Patient selectable knee arthroplasty devices

• US 8,690,945 B2
• Filed: 05/11/2010
• Issued: 04/08/2014
• Est. Priority Date: 05/25/2001
• Status: Expired due to Fees

• Current Assignee: Conformis Incorporated
• Original Assignee: Conformis Incorporated
• Inventors: Fitz, Wolfgang, Lang, Philipp, Steines, Daniel
• Primary Examiner(s): STEWART, JASON-DENNIS NEILKEN
• Application Number:
  US12/777,878
• Publication Number:
  US 20100305907A1
• Time in Patent Office: 1,428 Days
• Field of Search: 703/1, 703/2, 623/16.11
• US Class Current: 623/16.11
• CPC Class Codes: A61B 5/4504 Bones A61B5/4547 takes precedence
• CPC Class Codes: A61B 5/4514 Cartilage
• CPC Class Codes: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence
• CPC Class Codes: A61F 2/30756 Cartilage endoprostheses A61F2/3603 takes precedence
• CPC Class Codes: A61F 2/3094 Designing or manufacturing processes
• 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 2/3877 Patellae or trochleae
• CPC Class Codes: A61F 2002/30952 using CAD-CAM techniques or NC-techniques
• CPC Class Codes: A61F 2002/30957 using a positive or a negative model, e.g. moulds
• CPC Class Codes: A61F 2002/30962 using stereolithography
• CPC Class Codes: A61F 2002/4635 using minimally invasive surgery
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: G06T 2207/30052 Implant; Prosthesis
• CPC Class Codes: G06T 7/0014 using an image reference approach

Abstract

Disclosed herein are methods and devices for repairing articular surfaces in a knee joint. The articular surface repairs are customizable or highly selectable for each patient and geared toward providing optimal fit and function. Kits are also provided to enable customized repairs to be performed.

Claims

1. A method of selecting an articular repair system including an articular implant having an inner surface for attachment to a bone of a patient'"'"'s joint at an implantation site and an outer surface for providing an articular surface, the method comprising:

obtaining electronic image data of the patient'"'"'s joint;

deriving a shape of cartilage from the image data;

determining a desired shape for at least a portion of the outer surface of the articular implant at least in part from the derived shape of the cartilage;

selecting the articular implant from a library of implants such that at least a portion of the outer surface of the articular implant approximates the desired shape,

wherein the articular repair system further includes a surgical tool, the method further comprises virtually evaluating the fit of the surgical tool relative to the implantation site.

2. The method of claim 1, wherein the inner surface includes one or more planar portions configured to abut cut bone.

3. The method of claim 1, wherein the shape of the cartilage derived from the image is of, at least in part, normal articular cartilage.

4. The method of claim 1, wherein the shape of the cartilage derived from the image is of, at least in part, diseased articular cartilage.

5. The method of claim 4, further comprising:

deriving a shape of articular tissue surrounding or adjacent the diseased articular cartilage, wherein determining the desired shape is further based, at least in part, on the derived shape of the surrounding or adjacent articular tissue.

6. The method of claim 1, wherein determining the desired shape is further based, at least in part, on a shape of subchondral bone underlying the cartilage or articular tissue surrounding or adjacent the cartilage.

7. The method of claim 1, wherein the image data is obtained by one or more imaging techniques selected from the group consisting of MRI, CT, laser, ultrasound, digital tomosynthesis, optical coherence tomography, and optical imaging.

8. The method of claim 1, wherein the step of deriving the shape of the cartilage comprises obtaining a parametric surface that follows the contour of normal cartilage, the parametric surface comprising control points that extend the contour of the normal cartilage to diseased cartilage.

9. The method of claim 8, wherein the parametric surface comprises a B-spline surface.

10. The method of claim 1, wherein the step of deriving the shape of the cartilage comprises obtaining a binary image of the cartilage by extracting the cartilage from the image data, wherein diseased cartilage appears as indentations in the binary image;

and

performing a morphological closing operation to determine the shape of an implant to fill the areas of the diseased cartilage.

11. The method of claim 10, wherein the morphological closing operation is performed in two or three-dimensions using a structuring element.

12. The method of claim 10, wherein the morphological closing operation comprises a dilation followed by an erosion.

13. The method of claim 1, wherein the articular implant includes an attachment mechanism for fixing the articular implant to the patient'"'"'s joint.

14. A method of selecting an articular repair system including an articular implant for repairing a joint of a patient, the articular implant having an inner surface for facing bone and an outer surface for facing a cavity of the joint of the patient, the method including:

obtaining image data of the joint, the image data including shape information of cartilage of the joint;

deriving a shape of the cartilage from the image data;

selecting the articular implant, wherein at least a portion of the outer surface of the implant substantially matches the derived shape,

wherein the articular repair system further includes a surgical tool, the method further comprises virtually evaluating the fit of the surgical tool relative to the implantation site.

15. The method of claim 14, wherein the inner surface includes at least a planar portion configured to abut cut bone.

16. The method of claim 14, wherein the articular implant is configured for repairing one of a knee, hip, shoulder, elbow, wrist, hand, ankle and foot joint of the patient.

17. The method of claim 14, wherein the shape information includes curvature of subchondral bone underlying the cartilage.

18. A method of selecting an articular implant of an articular repair system for resurfacing a joint of a patient, the joint including a diseased articular cartilage surface, the articular implant having an inner surface for facing bone and an outer surface for facing a cavity of the joint, the method comprising:

determining shape information of cartilage associated with the joint;

deriving a desired shape of the outer surface of the articular implant from, at least in part, the determined shape of the cartilage; and

selecting the articular implant wherein at least a portion of the outer surface of the implant substantially matches the desired shape,

wherein the articular repair system further includes a surgical tool, the method further comprises virtually evaluating the fit of the surgical tool relative to the joint.

19. The method of claim 18, wherein the inner surface includes one or more planar portions configured to abut cut bone.

20. The method of claim 18, wherein the implant includes an attachment mechanism for fixing the implant to the joint, the method further comprising preparing an implantation site with substantially no subchondral bone loss except to accommodate the attachment mechanism.

21. The method of claim 18, wherein the joint of the patient is a knee, hip shoulder, elbow, wrist, hand, ankle or foot joint.