Anderson type II fracture of the odontoid process: results of anterior screw fixation.

Controversy exists in the literature regarding the adequacy of one or two screws for direct fixation of the odontoid process. Proponents of the two-screw technique believe that a single screw is not adequate to stabilize the fracture. Conversely, the insertion of two 3.5-mm screws in the medullary cavity of the odontoid process is technically difficult and can jeopardize the surface area left for fracture healing. The authors conducted a prospective study of 30 cases with Anderson type II fracture of the odontoid process treated by direct anterior fixation using the two-screw technique. The screws used were 2.7-mm cortical screws manufactured from titanium. Two C-arms were used to control reduction of the displaced fracture and for its direct anterior stabilization. The operation was performed with the patients under general anesthesia. The anterolateral incision was made at the level of C4 to facilitate exposure of the C2-C3 disk and for fracture fixation. No evidence of nonunion was encountered. Spontaneous fusion of the C2-C3 segment was found in one case. Limitation of rotation of the cervical spine was a subjective description in a single case. No major complications were attributed to the surgical technique. The two 2.7-mm self-tapping titanium cortical screws provided adequate stability for fixation of type II odontoid fractures.