Introduction: Anatomy of the sacral hiatus is having clinical importance during caudal epidural block. Present study is aimed at determining anatomy of sacrum specially sacral hiatus for caudal epidural block, with the help of morphometric measurements of the sacrum in relation to sacral hiatus in dry sacral bones.
Material & method: Total 103 complete and undamaged adult, dry sacral bones were measured with Vernier caliper (accuracy 0.1 mm) and anatomical measurements were obtained.
Results: Three bones were excluded because of total posterior closure defect. Agenesis of the sacral hiatus was detected in three sacral bones. Right and left superolateral sacral crests of the sacrum were taken as two points on dorsal surface of sacrum (forming the base of a triangle) because posterior superior iliac spines impose on the superolateral sacral crests. The distance between the two superolateral sacral crests (base of a triangle), the distances between the right and left superolateral sacral crest and the sacral apex were on average 60.61(SD 6.71), 61.95 (11.71) and 61.4 (11.98) mm respectively..
Summary: An equilateral triangle formed between the apex of the sacral hiatus and right and left superolateral sacral crests. This equilateral triangle will help in determining the location of the sacral hiatus during caudal epidural block.
Caudal epidural block; Sacrum, Sacral apex; Sacral hiatus