Atlantoaxial instability associated with an orthotopic os odontoideum: a multimodality imaging assessment.
Radiography, computed tomography (CT), and magnetic resonance imaging exams of the cervical spine were performed in a 29-year-old man who was ultimately diagnosed with an orthotopic os odontoideum during admission for injuries sustained in a motor vehicle collision. Initial radiography suggested either os odontoideum or an acute fracture of the dens. Further imaging with CT and flexion and extension radiographs confirmed os odontoideum and excluded a dens fracture. Although rare, os odontoideum is an important cervical spine anomaly to consider and to distinguish from an acute fracture of the dens.
Vargas
Tomas M
TM
Brigham and Women's Hospital, 75 Francis Street, Boston, MA, 02115, USA.
Rybicki
Frank J
FJ
Ledbetter
Stephen M
SM
MacKenzie
John D
JD
D000328:Adult; D001268:Atlanto-Axial Joint / Q000473:pathology*; D006801:Humans; D007593:Joint Instability / Q000175:diagnosis* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D009809:Odontoid Process / Q000473:pathology*; D014057:Tomography, X-Ray Computed