The ponticulus of the atlas vertebra: A systematic review and meta-analysis of its prevalence with its surgical relevance

A detailed understanding of the anatomical variations of the Atlas is essential to prevent adverse clinical outcomes during a cervical spine surgery. The Ponticulus Posticus (PP) and Ponticulus Lateralis (PL) are among these anatomical variations. This study aims to provide the most comprehensive assessment of the prevalence of PP and PL, based exclusively on extractable CT imaging data. We searched online databases for studies reporting on the prevalence of PP and PL. Forty-three studies, including data from 31587 patients, met the inclusion criteria. We then used meta-analysis techniques to estimate the prevalence of these anomalies. Forty-three studies ( n = 31,587) reported data on the prevalence of PP, with an overall prevalence of 21 %, which was more common in men (24 %) than in women (21 %). Unilateral and bilateral PP both had a prevalence of 10 %, and incomplete PP (18 %) was more common than the complete form (14 %). Six studies ( n = 9748) reported data on the prevalence of PL, with an overall prevalence of 5 %, which was more common in men (3 %) than in women (2 %). The unilateral PL configuration (4 %) was more common than the bilateral configuration (1 %). This systematic review and meta-analysis evaluated the prevalence and morphometry of PP and PL, finding PP to be common, while PL was rare. These variations are clinically important in cervical spine surgery, where advanced imaging like 3D CT angiography is essential. Future research should focus on underrepresented populations to enhance understanding. • Largest CT-based meta-analysis on prevalence of Ponticulus Posticus (PP) and Ponticulus Lateralis (PL). • An overall prevalence of 21 % for PP and 5 % for PL was observed across diverse populations. • A higher prevalence of left-sided PP was identified compared to right-sided configurations. • Incomplete PP (18 %) was found to be more common than the complete form (14 %). • The study underscores the importance of 3D CT imaging for ensuring safe cervical spine surgery involving PP and PL.