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. 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. A multicenter retrospective case-series study. 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. 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. 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. 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 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%. 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.
Ye et al. (Mon,) studied this question.