title: Finite Element-Derived Surrogate Models of Locked Plate Fracture Fixation Biomechanics.
abstract: Internal fixation of bone fractures using plates and screws involves many choices-implant type, material, sizes, and geometric configuration-made by the surgeon. These decisions can be important for providing adequate stability to promote healing and prevent implant mechanical failure. The purpose of this study was to develop mathematical models of the relationships between fracture fixation construct parameters and resulting 3D biomechanics, based on parametric computer simulations. Finite element models of hundreds of different locked plate fixation constructs for midshaft diaphyseal fractures were systematically assembled using custom algorithms, and axial, torsional, and bending loadings were simulated. Multivariate regression was used to fit response surface polynomial equations relating fixation design parameters to outputs including maximum implant stresses, axial and shear strain at the fracture site, and construct stiffness. Surrogate models with as little as three regressors showed good fitting (R2= 0.62-0.97). Inner working length was the strongest predictor of maximum plate and screw stresses, and a variety of quadratic and interaction terms influenced resulting biomechanics. The framework presented in this study can be applied to additional types of bone fractures to provide clinicians and implant designers with clinical insight, surgical optimization, and a comprehensive mathematical description of biomechanics.
authors.affiliation: Department of Orthopaedics and Rehabilitation, Penn State College of Medicine, 500 University Drive, Mail Code H089, Hershey, PA, 17033, USA.
authors.forename: Hwabok
authors.initials: H
authors.lastname: Wee
authors.affiliation: Department of Orthopaedics and Rehabilitation, Penn State College of Medicine, 500 University Drive, Mail Code H089, Hershey, PA, 17033, USA.
authors.forename: J Spence
authors.initials: JS
authors.lastname: Reid
authors.affiliation: Department of Public Health Sciences, Penn State College of Medicine, Hershey, PA, USA.
authors.forename: Vernon M
authors.initials: VM
authors.lastname: Chinchilli
authors.affiliation: Department of Orthopaedics and Rehabilitation, Penn State College of Medicine, 500 University Drive, Mail Code H089, Hershey, PA, 17033, USA. glewis1@hmc.psu.edu.
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Lewis
mesh_terms: D000465:Algorithms; D000818:Animals; D001860:Bone Plates; D020342:Finite Element Analysis; D005592:Fracture Fixation; D050723:Fractures, Bone / Q000601:surgery*; D006801:Humans; D008954:Models, Biological; D016474:Weight-Bearing
keywords: Finite element; Fracture fixation; Locking plate and screw; Response surface