The present invention is for a
systematic process of creating
patient specific implants by matching target mechanical properties (e.g.
elastic modulus of bone) based on a patient's CT scan images. The present invention creates a metamodel that matches the
elastic modulus values of lattice scaffolds to desired values by using a homogenization approach to determine the characteristics of the lattice structure at the unit-
cell level. This eliminates the computational cost associated with optimizing the lattice structures and works at
structural level.The present invention includes the following featured steps to adjust a
mechanical property (e.g., the
elastic modulus) of the
implant: 1) specifying a region requiring the
implant operation from the CT scan images of the affected part, 2) determining the
implant shape to be inserted into the specified region from the previous step, 3) dividing the implant shape into multiple partitioned three-dimensional regions, 4) assigning target elastic modulus values (Et) for each of the partitioned three-dimensional regions according to the
bone density information obtained from the CT scan images, 5) selecting a specific type of unit-
cell of lattice scaffolds with respect to the implant shape, 6) selecting a specific
implant material, which has the elastic modulus of Eo, and 7) determining the required strut
diameter and density of each unit-
cell of the lattice scaffolds to minimize the error between the target elastic modulus (Et) and the homogenized elastic modulus (Eh), which is calculated from the
implant material's elastic modulus value (Eo) obtained from the selected three-dimensional regions.The present invention creates
patient specific surgical implants with precisely designed lattice scaffolds. The implants are designed for long term use because the
stress shielding effect can be reduced by matching the elastic modulus of the implant to the elastic modulus of the bone of the affected area. Therefore, the present invention can significantly reduce the
side effect of the implant and prevent reoperations.