Bone and Joint Institute
Document Type
Article
Publication Date
1-1-2018
Journal
BioMed Research International
Volume
2018
URL with Digital Object Identifier
10.1155/2018/4650308
Abstract
© 2018 Jason Coquim et al. This investigation assessed the biomechanical performance of the metal plate and bone strut technique for fixing recalcitrant nonunions of femur midshaft segmental defects, which has not been systematically done before. A finite element (FE) model was developed and then validated by experiments with the femur in 15 deg of adduction at a subclinical hip force of 1 kN. Then, FE analysis was done with the femur in 15 deg of adduction at a hip force of 3 kN representing about 4 x body weight for a 75 kg person to examine clinically relevant cases, such as an intact femur plus 8 different combinations of a lateral metal plate of fixed length, a medial bone strut of varying length, and varying numbers and locations of screws to secure the plate and strut around a midshaft defect. Using the traditional “high stiffness” femur-implant construct criterion, the repair technique using both a lateral plate and a medial strut fixed with the maximum possible number of screws would be the most desirable since it had the highest stiffness (1948 N/mm); moreover, this produced a peak femur cortical Von Mises stress (92 MPa) which was below the ultimate tensile strength of cortical bone. Conversely, using the more modern “low stiffness” femur-implant construct criterion, the repair technique using only a lateral plate but no medial strut provided the lowest stiffness (606 N/mm), which could potentially permit more in-line interfragmentary motion (i.e., perpendicular to the fracture gap, but in the direction of the femur shaft long axis) to enhance callus formation for secondary-type fracture healing; however, this also generated a peak femur cortical Von Mises stress (171 MPa) which was above the ultimate tensile strength of cortical bone.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Notes
Copyright © 2018 Jason Coquim et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
The article was originally published as:
Jason Coquim, Joseph Clemenzi, Mohsen Salahi, Abdurahman Sherif, Pouria Tavakkoli Avval, Suraj Shah, Emil H. Schemitsch, Z. Shaghayegh Bagheri, Habiba Bougherara, Radovan Zdero, "Biomechanical Analysis Using FEA and Experiments of Metal Plate and Bone Strut Repair of a Femur Midshaft Segmental Defect", BioMed Research International, vol. 2018, Article ID 4650308, 11 pages, 2018. https://doi.org/10.1155/2018/4650308