Comparative FE biomechanical and microbial adhesion analyses on an implanted humerus

A Tropea; A Tisano; A Bruschetta; D Borzelli; A Migliorato; G Nirta; G Leonardi; F Trimarchi; A Alito

doi:10.1016/j.jor.2022.05.011

Comparative FE biomechanical and microbial adhesion analyses on an implanted humerus

J Orthop. 2022 May 19:32:78-84. doi: 10.1016/j.jor.2022.05.011. eCollection 2022 Jul-Aug.

Authors

A Tropea¹, A Tisano², A Bruschetta³, D Borzelli⁴, A Migliorato⁴, G Nirta⁵, G Leonardi⁶, F Trimarchi⁴, A Alito⁴

Affiliations

¹ Dep. of Research and Internationalization, Via C. del mare 41, 98121, Messina, Italy.
² Dep. of clinical e sperimental Medicine, University of Messina, 98125, Messina, Italy.
³ Orthopedic Institute "Franco Scalabrino" of Messina, Via Consolare Pompea, Messina, Italy.
⁴ Dep. of Biom., Dental Sciences and Morphological and Functional Images, University of Messina, 98125, Messina, Italy.
⁵ Radiology Unit, University Hospital A.O.U. "G. Martino", 98125, Messina, Italy.
⁶ Physical Rehabilitation Medicine Unit, University Hospital A.O.U. "G. Martino", 98125, Messina, Italy.

Abstract

Objective: In this study a multi fragment humeral fracture, treated with locking plate system implant, was investigate and compared with a healthy humerus by the mining of a Finite Element (FE) analysis. Locking plate implant, in this case AxSOS 3® Titanium produced by Stryker is the preferred solution in presence of multiple fracture or osteoporosis.

Methods: Loading conditions were imposed by rotating of 52,5° respect the vertical axe, both the humeri (healthy and fractured), fixing distal end, and loading the top of bones with a vertical force of 543 N (Newton). This finite element analysis aimed to compare stability of implanted humerus, implant-bone interface, stress shielding, with those related to a healthy one. A microbial adhesion analysis was also performed on the implant's material.

Results: Results obtained by FE analysis confirm a good agreement of the mechanical behavior of the models tested. The maximum values of the registered stressed, are of about 45 MPa (Mega Pascal) for the intact humerus and 113 MPa for the fractured one. Displacements, confirm higher values on the fractured humerus and no viable bacteria were found after microbial adhesion analyses.Conclusion: comparison between healthy and fractured humerus showed an optimal stability of the implant, when contact surfaces optimization and screws insertion are correctly performed.

Keywords: Biomechanics; Finite element analysis; Locking plate.