# Radiological and Clinical Outcomes After Navigated Tubular Unilateral Laminotomy for Bilateral Decompression (ULBD) for Lumbar Spinal Stenosis Among Patients with Concurrent Degenerative Scoliosis: A Short-Term Retrospective Case Series

## TL;DR

This study shows that a minimally invasive spinal surgery called navigated tULBD can reduce pain and disability in patients with mild adult spinal issues and stenosis, without major complications.

## Contribution

The study is one of the first to evaluate navigated tULBD for degenerative scoliosis and spinal stenosis, showing its potential as a less invasive alternative to fusion.

## Key findings

- Patients experienced significant reductions in back and leg pain after navigated tULBD.
- Disability scores improved significantly following the procedure.
- No neurological complications were observed, and spinal stability was not adversely affected.

## Abstract

Background/Objectives: Adult degenerative scoliosis (ADS) is a spinal disease causing pain and reduced mobility, often occurring with degenerative lumbar spinal stenosis (DLSS). While fusion stabilizes the spine, it has drawbacks like loss of motion and adjacent segment degeneration. Minimally invasive techniques, such as tubular unilateral laminotomy for bilateral decompression (tULBD), provide a less invasive alternative, but their impact on ADS with DLSS is underexplored. This study examines the short-term effects of navigated tULBD on radiological and clinical outcomes in this patient population. Methods: This retrospective single-center study analyzed patients aged ≥18 years with DLSS and ADS (Cobb angle ≥ 10°), with or without grade I spondylolisthesis, who underwent navigated tULBD between June 2019 and October 2022. Radiological parameters were assessed pre- and post-operatively using AI-powered FXA™ Version 1.33, Raylytic Software GmbH, Leipzig, Germany, while clinical outcomes were evaluated using the Oswestry Disability Index (ODI) and Numeric Rating Scale (NRS) for back and leg pain. Statistical analyses were conducted with R Studio. Results: This study included 20 patients (mean age 74.6 ± 7.6 years, body mass index [BMI] 26.08 ± 3.7 kg/m2), with a median follow-up of 2 months. Most underwent single-level decompression (45%), with a median of 2 surgical levels (IQR: 1–3). Radiological parameters showed no significant changes (p > 0.05). Clinically, the median NRS back improved from 5 (IQR: 3–9) preoperatively to 2 (IQR: 0–2) postoperatively (p = 0.009) and 1 (IQR: 0–4.5) at follow-up (p = 0.004). NRS leg scores dropped from 3.5 (IQR: 0–5) to 0 postoperatively and at follow-up (p = 0.02, p = 0.04). ODI improved from 37.8 (IQR: 29–42.5) preoperatively to 17.5 (IQR: 5–24) at follow-up (p = 0.04). There were no neurological complications. Conclusions: Navigated tULBD is a promising, minimally invasive option for mild ADS and DLSS. It provides significant pain and disability relief without adversely affecting stability and alignment. Long-term studies are needed to confirm durability and efficacy, particularly in severe cases.