Effects of Bone-Plate Material on the Predicted Stresses in the Tibial Shaft Comminuted Fractures: A Finite Element Analysis.

PURPOSE: In this research, low modulus carbon fiber (CF)-reinforced polyetheretherketone composite plates (CF-PEEK plates) were compared with traditional metal plates using finite element analysis to establish a reference for clinical application.

MATERIAL AND METHODS: Plates of stainless steel, titanium alloy (Ti6Al4V), or CF-PEEK with different carbon fiber reinforcement ratios (CF30, CF50, and CF60) were used to fix the tibial shaft comminuted fracture. The maximum stress, the maximum displacement of fracture and the stress shielding of cortex bone were analyzed.

RESULTS: Under 200 N axial compression, the maximum displacement was measured in the CF30 plate (4.62 mm) and the minimum in the stainless steel plate (0.23 mm). The stress shielding rates of stainless steel, titanium, CF30, CF50, and CF60 plates were 59.4%, 54.4%, 23.75%, 48.75% and 66.25%. Under 700 N axial compression, the internal fixation by the CF30 plate failed. Among the other 4 plates, the maximum displacement was measured in the CF50 plate (2.52 mm) and the minimum in the stainless steel plate (0.78 mm). The stress shielding rate of plates made of stainless steel, titanium, CF50, and CF60 were 57.1%, 52.0%, 48.1%, and 67.8%.

CONCLUSIONS: CF50 plates can be safely used in the tibial shaft comminuted fracture. The micromotion in the CF50 and CF60 plate was more beneficial to callus formation and fracture healing. The stress shielding of the cortex bone under the CF50 plate was the lowest. The finite element analysis indicated that the CF-PEEK material is worthy of further study because of its biomechanical advantages.