A morphometric study of the odontoid process using three-dimensional computed tomography (3-D CT) reconstruction

Objectives: The aim of this study was to evaluate the morphometric parameters of the odontoid process using 3-dimensional (3D) reconstruction of computed tomography (CT) images and investigate the applicability of using one or two screws for fixing odontoid process fractures. Methods: CT images of 100 patients (55 males, 45 females) were transferred to the OsiriX program in DICOM format and converted into three dimensional images using the 3D volume rendering feature. Male and female groups were divided into 8–30, 31–50 and over 50 age groups and features of the odontoid process were measured. Results: In the coronal plane, the minimum external transverse length of the odontoid process (OPmin) was highest in males over 50 year of age with a value of 11.3 mm. In the sagittal plane, the combination of anterior-posterior length of the odontoid process and vertebral body (OPAP) was highest in the males over 50 (14.5 mm). The length of the line taken from the anterior-inferior corner of the vertebral body to the top of odontoid process (LAIT) was measured the highest measured as 45.2 mm in males over 50. These measurements were higher in males than females. Conclusion: The results of this study showed that it is possible to use a single 4.5 mm or 3.5 mm cannulated screw in the Turkish population. The application of two 3.5 mm screws was found to be appropriate in 76% of males and 62% of females.