Spinopelvic Sagittal Alignment after Microendoscopic Laminotomy in Patients with Lumbar Degenerative...

Spinopelvic sagittal balance is important in managing lumbar diseases. We evaluated the change in spinal sagittal alignment after microendoscopic laminotomy in patients with low-grade degenerative spondylolisthesis (DS).

We retrospectively reviewed the records of 87 patients who underwent microendoscopic laminotomy. We enrolled 35 patients with DS and 52 patients without DS. Spinopelvic parameters were evaluated, including the sagittal vertical axis (SVA), lumbar lordosis (LL), sacral slope, pelvic tilt, and pelvic incidence (PI). Primary outcome was a change in spinopelvic alignment between the baseline and latest follow-up values (DS group versus non-DS group). Secondary outcomes were the relationships between improved global sagittal alignment and preoperative spinopelvic parameters.

Both groups showed significantly alleviated low back pain (LBP), leg pain, and leg numbness. Preoperative SVA and PI were significantly higher in the DS group than in the non-DS group (p < 0.05). SVA significantly decreased and LL significantly increased in the DS group (p < 0.05), whereas those parameters did not differ significantly from before versus after surgery in the non-DS group. In both groups, SVA improvement correlated significantly with preoperative SVA (DS: r = 0.702; non-DS: r = 0.397). There was also a significant intergroup difference in the correlation coefficient (z = 1.98; r = 0.048).

SVA and LL significantly improved after microscopic laminotomy in patients with low-grade DS and neurologic symptoms. SVA improvement in the DS group was correlated with preoperative spinopelvic sagittal imbalance. The strength of those correlations was greater in the DS group than in the non-DS group.