Total joint arthroplasty system

• US 8,801,719 B2
• Filed: 12/28/2012
• Issued: 08/12/2014
• Est. Priority Date: 05/15/2002
• Status: Active Grant

• Current Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Original Assignee: Otismed Corporation (Stryker Corporation)
• Inventors: Park, Ilwhan, Pearson, Lacerial, Samuel, Stephen M.
• Primary Examiner(s): BATES, DAVID W
• Application Number:
  US13/730,585
• Publication Number:
  US 20130190767A1
• Time in Patent Office: 592 Days
• Field of Search: 606/88, 606/86.R, 606/87
• US Class Current: 606/87
• CPC Class Codes: A61B 17/154 for preparing bone for knee prosthesis
• CPC Class Codes: A61B 17/155 Cutting femur
• CPC Class Codes: A61B 17/157 Cutting tibia
• CPC Class Codes: A61B 17/1668 for the upper femur A61B17/164 takes precedence
• CPC Class Codes: A61B 17/1675 for the knee
• CPC Class Codes: A61B 17/17 Guides or aligning means for drills , mills, pins or wires
• CPC Class Codes: A61B 17/1703 using imaging means, e.g. by X-rays
• CPC Class Codes: A61B 17/171 for external fixation
• CPC Class Codes: A61B 17/1739 specially adapted for particular parts of the body
• CPC Class Codes: A61B 17/1764 for the knee
• CPC Class Codes: A61B 2017/00526 Methods of manufacturing
• CPC Class Codes: A61B 2017/568 produced with shape and dimensions specific for an individual patient
• CPC Class Codes: A61B 2034/102 Modelling of surgical devices, implants or prosthesis
• CPC Class Codes: A61B 2034/104 Modelling the effect of the tool, e.g. the effect of an implanted prosthesis or for predicting the effect of ablation or burring
• CPC Class Codes: A61B 2034/105 Modelling of the patient, e.g. for ligaments or bones
• CPC Class Codes: A61B 2034/108 Computer aided selection or customisation of medical implants or cutting guides
• CPC Class Codes: A61B 2090/3762 using computed tomography systems [CT]
• CPC Class Codes: A61B 34/10 Computer-aided planning, simulation or modelling of surgical operations
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61F 2/30 Joints
• CPC Class Codes: B29C 64/386 : Data acquisition or data processing for additive manufacturing
• CPC Class Codes: B29C 64/393 : for controlling or regulating additive manufacturing processes
• CPC Class Codes: B33Y 50/00 : Data acquisition or data processing for additive manufacturing
• CPC Class Codes: B33Y 50/02 : for controlling or regulating additive manufacturing processes
• CPC Class Codes: B33Y 80/00 : Products made by additive manufacturing
• CPC Class Codes: G05B 19/4099 : Surface or curve machining, making 3D objects, e.g. desktop manufacturing
• CPC Class Codes: G05B 2219/35134 : 3-D cad-cam
• CPC Class Codes: G06F 30/20 : Design optimisation, verification or simulation optimisation, verification or simulation of circuit designs G06F30/30
• CPC Class Codes: G16H 50/50 : for simulation or modelling of medical disorders
• CPC Class Codes: G16Z 99/00 : Subject matter not provided for in other main groups of this subclass

Abstract

A method and system for performing a total joint arthroplasty procedure on a patient'"'"'s damaged bone region. A CT image or other suitable image is formed of the damaged bone surfaces, and location coordinate values (x_n,y_n,z_n) are determined for a selected sequence of bone surface locations using the CT image data. A mathematical model z=f(x,y) of a surface that accurately matches the bone surface coordinates at the selected bone spice locations, or matches surface normal vector components at selected bone surface locations, is determined. The model provides a production file from which a cutting jig and an implant device (optional), each patient-specific and having controllable alignment, are fabricated for the damaged bone by automated processing. At this point, the patient is cut open (once), the cutting jig and a cutting instrument are used to remove a selected portion of the bone and to provide an exposed planar surface, the implant device is optionally secured to and aligned with the remainder of the bone, and the patient'"'"'s incision is promptly repaired.

Claims

1. A method of manufacturing a custom arthroplasty jig for use in an arthroplasty procedure on a damaged bone of a patient, the method comprising:

obtaining a medical image of a selected region of the damaged bone of the patient;

using a computer processor to analyze the medical image to provide at least first, second and third location coordinate values for each of a selected sequence of surface point locations on the selected region of the damaged bone, the surface point locations corresponding to a surface shape of the selected region;

using the computer processor to construct a bone surface computer model including the surface shape of the selected region of the damaged bone by;

selecting a sequence of one or more polygons defined by the sequence of surface point locations, the polygons defining the surface shape of the selected region in the bone surface computer model; and

performing at least one of a point-to-point mapping or a surface normal vector mapping to construct the bone surface computer model; and

using the bone surface computer model to generate, via the computer processor, computer-readable automated instructions for a production machine to fabricate, before any incision in the patient, the custom arthroplasty jig configured for cutting and removing at least a portion of the selected region of the damaged bone, the custom arthroplasty jig including a patient specific mating surface that matches the surface shape of the selected region in the bone surface computer model such that the custom arthroplasty jig is capable of mating with the selected region of the damaged bone in only a single orientation during the arthroplasty procedure,

wherein the custom arthroplasty jig is configured such that, when the surface shape of the selected region of the damaged bone is matingly received in the patient specific mating surface, cutting the damaged bone with a cutting instrument guided by the custom arthroplasty jig provides at least one selected planar surface in the damaged bone that has a preoperatively planned alignment with a selected axis of the damaged bone.

