Mechanical Evaluation of Additive Manufactured PEEK-Based Intramedullary Nail for Femur Fracture Fixation: A Computational and Experimental Analysis

An intramedullary (IM) femur nail is an orthopedic implant for treating femur fractures, designed to bear body weight and mechanical stresses, reducing the load on fractured bone segments and allowing early patient mobilization. This study examines the biomechanical four-point bending test (ASTM F1264) of three-dimensional (3D)-printed fiber-reinforced polyether ether ketone (PEEK) IM nails, using both experimental methods and numerical simulation. Finite element analysis predicted the behavior of fiber-reinforced PEEK IM nails in a fractured femur model. Load-bearing capacity, bending strength, and stiffness were compared between carbon fiber (CF)- and glass fiber (GF)-reinforced PEEK IM nails. Experimental load versus displacement data showed strong correlation with simulation results, validating the finite element model. The CF PEEK nail withstood a force of 1,783.14[Formula: see text]N and showed 39.34% higher bending loads and a stiffness of 168.22[Formula: see text]N/mm, outperforming the GF PEEK nail’s 1,279.97[Formula: see text]N force and 120.75[Formula: see text]N/mm stiffness. Stress analysis indicated CF PEEK sustained higher stress (116.6[Formula: see text]MPa) compared to GF PEEK (83.68[Formula: see text]MPa), establishing CF PEEK as the superior material. The biomechanical tests demonstrated CF PEEK’s superior bending resistance and toughness over GF PEEK. The combined experimental and computational approach provided a comprehensive understanding of the mechanical behavior and stress responses of the implants, validating CF PEEK as a superior material and highlighting the potential of 3D printing with fiber-reinforced PEEK for orthopedic implants. The integration of experimental validation and computational prediction is essential for optimizing implant design and improving patient outcomes in orthopedic treatments.