STUDY OF DORSAL SURFACE OF SACRUM

Abstract

Introduction: Sacrum is a large triangular bone formed by fusion of five sacral vertebrae. It is place as a wedge between two innominate bones at superior posterior part of pelvic cavity. There is an opening present at the caudal end of sacral canal called sacral hiatus. It is formed by the nonfusion of the lamina of the fifth (occasionally fourth) sacral vertebra. For the perception it is bony concavity laid the sacred organs of procreation, the ovaries and uterus. The sacrum is usually last bone of a buried body to disintegrate because of its greater size.  Some evidence of the archaeology reported that to support the use of sacrum as a vessel to hold the sacrifice in ancient sacred rites. In the ancient period of Egypt it was considered as “Osiris” the god of resurrection and of agriculture. The application on knowledge and its Clinical application depend on availability of the variations seen in the sacrum. There are important when interpreting the radiographs and when considering the particular sites of the pathological features of bone and soft tissue. Therefore on the basis of surface anatomy sacral region is supposed to be an important aspect.

Objective: The main objective of this study is to observed the variations of sacral hiatus in both sex that help for better reliability of caudal epidural block.

Material and method: In this study total 100 human dry sacra of both sexes were used which was divided as male and female as 50 each. Morphometrical studies of dorsal surface of sacrum were done with respect to different parameters like level of sacral hiatus, composition of sacrum and deficiencies and apertures level of apex & base of sacral hiatus.

Result:  Level of apex of sacral hiatus at S4 (62%) was most common.  5% of the cases were Elongated sacral hiatus at the level of S2. 70% of cases showed normal 5 segments whereas 4 segmented sacra were observed in 4% of cases and 6% in sacralization of 5th lumbar vertebra and 20% as coccygeal ankylosis. Normal sacral cornua on both sexes were present in 41% followed by unilateral cornua in 21%.  13% of the cases showed absent of Sacral cornua and 25% cases of sacra showed deficiencies apertures in the bony dorsal wall of sacral canalwhich is most prevelanve to male gender. 

Conclusion:  Dorsal wall of sacrum has various anatomical variations. Hence there is a great importance of the normal sacral hiatus and their variation is of great clinical significance. These variations improved understanding reliability and success of caudal epidural anesthesia. The features of sacral hiatus associated with sexes reflected the structural and functional differences sacra and pelvis in both sexes.

Keywords: Sacral hiatus, Sacral canal, Sacrum, Caudal epidural anesthesia (CEA)