The Shape of the Greater Sciatic Foramen in Adults Based on Computed Tomography Data

The greater sciatic foramen (GSF) is a passageway for important neurovascular bundles of the pelvis and lower limb, making it a potential site for compression of these structures. Investigating the features of morphological variability in this region helps to identify the predisposing factors for neurological disorders, optimizes surgical approaches, and reduces the number of iatrogenic injuries to blood vessels and nerves. The aim of the study is to evaluate the variability in the shape of the bony margins of the greater sciatic foramen, characteristic of mature adult males and females, for subsequent application in clinical practice. Material and methods . The results of multispiral computed tomography scans of 70 patients aged 20–59 years were analyzed; linear and angular parameters of the foramen were determined on three-dimensional pelvic models . Geometric morphometrics was used to analyze the configuration of the GSF based on 20 landmarks placed on its bony margins. Results . Based on the linear and angular dimensions, four main shapes of the GSF were identified: deltoid, parallelogram, trapezoid, and irregular quadrilateral. It was established that the deltoid shape is statistically significantly more common in women, while the parallelogram shape is more common in men. The incidence of the trapezoid and irregular quadrilateral shapes did not differ significantly between the sexes. The geometric morphometric analysis revealed significant sex-related differences in the shape of the GSF. These variations are concentrated along a single canonical axis and are determined by the shape of the greater sciatic notch of the hip bone. Males are characterized by greater depth and concavity in the superior part of the notch, whereas females exhibit greater depth and concavity in its inferior part. Conclusion . Currently, there is no universal reference method for the precise determination of the GSF shape. The most reliable results can only be achieved through an integrated approach that combines traditional linear measurements with modern geometric morphometric methods.