OPTIMAL MESH CRITERIA IN FINITE ELEMENT MODELING OF HUMAN FOOT: THE DEPENDENCE FOR MULTIPLE MODEL OUTPUTS ON MESH DENSITY AND LOADING BOUNDARY CONDITIONS

The use of finite element models has gained popularity in the field of foot and footwear biomechanics to predict the stress–strain distribution and the treatment effectiveness of therapeutic insoles for pathological foot conditions. However, a comprehensive evaluation of mesh quality is often ignored, meanwhile no golden standard exists for the mesh density and selection of element size at an acceptable accuracy. Here, we make a convergence test and established anatomically-realistic foot models at different mesh densities. The study compared the discrepancy in output variables to the changes of element type and mesh density under barefoot and footwear conditions with compressive and shear loads, which are commonly encountered in foot and footwear biomechanics simulations. For a range of loading conditions simulated in 125 finite element models, the peak plantar pressure consistently converged with optimal mesh size determined at 2.5[Formula: see text]mm. The convergence variable of principal strains and stress tensors, however, varies significantly. The max von-Mises stress showed strong sensitive behavior to the changes of the mesh density. The pattern for contact pressure distribution became less accurate when the element sizes increase to 6.0[Formula: see text]mm; in particular, the locations of the pressure peak do not show remarkable changes, but the size of the area of contact still changes. The current study could offer a general guideline when generating a reasonable accurate finite element models for the analysis of plantar pressure distributions and stress/strain states employed for foot and footwear biomechanics evaluations.

Pelvic organ prolapse and uterine preservation: a cohort study (POP-UP study)

Background Abdominal and laparoscopic sacro-colpopexy (LSC) is considered the standard surgical option for the management of a symptomatic apical pelvic organ prolapse (POP). Women who have their uterus, and for whom an LSC is indicated, can have a laparoscopic sacro-hysteropexy (LSH), a laparoscopic supra-cervical hysterectomy and laparoscopic sacro-cervicopexy (LSCH + LSC) or a total laparoscopic hysterectomy and laparoscopic sacro-colpopexy (TLH + LSC). The main aim of this study was to compare clinical and patient reported outcomes of uterine sparing versus concomitant hysterectomy LSC procedures. Methods A retrospective analysis of clinical, imaging and patient reported outcomes at baseline, 3 and 12 months after LSH versus either LSCH + LSC or TLH + LSC between January 2015 and January 2019 in a tertiary referral urogynecology center in Pilsen, the Czech Republic. Results In total, 294 women were included in this analysis (LSH n = 43, LSCH + LSC n = 208 and TLH + LSC n = 43). There were no differences in the incidence of perioperative injuries and complications. There were no statistically significant differences between the concomitant hysterectomy and the uterine sparing groups in any of the operative, clinical or patient reported outcomes except for a significantly lower anterior compartment failure rate (p = 0.017) and higher optimal mesh placement rate at 12 months in women who had concomitant hysterectomy procedures (p = 0.006). Conclusion LSH seems to be associated with higher incidence of anterior compartment failures and suboptimal mesh placement based on postoperative imaging techniques compared to LSC with concomitant hysterectomy.

Pelvic organ prolapse and uterine preservation: A cohort study (POP-UP study)

Background: Abdominal and laparoscopic sacro-colpopexy (LSC) is considered the standard surgical option for the management of a symptomatic apical pelvic organ prolapse (POP). Women who have their uterus, and for whom an LSC is indicated, can have a laparoscopic sacro-hysteropexy (LSH), a laparoscopic supra-cervical hysterectomy and laparoscopic sacro-cervicopexy (LSCH+LSC) or a total laparoscopic hysterectomy and laparoscopic sacro-colpopexy (TLH+LSC). The main aim of this study was to compare clinical and patient reported outcomes of uterine sparing versus concomitant hysterectomy LSC procedures. Methods: A retrospective analysis of clinical, imaging and patient reported outcomes at baseline, 3 and 12 months after LSH versus either LSCH+LSC or TLH+LSC between January 2015 and January 2019 in a tertiary referral urogynecology center in Pilsen, the Czech Republic. Results. In total, 294 women were included in this analysis (LSH n = 43, LSCH+LSC n = 208 and TLH+LSC n = 43). There were no differences in the incidence of perioperative injuries and complications. There were no statistically significant differences between the concomitant hysterectomy and the uterine sparing groups in any of the operative, clinical or patient reported outcomes except for a significantly lower anterior compartment failure rate (p= 0.017) and higher optimal mesh placement rate at 12 months in women who had concomitant hysterectomy procedures (p = 0.006).Conclusion. LSH seems to be associated with higher incidence of anterior compartment failures and suboptimal mesh placement based on postoperative imaging techniques compared to LSC with concomitant hysterectomy.

Deep Learning Driven Self-adaptive Hp Finite Element Method

The finite element method (FEM) is a popular tool for solving engineering problems governed by Partial Differential Equations (PDEs). The accuracy of the numerical solution depends on the quality of the computational mesh. We consider the self-adaptive hp-FEM, which generates optimal mesh refinements and delivers exponential convergence of the numerical error with respect to the mesh size. Thus, it enables solving difficult engineering problems with the highest possible numerical accuracy. We replace the computationally expensive kernel of the refinement algorithm with a deep neural network in this work. The network learns how to optimally refine the elements and modify the orders of the polynomials. In this way, the deterministic algorithm is replaced by a neural network that selects similar quality refinements in a fraction of the time needed by the original algorithm.

Pelvic organ prolapse and uterine preservation: A case control study (POP-UP study)

Background: Abdominal and laparoscopic sacro-colpopexy (LSC) is the preferred surgical option for the management of a symptomatic apical pelvic organ prolapse (POP). Women who have their uterus, and for whom an LSC is indicated, can have a laparoscopic sacro-hysteropexy (LSH), a laparoscopic supra-cervical hysterectomy and laparoscopic sacro-cervicopexy (LSCH+LSC) or a total laparoscopic hysterectomy and laparoscopic sacro-colpopexy (TLH+LSC). The main aim of this study was to compare clinical and patient reported outcomes of uterine sparing versus concomitant hysterectomy LSC procedures. Methods: A retrospective analysis of clinical, imaging and patient reported outcomes at baseline, 3 and 12 months after LSH (cases) versus either LSCH+LSC or TLH+LSC between January 2015 and January 2019 in a tertiary referral urogynecology center in Pilsen, the Czech Republic. Results. In total, 294 women were included in this analysis (LSH n = 43, LSCH+LSC n = 208 and TLH+LSC n = 43). There were no differences in the rates of perioperative injuries and complications. Operating time and blood loss were higher in the concomitant hysterectomy compared to the uterine sparing group but this was only significant when comparing LSH to TLH+LSC (p = 0.048). There were no statistically significant differences in any of the clinical or patient reported outcomes except for a significantly lower anterior compartment failure rate (p= 0.017) and higher optimal mesh placement rate at 12 months in women who had concomitant hysterectomy procedures (p = 0.006).Conclusion. LSH is associated with shorter operative time and intraoperative blood loss; nevertheless, higher rates of anterior compartment failures and suboptimal mesh placement.