Assessment of Morphological and Morphometrical Variations of Sacral Hiatus in Dry Human Sacrum in Ethiopia.

Background: The sacral hiatus is an opening present at the lower end of the sacral canal. The anatomy of the sacral hiatus and its variations are clinically important during administration of caudal epidural block (CEB) in obstetrics and gynecology, orthopedic, urology and general surgical practices. The success and reliability of CEB depends upon the sound knowledge of anatomical variations of the sacral hiatus.

Objective: The aim of this study was to assess the morphological and morphometric variation of the sacral hiatus in dry human sacrum.

Methods: An institution-based observational cross-sectional study design was conducted to assess morphological and morphometric variations of the sacral hiatus in 61 dry human sacrum specimens at the anatomy departments of Gondar, Addis Ababa, Hawassa and Jimma universities and Hayat and Korea Medical Colleges in Addis Ababa. Descriptive analysis was applied to analyze the data.

Results: The most commonly recorded shape of the sacral hiatus is inverted-V (41%) followed by inverted-U (37.7%). The least common was complete bifida (1.6%). The apex of the sacral hiatus is mostly seen at the level of the 4th sacral vertebra (60.7%), while the base is commonly located at the level of the 5th sacral vertebra (78.7%). The mean length of the sacral hiatus is 22.67 ± 11.84 mm. The mean transverse width and mean anteroposterior diameter of the sacral hiatus at the apex are 13.14 mm ± 2.85 mm and 5.57 mm ± 1.53 mm, respectively.

Conclusion: The sacral hiatus has anatomical variations. These variations should be kept in mind during administration of caudal epidural anesthesia and analgesia.