Relationship between the shape of the obturator foramen and the shape of the pelvic cavity in adult women

Abstract
Objectives: There is variable information on the efficiency of surgical treatment of urinary incontinence (SUI). To date, there is no common understanding of the role of variations in the pelvic anatomy for the success of surgical treatment of SUI. The aim of the present study was to investigate the relationship between the morphometric characteristics of the pelvis, and particularly the shape of the obturator foramen with the shape of pelvic cavity, in adult women. Methods:Sixty-one articulated specimens of female pelvis from the bone collection of the Museum of the St. Petersburg Military Medical Academy named after S.M. Kirov were studied. A pelviometric form was developed, according to the linear and angular parameters of the pelvis and the obturator foramen, and indices of the pelvic cavity and the obturator foramen were evaluated. The discriminant analysis was used to determine the parameters that have the greatest effect on the shape of the obturator foramen. Results: Based on the calculated indices of the pelvic cavity, the form of the pelvic cavity was determined as: narrowing downwards, cylindrical, and expanding downwards. For pelviometric parameters, for each form of the pelvic cavity, significant differences were defined, and a wide range of anatomical variations anatomy were also demonstrated. A mathematical model for predicting the shape of the obturator foramen was developed with the help of the discriminant analysis. At the same time, two main forms of the obturator foramen were marked out as triangular and ellipsoid. The triangular form was predominantly found in cylindrical and narrowing downwards pelvis groups, and the ellipsoid form dominated in the expanding downwards group. Conclusion: Longitudinal and transverse indices of the pelvic cavity may allow us to determine its shape as narrowing downwards, cylindrical or expanding downwards. The obturator foramen has a typical shape in each particular configuration of the pelvis.