Interactive prosthesis design system for implantable prosthesis

• US 5,360,446 A
• Filed: 12/18/1992
• Issued: 11/01/1994
• Est. Priority Date: 12/18/1992
• Status: Expired due to Term

• Current Assignee: Zimmer Technology Incorporated (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Zimmer Incorporated (Zimmer Biomet Holdings, Inc.)
• Inventors: Kennedy, Patrick W.
• Primary Examiner(s): Willse, David H.
• Application Number:
  US07/993,288
• Time in Patent Office: 683 Days
• Field of Search: 623/18, 623/23, 623/20(U.S. only), 623/16, 623/901, 623/, 364/413.13, 364/474.24
• US Class Current: 128/898
• CPC Class Codes: A61B 17/1659 Surgical rasps, files, planes, or scrapers
• CPC Class Codes: A61B 17/1668 for the upper femur A61B17/164 takes precedence
• CPC Class Codes: A61B 17/175 for preparing the femur for hip prosthesis insertion
• 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 2/32 for the hip
• CPC Class Codes: A61F 2/367 Proximal or metaphyseal parts of shafts trochanteric devices connected to said proximal parts A61F2/30739
• CPC Class Codes: A61F 2/3676 Distal or diaphyseal parts of shafts
• CPC Class Codes: A61F 2002/3082 Grooves
• CPC Class Codes: A61F 2002/30879 Ribs
• CPC Class Codes: A61F 2002/30952 using CAD-CAM techniques or NC-techniques
• CPC Class Codes: A61F 2002/3627 with lateral apertures, holes or openings
• CPC Class Codes: A61F 2002/3631 with an integral complete or partial peripheral collar or bearing shoulder at its base
• CPC Class Codes: A61F 2002/365 Connections of heads to necks
• CPC Class Codes: G05B 19/4099 Surface or curve machining, making 3D objects, e.g. desktop manufacturing
• CPC Class Codes: G05B 19/4207 in which a model is traced or scanned and corresponding data recorded
• CPC Class Codes: G05B 2219/45168 Bone prosthesis
• CPC Class Codes: Y10S 623/901 Method of manufacturing prosthetic device
• CPC Class Codes: Y10S 623/914 Bone

Abstract

The present invention involves a system for interactively designing prosthetic implants using two x-ray images, for example two femoral x-rays for designing a hip implant. The x-rays are scanned into a computer which electronically stores and displays the representations of the images. The computer allows the user to select points on the representations which relate to the location of the hip implant, particularly the medullary canal and other related points. The selected points are associated and stored along with the electronically stored representations. Based on the medullary canal definition and other parameters, an implant topology is generated which may be displayed and templated for medical evaluation. The system allows for the points and other parameters to be altered for calculating another implant topology. Also, the system provides for the automated manufacture of the implant and its corresponding rasp broach wherein the stock material of the implant is milled in an orientation which minimizes gouging, processing time, and tool damage.

Claims

1. A method of designing a prosthetic implant, said method utilizing first and second two dimensional x-ray radiograph images relating to the location of the implant, said method comprising the steps of:

optically scanning and digitizing the first and second two dimensional x-ray radiograph images to create representation of the first and second two dimensional x-ray radiograph images and electronically storing said representations;

displaying said representations of the first and second two dimensional x-ray radiograph images;

selecting a first and second plurality of points on said first and second representations which correspond to the location for the implant;

storing said first and second plurality of points in association with location information of said first and second plurality of points on said representations; and

calculating a topology for a prosthetic implant using said first and second plurality of points.

2. The method of claim 1 further including the step of displaying an outline view of said calculated topology.

3. The method of claim 2 wherein said outline view corresponds to one of said first and second images.

4. The method of claim 1 wherein the first and second two dimensional x-ray radiograph images are magnified by a corresponding magnification factor, and said selecting step includes normalizing said first and second plurality of points to the corresponding magnification.

5. The method of claim 1 further comprising the step of generating a series of machine tool instructions for manufacturing a prosthetic implant according to said calculated topology.

6. The method of claim 5 further comprising the step of manufacturing a prosthetic implant generally having an outer surface corresponding to said calculated topology.

