<p>Lattice structures are increasingly employed in orthopedic applications due to their high strength-to-weight ratio and potential for multifunctional performance. Leveraging the geometric flexibility of additive manufacturing (AM), this study employs finite element analysis (FEA) to systematically evaluate the mechanical behavior of seven biocompatible NiTi lattice designs. These structures vary in unit cell topology (hexagonal, x-shape, soft box, octagonal, pyritohedron, and tetrahedral), unit cell size, and porosity. Simulation results reveal that the optimized hexagonal topology offers superior mechanical performance, including reduced stress concentrations and enhanced stiffness, compared to conventional configurations. Moreover, the study shows that mechanical properties can be significantly tuned by controlling porosity, providing valuable insight for the design of AM-based biomedical implants. These findings underscore the effectiveness of simulation-driven design frameworks in accelerating materials innovation for orthopedic and other biomedical applications.</p> Graphical Abstract <p></p>