Computed Tomography–Based Morphometric Analysis of Extended Strip Craniectomy for Sagittal Synostosis

Abstract

The purpose of this study is 2-fold: (1) to identify computed tomography (CT)-based morphometric parameters that differentiate the normal skull from one with sagittal synostosis and (2) to evaluate correction of sagittal synostosis with extended strip craniectomy and postoperative helmeting based on morphometric parameters. An institutional review board-approved, retrospective review was carried out at the Hospital for Sick Children for all patients who underwent an extended strip craniectomy and postoperative helmeting for sagittal synostosis from 1999 to 2005. Inclusion criteria consisted of patients who underwent a routine craniofacial CT preoperatively and 12 months postoperatively. Craniofacial CT scans of age-matched control subjects were used for preoperative and postoperative comparison. Thirty-nine patients with sagittal synostosis met inclusion criteria. Median age at preoperative CT was 3.0 months. Nine control subjects were identified, with a median age at CT scan of 5.0 months. Patients with sagittal synostosis preoperatively had a significantly longer maximum cranial length, smaller maximum cranial breadth, more acute frontal takeoff and occipital incline angles, lower cephalic index, and an anteriorly positioned vertex. Postoperative CT scans (median, 17.0 months) were compared with 10 control subjects (median, 19.0 months). Patients with sagittal synostosis postoperatively had equivalent maximum cranial breadth, frontal takeoff, and occipital incline angles as compared with controls. Sagittal synostosis patients remained with a significantly longer maximum cranial length, lower cephalic index, and anteriorly positioned vertex. Twelve months following extended strip craniectomy and helmeting for sagittal synostosis, CT-based morphometric analysis demonstrated correction of cranial breadth, frontal bossing, and occipital bulleting. Skull length and vertex position did not fully correct.