Acute fractures of the odontoid process

Abstract

✓ Between 1969 and 1974, 45 cases of acute odontoid fracture were diagnosed and treated at this institution. The group consisted of 35 men and 10 women; 24 were between 19 and 40 years of age, and 21 were over 40 years old. Detectable myelopathy was appreciated in eight cases (18%). Diagnosis was established within 72 hours of the traumatic event. Initial evaluation disclosed displacement of the fracture in 17 cases (38%). Following reduction, the initial treatment was posterior fusion in three cases, and external immobilization in 42 cases. Excluding two deaths within the first week of treatment, 40 cases were available for follow-up analysis. Bone union failed to occur following periods of immobilization ranging from 4 to 6 months in 13 cases (33%). Fibrous union with no evidence of instability was apparent in two cases. Nonunion in displaced fractures was seen in 60%, with a rate of 88% in those displaced more than 4 mm. The rate of nonunion in undisplaced fractures was 16%. The rates of incidence of displacement (53% vs 26%) and nonunion (78% vs 33%) in those displaced were higher in individuals over 40 years of age than in those under 40 years. The incidence of nonunion in individuals aged under 40 with nondisplaced fractures was 12%; it was 25% for individuals over 40 years old. A total of 13 patients underwent posterior fusion. All eventually manifested stability at the C1–2 level. However, 69% failed to show bone union at the fracture site in a 6- to 18-month follow-up period. This review indicates that in consideration of the fracture, external immobilization is the initial treatment of choice in all nondisplaced fractures. Displaced fractures occurring in patients over 40 years old, and those displaced more than 4 mm are candidates for internal stabilization and fusion as a primary mode of treatment.