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

Patent metadata

Field	Value
Publication number	US-9504579-B2
Application number	US-201213533552-A
Country	US
Kind code	B2
Filing date	Jun 26, 2012
Priority date	Mar 17, 2006
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

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.

First claim

What is claimed is:

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.

Assignees

• Mahfouz Mohamed
• Earl Brian D
• Zimmer Inc

Inventors

• Mahfouz Mohamed
• Earl Brian D

Classifications

• A61B2034/108

  Computer aided selection or customisation of medical implants or cutting guides · CPC title

• A61F2/3859

  Femoral components · CPC title

• A61B34/10 Primary

  Computer-aided planning, simulation or modelling of surgical operations · CPC title

• A61F2/30942 Primary

  for designing or making customized prostheses, e.g. using templates, CT or NMR scans, finite-element analysis or CAD-CAM techniques · CPC title

• A61B5/4528

  Joints (A61B5/4533, A61B5/4538 take precedence) · CPC title