Treatment of basilar invagination associated with Chiari I malformations in the pediatric population: cervical reduction and posterior occipitocervical fusion

Object. The reduction of basilar invagination associated with Chiari I malformations in pediatric patients is often possible. Eleven children ranging in age from 1.5 to 17 years underwent a novel treatment method involving decompression, manual reduction, and posterior instrumentation-augmented fusion. Outcomes were evaluated retrospectively. Methods. After decompression of the lesion, manual craniocervical distraction and extension were performed, followed by posterior occipitocervical fusion involving rigid internal fixation. All patients were symptomatic at presentation. lntraoperative monitoring included somatosensory evoked potentials, fluoroscopy, and direct intradural demonstration of the craniocervical junction. No new neurological deficits occurred immediately after surgery. Perioperatively, symptoms in seven patients improved significantly and in four they remained unchanged. Three patients required subsequent transoral resections. During long-term follow up (mean 39.4 months, range 3-92 months) symptoms improved markedly in nine, remained unchanged in one, and progressively worsened in one patient. Conclusions. In selected cases, manual cervical distraction and extension, posterior fixation, and fusion appear to provide a safe, effective standalone treatment for basilar invagination associated with Chiari malformation in children.