statistically significant among the groups. The 3D-FAAs at L4 in the DS group were significantly lower than in the control group. There was no significant difference in other factors. Conclusions. 3D morphometric analysis clarified that DS is significantly correlated with horizontalization (higher 3D-FSA), but is not correlated with sagittalization (lower 3D-FAA) and tropism (3D-FAA tropism) of facet joints or horizontalization of laminae (3D-LIA). There were no morphometric characteristics at the cranial adjacent segment of DS.