Biomechanical Study of Different Fixation Techniques for Unstable Pelvic Fractures Using 3D Nonlinear Finite Element Models of Spine-Pelvis-Femur Complex and Biomechanical Experiments

Project: C - Project of Alliancel - National Taiwan University of Science and Technology

Description

Unstable pelvic fracture represents a severe injury associated with high morbidity and mortality. In the past, several types of fixators were used to treat this unstable fracture, including external fixators, plates, sacral bars, iliosacral screws, and pre-tensed curved bar. However, the biomechanical performances of the above fixation techniques were mainly evaluated according to the outcomes of clinical applications, and only one of the fixation techniques was selected and evaluated. To our knowledge, there were few studies to analyze and compare the biomechanical performances of different pelvic fixation techniques. In addition, the past studies had investigated one of the fixation techniques by using finite element methods. However, there has been no study that investigated the biomechanical performances of the fixation techniques by using 3D nonlinear finite element models of spine-pelvis-femur complex. Thus, the purpose of this study was to analyze and investigate the biomechanical performances of different pelvic fixation techniques for the treatment of unstable pelvic fracture.
Three-dimensional nonlinear finite element models of spine-pelvis-femur complex were developed to investigate the biomechanical performances of different pelvic fixation techniques by using ANSYS Workbench 14.5. Concurrently, the biomechanical experiment was developed to validate the numerical results. In this study, three types of the pelvic fixators were evaluated and discussed, including posterior iliosacral screws, sacral bars, and locking compression plate. The fixation stability, pelvic stress, and implant strength were obtained and used to evaluate the strength and limitation of each fixation technique.
The results of this study showed that the posterior iliosacral screws had better fixation stability compared with the sacral bars and the locking compression plate. Additionally, the locking compression plate revealed higher stress concentration effects on the pelvis and the implants compared with others. We hope that the outcomes of this study could directly provide the surgical suggestion to orthopedic surgeons and help them to understand the biomechanics of different pelvic fixation techniques.
StatusFinished
Effective start/end date1/1/142/28/15

Keywords

  • Biomechanical tests
  • Finite element analyses
  • Implant strength
  • Fixation stability
  • Unstable pelvic fracture