Lateral Ponticle Prevalence in 754 Atlas Vertebrae: A South African Skeletal Population

Background: A lateral ponticle (LP) is an anatomical variation on the atlas vertebra of the cervical spine. An anomalous bony bridge extends between the lateral mass and the transverse process on one or both sides, forming a supratransverse foramen. This study aimed to determine the prevalence of LP in a previously unstudied South African skeletal population. Methods: Nine hundred and forty-nine adult skeletons were appraised, and after applying exclusion criteria, the sample was 754 atlases (529 males and 225 females). The atlases were stored in the Pretoria Bone Collection at the University of Pretoria, South Africa. Data were analyzed for prevalence, frequency of side, sex, population affinity, and age. Results: A partial or complete LP was observed in 4.6% of atlases (n = 35). LP was most prevalent on the left side (42.9%), followed by the right (37.1%) and bilateral presentation (20.0%). Complete bridging (34.3%) was more common than partial bridging (28.6%). LP was marginally more common in females than in males (5.0% vs. 4.5%; P = 0.0434). Notably, 68.6% of LP-containing atlases had a concomitant arcuate foramen (AF). Significant associations were found between the presence of LP and AF (P = 0.000) and the bilateral presentation of AF when LP was present (P = 0.000). Conclusions: This study sampled the second-largest South African skeletal repository, finding a prevalence of 4.6%. An LP was more frequent in females, presented more often on the left side, and had a higher incidence of complete bridging. Clinically, these results aid in morphological recognition and may contribute to mitigating adverse events in clinical practice.