Biomechanical Evaluation of Uterine Morphology and Tissue Mechanical Properties in a Computational Model of the Pelvic Cavity

Female pelvic organ prolapse (POP) is a gynecological disorder characterized by pelvic organ descent that significantly impacts quality of life. With increasing global burden, approaches for early diagnosis are essential. This study illustrates a patient-specific computational model of the pelvic cavity, updating the uterine and cervical geometric model and assigning cervical tissue properties. Three distinct uterine geometric models were assembled, based on literature measurements and magnetic resonance images for comparison and validation. Human cervical properties were extrapolated from biomechanical testing of ovine pelvic tissues. Finite elements simulations of the Valsalva maneuver were conducted to analyze the biomechanical effects of varying uterine morphology and tissue properties on the pelvic cavity, including the bladder neck, vagina, and uterosacral ligaments (USLs). Results show that a uterus with softer properties assigned exhibits less vertical displacement and relies more on USLs support than a stiffer one. Furthermore, uterine volume and morphology significantly influence pelvic dynamics: a larger uterus tends toward anteversion, while a smaller uterus increases vertical vaginal displacement (10.57 mm vs 6.04 mm) and requires greater USLs support. Anatomical variations directly constrain bladder neck displacement. These computational advancements aim to enhance patient-specific modeling, assisting clinical decision-making.