Granted Patent B2

US 8,177,841 · App. 12/027,121 · Granted May 15, 2012

Assignee: Arthrosurface Inc.

Abstract

Claims (23)

1. An implant for replacing a portion of an articular surface of a bone comprising:

first, second, and third segments each comprising a truncated, generally circular perimeter having a center corresponding to a center of a first, second, and a third generally circular excision site formed in said articular surface, respectively, wherein said second and said third segments partially overlap said first segment on opposing ends of said first segment, said first, said second, and said third segments comprise a bone contacting surface and a load bearing surface, said load bearing surface comprising an anterior-posterior (AP) curvature and a medial lateral (ML) curvature, wherein said AP curvature comprises at least two tangential curves of said portion of said articular surface of said bone, said tangential curves having different radii of curvature.

2. The implant of claim 1 , wherein said first, said second, and said third segments each comprise a generally circular shape truncated along said AP curvature of said implant.

3. The implant of claim 1 , wherein said first, said second, and said third segments each comprise a generally circular shape truncated along said ML curvature of said implant.

4. The implant of claim 1 , wherein said bone contacting surface comprises at least one mounting feature configured to secure said implant to said bone.

5. The implant of claim 4 , wherein said at least one mounting feature is configured to securely engage with a mounting screw.

6. The implant of claim 5 , wherein said at least one mounting feature includes an opening configured to engage with a post of said mounting screw.

7. The implant of claim 1 , wherein said first, said second, and said third truncated, generally circular segments comprise first, second, and third axes extending through respective centers of said segments, respectively, wherein said first axis is substantially normal to said portion of said articular surface.

8. The implant of claim 7 , wherein said second and said third axes are substantially normal to said portion of said articular surface.

9. The implant of claim 8 , wherein a first angle α 1 between said first axis and said second axis and a second angle β 1 between said first axis and said third axis are substantially symmetrical.

10. A method of forming an implant for replacing a portion of an articular surface extending across at least two tangential curves of a bone, said tangential curves having different radii of curvature, said method comprising:

establishing a reference axis extending substantially normal to a point of origin on said portion of said articular surface;

establishing a reference plane that is parallel to a tangential plane extending through said point of origin on said articular surface;

measuring a first distance between said reference plane and a first point on said articular surface at a distance R 1 along an anterior-posterior (AP) curvature of said portion of said articular surface from said reference axis;

measuring a second distance between said reference plane and a second point on said articular surface at a distance R 2 along said AP curvature of said portion of said articular surface from said reference axis, wherein R 1 is less than R 2 ; and

providing an implant comprising:

first, second, and third segments each comprising a truncated, generally circular perimeter having a center corresponding to a center of a first, second and third generally circular excision site formed in said articular surface, respectively, wherein said second and said third segments partially overlap said first segment on opposing ends of said first segment, said first, said second, and said third segments comprise a bone contacting surface and a load bearing surface, said load bearing surface comprising an AP curvature and a ML curvature, wherein said AP curvature of said implant comprises said at least two tangential curves of said portion of said articular surface of said bone, said tangential curves having different radii of curvature.

11. The method of claim 9 , wherein said first, said second, and said third segments comprise a first, a second, and a third axis extending through a center of a respective one of said segments, respectively, and wherein a first angle α 1 between said first axis and said second axis and a second angle β 1 between said first axis and said third axis are substantially symmetrical.

12. The method of claim 10 , further comprising:

measuring at least two distances between said reference plane and a third and fourth point on said articular surface at a distance along a medial-lateral (ML) curvature of said portion of said articular surface from said reference axis; and

providing said load bearing surface comprising a second curvature approximating said ML curvature of said portion of said articular surface.

13. The method of claim 10 , wherein said first curvature approximating said at least two tangential and different curves of said articular surface is determined based on only said first and said second distances taken at distances R 1 and R 2 , respectively, from the reference axis.

14. The method of claim 10 , comprising measuring two points at a distance R 2 along said AP curvature of said portion of said articular surface from said reference axis, wherein one of said two points is taken at a point anterior from said reference axis and said other said two points is taken at a point posterior from said reference axis.

Assignments (2)

Continuity (8)