3D simulation of pelvic system numerical simulation for a better understanding of the contribution of the uterine ligaments.

ABSTRACT

INTRODUCTION AND HYPOTHESIS: Genital prolapse remains a complex pathological condition. Physiopathology remains poorly understood, aetiology is multi-factorial, surgery is not always satisfying, as the rate of relapse cannot be overlooked. More over a good anatomical result will not always guarantee functional satisfaction. The aim of our study is to have a better understanding of the involvement of uterine ligaments in pelvic statics via 3D simulation. METHODS: Simulation of pelvic mobility is performed with a validated numerical model in a normal situation (standing up to lying down) or induced pathological ones where parts of the constitutive elements of the model are virtually "cut" independently. Displacements are then discussed. RESULTS: Numerical results have been compared with dynamic MRI for two volunteers. Dynamic sequences had 90 images, and 180 simulations have been validated. Results are coherent with clinical data and the literature, thus validating our mechanical approach. Uterine ligaments are involved in pelvic statics, but their lesions are not sufficient to generate a genital prolapse. Round ligaments play a part in uterine orientation; the utero-sacral ligaments support the uterus when standing up. CONCLUSIONS: Pelvic normal and pathological mobility study via modelling and 3D simulation is a new strategy in understanding the complex multifactorial physiopathology of genital prolapse. This approach must be validated in a larger series of patients. Nevertheless, pelvic ligaments seem to play an important role in statics, especially, in agreement with a literature survey, utero-sacral ligaments in a standing position.