The Effect of Pubococcygeus Muscle Avulsion on the Anterior Vaginal Wall Support: A Biomechanical 3D Finite Element Modeling Study

Levator ani muscle defects are common in women after vaginal birth and have been associated with the development of pelvic organ prolapse (Kearney et al 2006, DeLancey et al 2007, and Dietz and Lanzarone 2005). Sometimes there is a loss of muscle substance but the overall shape of the muscle remains intact. In other instances, gross distortion of the muscle origin occurs (Huebner et al. 2008) presumably due to avulsion of muscle from the pubic bone. Theoretical biomechanical modeling work has showed that even with intact pubic origin, weakening of levator ani muscle leads to the development of cystocele (Chen et al, 2009). The biomechanical effects of avulsion of the pubic origin of the pubococcygeal muscle have not been fully explored. The objective of this study if to use a finite element model to perform a biomechanical analysis of how pubococcygeus muscle avulsion affects the descent of the anterior vaginal wall during a Valsalva.