Anatomical variations of sacral hiatus in dry human sacra

ABSTRACT

To observe anatomical variations of sacral hiatus in dry human sacra and its significance in caudal epidural block. An observational study. The study was conducted at Islamic International Medical College Rawalpindi from July 2011 to January2012. We studied 191 dry human sacra without discrimination of sex, geographical and ethnic group consideration. The bones were examined for various shapes of the sacral hiatus and level of apex and base of the sacral hiatus. Sacral cornua and median crest was also observed. The sacral hiatus were divided into six groups. [Group l-inverted U, group II- inverted V, group 111= irregular, group IV- M shape, group Vl-dumbbell shape]. SPSS 17 was used for the statistical analysis of the data. Out of 191 bones, inverted U shaped 76 [39%] and V shaped 56 [29%] sacral hiatus were most common and irregular 29 [15%] sacral hiatus was least common. Sacral cornua were prominent bilaterally in 83 [46.5%] bones while flat cornua were seen in 16 [9%]. The apex of hiatus was lying against 4th sacral vertebra in 129 [73%] bones while base of was present against 5th sacral segment in 183 [91%] of cases. The sacral hiatus has variations in shape. Inverted U shaped and inverted V shaped hiatus are most common shapes in dry human sacra. Sacral cornua are a reliable landmark in Caudal Epidural Block [CEB]