Biomechanical Evaluation of the Stabilization Used in the Treatment of Distal Humerus Intra-articular Fractures

A stable fixation of particular bone fragments is crucial for the treatment of complex intra-articular fractures of the distal humerus. The presented analysis was focused on the evaluation of mechanical condition of a bone fracture union resulting from the usage of various configurations of the stabilizer. Numerical analyses ( finite element method) were the main tool used in the research. A geometrical model of the fractured humerus ( 13-C1 according to AO/OTA) was prepared on the basis of CT-data. A simplified material model was applied to consider the bone tissue inhomogeneity. The geometry of the stabilizer was modeled on the basis of the VariAx (R) Elbow System ( Stryker, Inc.). Two plating techniques: parallel ( medial and lateral plates) and orthogonal ( medial and postero-lateral plates) were taken into consideration. Loadings occurring during the flexion of the elbow joint were used during the analysis. The evaluation of the global construct stiffness shows that there are no crucial differences between both stabilizer configurations. However, the analysis of relative displacement between articular bone fragments indicates that a higher stability can be ensured with the use of parallel plate arrangement.