Skull Vertex Position as a Novel Craniometric Measurement to Assess Severity and Surgical Outcomes in Sagittal Craniosynostosis

Background: Cephalic index (CI) has traditionally been used to assess preoperative severity and postoperative outcomes following surgical correction of sagittal synostosis. However, CI is a 2-dimensional measurement that fails to describe the overall head shape. This study aims to define a novel measurement, skull vertex position, in patients who underwent cranioplasty for sagittal synostosis to better assess craniometric and esthetic outcomes. Methods: Patients with a history of isolated, nonsyndromic sagittal craniosynostosis who underwent open vault cranial reconstruction at a tertiary care children’s hospital from 2009 to 2020 were included. Cases were age and gender-matched to patients without any cranial bony pathology. Craniometric analysis was performed on pre- and postoperative CTs using Analyze Pro (V12, Overland Park, Kansas). Measurements included CI and vertex position. After orienting the skull to the sella-nasion plane, the vertex was defined as the highest point and expressed as a fraction of the occipitofrontal diameter. Results: Twenty-four patients met inclusion criteria (87.5% male). Mean ages at initial head CT and immediate postoperative CT for the entire cohort were 1.57 ± 1.70 years (n = 24) and 2.00 ± 1.65 years (n = 24), respectively. Thirteen patients had an additional long-term follow-up CT at a mean age of 4.28 ± 1.92 years. There were significant differences in both the CI and vertex position when comparing controls with pre-operative patients with sagittal synostosis ( P < .001). Importantly, there was significant improvement in caudal repositioning of the vertex in patients who underwent long-term CT imaging when compared to control patients ( P = .043) but no significant change in CI in this same population. Discussion: CI is the currently accepted measure of deformity severity and postoperative efficacy in sagittal synostosis. Our study introduces a novel measurement, skull vertex position, as an objective and reproducible measure for guidance in surgical planning and outcome assessment to maximize aesthetic and clinical outcomes.