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.