Methods of predetermining the contour of a resected bone surface and assessing the fit of a prosthesis on the bone

• US 9,504,579 B2
• Filed: 06/26/2012
• Issued: 11/29/2016
• Est. Priority Date: 03/17/2006
• Status: Active Grant

• Current Assignee: Zimmer Incorporated (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Mohamed Mahfouz, Zimmer Incorporated (Zimmer Biomet Holdings, Inc.)
• Inventors: Mahfouz, Mohamed, Earl, Brian D.
• Primary Examiner(s): Ramana, Anu
• Application Number:
  US13/533,552
• Publication Number:
  US 20120265499A1
• Time in Patent Office: 1,617 Days
• Field of Search: 606/86.R, 606/102
• US Class Current: 1/1
• CPC Class Codes: A61B 2034/108 Computer aided selection or customisation of medical implants or cutting guides
• CPC Class Codes: A61B 34/10 Computer-aided planning, simulation or modelling of surgical operations
• CPC Class Codes: A61B 5/1075 for measuring dimensions by non-invasive methods, e.g. for determining thickness of tissue layer A61B8/0858 takes precedence
• CPC Class Codes: A61B 5/1077 Measuring of profiles
• CPC Class Codes: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence
• CPC Class Codes: A61F 2/30942 for designing or making customized prostheses, e.g. using templates, CT or NMR scans, finite-element analysis or CAD-CAM techniques
• CPC Class Codes: A61F 2/3859 Femoral components
• CPC Class Codes: A61F 2002/30892 parallel
• CPC Class Codes: A61F 2002/30948 using computerized tomography, i.e. CT scans

Abstract

Methods for predetermining a contour of a resected bone surface and assessing a fit of a prosthesis on the resected bone surface, for designing prostheses to fit discrete patient populations, and for designing customized prostheses.

Claims

1. A method of designing a prosthesis to substantially fit a resected bone surface based on a population of bones from a plurality of patients, the method comprising the steps of:

creating a plurality of two-dimensional outlines corresponding to each resected bone surface for each bone of the population of bones from the plurality of patients using a computer, wherein the creating step comprises;

obtaining a three-dimensional contour of each resected bone surface based upon images of the population of bones;

identifying a vertex between a first planar surface of each resected bone surface and a second planar surface of each resected bone surface;

manipulating the first planar surface to be coplanar with the second planar surface; and

outlining a perimeter of the first planar surface and the second planar surface to define the two-dimensional outline for each resected bone surface;

determining a contour of a bone engaging surface of a prosthesis using the plurality of two-dimensional outlines and a best fit approximation of the plurality of two-dimensional outlines of the resected bone surface; and

comparing the contour to the plurality of two-dimensional outlines of the resected bone surface derived from the population of bones from the plurality of patients to assess a fit of the prosthesis with the population of bones.

2. The method of claim 1, wherein manipulating the first planar surface to be coplanar with the second planar surface includes unfolding a three-dimensional outline.

3. A method of creating a prosthesis for placement on a resected bone surface of a bone, the method comprising the steps of:

creating a two-dimensional outline of the resected bone surface using a computer, wherein the creating step comprises;

obtaining a three-dimensional contour of the resected bone surface based upon an image of the bone,

identifying a vertex between a first planar surface of the resected bone surface and a second planar surface of the resected bone surface,

manipulating the first planar surface to be coplanar with the second planar surface,

outlining a perimeter of the first planar surface and the second planar surface to define the two-dimensional outline of the resected bone surface; and

determining a contour of a bone engaging surface of a prosthesis using the two-dimensional outline of the resected bone surface, wherein the determining step comprises;

measuring the two-dimensional outline of the resected bone surface and a two-dimensional outline of the prosthesis, and

determining a deviation between the two-dimensional outline of the resected bone surface and the two-dimensional outline of the prosthesis based on the measuring step; and

comparing the two-dimensional outline of the resected bone surface with the two-dimensional outline of the prosthesis to assess a fit of the prosthesis with the bone.

4. The method of claim 3, wherein the resected bone surface is defined by a plurality of intersecting cut planes, wherein the step of creating the two-dimensional outline of the resected bone surface includes the step of outlining the plurality of intersecting cut planes to obtain a three-dimensional profile of the resected bone surface, the two-dimensional outline of the resected bone surface being based on the three-dimensional profile of the resected bone surface.

5. The method of claim 3, wherein the step of determining a contour of a bone engaging surface of a prosthesis using the two-dimensional outline of the resected bone surface includes the step of manipulating a three-dimensional profile of the resected bone surface to form the two-dimensional outline of the resected surface.

6. The method of claim 3, wherein the prosthesis includes at least one surface configured to be positioned adjacent to the resected bone surface, and wherein a two-dimensional outline of the prosthesis corresponds to the at least one surface of the prosthesis.

7. The method of claim 3, wherein manipulating the first planar surface to be coplanar with the second planar surface includes unfolding a three-dimensional outline.

8. A method of creating a prosthesis for placement on a resected bone surface of a bone, the method comprising the steps of:

obtaining a three-dimensional model of the bone based upon an image of the bone;

virtually resecting the three-dimensional model of the bone using a computer by defining a plurality of cut planes based upon a proposed prosthesis design and known surgical techniques specified for the proposed prosthesis design;

preparing a bone profile of the virtual resection of the bone;

creating a two-dimensional outline of the resected bone surface including manipulating a first planar surface to be coplanar with a second planar surface;

creating a two-dimensional outline from a profile of a prosthesis based on a three-dimensional contour of a surface of the prosthesis; and

comparing the two-dimensional outline of the resected bone surface with the two-dimensional outline of the profile of the prosthesis to assess a fit of the prosthesis with the bone.

9. The method of claim 8, wherein the two-dimensional outline of the resected bone surface includes a two-dimensional outline of the first planar surface coplanar with the second planar surface.

10. The method of claim 8, wherein the comparing the two-dimensional outline of the resected bone surface with the two-dimensional outline of the profile of the prosthesis comprises the steps of measuring the two-dimensional outline of the resected bone surface and the two-dimensional outline of the profile of the prosthesis and determining a deviation between the two-dimensional outline of the resected bone surface and the two-dimensional outline of the profile of the prosthesis based on the measuring step.

11. The method of claim 8, wherein manipulating the first planar surface to be coplanar with the second planar surface includes unfolding a three-dimensional outline.