Filum Terminale

Objective: The purpose of the study was found out the anatomical variation in the sacral hiatus which is the sacral canal caudal opening. Its clinical significance is due to the fact that caudal epidural anesthesia is administered through the sacral hiatus and a knowledge of its anomalies is paramount to the success of epidural block. Materials and Method: This study was of three-month duration from September 2019 to December 2019 and was carried out at Khyber Medical College, Peshawar.48 dry sacra from the Anatomy department of Khyber Medical College were studied and the shape of their sacral hiatus was observed along with the level of its apex and base. Results: A total of 48 dry sacra were studied. The sacral hiatus shape was observed which revealed that it was inverted U shaped in 21 (43.8%) cases, inverted V shaped in 14 (29.2%) cases, irregular in 7 (14.5%) cases, M shaped in 4 (8.3%) cases and dumb bell shaped in 2 (4.2%) cases. In majority of the cases the apex was against the fourth sacral vertebrae and the base at the level of fifth sacral vertebrae. Conclusion: Anatomical variation does exist in the shape and size of sacral hiatus and a knowledge of variation in the shape, size, level of the apex and base of sacral hiatus is of importance to the clinicians as epidural anesthesia for therapeutic and diagnostic purposes is administered through the sacral hiatus.