Anatomic basics and technical approaches: sacral preauricular extensions, preauricular sulci and dorsal pubic pits in modern anatomical specimens.

The aim of this study is the evaluation of three selected osseous pelvic features in modern anatomical specimen - the sacral preauricular extension, the preauricular sulcus and pits on the dorsal side of the pubic bone laterally to the symphysis. The specificity and significance of these features are under debate and their genesis is largely unclear. Descriptive data of specific soft tissue structures surrounding the anterior sacroiliac joint gap and the pubic symphysis were generated by assessing 20 fresh pelves and 12 embalmed hemipelves from human body donors. Computed tomography (CT) was performed on all specimens and three-dimensional (3D) surface models were generated and analysed. Afterwards, all the specimens underwent anatomical dissection and finally maceration. During dissection, it became apparent that the anterior sacroiliac ligament, due to its position, shape and potential impact on the sacroiliac joint and adjacent osseous structures, requires a detailed analysis of its dimension. The most promising result, in terms of the sacral preauricular extension, was that the measurements of the triangular part of the anterior sacroiliac ligament were significantly longer in females than in males. Pelvic floor muscle fibres and fascial parts were directly connected to this ligament in some specimens, which is an important starting point for a larger in-depth study. The evaluation of the anatomic structures in connection to dorsal pitting refutes the assumption that the pelvic floor muscles or fasciae could exert influence on its formation. A histological evaluation of the ligaments of the pubic symphysis, especially the dorsal pubic ligament, would be expedient to clarify the etiology of this feature.