NONUNION OF A TYPE-II ODONTOID FRACTURE AFTER AN APPARENT RADIOGRAPHIC FUSION - CASE-REPORT

THE TYPE II odontoid fracture, initially described by Anderson and D'A lonzo, is the most common axis fracture. Several factors that predict the need for operative intervention have been discussed in the literat ure; however, the initial treatment remains somewhat controversial. We present the case of a 20-year-old woman who suffered a Type II odonto id fracture during a skiing accident. She was managed initially with h alo-vest immobilization, and after 12 weeks, bony fusion was documente d by plain spine radiographs and tomography. Routine follow-up cervica l spine films at 8 months after her injury revealed no union at the pr evious fracture site and resultant atlantoaxial instability. A posteri or C1-C2 fusion was therefore performed, leading to a long-term solid bony fusion. There are no previous reports in the literature describin g a nonunion after radiographically documented healing of a Type II od ontoid fracture. We present this case in order to emphasize the import ance of scheduled follow-up examinations, including cervical spine fil ms, for at least 12 months after a documented fusion. Further reports of similar cases may generate a more thorough understanding of the pat hogenesis of delayed nonunion and may elicit factors that will predict its development.