Study of the Level at which the Sacral Hiatus Opens in South Indian Population

The sacrum is a triangular bone which is formed by the fusion of five vertebrae and forms the posterosuperior wall of the pelvic cavity. The bone is wedged between two hip bones. Rostrally the bone articulates with the fifth lumbar vertebrae and caudally it articulates with coccyx. The spines of the sacral vertebrae are fused to form the medial sacral crest. The medial sacral crest presents below a sacral hiatus which is arched and is produced by the failure of the lamina of the fifth sacral vertebra to meet in the median plane. If the laminae of the higher sacral vertebrae are not fused, then the hiatus will be seen at a higher level.100 Sacrum were observed and the level at which the sacral hiatus opens is reported. Orthopaedicians and anaesthetists need to be aware of such conditions and their frequency in the local populations because the success of caudal epidural anaesthesia and analgesia depends on the anatomical variations of sacral hiatus.