A method for designing a patient-specific implant includes obtaining image data of a region of interest of the spine of a patient, measuring one or more geometric characteristic of the region of interest from the image data, comparing a measurement obtained for at least one of the one or more geometric characteristics to a mathematical rule associated with the particular geometric characteristic, and generating three-dimensional implant geometry data if the measurement of the at least one of the one or more geometric characteristics conforms with the associated mathematical rule, the implant geometry data configured to guide an additive manufacturing operation.