| ORIGINAL ARTICLE
|Year : 2020 | Volume
| Issue : 6 | Page : 1361--1366
Feasibility of Double Anterior Odontoid Screw: A CT-Based Morphometric Analysis of the Axis in Adult Indian Population
Krishnaveer Singh Choudhary1, Ramesh Sharanappa Doddamani1, Leve J Devarajan2, Mohit Agrawal1, Dattaraj Sawarkar1, Rajesh Kumar Meena1, Satish Varma1, Amandeep Kumar1, Pankaj Singh1, P Sarat Chandra1, Shashank Sharad Kale1
1 Department of Neurosurgery, All India Institute of Medical Sciences, New Delhi, India
2 Department of Neuroradiology, All India Institute of Medical Sciences, New Delhi, India
Background: The fractures of the odontoid process constitute 10% of all cervical spine injuries. Odontoid screw placement, although technically challenging, in indicated cases is the ideal treatment. Hence, a thorough knowledge of the odontoid dimensions is necessary prior to the surgical endeavor, more so for planning double odontoid screws.
Materials and Methods: A prospective morphometric analysis of retrospective data of 250 patients was acquired at our institute using Somatom Definition edge 128 slice 64-row detector Siemens CT scanner. The dimensions of the odontoid process were measured at the waist (narrowest portion), widest diameter both in anteroposterior and transverse diameters. The dimensions of the C2 vertebra were measured at the level of the superior and inferior endplate in both the planes.
Results: A total of 250 patients were evaluated with age ranging from 1 to 80 years. Males constituted 174 (69.6%) and 76 (30.4%) were females. The mean transverse diameter (TD) at the odontoid waist (narrowest diameter) was 8.66 mm. The mean TD at the widest point of odontoid was 9.68 mm. Mean anteroposterior (AP) diameter 2.5 mm away from the midline on the left side at the level of the waist was 9.51 mm and 2.5 mm on the right of midline was 9.01 mm. The mean AP diameter at the C2 base was 15.824 mm in males and 14.833 mm in females (P < 0.001).
Conclusion: Double odontoid screw insertion is feasible in only 36% of Indians in the transverse plane, whereas 98.4% of the odontoids can accommodate double screws in the sagittal plane.
Additional Professor Department of Neurosurgery, Room No 715, CN Centre, All India Institute of Medical Sciences, New Delhi - 110029
Ramesh Sharanappa Doddamani
Associate Professor Department of Neurosurgery, Room No 715, CN Centre, All India Institute of Medical Sciences, New Delhi - 110029
Source of Support: None, Conflict of Interest: None
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