Will the Strength of the Clavicle Plate be Increased by Inserting Small Screws into the Empty Holes above the Fracture Site?

Abstract

Background: Open reduction and plate fixation is the standard surgery for displaced midshaft clavicle fractures because of biomechanical stability. Implant failure like plate breakage or deformation is the most serious complication of plate fixation. Several plate designs for midshaft clavicle fractures have been introduced, but traditional superior plate has been mostly used.Methods: We generated the clavicle 3D image using the computed tomography (CT) of the left normal clavicle of a 54-year-old female, and then made the comminuted midshaft clavicle fracture model with 10-mm fracture site gap. The fracture model was fixed with 7-hole superior locking compression plate. Finite element analysis (FEA) was performed between the presence (model B) and absence (model A) of screws above the fracture site.Results: The average peak stress from the cantilever bending force was much greater than the peak stress from the axial compression and axial torsion force. This means that the cantilever loading force is the main force which could cause plate breakage or deformation. The maximal stress of the model B was lower than the one of the model A. Therefore, model B showed superior biomechanical property than model A under all loading conditions, especially cantilever bending force.Conclusions: The peak stress of the superior clavicle plate could be decreased just by inserting a small screw into the screw hole above the fracture site.