title: Hierarchical tailoring of strut architecture to control permeability of additive manufactured titanium implants.
abstract: Porous titanium implants are a common choice for bone augmentation. Implants for spinal fusion and repair of non-union fractures must encourage blood flow after implantation so that there is sufficient cell migration, nutrient and growth factor transport to stimulate bone ingrowth. Additive manufacturing techniques allow a large number of pore network designs. This study investigates how the design factors offered by selective laser melting technique can be used to alter the implant architecture on multiple length scales to control and even tailor the flow. Permeability is a convenient parameter that characterises flow, correlating to structure openness (interconnectivity and pore window size), tortuosity and hence flow shear rates. Using experimentally validated computational simulations, we demonstrate how additive manufacturing can be used to tailor implant properties by controlling surface roughness at a microstructual level (microns), and by altering the strut ordering and density at a mesoscopic level (millimetre).
authors.affiliation: Department of Materials, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK.
authors.forename: Z
authors.initials: Z
authors.lastname: Zhang
authors.forename: D
authors.initials: D
authors.lastname: Jones
authors.forename: S
authors.initials: S
authors.lastname: Yue
authors.forename: P D
authors.initials: PD
authors.lastname: Lee
authors.forename: J R
authors.initials: JR
authors.lastname: Jones
authors.forename: C J
authors.initials: CJ
authors.lastname: Sutcliffe
authors.forename: E
authors.initials: E
authors.lastname: Jones
mesh_terms: D003198:Computer Simulation; D017076:Computer-Aided Design; D057446:Hydrodynamics; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D010539:Permeability; D016062:Porosity; D019736:Prostheses and Implants; D014025:Titanium / Q000737:chemistry*; D055114:X-Ray Microtomography
chemical_list: D014025:Titanium
keywords: Additive manufacturing; Bone ingrowth; Permeability; Selective laser melting; Titanium porous structures