An implant comprising a porous microstructure is disclosed which has an external surface, where at least a region of the external surface is formed of the porous microstructure. The microstructure is defined by at least one lattice of cells. Each cell has a predetermined cell topology and a plurality of edges. One or more of the edges of each cell connect to an adjacent cell along a corresponding edge thereof. Collectively, the cells have a periodic or aperiodic arrangement within the at least one lattice.