7. The method of claim 1 wherein said implant is to be attached within a bone canal having generally parallel sides, and said selecting step includes selecting an axial center of said canal on said first representation and adjusting the position of two lines which are parallel and equidistant to said axial center on said first representation.

8. The method of claim 7 wherein said selecting step further includes selecting additional contour points extending from said straight sides of said canal.

9. The method of claim 7 wherein said selecting step includes selecting an axial center of said canal on said second representation and automatically creating and displaying two lines which are parallel and equidistant to said axial center on said second representation.

10. The method of claim 1 further comprising the step of displaying a template of said calculated topology with one of said first and second representations.

11. The method of claim 1 further comprising the step of altering at least one of said points of said first and second plurality of points then recalculating a new implant topology using said first and second plurality of points.

12. An apparatus for designing a prosthetic implant, said apparatus utilizing first and second two dimensional x-ray radiograph images relating to the location of the implant, said apparatus comprising:

means for optically scanning and digitizing the first and second two dimensional x-ray radiograph images to create representations of the first and second two dimensional x-ray radiograph images and electronically storing said representations;

means for displaying said representations;

means for selecting a first and a second plurality of points on said first and second representations which correspond to the location for the implant;

means for storing said first and second plurality of points in association with location information of said first and second plurality of points on said representations; and

means for calculating a topology for a prosthetic implant using said first and second plurality of points.

13. The apparatus of claim 12 wherein said displaying means includes means for displaying a sectional view of said calculated topology.

14. The apparatus of claim 13 wherein said sectional view corresponds to one of said first and second two dimensional x-ray radiograph images.

15. The apparatus of claim 12 wherein the first and second two dimensional x-ray radiograph images are magnified by a corresponding magnification factor, and said selecting means includes means for normalizing said first and second plurality of points to the corresponding magnification.

16. The apparatus of claim 12 further comprising means for generating a series of machine tool instructions for manufacturing a prosthetic implant according to said calculated topology.

17. The apparatus of claim 16 further comprising means for manufacturing a prosthetic implant generally having an outer surface corresponding to said calculated topology.

18. The apparatus of claim 12 wherein said implant is to be attached within a bone canal having generally parallel sides, and said selecting means includes means for selecting an axial center of said canal on said first representation and means for adjusting the position of two lines which are parallel and equidistant to said axial center on said first representation.

19. The apparatus of claim 18 wherein said selecting means further includes means for selecting additional contour points extending from said cylindrical canal.

20. The apparatus of claim 18 wherein said selecting means includes means for selecting an axial center of said canal on said second representation and means for automatically creating and displaying two lines which are parallel and equidistant to said axial center on said second representation.

21. The apparatus of claim 12 wherein said displaying means includes means for presenting a template of said calculated topology with one of said first and second representations.

22. The apparatus of claim 12 further comprising means for altering at least one of said points of said first and second plurality of points then recalculating a new implant topology using said first and second plurality of points.

23. A method of designing a prosthetic implant, said method utilizing first and second two dimensional x-ray radiograph images relating to the location of the implant, said method comprising the steps of:

optically scanning and digitizing the first and second two dimensional x-ray radiograph images to create representations of the first and second two dimensional x-ray radiograph images and electronically storing said representations;

displaying said representations of the first and second two dimensional x-ray radiograph images;

selecting a first and a second plurality of points on said first and second representations which correspond to the location for the implant;

storing said first and second plurality of points in association with location information of said first and second plurality of points on said representations;

calculating a topology for a prosthetic implant using said first and second plurality of points; and

generating a series of machine tool instructions for manufacturing a prosthetic implant according to said calculated topology.

24. A method of designing a prosthetic implant, said method utilizing first and second two dimensional x-ray radiograph images relating to the location of the implant, said method comprising the steps of:

optically scanning and digitizing the first and second two dimensional x-ray radiograph images to create representations of the first and second two dimensional x-ray radiograph images and electronically storing said representations;

displaying said representations of the first and second two dimensional x-ray radiograph images;

selecting a first and a second plurality of points on said first and second representations which correspond to the location for the implant;

storing said first and second plurality of points in association with location information of said first and second plurality of points on said representations;

calculating a topology for a prosthetic implant using said first and second plurality of points; and

manufacturing a prosthetic implant generally having an outer surface corresponding to said calculated topology.