Changes in spinopelvic sagittal parameters and functional outcomes after unilateral microscopic decompression for...

We evaluated short-term clinical and standing sagittal changes after unilateral microscopic channel-assisted decompression for lumbar spinal stenosis and examined their associations with disability and leg-pain improvement.

This retrospective cohort included 68 patients treated between June 2024 and June 2025 and followed for 6-12 months. Oswestry Disability Index (ODI), leg-pain visual analog scale (VAS), pelvic tilt (PT), pelvic incidence (PI), sacral slope (SS), lumbar lordosis (LL), sagittal vertical axis (SVA), and thoracic kyphosis (TK) were assessed before surgery and at final follow-up. Changes were calculated as final follow-up minus preoperative values. Correlations with ODI and VAS improvement rates were tested with Holm correction. Interobserver and intraobserver reliability were assessed using intraclass correlation coefficients. An adjusted association analysis included age, body mass index, baseline ODI, and decompression extent.

ODI and VAS decreased significantly after surgery. PT and SVA decreased, whereas SS, LL, and TK increased; PI did not change significantly. The increase in LL was modestly associated with ODI improvement (Pearson r = 0.360, 95% CI 0.133-0.551; Holm-adjusted p = 0.026). No sagittal parameter was significantly correlated with VAS improvement after correction. In the adjusted analysis, ΔLL was not independently associated with ODI improvement (B = -0.108, 95% CI -0.276-0.060; p = 0.207). Follow-up duration was not associated with ΔLL or ΔSVA. Reliability was good to excellent.

Clinical outcomes and standing sagittal parameters changed over follow-up. In this cohort, a greater increase in LL was modestly associated with greater ODI improvement only in the unadjusted analysis. The sagittal changes may represent functional postural adaptation rather than structural correction, but the observational design does not establish causality.