The Retrotransverse Foramen of the Atlas Is not a Modern Anatomic Variation.

ABSTRACT

BACKGROUND: The retrotransverse foramen (RTF) is a nonmetric variant of the atlas vertebra that consists of an abnormal accessory foramen located on the posterior root of the transverse process and it extends from the posterior root of the transverse process to the root of the posterior arch. Its presence has been related to regional variations of the venous circulation. It is currently unknown whether the RTF is a modern or an ancient anatomic variation. CASE DESCRIPTION We analyzed the skeletal remains from the late-ancient Roman necropolis (II-VI centuries ad) of La Boatella (Valencia, Spain) and we found a well-preserved individual skeleton that presented with a left retrotransverse foramen in C1. CONCLUSIONS: The RTF is not a modern anatomic variation. As a result, ancient individuals had the same modifications in the regional circulation as modern subjects present today.