Year: 2026
Type: article
Study design: Observational Study
Abstract: Background Sagittal synostosis is increasingly recognized as a heterogeneous condition. Whether distinct anatomical phenotypes differ in Chiari type I malformation (CM-I) burden, and how posterior fossa morphology contributes to this heterogeneity, remains unclear. Methods We retrospectively studied 241 children with sagittal synostosis who underwent preoperative three-dimensional CT volumetry and MRI between January 2023 and December 2025. Patients were classified as anterior fossa–involved (Group A, n = 63), posterior fossa–involved (Group B, n = 53), or isolated sagittal synostosis (Group C, n = 125). Residualized posterior fossa volume (PFV_adj) was derived from PFV regressed on preoperative intracranial volume and age at surgery. ANCOVA and sequential logistic regression models were used, with Firth penalized regression as a sensitivity analysis. Results CM-I prevalence differed across subtypes ( P = 0.012) and was highest in Group B (28.3%) versus Group A (11.1%) and Group C (12.0%). In the subtype-only model, Group B had higher CM-I odds than Group C (OR = 2.89, 95% CI 1.29–6.48; P = 0.010). Group B also showed significantly lower PFV_adj ( P < 0.001). In morphology-adjusted analyses, greater tentorial angle (OR = 3.20 per 5°, 95% CI 2.10–4.88; P < 0.001) and lower PFV_adj (OR = 0.74 per 10 mL, 95% CI 0.62–0.89; P = 0.002) were associated with CM-I. Model AUC increased numerically from 0.869 to 0.885 after adding PFV_adj. Firth regression yielded consistent results. Conclusions The posterior fossa–involved phenotype carries the greatest overall CM-I burden and is characterized by relative posterior fossa deficiency and a steeper tentorial configuration. PFV_adj provides a developmentally adjusted measure that complements anatomical subtype classification.
Source: Frontiers in Surgery
Language: English
Subfield: Surgery
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,801
OpenAlex ID: W7223300287