title: Retrodental synovial cyst which disappeared after posterior C1-C2 fusion: A case report.
abstract: Synovial cysts of the cervical spine are extremely rare. We describe an 8-year-old boy with atlantoaxial subluxation and hypoplasia of the dens. Magnetic resonance imaging showed a round lesion, posterior to the odontoid process. This mass was characterized by a low signal intensity on T1-weighted images, and high signal intensity on T2-weighted images. The retrodental synovial cyst disappeared after posterior atlantoaxial arthrodesis.
authors.affiliation: Department of Orthopaedic Surgery, Yamagata University School of Medicine, Yamagata City, Japan.
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Ito
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hayashi
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Ogino