Surgical correction of unilateral lambdoid synostosis: occipital rotation flap.

Virchow (1851) is credited with initially describing calvarial development following premature closure of individual sutures. He noted that resultant compensatory growth occurred perpendicular to the fused suture, resulting in asymmetrical calvarial development. Lambdoid synostosis, whether unilateral, bilateral, or associated with other cranial fusions, is reasonably uncommon. Previous authors report an incidence of less than 10% of all reported cases of premature fusion of the calvarial or skull base sutures. We report 27 patients (20 boys, 7 girls) ranging in age from 3 months to 8 years with unilateral lambdoid craniosynostosis followed over a three-year period. In 19 patients, calvarial reshaping was performed by repositioning a parietooccipital bone flap stabilized with lag-screw fixation to provide an increased radius of curvature to the affected area and to reestablish the resultant craniectomy between the parietooccipital junction and into the posterior fossa retromastoid occipital bone as an appropriate site for growth. Indications for one-stage calvarial reshaping included untreated lambdoid stenosis in older children or a failed simple lambdoid synostectomy after approximately 18 months. Each child experienced significant improvement in calvarial shape and ipsilateral ear position. Although we had no operative complications, two children underwent a second outpatient procedure for removal of hardware palpated by their parents.