Lattice Structures for Bone Replacement: The Intersection of Bone Biomechanics, Lattice Design, and Additive Manufacturing

Abstract

Additive manufacturing (AM) has enabled the development of highly porous orthopedic implants by incorporating lattice structures that mimic the micro-architecture of natural bone. Lattices can be tuned to replicate bone's mechanical properties, creating implants that preserve the bone environment and allow bone formation within lattice pores. This review examines the intersection of bone biology, lattice design, and AM technologies to guide the development of such biomimetic structures. The hierarchical structure, mechanical properties, anisotropy, and heterogeneity of bone are identified as critical factors influencing bone remodeling, which is regulated by mechanical stimuli and can inform lattice design. Lattice mechanical behavior can be tailored through base material, relative density, topology, anisotropy, and size, which in turn affect biological responses, including cell function, tissue growth, and vascularization. Among available AM methods, powder bed fusion demonstrates the greatest capacity for producing complex geometries with high precision and reproducibility. Post-processing techniques, such as surface and thermal treatments and biomimetic coatings, are increasingly recognized as crucial for enhancing mechanical and biological performance. Still, current clinical and preclinical applications underscore remaining challenges in improving fatigue life, implant stabilization, vascularization, and bioactivity. This review provides a framework for advancing the design and clinical translation of lattice-based orthopedic implants.