The Influence of Mechanical and Microstructural Characteristics on the Durability of a Femoral Implant Made of Different Alloys

The long-term success of orthopedic implants is fundamentally dependent on the synergy between mechanical performance and biological integration. Thus, a comprehensive investigation of both mechanical characteristics and microstructural parameters is essential for the development of reliable implant systems in hip arthroplasty, both in human medicine and veterinary practice. The present study provides a detailed analysis of the mechanical properties, microstructure, and chemical composition of a Ti-6Al-4V-based femoral implant using nanoindentation, scanning electron and optical microscopy, and energy-dispersive X-ray spectroscopy. Then, using finite element analysis, the influence of Young’s modulus on the stress–strain state of the endoprosthesis was evaluated. Dynamic loading conditions were considered by analyzing an impact on a cantilever beam, simulating an animal’s jump onto a supporting limb. For reliable numerical simulation, the model geometry was constructed utilizing computed X-ray microtomography. The numerical simulations were performed for three material cases: reference Ti-6Al-4V, experimentally characterized Ti-6Al-4V (with properties determined by nanoindentation), and CoCrMo alloy, which is also widely used in endoprosthetic applications. The influence of the founded mechanical characteristics on the stress–strain state of the prostheses was assessed. In particular, the results indicate that under dynamic loading conditions, the load-bearing capacity of CoCrMo is lower by approximately 30% and 21% compared to the reference and experimentally characterized Ti-6Al-4V, respectively.