Acute fractures of the odontoid process

Abstract

Between 1969-1974, 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 19-40 yr old, and 21 were over 40 yr old. Detectable myelopathy was appreciated in 8 cases (18%). Diagnosis was established within 72 h of the traumatic event. Initial evaluation disclosed displacement of the fracture in 17 cases (38%). Following reduction, the initial treatment was posterior fusion in 3 cases, and external immobilization in 42 cases. Excluding 2 deaths within the 1st wk of treatment, 40 cases were available for follow-up analysis. Bone union failed to occur following periods of immobilization ranging from 4-6 mo. in 13 cases (33%). Fibrous union with no evidence of instability was apparent in 2 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 yr old than in those under 40 yr. The incidence of nonunion in individuals aged under 40 with nondisplaced fractures was 12%; it was 25% for individuals over 40 yr 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 6-18 mo. 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 yr old and those displaced more than 4 mm are candidates for internal stabilization and fusion as a primary mode of treatment.