Published online Jan 31, 2010.
https://doi.org/10.12671/jkfs.2010.23.1.83
A Finite Element Analysis of Biomechanical Stability of Compression Plate Fixation System in according to Existing of Fracture Gap after Bone Fracture Augmentation
Abstract
Purpose
This study using the finite element analysis (FEA) focused on evaluating the biomechanical stability of the LC-DCP in accordance with existing of the fracture gap at the facture site after bone fracture augmentation.
Materials and Methods
For FEM analysis, total eleven types with different fracture models considering clinical fracture cases were constructed according to the fracture gap sizes (0, 1, 4 mm)/widths (0, 25, 50, 75, 100%). Limited contact dynamic compression plate (LC-DCP) fixation system was used in this FEM analysis, and three types of load were applied to the bone-plate fixation system: compressive, torsional, bending load.
Results
The results in FEM analysis showed that the 1, 4 mm fracture gap sizes and 75% or more fracture gap widths increased considerably the peak von Mises stress (PVMS) both the plate and the screw under all loading conditions. PVMS were concentrated on the center of the LC-DCP bone-plate, and around the necks of screws.
Conclusion
Based on the our findings, we recommend at least 50% contact of the fracture faces in a fracture surgery using the compression bone-plate system. Moreover, if x-ray observation after surgery finds 100% fracture gap or 50% or more fracture gap width, supplementary measures to improve biomechanical stability must be taken, such as restriction of walking of the patient or plastering.
Fig. 1
Bone fracture augmentations with compressing plate (A), the arrow indicates the fracture gap at the bone fracture site (B), and the arrow indicates callus formation around the bone fracture site (C).
Fig. 2
Test specimen with LC-DCP fixation system for validating the 3-D FEM model (A), the bone-plate fixation system 3-D FEM model (B), and the fracture gap sizes and widths (C).
Fig. 3
Von Mises stress distributions and levels on the screws (A) and the plates (B) according to the changes of the fracture gap size and fracture gap width under compressive load.
Fig. 4
Comparisons of peak von Mises stress (PVMS) according to the change of fracture gap size and width under the compressive load.
Fig. 5
Comparisons of peak von Mises stress (PVMS) according to the change of fracture gap size and width under the torsional load.
Fig. 6
Comparisons of peak von Mises stress (PVMS) according to the change of fracture gap size and width under the 4-point bending load.
Table 1
Mechanical properties and component interface conditions assigned to FEA models
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