Author: Ukoha Ukoha U, Okafor Joseph I, Anyabolu Arthur E, Ndukwe Godwin U, Eteudo Albert N, Okwudiba Nchedo J
Background: The sacrum is a large triangular bone formed by the fusion of the five sacral vertebrae and forms the caudal region of the vertebral column. Aims: This was aimed at studying the morphometry of the sacral hiatus noting its anatomical variations that is useful in caudal epidural anaesthesia. Materials and Methods: Eighty three intact adult sacra of unknown sex were measured with vernier callipers and the various shapes of the sacral hiatus were also noted. Results: The findings revealed that inverted U (48.2%) was the most predominant shape; followed by inverted V (34.9%), dumbbell (4.8%), bifid (4.8%) and irregular (4.8%). The mean anteroposterior diameter at the apex was 5.52 ± 1.89mm. The mean length of the sacral hiatus was 20.05 ± 9.22mm and the transverse width at base of hiatus was 12.35 ± 3.12mm. There was complete spina bifida in 1.2% and absence of sacral hiatus in another 1.2%. Conclusion: The knowledge of anatomical variations of sacral hiatus is important in the administration of caudal epidural anaesthesia in the studied population and may help to reduce its failure rate.
Keywords: Sacral hiatus, caudal epidural block (CEB), sacral vertebra.