Manufacturability and Mechanical Assessment of Ti-6Al-4V 3D Printed Structures for Patient-Specific Implants

Recent advancements in additive manufacturing technology for metallic materials have paved the way for the creation of patient-specific implants with tailored mechanical properties for bone tissue reconstruction. To address the issue of stress shielding and improve osseointegration, the implants feature an architected internal structure with a unique design capable of mimicking the mechanical properties of the damaged bone. This study proposes a fast, simple, and clinically applicable approach for designing trabecular-like structures for tailored implants, specifically for the tibia component in knee joint replacement. The lattice structures with different solid fractions were designed and fabricated using the selective laser melting (SLM) technique and Ti-6Al-4V alloy. The mechanical behavior of the structures was evaluated through computational and experimental analysis, and compared with that of natural tibia bone. Moreover, the manufacturing robustness of the printed structures was assessed using X-ray computed tomography and microscopic examinations. Results show that the permeability of the fabricated structures ranges from 0.16 × 10–9 to 0.38 × 10–9 m2, comparable to that of trabecular bones. The stiffness and strength of the designed structures range from 1.08 to 4.47 GPa and 147 to 295 MPa, respectively, reasonably consistent with natural bone. Finally, the study proposes a conceptual design framework that isolates the correlation between the solid fraction of the lattices and the expected biomechanical behavior. Overall, the study highlights the potential of additive manufacturing in creating geometrically complex and mechanically tailored implants for bone tissue reconstruction.