Biomechanical analysis of a novel plating for intra-articular distal humerus fractures: combined anteromedial and anterolateral plating.

Purpose: The traditional strategy for fixing intra-articular distal humerus fractures is double plating placed in an orthogonal or parallel configuration, based on posterior approach. With a combined medial and lateral approach, a novel configuration of plating (combined anteromedial and anterolateral plating) has been used. In this study, we investigated the biomechanical properties of the novel plating by comparing it with orthogonal plating.

Methods: Based on the 3D morphology of a healthy subject's humerus, the models of simple intra-articular distal humerus fractures were simulated. Two configurations of plating were applied to fix the models: the novel plating (with one plate anteromedially and the other anterolaterally on distal humerus), and orthogonal plating. Stresses, displacement, and stiffness were simulated and calculated under the conditions of axial compression, rotation torsion, bending torsion, and valgus torsion by using finite element analysis.

Results: In all the conditions, the maximal von Mises stresses of the novel plating are similar to those of orthogonal plating, and the patterns of stress distribution are similar between these two configurations. However, the impact of high stresses was weaker on the novel plating. The maximal displacement of the novel plating is smaller than that of orthogonal plating. The stiffness of the novel plating is superior to that of orthogonal plating, with the improvements of 19.4%, 122.7%, 25.0%, and 54.2% in axial compression, rotation torsion, bending torsion, and valgus torsion, respectively.

Conclusions: The novel plating is stronger than orthogonal plating without increasing stress magnitude when fixing simple intra-articular distal humerus fractures, which makes it a feasible alternative. Further biomechanical and clinical studies are needed for a decisive conclusion.