Dorsal sacral dimensional anatomy-revisited.

ABSTRACT

Background: Determination apex of sacral hiatus (SH) is of paramount importance to Anaesthetists, Orthopaedicians, Obstetricians and Gynaecologists for caudal epidural block (CEB). Dorsal sacral dimensions were therefore taken to facilitate them for easy location of SH. Methods: Following parameters of each of the sixty human sacra were measured using vernier calipers at the level of spinous process of second sacral vertebra (S2). a) Distance between the two supero-lateral crests b) Distance between the right supero-lateral crest level to the apex of sacral hiatus (SH) c) Distance between the left supero-lateral crest to the apex of SH d) Distance from the spinous process of S2 to the apex of SH e) Distance from the spinous process of S2 to the base of SH The data obtained was analysed statistically. Results: Mean of the distance between the two supero-lateral crests was 51 ± 6.37 mm and 52.7 ± 5.30 mm in males and females respectively, mean of the distance between the right supero-lateral crest and the left supero-lateral crest to the apex of SH was 45.91 ± 6.94 mm in males 42.50 ± 11.23 mm in females and 44.74 ± 6.77 mm in males and 42.50 ± 10.97 mm in females respectively , vertical distance from spinous process of S2 to the apex of SH in males and females was 38.83 ± 9.33 mm and 32.4 ± 1.64 mm respectively. Vertical distance from spinous process of S2 to the base of sacral hiatus was 59.20 mm ± 10.81 mm in males and 52.80 ± 9.18 mm in females. Conclusion: From the data obtained it was concluded that an isosceles triangle was formed between the two supero-lateral crests at the level of spinous process of S2 and the apex of SH.