[Design & fabrication of porous core implant with preset channel network for osteonecrosis of the femoral head].

Referring to the anatomical characterization of natural spongy bone and channel network in cortical bone, we designed a new pattern of biomimetic impalnt with preset channel for blood vessel inserting to treat early femoral head necrosis. The surgical ptrocedure was simulated by CAD model. Ceramic stereolithography was applied to fabricate the green part. Other process, such as dehydration, rinsing, drying and sintering, were taken successively. The final ceramic part kept identical with the engineered part either in the shape or in the internal structure. No deformation or crack happened. Pore size, interconnected pore size, porosity and interconnected porosity of ceramic part could satisfy cellular grouth. Spectrum analysis showed that no phase transition or chemical reaction happened during fabrication process. The biocompatibility of the final part kept the same with original during beta-TCP powder. The compressive strength was 23.54 MPa, close to natural spongy bone. It is an ideal implant to treat early femoral head necroseis because it makes preimplantation of cells and biological factors, blood velssel inserting, early establishment of blood supply possible. At the same time, it could provide enough mechanical support to prevent collapse of femoral head. It could provide a wide clinical foreground.