Journal Article

Posterior L5–S1 fusion with complete reduction for pediatric high-grade dysplastic spondylolisthesis: a multicenter retrospective case series with exploratory analysis of residual sagittal imbalance

Du, You, Yao, Ziming, Zhang, Jianguo, Wang, Shengru, Ye, Xiaohan, He, Xiaoyan, Guo, Dong, Zhao, Yiwei, Zhang, Xuejun, Li, Chenkai, Lin, Guanfeng, Yang, Yang

2026

Overview

Background context High-grade dysplastic spondylolisthesis (HGDS) is a rare pediatric spinal deformity characterized by severe lumbosacral dysplasia and sagittal malalignment. The optimal surgical strategy for achieving deformity correction while minimizing neurological risk remains controversial. Purpose To evaluate radiographic and clinical outcomes of sacral dome osteotomy combined with complete L5 reduction and single-level posterior L5–S1 fusion in pediatric patients with HGDS, and to explore factors associated with residual postoperative sagittal imbalance. Study design A multicenter retrospective case-series study. Patient sample Thirty-one patients (30 females, 1 male; mean age 9.66 ± 2.27 years) with L5 high-grade dysplastic spondylolisthesis who underwent sacral dome osteotomy, complete L5 reduction, and posterior L5–S1 single-level fusion between 2008 and 2023. Outcome measures The primary outcome was residual sagittal imbalance at the latest follow-up, defined as sagittal vertical axis (SVA) > 5.0 cm or pelvic tilt to sacral slope ratio (PT/SS) > 1. These criteria represented global and regional malalignment, respectively. Methods Clinical and radiographic data were retrospectively reviewed. Patients were categorized according to the presence of residual sagittal imbalance at the final follow-up. Univariable and multivariable logistic regression analyses were performed in an exploratory manner to examine associations between selected clinical and radiographic variables and residual sagittal imbalance. Receiver operating characteristic (ROC) curve analysis was conducted to assess the discriminatory ability of preoperative sagittal vertical axis within this cohort. Results Mean follow-up was 3.05 ± 2.01 years. Slip percentage improved from 61.0 ± 11.0 preoperatively to 13.0 ± 10.0 postoperatively (p < 0.001) and remained stable at 9.0 ± 12.0 at the latest follow-up. Lumbosacral and global sagittal alignment parameters demonstrated significant correction that was largely maintained over time. Seven patients (22.6%) demonstrated residual sagittal imbalance (SVA > 5.0 cm or PT/SS > 1). Greater preoperative SVA values were associated with residual postoperative sagittal imbalance (OR 1.04, 95% CI 1.00–1.08, p = 0.037). Exploratory ROC analysis identified a preoperative SVA value of 4.0 cm with high sensitivity (100%) and moderate specificity (75%) for residual imbalance in this cohort. Transient neurological complications occurred in 12.9% of patients, and radiographic adjacent segment degeneration requiring revision occurred in 9.7%. Conclusions Sacral dome osteotomy with complete L5 reduction and single-level posterior L5–S1 fusion achieved durable radiographic correction of sagittal and coronal deformities in pediatric patients with high-grade dysplastic spondylolisthesis. Exploratory analyses suggested that greater preoperative sagittal vertical axis values were associated with residual postoperative sagittal imbalance, highlighting the importance of careful postoperative follow-up.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Abnormalities / Back pain / Back surgery / Care and treatment / Children / Complete reduction / Epidemiology / High-grade dysplastic spondylolisthesis (HGDS) / Internal Medicine / Measurement techniques / Medicine / Medicine & Public Health / Methods / Neurological complications / Orthopedics / Osteotomy / Patient outcomes / Patients / Pediatric / Pediatrics / Rehabilitation / Rheumatology / S1 dome resection / Sacrum / Sagittal alignment / Single-level fusion / Spinal fusion / Spine / Spondylolisthesis / Sports Medicine / Surgery / Vertebrae