Design, optimization, and selective laser melting of vin tiles cellular structure-based hip implant

Cellular biomaterials with highly controlled microstructures are auspicious materials for medical orthopedics applications either as scaffold or implants due to their capability of encouraging better osseointegration and cell proliferation. This work focuses on the design and optimization of the hip implant by introducing a cellular structure into a solid implant to allow bone tissue ingrowth and reduce stress shielding. The cellular hip implant is incorporated with vintiles lattice topologies having different strut thickness and unit cell sizes to achieve the requirements of bone ingrowth and biomechanical mimic strength. All four optimized cellular hip implants with different unit cell size and porosity were manufactured via selective laser melting (SLM) using the Ti6Al4V material. To predict the mechanical property of hip cellular implant, finite element analysis (FEA) was employed and optimization methods were used for improving the mechanical performance of the hip cellular implant. To evaluate the reduction in stiffness of hip cellular implants, experimental tests were performed based on ISO 7206-4(2010) under static loading conditions. The experimental and simulation force-displacement results show that the optimized cellular hip implant has 62% lower stiffness than its solid counterpart. Moreover, the cellular hip implant was 50% lower in weight than the solid implant. Finally, the result of this study shows that the cellular implants with porosity of 56% and 58% have the potential to be used in orthopedic and prosthetic applications to improve osseointegration.