Patent ID: 9554868
Date: 2017-01-31
CPC Classifications: A61B

Claim:
1. A method of reducing malalignment of a fractured bone that defines a proximal bone fragment and a distal bone fragment that is separated from the proximal bone fragment by a fracture, the method comprising: identifying at least one first anatomical landmark on the proximal bone fragment, and identifying at least one second anatomical landmark on the distal bone fragment; providing a first set of images of a bone that is contralateral with respect to the fractured bone, and a second set of images of the fractured bone including the first and second anatomical landmarks; obtaining a first 3D representation of the proximal bone fragment and the at least one first anatomical landmark from the second set of images, a second 3D representation of the distal bone fragment and the at least one second anatomical landmark from the second set of images, and a mirrored 3D representation of the contralateral bone from the first set of images; extracting a first set of 3D coordinates of the at least one first anatomical landmark from the first 3D representation, and a second set of 3D coordinates of the at least one second anatomical landmark from the second 3D representation; transferring the first set of 3D coordinates onto the mirrored 3D representation, and transferring the second set of 3D coordinates onto the mirrored 3D representation; determining a planned relative position between the proximal bone fragment and the distal bone fragment based on a position of the transferred first set of 3D coordinates relative to the transferred second set of 3D coordinates; after the determining step, reducing the fractured bone by moving at least one of the proximal bone fragment and the distal bone fragment relative to the other of the proximal bone fragment and the distal bone fragment; ascertaining an on-site actual relative position between the identified at least one first anatomical landmark of the proximal bone fragment and the identified at least one second anatomical landmark of the distal bone fragment by (a) positioning the proximal and the distal bone fragments on an upper, flat surface of a reference plate, the upper surface having a plurality of adjacent markings separated by a known distance between adjacent markings; (b) acquiring a first-moved set of at least two fluoroscopic images with different perspectives of the proximal bone fragment, and a second-moved set of at least two fluoroscopic images with different perspectives of the distal bone fragment; (c) extracting a first moved-set of 2D image coordinates of the first anatomical landmark on the proximal bone fragment from the first-moved set of at least two fluoroscopic images, and extracting a second-moved set of 2D image coordinates of the second anatomical landmark on the distal bone fragment from the second-moved set of at least two fluoroscopic images; (d) calculating a first moved-set of 3D coordinates of the first anatomical landmark on the proximal bone fragment and a second moved-set of 3D coordinates of the second anatomical landmark on the distal bone fragment with respect to the plurality of adjacent markings on the reference plate by using the first and second moved-sets of 2D image coordinates of the first and second anatomical landmarks on the proximal bone fragment and the distal bone fragment, respectively; and (e) determining the on-site actual relative position between the first anatomical landmark on the proximal bone fragment and the second anatomical landmark on the distal bone fragment after the reducing step based upon the calculated first moved-set of 3D coordinates of the first anatomical landmark on the proximal bone fragment and the calculated second moved-set of 3D coordinates of the second anatomical landmark on the distal bone fragment; and calculating a set of malalignment parameters by comparing the on-site actual relative position to the planned relative position.