title: Factors associated with nonunion in conservatively-treated type-II fractures of the odontoid process.
abstract: In type-II fractures of the odontoid process, the treatment is either conservative in a halo vest or primary surgical stabilisation. Since nonunion, requiring prolonged immobilisation or late surgery, is common in patients treated in a halo vest, the identification of those in whom this treatment is likely to fail is important. We reviewed the data of 69 patients with acute type-II fractures of the odontoid process treated in a halo vest. The mean follow-up was 12 months. Conservative treatment was successful, resulting in bony union in 32 (46%) patients. Anterior dislocation, gender and age were unrelated to nonunion. However, nonunion did correlate with a fracture gap (> 1 mm), posterior displacement (> 5 mm), delayed start of treatment (> 4 days) and posterior redisplacement (> 2 mm). We conclude that patients presenting with these risk factors are unlikely to achieve bony union by treatment in a halo vest. They deserve careful attention during the follow-up period and should also be considered as candidates for primary surgical stabilisation.
authors.affiliation: Department of Radiology, Helsinki University Hospital, Helsinki, Finland.
authors.forename: M P
authors.initials: MP
authors.lastname: Koivikko
authors.forename: M J
authors.initials: MJ
authors.lastname: Kiuru
authors.forename: S K
authors.initials: SK
authors.lastname: Koskinen
authors.forename: P
authors.initials: P
authors.lastname: Myllynen
authors.forename: S
authors.initials: S
authors.lastname: Santavirta
authors.forename: L
authors.initials: L
authors.lastname: Kivisaari
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D005599:Fractures, Ununited / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009809:Odontoid Process / Q000293:injuries* / Q000601:surgery; D012044:Regression Analysis; D012307:Risk Factors