Radiological and Clinical Outcomes after Tubular Unilateral Laminotomy for Bilateral Decompression for Lumbar Spinal Stenosis among Patients with Degenerative Scoliosis: A Retrospective Case Series.

Introduction: Degenerative lumbar scoliosis (DLS) in adults results in spinal issues and has traditionally been treated with complex fusion surgery. However, this poses risks for older or medically complex patients. Minimally invasive methods like Unilateral Laminotomy for Bilateral Decompression (ULBD) aim to address this. Our study examines how ULBD affects spinal stability and curvature in those with degenerative spinal stenosis and concurrent scoliosis.

Methods: In this retrospective case series, we examined DLS patients who underwent ULBD for lumbar spinal stenosis at a tertiary center between June 2019 and October 2022. We analyzed pre- and post-surgery radiographic parameters (including Pelvic Incidence, Pelvic Tilt, Lumbar Lordosis (LL), Sagittal Vertical Axis (SVA), Global Cobb Angle (GCA), and Segmental Cobb Angle (SCA)) using FXA™ software and assessed clinical outcomes with the ODI and VAS. Statistical comparisons between time points used either the Wilcoxon Signed Rank Test or paired t-test, with a significance level of 0.05. All analyses were conducted in R Studio.

Results: The study included 20 patients, with an average follow-up of 2 months. They were mostly males (60%) with an average age of 74.6 ± 7.6 and preoperative weakness (65%). The surgery involved a median of 2 levels, took about 130.1 minutes on average, and required a median hospital stay of 29 hours. Radiological parameters showed no significant differences before and after surgery: LL (42.8° vs. 42.4°, p=0.75), SVA (34.4 vs. 36.2, p=0.53), GCA (18.6° vs 19.6°, p=0.08), SCA (6.0° vs. 5.7°, p=0.53). However, clinical outcome scores improved significantly at follow-up: Back VAS (5 vs 1, p=0.004), Leg VAS (3.5 vs 0, p=0.04), and ODI (37.8 vs. 17.5, p=0.004).

Conclusion : Preliminary findings indicate minimal differences in spinal curvature and stability before and after tubular ULBD in scoliosis patients. Longer-term outcomes are being studied, and future studies will compare them to open laminectomy.