S7A-01 SESSION 7A: SAGITTAL SYNOSTOSIS PROGRESSION OF SCAPHOCEPHALY IN UNTREATED SAGITTAL SYNOSTOSIS OVER THE FIRST YEAR OF AGE

Abstract

Introduction: The timing of surgical treatment of sagittal craniosynostosis (SC) within the first year of life varies by technique and patient presentation. It is important to determine whether scaphocephaly associated with SC is static in this first year, or if there is progression that should be included in surgical decision-making. The purpose of this study was to perform quantitative analysis of the mean changes in pre-operative SC skull shape to determine which characteristics improve, and which deteriorate. Methods: We compared CT scans from consecutive untreated isolated SC cases who were less than one year old with an age matched normal cohort. Craniofacial landmarks were marked using 3D Slicer, and standardized measures of shape were calculated using custom software developed from open source image analysis libraries (ITK, VTK and Morpho). Shape measures were compared between SC and normal cohorts across three age groups: 0–3 months, 3–6 months, and 6–12 months. Results: We included 109 patients with SC from 2003 to 2016 and 50 control patients. Over the first year, cephalic index in SC remained stable and lower than normal. Frontal bossing was highest in the young age groups, and approached normal by one year. Occipital ratio and coronal constriction both became narrower with time, whereas they were stable in normal patients. Conclusion: Scaphocephaly and pterion constriction remains abnormal through the first year of life in patients with SC and need to be addressed in any surgical technique. The worsening of occipital ratio after six months of age implies that techniques performed in this later window specifically need to address occipital constriction. Frontal bossing appears to continue to normalize in untreated SC cases without surgery, indicating surgery should focus on the middle and posterior cranial vaults.