Abstract
OBJECTIVES: Spina bifida occulta (SBO) is a congenital spinal defect characterised by incomplete closure of the posterior neural arch. Despite its clinical relevance, discrepancies remain in the published literature. This study aimed to determine the distribution pattern and prevalence of SBO in the Northern Indian population using three-dimensional reconstructed specimens of the lumbosacral spine. METHODS: This retrospective study was conducted between March 2023 and November 2024 at the All India Institute of Medical Sciences Patna, India. A total of 241 computed tomography (CT) scans of the spine from patients aged over 18 years were analysed. Three-dimensional images were reconstructed using DICOM to Print and Geomagic Freeform Plus software to assess the presence of SBO in the lumbosacral spine. RESULTS: SBO was identified in 48 specimens. Of these, 30 involved the S1 vertebral level, while 8 demonstrated a defect extending from S1 to S5. The overall prevalence of SBO was 19.91% (95% confidence interval: 15.18-25.64%). The defect was significantly more common in males (P = 0.042). A statistically significant association was also observed between SBO and transitional vertebrae (P = 0.00001). CONCLUSION: Awareness of SBO has important implications for surgical practice. A comprehensive understanding of fusion failure in the spinal column is essential for accurate diagnosis and effective treatment. This congenital defect should be carefully considered before performing caudal epidural blocks to reduce the risk of dural puncture.