Title : Morphological differences of facet joints in Lumbar Spinal Stenosis Patients (LSSP) with and without degenerative spondylolisthesis
Abstract:
Objective: To investigate the morphological differences of facet joints in patients with Lumbar Spinal Stenosis (LSS) with and without degenerative Lumbar Spondy Lolisthesis (DSL).
Methods: A retrospective analysis was performed on 80 patients with LSS complicated by DLS admitted to our hospital from August 2021 to October 2022. Among them, 60 patients with L4–5 spondylolisthesis were assigned to the DLS-a group, and 20 patients with L5–S1 spondylolisthesis were assigned to the DLS-b group. Concurrently, 80 patients with simple degenerative LSS admitted during the same period were enrolled, including 66 patients with L4–5 stenosis (LSS-a group) and 14 patients with L5–S1 stenosis (LSS-b group). All patients underwent lumbar Computed Tomography (CT) examination. The degree of spondylolisthesis was quantified using the Taillard index. Facet Joint Angle (FJA), pedicle-facet angle (P-FA), and facet tropism (FT) at the L4–5 and L5–S1 levels were measured using multiplanar reconstruction and compared among the four groups. Correlation analysis was performed between FJA and the degree of spondylolisthesis. The severity of facet joint degeneration at the L4–5 and L5–S1 levels was assessed under consistent window settings and graded according to the Kalichman classification, with comparisons made between the DLS and LSS groups.
Results: The majority of patients in the DLS group presented with grade I or II spondylolisthesis, with a female predominance. In the DLS-a group, the mean FJA and P-FA at L4–5 were 30.87° ± 8.82° and 119.10° ± 5.93°, respectively, which differed significantly from those in the LSS-a group (42.58° ± 9.39° and 109.94° ± 6.77°, respectively; both P < 0.05). The Taillard index showed a significant positive correlation with P-FA in the DLS group (P < 0.05). The prevalence of FT was significantly higher in the DLS group (47/80, 58.75%) compared with the LSS group (36/80, 45.00%) (P < 0.05). However, the severity of FT was not significantly correlated with FJA, P-FA, or the Taillard index in either group (all P > 0.05). The degree of facet joint degeneration differed significantly between the DLS and LSS groups (P < 0.05). Within the DLS-a group, the severity of facet joint degeneration was significantly correlated with both P-FA and the Taillard index (P < 0.05).
Conclusions: Significant differences exist in FJA between LSS patients with and without degenerative spondylolisthesis. Compared with LSS patients, those with DLS exhibit smaller FJA and larger P-FA at the affected segment, indicating a more sagittally and horizontally oriented facet joint morphology. The Taillard index is linearly correlated with P-FA, with larger P-FA associated with greater slip severity. FT is more prevalent in DLS patients and is associated with more advanced facet joint degeneration.
