Biomechanical Effects of a Cross Connector in Sacral Fractures

A Finite Element Analysis

authored by: Meike Gierig, Fangrui Liu, Lukas Weiser, Wolfgang Lehmann, Peter Wriggers, Michele Marino, Dominik Saul
Abstract: Background: Spinopelvic fractures and approaches of operative stabilization have been a source of controversial discussion. Biomechanical data support the benefit of a spinopelvic stabilization and minimally invasive procedures help to reduce the dissatisfying complication rate. The role of a cross connector within spinopelvic devices remains inconclusive. We aimed to analyze the effect of a cross connector in a finite element model (FE model). Study Design: A FE model of the L1-L5 spine segment with pelvis and a spinopelvic stabilization was reconstructed from patient-specific CT images. The biomechanical relevance of a cross connector in a Denis zone I (AO: 61-B2) sacrum fracture was assessed in the FE model by applying bending and twisting forces with and without a cross connector. Biomechanical outcomes from the numerical model were investigated also considering uncertainties in material properties and levels of osseointegration. Results: The designed FE model showed comparable values in range-of-motion (ROM) and stresses with reference to the literature. The superiority of the spinopelvic stabilization (L5/Os ilium) ± cross connector compared to a non-operative procedure was confirmed in all analyzed loading conditions by reduced ROM and principal stresses in the disk L5/S1, vertebral body L5 and the fracture area. By considering the combination of all loading cases, the presence of a cross connector reduced the maximum stresses in the fracture area of around 10%. This difference has been statistically validated (p < 0.0001). Conclusion: The implementation of a spinopelvic stabilization (L5/Os ilium) in sacrum fractures sustained the fracture and led to enhanced biomechanical properties compared to a non-reductive procedure. While the additional cross connector did not alter the resulting ROM in L4/L5 or L5/sacrum, the reduction of the maximum stresses in the fracture area was significant.
Organisation(s): Institute of Continuum Mechanics
External Organisation(s): University of Göttingen
Tor Vergata University of Rome
Mayo Clinic Rochester MN
Type: Article
Journal: Frontiers in Bioengineering and Biotechnology
Volume: 9
Publication date: 26.05.2021
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Biotechnology, Bioengineering, Histology, Biomedical Engineering
Electronic version(s): https://doi.org/10.3389/fbioe.2021.669321 (Access: Open)
: Details in the research portal "Research@Leibniz University"

BibTeX

@article{14a58ac72226462bb6eadaa998a12a60,
title = "Biomechanical Effects of a Cross Connector in Sacral Fractures: A Finite Element Analysis",
abstract = "Background: Spinopelvic fractures and approaches of operative stabilization have been a source of controversial discussion. Biomechanical data support the benefit of a spinopelvic stabilization and minimally invasive procedures help to reduce the dissatisfying complication rate. The role of a cross connector within spinopelvic devices remains inconclusive. We aimed to analyze the effect of a cross connector in a finite element model (FE model). Study Design: A FE model of the L1-L5 spine segment with pelvis and a spinopelvic stabilization was reconstructed from patient-specific CT images. The biomechanical relevance of a cross connector in a Denis zone I (AO: 61-B2) sacrum fracture was assessed in the FE model by applying bending and twisting forces with and without a cross connector. Biomechanical outcomes from the numerical model were investigated also considering uncertainties in material properties and levels of osseointegration. Results: The designed FE model showed comparable values in range-of-motion (ROM) and stresses with reference to the literature. The superiority of the spinopelvic stabilization (L5/Os ilium) ± cross connector compared to a non-operative procedure was confirmed in all analyzed loading conditions by reduced ROM and principal stresses in the disk L5/S1, vertebral body L5 and the fracture area. By considering the combination of all loading cases, the presence of a cross connector reduced the maximum stresses in the fracture area of around 10%. This difference has been statistically validated (p < 0.0001). Conclusion: The implementation of a spinopelvic stabilization (L5/Os ilium) in sacrum fractures sustained the fracture and led to enhanced biomechanical properties compared to a non-reductive procedure. While the additional cross connector did not alter the resulting ROM in L4/L5 or L5/sacrum, the reduction of the maximum stresses in the fracture area was significant.",
keywords = "cross connector, finite element analysis, sacrum fracture, spinopelvic fracture, spinopelvic stabilization",
author = "Meike Gierig and Fangrui Liu and Lukas Weiser and Wolfgang Lehmann and Peter Wriggers and Michele Marino and Dominik Saul",
note = "Funding Information: The authors thank Lennart Viezens for his technical support. Funding. DS was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) ? 413501650. MG, MM, and PW acknowledge the Masterplan SMART BIOTECS (Ministry of Science and Culture of Lower Saxony, Germany). MM was also funded by the Ministry of Education, University and Research (Italy) in the 2017 Rita Levi Montalcini Program for Young Researchers.",
year = "2021",
month = may,
day = "26",
doi = "10.3389/fbioe.2021.669321",
language = "English",
volume = "9",
journal = "Frontiers in Bioengineering and Biotechnology",
publisher = "Frontiers Media S.A.",
}