The “tear drop” (or avulsed) fracture of the anterior inferior angle of the axis

Summary

Fourteen cases of an anterior inferior angle fracture of the axis treated in the Orthopaedic Department of the University of Athens from January 1970 to December 1992 were analysed. The mean follow-up time was 8.5 years. The so-called “tear drop” fracture of the axis composes a special entity characterised by an avulsed fragment, of varying size, from the anterior inferior angle of the body of the axis as a result of hyperextension. This type of injury is not a frequent one, representing 3% of the cervical spine trauma in our Department. There were eight men and six women with a mean age of 47 years. Road traffic accident is by far the most common mode of aetiology. The stability of this lesion is questioned by certain authors, resulting in disagreement concerning the choice of treatment to be followed. All the patients in our series were treated conservatively, consisting at the beginning with Glisson traction and then the use of a simple cervical collar. The rotation of the detached fragment, its anterior displacement, the posterior displacement of the vertebral body as well as the presence of instability at the C1-3 levels were analysed. The high incidence of co-existing lesions at the same or at a more distal level is discussed. This study revealed that there was no significant displacement of the vertebral body, and thus disturbance of the posterior ligaments, rendering the fracture stable. The rotation of the avulsed bony fragment along with its anterior displacement did not influence the final outcome. We believe that surgery has no place in the treatment for this injury.