Comparative analysis of tissue ingrowth in printable porous lattice structured implants: An in silico study

The application of lattice structures in porous titanium implants has emerged as a promising approach in the load-bearing orthopaedic implant industry. Complex-shaped medical implants have been effectively produced using metal AM techniques. However, there remains ambiguity regarding the suitable porous lattice structure, which significantly influences bone formation. The study aims to evaluate and compare the tissue ingrowth capability of different porous lattice structure implants on their surface using mechanoregulatory tissue differentiation algorithm. Computer-aided design (CAD) models of five topologies, namely cubic, X-shape, cubic centre, face centre, and octet, were created using Solidworks with similar porosities (60 %). Further, the study entailed the 3D microscale modelling of regular porous structured implants with five distinct repeating cells on their surface were constructed using Solidworks. Additionally, five FE microscale models of bone-implant interface were modelled, with each model representing a distinct porous lattice structure implant. Lattice tissue ingrowth behaviour is evaluated by employing a mechanobiological algorithm to every FE microscale model. The bone ingrowth efficiencies of the five porous lattice structure implants were ranked. By observing the results, it was found that each lattice structure displays distinct tissue differentiation behaviour. Results demonstrate that highest bone tissue ingrowth was seen in implant with cubic lattice followed by FCC, octet, cubic centre, and X-shape lattice structure implant. Among the five lattice structure implants analysed, the X-shape lattice structure implant promotes lowest bone tissue ingrowth. Overall, the findings derived from this study have the potential to improve Ti6Al4V prosthetic devices inserted in different human anatomical regions.