A Morphometric and Radiological Study of Sacral Hiatus in Human Adult Sacra and Its Clinical Relevance in Caudal Epidural Anaesthesia

Radiographic assessment of sacral hiatus anatomy with backache

Objectives

To determine hiatal variations in cases of backache and controls on radiographs and association of age groups with hiatal parameters in patients with backache versus normal individuals.

Methods

This case control study on 178 patients (89 cases and 89 controls), aged from 18-65 years, selected by non-probability convenience sampling was conducted at Radiology Department of PNS Shifa Hospital, Karachi over six months.The sacral hiatus was identified on lumbosacral spine radiographs. Both metric and non-metric parameters of hiatus with respect to sacral vertebra were noted and compared between the groups.

Results

Inverted "U" was the most common type observed in cases with base of hiatus at S5 level. Comparison of hiatal shape among different age groups showed inverted "U" and inverted "V" types among all age groups. Hiatal anteroposterior diameter and width were greatest in 36-45-year age group, and it was longest in 46-55-year age group. Determination of relationship between sacral hiatal parameters and incidence of low back pain showed positive association of inverted "U" and "M" shapes with back pain. Increased risk of back pain was observed with high apex (first sacral vertebra (S1)).

Conclusion

Strong positive correlation was determined with inverted "U" and "M" shapes, and level of apex at S1 with low backache.

Sacralization of Coccygeal Vertebra: A Descriptive Observational Study in Bangladesh

Background: In the sacrococcygeal region, anatomical variation is due to the sacralization of the coccygeal vertebra, which is the due union of/fusion of the fifth sacral with the first coccygeal vertebra of five couples of sacral foramina under-detected or asymptomatic beyond radiological assessment. That is why it is challenging to know the cause of coccydynia, caudal block failure, the difficult second stage of labor, and perineal tears. The present study aims to improve knowledge about the anatomical variation of sacralization of the coccygeal vertebra. Additionally, to find the prevalence of sacralization of coccygeal vertebra in Sylhet, Bangladesh.

Methods: This study was performed on 60 parched, totally calcified, typical sacra of mature-age individuals of undetermined sexes, fulfilling the inclusion criteria from the bone bank of the osteology museum of the Department of Anatomy, Sylhet MAG Osmani Medical College, Sylhet, Bangladesh, from July 2017 to June 2018. Sex determination of the collected unknown sacra was conducted using discriminant function analysis. It was found that 50% (30) were male and 50% (30%) were female. The unpaired t-tests and chi-square were utilized to determine the statistical significance.

Results: Out of 60 sacra, eight (13.33%) samples presented with sacralization. This study found that males had significantly higher straight (p=0.05) and curved (p=0.05) lengths of sacrococcygeal vertebrae. The sacrococcygeal curvature index (SCI) showed statistically significant (p=0.05) differences between the sexes.

Conclusion: Sacralization may exert an impact on the caudal block. It could extend the second stage of the labor process with perineal tears. Therefore, knowledge about the anatomical variation of the coccygeal vertebra is essential.