Murilo Tavares Daher, Sérgio Daher, Marcello Henrique Nogueira-Barbosa, Helton Luíz Aparecido Defino


October 2011, Volume 20, Issue 11, pp 1908 - 1914 Original Article Read Full Article 10.1007/s00586-011-1879-2

First Online: 21 June 2011

Introduction

Odontoid diameter in some individuals may not be large enough to accommodate two 3.5-mm cortical screws for anterior odontoid fracture fixation. The study was performed to evaluate, in a Brazilian population, the diameter of the odontoid process and the feasibility of using two 3.5-mm cortical screws for anterior odontoid fracture fixation.

Materials and methods

Computed tomographic (CT) scans of 88 adult patients (aged 18–78 years) were analyzed; 40 patients (45%) were male (mean age: 43.08 years) and 48 (55%) were female (mean age: 43.39 years). The minimum external and internal anteroposterior and transverse diameters of the odontoid process on sagittal and coronal planes were measured on CT multiplanar reconstructions of the cervical spine.

Results

The mean value of the minimum external anteroposterior diameter was 10.83 ± 1.08 and 7.53 ± 1.10 mm for the minimum internal anteroposterior diameter. The mean value of the minimum external transverse diameter was 9.19 ± 0.91 and 6.07 ± 1.08 mm for the minimum internal transverse diameter. The mean AP diameter was significantly larger than the mean transverse diameter; 57 (65%) individuals had the minimum external transverse diameter >9.0 mm that would allow the insertion of two 3.5-mm cortical screws with tapping, and five (6%) individuals had the minimum internal transverse diameter >8.0 mm that would allow the insertion of two 3.5-mm cortical screws without tapping.

Conclusions

The insertion of two 3.5-mm cortical screws was possible for anterior fixation of odontoid fracture in 57 (65%) individuals of our study, and there was no statistical difference between males and females.


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