Moment of inertia as a means to evaluate the biomechanical impact of pelvic organ prolapse

Abstract

Objectives: To present an alternative measure (moment of inertia) to describe the anatomical features of the pelvic organ prolapse. Methods: A total of 30 women (21 diagnosed as having pelvic organ prolapse and 9 as controls) were evaluated by clinical scales and magnetic resonance imaging. Imaging biometric measures were carried out. Moment of inertia, pubovisceral muscle thickness and area, and levator hiatus anterior-to-posterior and lateral measures were compared by means of non-parametric tests, as well as their correlation with demographic features of the two sample groups. Results: Moment of inertia, muscle area and levator hiatus diameters were statistically different between patients and controls. Furthermore, they were also well correlated with prolapse-associated factors, such as the number of vaginal deliveries and age, as well as Pelvic Organ Prolapse Quantification system and imaging staging of levator ani defects. Conclusions: Moment of inertia can be used as a new parameter to evaluate pelvic floor damage resulting from prolapse. © 2012 The Japanese Urological Association.