Variants and deformities of atlas vertebrae in eastern Anatolian people

At the craniocervical junction, developmental anomalies of the atlas may produce clinical symptoms by compressing on the vertebral artery, particularly during extreme rotational movements of the cervical spine. The aim of the present study was to investigate several varieties and deformities of the atlas vertebra from the skeletal specimens of Eastern Anatolian people. This study was carried out over a 3-year period, 2000 through to 2002 in the Department of Anatomy, Firat, Yuzuncu Yil and Ataturk University, Turkey. Developmental anomalies and the variants of the first vertebrae were investigated on 86 atlas. Ponticulus posterior was observed with a low frequency on right as 2.3%. The bilateral localization was 10.5% and the left-side localization was 9.3%. Ponticulus lateralis showed an equal localization as 1.2% on the right, 1.2% on the left and 1.2% bilateral. In the present study, a complete subdivision of the joint surface was observed in 11 atlases [12.8%]. Processus infratransversarius atlantis with a frequency between 1.2-7%, arthrotic formation and corona atlantis peridentals in 8 cases [9.3%] were also found. The low frequency for fonticulus posterior might be peculiar to the population living in this area

Agenesia del arco posterior del atlas y fusión de su arco anterior al occipital. Informe de un caso con reconstrucción tridimensional por tomografía axial computada / Congenital absence of the posterior arch of the atlas and bony fusion of its anterior arch to the occipital. Tridimentional reconstruction by computarized tomography. Case report

Se presenta el caso asintomático de un soldado de 22 años con agenesia del arco posterior del atlas y con su arco anterior fusionado al occipital en presencia de la apófisis odontoides del axis normal. El defecto fue detectado fortuitamente en la radiografía lateral de la columna cervical cuando el paciente ingresó al Hospital Central Militar de México por traumatismos múltiples y fractura expuesta del olécranon izquierdo. La malformación se representa en este estudio con reconstrucción tridimensional por tomografía axial computada, donde puede verse la cara posterior al cuerpo del axis y su apófisis odontoides sin la presencia del arco posterior del atlas. Se considera la posibilidad de desarrollar un catastro cervical prospectivo, puesto que la literatura informa de defectos congénitos de la región cráneo-cervical sin evidencia de indicios exteriores.