Can the fracture line of type ii odontoid fractures come to a neutral position after anterior odontoid screw fixation without a manipulation?

AIM: Anterior odontoid screw fixation (AOSF) is known as a safe and effective method in type II odontoid fractures but in displaced cases, it is recommended to turn the displaced fracture line into neutral position with post-anesthesia manipulation and to return to posterior technique in cases where this is not possible. The aim of the study was to examine whether there was an improvement in the displaced fracture line in the follow-up, in which AOSF was performed without manipulation and to determine the “displacement angle range” in which AOSF was possible. MATERIAL and METHODS: 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.