TMSS Medical College Journal

Background: Morphological variations occur frequently in the lower region of the vertebral column, and the sacrum is the most variable portion. The present study was undertaken to analyze the morphometric characteristics of the sacral hiatus and its sex differences to provide baseline data for the northern region of Bangladesh. Materials and Methods: A cross-sectional observational study was conducted among 100 dry adult human sacra collected from the Department of Anatomy, TMSS Medical College and Shaheed Ziaur Rahman Medical College, Bogura. Data were recorded using a pre-designed questionnaire prepared for the study. Sex determination was done by using discriminant function analysis (DFA) and found 43 male and 57 female sacra. Location and shape of sacral hiatus were observed and noted. With the help of digital slide calipers, different measurements of sacral hiatus were recorded to the nearest millimeter. Results: The most common shape of sacral hiatus was found as inverted U shaped in both sexes and it was 48.84% in male and 44.83% in female. The second common type was inverted V shaped, and the frequency was 23.26% and 25.86% in male and female respectively. Location of apex of sacral hiatus at the level of 4th sacral vertebra was found most commonly, 67.44% in male and 56.90% in females. In most of the sacra, location of base of the sacral hiatus was found at the level of 5th sacral vertebra; 95.35% in male and 91.38% in female. Regarding different other parameters of sacral hiatus there was no statistically significant difference between male and female sacra. Conclusion: Though findings of the present study regarding different parameters of sacral hiatus were not statistically different between male and female, it can provide baseline data associated with clinical application in caudal epidural block.