Joint implants having porous structures formed utilizing additive manufacturing and related systems and methods
A medical implant which comprises a porous lattice is fabricated with additive manufacturing techniques such as direct metal laser sintering. A CAD model of the porous lattice is created by defining a trimming volume and merging some lattice elements with adjacent solid substrate.
1. A method for fabricating an implant device comprising a porous lattice, the method comprising:
creating, by a computing device, a model of the implant device comprising the porous lattice, the creating comprising:
defining an initial lattice volume having a bounding surface for the implant device;
populating the initial lattice volume with a plurality of seed points,
populating the initial lattice volume with a plurality of nodes and struts using a Voronoi tessellation to divide the initial lattice volume into a plurality of 3-dimensional regions, thereby defining an initial lattice;
defining a second volume within the initial lattice volume such that a trimming boundary is defined between the initial lattice volume and the second volume;
removing struts and nodes, and portions thereof from the model that are located outside the trimming boundary; and
fabricating the implant device comprising the porous lattice at least in part by exposing fusible material to a heating source according to the model.
2. The method of claim 1 , wherein a distribution of the plurality of seed points is at least partially random or pseudo-random.
3. The method of claim 1 , wherein the distribution of seed points has a higher density in some regions of the lattice than others.
4. The method of claim 1 , wherein a distribution of the plurality of seed points is based at least in part on a Poisson-disc sampling strategy.
5. The method of claim 1 , wherein all locations within each 3-dimensional region are closer to the respective seed point than to any other seed point.
6. The method of claim 1 , wherein creating the model of the implant device further comprises adjusting at least some of the plurality of struts to have a desired thickness and a desired cross-sectional geometry.
7. The method of claim 6 , wherein the adjusting varies in different regions of the lattice.
8. The method of claim 7 , wherein the adjusting is different at different distances from an outer surface of the lattice.
9. The method of claim 6 , wherein the desired cross-sectional geometry is a substantially circular geometry.
10. The method of claim 1 , wherein the porous lattice comprises a Gaussian distribution of pore diameters centered around a desired mean pore diameter in at least one region of the lattice.
11. The method of claim 1 , wherein the implant device comprises at least one post configured to anchor bone of a patient to the implant device.
12. The method of claim 1 , wherein the implant device comprises a patellar implant.
13. The method of claim 1 , wherein the fusible material comprises titanium or a titanium alloy.
14. The method of claim 1 , wherein the heating source comprises a laser.
15. A method for generating a fabrication model for an implant device comprising a porous lattice, the method comprising:
creating, by a computing device, a model of the implant device comprising the porous lattice, the creating comprising:
defining an initial lattice volume having a bounding surface for the implant device;
populating the initial lattice volume with a plurality of seed points;
populating the initial lattice volume with a plurality of nodes and struts using a Voronoi tessellation to divide the initial lattice volume into a plurality of 3-dimensional regions, thereby defining an initial lattice;
defining a second volume within the initial lattice volume such that a trimming boundary is defined between the initial lattice volume and the second volume; and
removing struts and nodes, and portions thereof from the model that are located outside the trimming boundary.
16. The method of claim 15 , wherein a distribution of the plurality of seed points is at least partially random or pseudo-random.
17. The method of claim 15 , wherein the distribution of seed points has a higher density in some regions of the lattice than others.
18. The method of claim 15 , wherein a distribution of the plurality of seed points is based at least in part on a Poisson-disc sampling strategy.
19. The method of claim 15 , wherein all locations within each 3-dimensional region are closer to the respective seed point than to any other seed point.
20. The method of claim 15 , wherein creating the model of the implant device further comprises adjusting at least some of the plurality of struts to have a desired thickness and a desired cross-sectional geometry.