Prosthetic implant

• US 5,755,803 A
• Filed: 05/17/1996
• Issued: 05/26/1998
• Est. Priority Date: 09/02/1994
• Status: Expired due to Term

• Current Assignee: Biomet Manufacturing, LLC (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Hudson Surgical Design, Inc.
• Inventors: Haines, Timothy G., Goldstein, David B.
• Primary Examiner(s): ISABELLA, DAVID J
• Application Number:
  US08/649,465
• Time in Patent Office: 739 Days
• Field of Search: 623/18, 623/20
• US Class Current: 623/20.14
• CPC Class Codes: A61B 17/155 Cutting femur
• CPC Class Codes: A61B 17/157 Cutting tibia
• CPC Class Codes: A61B 17/1675 for the knee
• CPC Class Codes: A61B 17/1764 for the knee
• CPC Class Codes: A61B 17/1767 for the patella
• CPC Class Codes: A61B 2017/1602 Mills
• CPC Class Codes: A61F 2/3859 Femoral components

Abstract

An implant is provided for which has an outer bearing surface and an inner attachment surface. The outer bearing surface functions as a joint contact surface for a reconstructed bone joint. The inner attachment surface contacts a bone and is attached thereto. The inner attachment surface of the implant is curvilinear from the anterior to the posterior area of the femur, and is also curvilinear from the medial to the lateral areas of the femur to approximates the shape of natural femur. The resection of the femur for accommodating the implant can be properly performed by a milling device employing one or more curvilinear milling bits.

Claims

1. A prosthetic implant for attachment to a resected femur for total knee arthroplasty comprising:

an outer bearing surface having medial and lateral condyles formed thereon,

said medial and lateral condyles being of three dimensionally curved convex geometry to serve an articular function;

said medial and lateral condyles interconnected by a patellar groove, said patellar groove being of a three dimensionally curved concave geometry;

an inner contact surface in back to back disposition with said outer bearing surface, said inner contact surface including inner medial and lateral condylar areas corresponding to the medial and lateral condyles formed on the outer bearing surface,

each of said inner medial and lateral condylar areas being of a three dimensionally curved concave geometry, said concave geometry curved along a medio-lateral direction and an anterior-posterior direction;

each of said inner medial and lateral condyle areas interconnected by an inner patellar groove area, said inner patellar groove area being of a three dimensionally curved convex geometry, said convex geometry curved along a medio-lateral direction and an anterior posterior direction;

said inner contact surface geometry further defined as a surface of revolution generated by sweeping a continuous non-collinear medio-lateral profile about a curved anterior-posterior path;

said medio-lateral profile and said anterior-posterior path being planar geometries in orthogonal relation to each other; and

said inner contact surface geometrically corresponding to a geometry of a resected femur having a three dimensionally curved convex medial and lateral condylar geometry, and a three dimensionally curved concave patellar groove geometry, for full contact and attachment of said inner contact surface with a resected femur.

2. The implant of claim 1 wherein the inner contact surface geometrically approximates the outer bearing surface.

3. The implant of claim 1 wherein the inner contact surface geometrically matches the outer bearing surface.

4. The implant of claim 2 wherein the inner contact surface approximates the geometry of a non-resected bone to be reconstructed.

5. The implant of claim 1 wherein the curved surfaces of a bone are formed by at least one milling bit having a curvilinear profile.

6. The implant of claim 1 wherein the anterior-posterior curvature of the inner contact surface varies along the implant to approximate the geometry of a bone.

7. The implant of claim 1 wherein the thickness of the implant between the outer bearing surface and the inner contact surface is uniform for the implant.

8. The implant of claim 1 wherein fins are interconnected with the inner contact surface of the implant.

9. A prosthetic implant for attachment to a resected bone comprising:

an outer bearing surface;

an inner contact surface including inner medial and lateral condylar areas;

each of said inner medial and lateral condylar areas being of a three dimensionally curved concave geometry, said concave geometry curved along a medio-lateral direction and an anterior-posterior direction;

each of said inner medial and lateral condyle areas interconnected by an inner patellar groove area, said inner patellar groove area being of a three dimensionally curved convex geometry, said convex geometry curved along a medio-lateral direction and an anterior posterior direction;

said inner contact surface geometry further defined as a surface of revolution generated by sweeping a continuous non-collinear medio-lateral profile about a curved anterior-posterior path;

said medio-lateral profile and said anterior-posterior path being planar geometries in orthogonal relation to each other; and

said inner contact surface geometrically corresponding to a geometry of a resected femur having a three dimensionally curved convex medial and lateral condylar geometry, and a three dimensionally curved concave patellar groove geometry, for full contact and attachment of said inner contact surface with a resected femur.

10. The implant of claim 9 wherein the inner contact surface geometrically approximates the outer bearing surface.

11. The implant of claim 9 wherein the inner contact surface geometrically matches the outer bearing surface.

12. The implant of claim 10 wherein the inner contact surface approximates the geometry of a non-resected bone to be reconstructed.

13. The implant of claim 9 wherein the curved surfaces of a bone are formed by at least one milling bit having a curvilinear profile.

14. The implant of claim 9 wherein the anterior-posterior curvature of the inner contact surface varies along the implant to approximate the geometry of a bone.

15. The implant of claim 9 wherein the thickness of the implant between the outer bearing surface and the inner contact surface is uniform for the implant.

16. The implant of claim 9 wherein fins are interconnected with the inner contact surface of the implant.