Customized patient-specific orthopaedic surgical instrument using patient-specific contacting bodies and parametric fixed geometry

One or more computer-readable media comprising a plurality of instructions that, when executed by a computing device, cause the computing device to:

• generate a contacting body of a patient-specific surgical instrument model based on a parameterized model of a patient's bone, wherein the parameterized model comprises a predetermined number of polygons, and wherein each polygon has a predetermined position relative to the patient's anatomy, wherein to generate the contacting body comprises to:
• (i) determine a bounding spline based on a predetermined set of polygons of the parametrized model, (ii) generate a bounded surface surrounded by the bounding spline, and (iii) extend the bounded surface away from the parametrized model of the patient's bone and toward the parameterized model of the patient's bone to generate the contacting body, wherein the contacting body intersects a surface of the parameterized model;
• add a bridging body connected to the contacting body of the patient-specific surgical instrument model based on the parameterized model, wherein the bridging body intersects the surface of the parametrized model and wherein the bridging body has a parametric fixed geometry, wherein to add the bridging body comprises to determine a parameter of the parametric fixed geometry of the bridging body based on the parameterized model;
• and
• subtract a three-dimensional model of the patient's bone from the patient-specific surgical instrument model to create a contacting surface, wherein the contacting surface is positioned on the contacting body and the bridging body.