Experimentelle Bewertung der Spannungen und der zugehörigen Implantate bei anterioren Beckenfrakturen vom Typ I

Scientific Conference (2022, October 28)

Biomechanische Untersuchung zu verschiedenen Verfahren der Stabilisierung von Insuffizienzfrakturen des vorderen Beckenringes

Poster (2022, October 26)

INVESTIGATING THE INFLUENCE OF PERSONALIZED MUSCULOSKELETAL MODELS ON THE CALCULATED STRESSES IN THE PELVIC RING

Poster (2021, September)

This study investigates the influence of personalizing musculoskeletal models (MS) on muscles, contact joints forces and on stresses in the pelvic ring bones during normal gait loading cycle. All ... [more ▼]

This study investigates the influence of personalizing musculoskeletal models (MS) on muscles, contact joints forces and on stresses in the pelvic ring bones during normal gait loading cycle. All calculated forces are utilized to predict stress states in pelvis bones using Finite Element (FE) software. Customized MS models provides more precise muscle and contact forces. Additionally, it enables more automatic coupling between MS and FE environments by data transfer. [less ▲]

Numerical Assessment of two Implants for Pubic Ramus Fracture of human Pelvis applying Normal Gait loading

Poster (2020, October)

Fractures of the anterior pelvic ring reduce patients` mobility and independence and increase mortality. Pelvic instability impairs the load transfer to the lower extremity. Restoring stability has ... [more ▼]

Fractures of the anterior pelvic ring reduce patients` mobility and independence and increase mortality. Pelvic instability impairs the load transfer to the lower extremity. Restoring stability has therefore been a crucial point of research. Most of the reported studies refer to loading on one leg stand without consideration of physiological muscle and contact-joint forces of the common vital daily movements. Our present study considers physiological gait loading of all acting muscles and Hip Joint Contact (HJC) forces of the pelvis. Those muscles and HJC forces were calculated by inverse dynamics for normal gait motion data and applied in Finite Element Analyses (FEA). The biomechanical stability provided to the anterior pelvic ring by two reconstructive techniques was investigated numerically: the iliopubic Subcutaneous Plate (SP) and the Supra-Acetabular External Fixator (SAFE). Numerical biomechanical assessment of two reconstructive devices for pubic ramus fracture. All muscles and HJC forces of normal gait were calculated by means of inverse dynamics software for a healthy patient considering a musculoskeletal model previously validated experimentally. The Finite Element (FE) model was developed for a pelvis with and without superior and/or inferior rami fractures. Furthermore, two FE models for SP and SAFE mounted on the rami fractured pelvis were designed considering fixation bearing at the lumbosacral joint. The calculated forces were implemented on the FE models following the anatomical orientation and attachments/insertions of each muscle. During the two moments of the gait with higher stresses: Left Heel Strike (LHS) and Right Toe-Off (RTO), strains and displacements were recorded and investigated at the fracture location in addition to the implant fixation points. Considering only right superior ramus fracture during LHS and RTO, recorded strains and displacements for both implants showed similar results. However, during RTO, the SAFE showed a slight reduction of strains at the posterior location by 6% compared to SP. When including both superior and inferior right ramus fractures, both devices did not show considerable difference in recorded strains. However, there were significant differences in the displacements between fracture extremities. The SP technique reduced these motions for both LHS and RTO by 40% compared to the gold standard SAFE technique. In cases of superior ramus fracture only, displacements for both reconstructive devices were similar due to the remaining stability provided by the intact inferior ramus. Both devices reduced stresses of the sacrum wing in LHS and RTO with slightly better results for SAFE. In case of superior and inferior pubic ramus fractures, the SP technique reduced the frontal opening of the fractured right pubic bone. The SAFE did not provide any improvements compared to the SP technique. [less ▲]

Finite element analysis of the pelvis including gait muscle forces: an investigation into the effect of rami fractures on load transmission

in Journal of Experimental Orthopaedics (2018), 5(33), 1-9

An advanced approach to design experiments to investigate the biomechanics of the pelvis

Scientific Conference (2017)