A finite element analysis of different postures and intra-abdominal pressures for the uterine ligaments in maintaining the normal position of uterus

Uterine prolapse is a common gynecological disease, which seriously affects the quality of life and physical and mental health of elderly women. The aim of this study was to analyze the influence of different conditions (intra-abdominal pressure (IAP) and posture) on stress and displacement of uterine ligaments using the finite element method, and evaluate the contribution of uterine ligaments on uterus. The three-dimensional (3D) models of retroverted uterus and its accessory ligaments were established, loads and constraints were set in ABAQUS software, and the stress and displacement of uterine ligaments were calculated. The uterine displacement increased with the increase of IAP, and then the stress and displacement of each uterine ligament also increased. The uterine displacement was in the order of forward < upright < backward with different postures, and USL, CL and RL got larger values when the body was backward, while BL got a larger value when the body was forward. With the same condition, the stress of the uterine ligaments was in the order of USL > BL > CL > RL, and the displacement of the ligaments was in the order of BL > RL > USL > CL. The contribution of each uterine ligament changing with different IAP and postures was studied through finite element analysis, and the research results were consistent with the clinical data, which can provide a basis for exploring the mechanism of uterine prolapse.