Background: Although most craniosynostoses can be determined by pattern recognition, some patients defy phenotypic diagnosis and require computed tomography to determine sutural fusions.
Methods: The authors' craniofacial database was reviewed for patients treated for craniosynostosis between 1989 and 2007. Children with single-suture synostosis, isolated bilateral coronal synostosis, and pansynostosis were excluded. Recorded variables included the pattern of sutural fusion, age at presentation, cranial shape, presence of elevated intracranial pressure, genetic testing, and types of operative correction.
Results: Thirty-nine of 518 patients (7.5 percent) had phenotypically unusual combined forms of craniosynostoses. The most common were bilateral coronal-sagittal (30.8 percent), unilateral coronal-sagittal (10.3 percent), metopic-sagittal (10.3 percent), and bilateral lambdoid-sagittal (7.7 percent). Patients with fusion patterns involving both coronal sutures were more likely to have a mutation than those with other combinations (p = 0.01). Elevated intracranial pressure was noted in 76.9 percent of children. All patients underwent cranial repair; 33.3 percent had staged procedures, including early expansion followed by more definitive remodeling. Patients with bilateral coronal-sagittal or bilateral lambdoid-sagittal fusion had relatively normal head shapes (balanced dysmorphism). This subgroup was more likely to be syndromic and have operative intervention at an older age (p = 0.04).
Conclusions: Children with phenotypically unusual combined craniosynostoses are likely to have a syndromic diagnosis and elevated intracranial pressure. Cranial expansion was delayed in patients with a balanced dysmorphism. Patients with combined synostoses often require staged procedures because of elevated intracranial pressure or major cranial asymmetry.