A 3D finite element model of uterus support to evaluate mechanisms underlying uterine prolapse formation

Uterine prolapse (UP) seriously affects the quality of life and physical and mental health of elderly women, which can easily be caused by ligament injury or intra-abdominal pressure (IAP) increasing. The objective of this manuscript was to study the influence of IAP and ligament injury on uterus and its surrounding ligaments using the finite element method. First, the three-dimensional (3D) models of retroverted uterus and its surrounding ligaments were established, and loads and constraints were set in ABAQUS software, then the stress and deformation of uterine ligaments and uterine displacement were calculated. The study found that the uterine displacement and the stress and deformation of the ligaments increased when IAP and ligament injury increased alone or simultaneously. Then, the stress and sensitivity of the ligaments to the changes of IAP or ligament injury were in the order of uterosacral ligament (USL), broad ligament (BL), cardinal ligament (CL) and round ligament (RL), while the deformation and sensitivity the changes of the ligaments were in the order of BL > RL > USL > CL. Moreover, the ligament injury had a greater influence on the uterus and uterine ligaments than IAP. The results of this study can provide guidance for optimization of surgical scheme of uterus prolapsed in clinic and exploration of pathogenesis.