Customized patient-specific contact segments for orthopaedic surgical instrument using bone silhouette curves

Abstract

An orthopaedic surgical instrument includes a customized patient-specific surgical instrument having a body. The body has a bone-facing surface and an outer surface positioned opposite the bone-facing surface. The body includes a number of bone-contacting segments raised relative to the bone-facing surface. The bone-contacting segment include negative contours shaped to match corresponding positive contours of a patient's bone. The positive contours correspond to silhouette curves of a three-dimensional model of the patient's bone that correspond to contours of the patient's bone captured in images used to generate the model. The body further includes a number of surgical guides extending from the outer surface to the bone-contacting surface or the bone-facing surfaces. A method associated with the instrument is also disclosed.

1 . A method for creating a patient-specific resection guide, the method comprising:
 generating a three-dimensional model of a patient's bone based on a plurality of images, wherein each image views the patient's bone in a different imaging plane of a plurality of imaging planes;   mapping the three-dimensional model to a plurality of silhouette curves, wherein each silhouette curve corresponds to a contour of the patient's bone captured in an image of the plurality of images; and   determining a plurality of customized patient-specific negative contours based on the plurality of silhouette curves, wherein each customized patient-specific negative contour is shaped to match and receive a corresponding positive contour of the patient's bone, and wherein each positive contour corresponds to a silhouette curve of the plurality of silhouette curves.   
     
     
         2 . The method of  claim 1 , further comprising imaging the patient's bone in the plurality of imaging planes to generate the plurality of images. 
     
     
         3 . The method of  claim 1 , further comprising generating a guide having a polymeric body including a bone-facing surface and an outer surface positioned opposite the bone-facing surface and a plurality of bone-contacting surfaces coupled to the bone-facing surface and raised relative to the bone-facing surface, wherein each bone-contacting surface defines a customized patient-specific negative contour of the plurality of patient-specific negative contours. 
     
     
         4 . The method of  claim 3 , wherein the bone-facing surface is devoid of any negative contour shaped to match and receive a corresponding positive contour of the patient's bone. 
     
     
         5 . The method of  claim 3 , wherein generating the guide comprises molding the polymeric body. 
     
     
         6 . The method of  claim 3 , wherein generating the guide comprises additively manufacturing the polymeric body. 
     
     
         7 . The method of  claim 3 , wherein the polymeric body further includes a cutting guide defined by inner walls that extend from the outer surface to the bone-facing surface and to a bone-contacting surface of the bone-contacting segment.