Finite element analysis of new design assembly locking compression plate with low modulus titanium alloy in the treatment of middle femoral comminuted fracture

Abstract

Objective To explore the stress distribution of new design assembly locking compression plate (NALCP) with different modulus in the treatment of middle femoral comminuted fracture by finite element analysis (FEA). Methods A male volunteer received CT scanning with 0.625 mm slice thickness. The CT data was converted to middle femoral comminuted fracture FEA model by Mimics, Geomagic studio 12.0, etc. The femoral fracture was fixated by Ti-6Al-4V (high modulus group, E=110 GPa) and Ti2448 (low modulus group, E=30 GPa) respectively, and loads were applied on the three models to simulate a person slowly walking by one leg or torsion. The stress distribution of the plate and bone was observed. Results In two conditions, the stress distribution tendency of the three kinds of plates was uniformity roughly. The maximum stress was situated in the locking-hole which links the main plate and the runner plate. The stress forces of the main plate in two groups were almost the same. In two conditions of slow walking by one leg or torsion, compared with group Ti-6Al-4V, the maximum stress of runner plate in group Ti2448 were reduced 20.6% and 15.2%, and the axial maximum stress of the bone block were increased 95.8% and 95.7%. Conclusions NALCP with low modulus titanium alloy would provide adequate mechanical stability and stress stimulation, which would apt to fixate the bone block. Key words: Femoral fracture; Fracture fixation, internal; Elastic modulus; Finite element analysis; Biomechanics