Mature bone mechanoregulation modelling for the characterization of the osseointegration performance of periodic cellular solids

Abstract

Osseointegration is an essential process for the clinical success of some orthopedic implants. Delayed osseointegration can lead to post-operative complications and implant failure, which may require revision surgery. Advances in additive manufacturing allow 3D printing cellular solids to provide a favourable biomechanical environment that stimulates bone formation. Thus, this study aimed to simulate the performance of Ti-6Al-4 V strut-based lattice structures for mature bone growth. Mechano-regulation theory is applied to evaluate the osseointegration performance of six lattice topologies, including Diamond, BCC, Tetrahedron, Octet, Cubic, and Rhombic Dodecahedron, taking into consideration their horizontal and vertical orientations. The effect of the lattice relative density is also considered where the lattice topologies are simulated at ten discrete relative densities (5%:5%:50%) subjected to pressures of 0.5 MPa: 1 MPa: 1.5 MPa: 2 MPa. Results showed that Diamond, BCC, Tetrahedron, and Rhombic Dodecahedron with horizontal orientation provide an ideal biomechanical environment for bone growth. Between 10% and 30% relative density, most topologies had 100% of their void space within the optimal biomechanical stimulation for bone growth. The amplitude of the applied load had a substantial influence on the results. This data may help select the best lattice topology with the optimum microscopic attributes for the best biomechanical environment for a specific implant design.