Arcuate foramen prevalence in South African subjects: A cadaveric study based on 120 atlas vertebrae

Background: This study was a prospective cadaver-derived skeletal study looking at the skeletal remains of a modern human population. The complete arcuate foramen (AF) is an anatomical variant of the atlas vertebra with a complete osseous bridge over the groove for the vertebral artery (VA). Awareness of the anatomic variations of the atlas related to the course of the VA, such as the AF, is important because the course and variations of VAs are critical to spine surgeons. We aimed to detect the prevalence of AF in sub-Saharan African subjects. Materials and methods: We analyzed the prevalence of AF in 120 atlas vertebrae from the Raymond A Dart Collection of the University of the Witwatersrand, Johannesburg, South Africa. Results: Twelve (13.3 %) atlases of the 90 that were from sub-Saharan African ancestry subjects presented at least one AF: the presence of AF frequency was 6.7 % in the Sotho sample, 23.3 % in the Xhosa sample and 10.0 % in the Zulu sample. However, no significant difference was found in their distribution regarding the presence of AF ratios (p = 0.221). The AF frequency was 3.3 % in the South African Caucasian subjects. No significant differences were found in their distribution regarding the presence of AF ratios between the Caucasian and the Sotho (p = 1.000), Zulu (p = 0.612) and Xhosa (p = 0.052) samples. Conclusions: Our research shows a tendency for a higher AF presence in Xhosa subjects. It has increased the knowledge of the AF prevalence in sub-Saharan Africa, drastically increasing the population.