LAUSR

The purpose of this study was to compare the degeneration of sacroiliac joints (SIJs) between adult spinal deformity (ASD) patients with sagittal imbalance and an age- and sex-matched lumbar spinal stenosis (LSS) patients without sagittal imbalance. The age- and sex-matched case–control study consists of two groups: the ASD group and the other group consisting of patients with LSS (LSS group). The study population consisted of 98 patients in each group. The spinopelvic parameters such as pelvic incidence (PI), sacral slope, pelvic tilt, lumbar lordosis, and sagittal vertical axis (SVA) were measured. To evaluate degeneration of SIJ, two protocols (Backlund's grade and Eno’s classification) were used. SIJ degeneration in the ASD group was more severe than that in the LSS group, as assessed by both Backlund’s grade and Eno’s classification (P < 0.001 for both). Age correlated significantly with PI in both the ASD and LSS groups (r = 0.285; P = 0.005, r = 0.218; P = 0.031, respectively). The total Backlund’s grading score and the SVA were significantly correlated with PI in the ASD group (r = 0.344; P < 0.001, r = 0.276; P = 0.007, respectively), but not in the LSS group (r = 0.156; P = 0.126, r = 0.189; P = 0.067, respectively). ASD patients with sagittal imbalance demonstrated more severe SIJ degeneration compared to the age- and sex-matched LSS group. PI was significantly correlated with both SIJ degeneration and SVA only in the ASD group.