Can The Fracture Line of Type II Odontoid Fractures Come to A Neutral Position After Anterior Odontoid Screw Fixation without a Manipulation?

Aim: To examine whether there was an improvement in the displaced fracture line in the follow-up, in which Anterior odontoid screw fixation (AOSF) was performed without manipulation and to determine the "displacement angle range" in which AOSF was possible.
Material and Methods: A total of 11 patients with the diagnosis of type II odontoid fracture who underwent AOSF without manipulation were analyzed retrospectively. A control group of 30 cases was formed and odontoid related angle measurements were performed on cervical computed tomographies (CT) of the control group and the patients who were operated.
Results: In 6 of 7 cases in the posterior-displaced group along with all cases in the anterior-displaced group, it was determined that the displacement angles returned to the normal range in the 1st year follow-up. In 1 case having posterior displacement with posterior longitudinal ligament (PLL) damage, it was observed that the displacement angle improved to the normal range significantly, but the displacement continued.
Conclusion: AOSF is a minimally invasive, safe and effective method in patients with displaced type II odontoid fracture, which is between the median odontoidobasal angle range of 100°-134°, whose PLL is preserved, and which cannot be manipulated.