2. The method of claim 1, wherein said process of constructing said bone surface computer model of said damaged bone comprises:

for at least one polygon in said sequence of said polygons, determining a number V of vertices of the at least one polygon; and

providing a polynomial z=f(x,y) of degree at most V−

1 in said first location coordinate x and of degree at most V−

1 in said second location coordinate y, defined on the at least one polygon, where the polynomial has a value equal to a selected value of z at each of the V vertices of the at least one polygon.

3. The method of claim 2, further comprising selecting said polynomial f(x,y) to have a minimum polynomial degree in said coordinate x and to have a minimum polynomial degree in said coordinate y.

4. The method of claim 2, further comprising selecting each of said selected values z to correspond to said third location coordinate value for each of said vertices of said at least one polygon.

5. The method of claim 2, further comprising choosing said at least one polygon to be a triangle with non-zero included area.

6. The method of claim 2, further comprising choosing said at least one polygon to be a quadrilateral with non-zero included area.

7. The method of claim 1, wherein said process of constructing said bone surface computer model of said damaged bone comprises:

providing component values of a surface normal vector at each of at least three vertex locations of a selected surface element on the selected region of the damaged bone;

providing a surface element defined by a selected polynomial of second degree in at least two of three Cartesian location coordinates (x,y,z), the polynomial having at least six initially undetermined parameters; and

determining values for the undetermined parameters so that a surface normal vector of the surface element has the provided surface normal vector component values at each of the at least three vertex locations.

8. The method of claim 7, further comprising selecting said polynomial to represent an ellipsoid in three dimensions.

9. The method of claim 1, further comprising choosing a joint associated with said damaged bone from a group of joints consisting of a hip joint, a knee joint, a foot joint, a toe joint, a shoulder joint, an elbow joint, a wrist joint, a finger joint and a neck joint.

10. The method of claim 1, wherein the selected axis of the damaged bone is a femoral mechanical axis.

11. The method of claim 10, wherein the femoral mechanical axis extends through a center of the femoral head and a center of the knee.

12. The method of claim 11, wherein the preoperatively planned alignment of the at least one selected planar surface is perpendicular to the femoral mechanical axis.

13. The method of claim 12, wherein information relating to the at least one selected planar surface is used to define a resection guide surface in the custom arthroplasty jig, the resection guide surface configured to guide the cutting instrument in cutting the damaged bone to provide the at least one selected planar surface.

14. The method of claim 1, wherein the custom arthroplasty jig further comprises a resection guide surface that is configured to guide the cutting instrument in cutting the damaged bone.

15. The method of claim 1, wherein the custom arthroplasty jig further comprises:

a first component that includes the patient specific mating surface; and

a second component that is removeably coupled to the first component of the custom arthroplasty jig,

wherein the second component includes at least a first portion of a resection guide surface that is configured to guide the cutting instrument in cutting the damaged bone.

16. The method of claim 15, wherein the first component further includes at least a second portion of a resection guide surface that is configured to guide the cutting instrument in cutting the damaged bone.

17. The method of claim 1, wherein the medical image comprises a CT image or an MRI image.

18. A method of manufacturing a custom arthroplasty jig for use in an arthroplasty procedure on a damaged femur bone of a patient, the method comprising:

obtaining a medical image of a selected region of the damaged femur bone;

using a computer processor to analyze the medical image to provide at least first, second and third location coordinate values for each of a selected sequence of surface point locations on the damaged femur bone;

using the computer processor to generate a computer bone model of a selected portion of a surface of the selected region of the damaged femur bone by implementing at least one of a point-to-point mapping or a surface normal vector mapping for each of a selected sequence of one or more polygons defined by the sequence of surface point locations;

using the computer bone model in generating computer readable automated instructions for a fabrication machine, the automated instructions configured to instruct the fabrication machine to fabricate, before any incision in the patient, the custom arthroplasty jig for use in cutting and removing at least a part of the selected portion during the arthroplasty procedure; and

fabricating with the fabrication machine the custom arthroplasty iig having a patient specific mating surface and a cutting guide, the fabrication machine utilizing the automated instructions,

wherein the patient specific mating surface substantially matches at least a portion of a surface of the computer bone model and is configured to matingly receive the selected portion of the selected region of the damaged femur bone such that the custom arthroplasty jig is capable of mating with the selected portion of the selected region of the damage femur bone in only a single orientation, and further wherein the cutting guide is configured to guide a cutting instrument in cutting the selected portion of the selected region of the damaged femur bone during the arthroplasty procedure to create a planar resection in the damaged femur bone that is perpendicular to a femoral mechanical axis of the femur bone.

19. The method of claim 18, wherein the femoral mechanical axis extends through a center of the femoral head and a center of the knee.

20. The method of claim 18, wherein the medical image comprises a CT image or a MRI image.

21. The method of claim 18, wherein said process of generating said computer bone model of the selected portion of the selected region of said damaged femur bone comprises:

for at least one polygon in said sequence of said polygons, determining a number V of vertices of the at least one polygon; and

providing a polynomial z=f(x,y) of degree at most V−

1 in said first location coordinate x and of degree at most V−

1 in said second location coordinate y, defined on the at least one polygon, where the polynomial has a value equal to a selected value of z at each of the V vertices of the at least one polygon.

22. The method of claim 21, further comprising selecting said polynomial f(x,y) to have a minimum polynomial degree in said coordinate x and to have a minimum polynomial degree in said coordinate y.

23. The method of claim 21, further comprising selecting each of said selected values z to correspond to said third location coordinate value for each of said vertices of said at least one polygon.

24. The method of claim 21, further comprising choosing said at least one polygon to be a triangle with non-zero included area.

25. The method of claim 21, further comprising choosing said at least one polygon to be a quadrilateral with non-zero included area.