| abstract |
A surgical implant including a cage having a first porosity and a first modulus; and a core bounded by said cage, said core having a second porosity that is higher than said first porosity of said cage, and said core having a second modulus that is lower than said first modulus of said cage. The implant may be functionally graded in a transverse direction, a longitudinal direction, or a radial direction thereof. The implant is made by preparing a first formulation for the cage within a first extruder and a second formulation for the core within a second extruder, extruding the first formulation through a co-extrusion die while simultaneously extruding said second formulation through the co-extrusion die so as to form an extrudate that includes said cage component and said core component bounded by said cage component. |