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Updated: Oct 22, 2026
Percutaneous Endoscopic Unilateral-Approach Bilateral Decompression for Lumbar Spinal Stenosis
Published on: February 9, 2024
Clinical and radiographic factors associated with residual low back pain after single-level decompression for lumbar
Yudai Kumanomido1, Koji Nakajima1, Yutaro Oba2
1Department of Orthopaedic Surgery, The University of Tokyo 7-3-1, Hongo, Bunkyo-Ku, Tokyo, 113-8655, Japan; University of Tokyo Spine Group (UTSG), 7-3-1, Hongo, Bunkyo-Ku, Tokyo, 113-8655, Japan.
Background Context:
Residual low back pain (LBP) after decompression for lumbar spinal stenosis (LSS) varies considerably and is likely multifactorial. It remains unclear how residual LBP differs by preoperative severity and which factors are independently associated with it.
Purpose:
To examine how postoperative LBP improves across preoperative severity groups and to identify clinical and radiographic factors independently associated with residual LBP.
Study Design/Setting:
Multicenter retrospective cohort study.
Patient Sample:
A total of 450 patients undergoing primary single-level posterior decompression for LSS at six institutions (2017-2023).
Outcome Measures:
The primary outcome was the 1-year postoperative numerical rating scale (NRS) score for LBP. Secondary outcomes were buttock and leg pain NRS, Oswestry Disability Index, EuroQol 5-Dimension, and postoperative satisfaction.
Methods:
Patients were stratified into three predefined preoperative LBP severity groups (Mild 0-3, Moderate 4-7, Severe 8-10). Inverse probability weighting (IPW) was applied for three-group comparisons. Unweighted multivariable linear regression for postoperative LBP NRS included preoperative LBP NRS together with patient, surgical, and radiographic factors as covariates. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. The authors report no study-specific conflicts of interest.
Results:
The IPW-adjusted Severe group showed the largest LBP NRS improvement (4.5 points) but the highest residual LBP NRS (4.1). Dissatisfaction did not differ across groups (p=.244). Factors independently associated with residual LBP were preoperative LBP NRS (B=0.381, p<.001), pelvic incidence-lumbar lordosis (PI-LL) >20° (B=0.681, p=.024), and American Society of Anesthesiologists Physical Status (ASA-PS) ≥3 (B=1.298, p=.017).
Conclusions:
Greater preoperative LBP severity was associated with both larger improvement and higher residual LBP. Preoperative LBP severity, PI-LL >20°, and ASA-PS ≥3 were independent factors for residual LBP.