Metal tibial anchoring part for a partial knee joint prosthesis

• US 4,963,153 A
• Filed: 06/10/1988
• Issued: 10/16/1990
• Est. Priority Date: 06/30/1987
• Status: Expired due to Fees

• Current Assignee: Protek AG (Sulzer AG)
• Original Assignee: Protek AG (Sulzer AG), Sulzer Brothers, Ltd (Sulzer AG)
• Inventors: Noesberger, Bruno, Frey, Otto
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Iantorno, Stephanie L.
• Application Number:
  US07/205,466
• Time in Patent Office: 858 Days
• Field of Search: 623/20
• US Class Current: 623/20.32
• CPC Class Codes: A61F 2/389 Tibial components A61F2/3868 takes precedence
• CPC Class Codes: A61F 2002/3895 unicompartimental

Abstract

The tibial anchoring part is formed of a flat semi-circular bearing element which defines a tibia plateau for receiving a plastic bearing element as well as a blade-like fixing element. This fixing element extends at an incline from ventral to dorsal in a distal direction and has a cutting edge at the dorsal edge for penetrating into the bone. An enlargement is also provided distally of the fixing element to prevent inadvertent pullout of the part and is also provided with a cutting edge at the dorsal edge of the anchoring part.

Claims

1. A metal tibial anchoring part for a partial knee joint prosthesis, said part comprising

a flat semicircular bearing element defining a tibial plateau for receiving a plastic bearing element for a femur condyle;

and

a fixing element secured to and extend from said bearing element, said fixing element having a lower edge sloping in a downward direction from ventral to dorsal in a distal direction and having a cutting edge along a dorsal front edge.

2. An anchoring part as set forth in claim 1 wherein said fixing element has a blade-like stem extending perpendicularly from said bearing element and an enlargement at a distal end of said stem.

3. An anchoring part as set forth in claim 2 wherein said stem and enlargement of said fixing element define a T-shaped cross-section.

4. An anchoring part as set forth in claim 3 wherein said stem has a pair of side walls defining said cutting edge centrally thereof and said enlargement has a one-sided cutting edge sharpened to distal.

5. An anchoring part as set forth in claim 1 wherein said fixing element has openings therein for ingrowth of bone tissue.

6. An anchoring part as set forth in claim 1 wherein said fixing element has a dorsal edge and a ventral edge, each said edge being inclined to ventral.

7. A metal tibial anchoring part for a partial knee joint prosthesis, said part including

a semi-circular bearing element defining a tibial plateau for receiving a bearing element for a femur condyle;

and

a blade-like fixing element extending perpendicularly from said bearing element and having a cutting edge at a dorsal edge for penetrating into a tibia.

8. An anchoring part as set forth in claim 7 wherein said fixing element has a pair of side walls defining said cutting edge centrally thereof.

9. An anchoring part as set forth in claim 7 wherein said fixing element has openings therein for ingrowth of tissue.

10. An anchoring part as set forth in claim 7 wherein said fixing element has an enlargement along a distal edge thereof, said distal edge being inclined relative to said tibial plateau.

11. An anchoring part as set forth in claim 10 wherein said enlargement has a cutting edge along a dorsal edge thereof.

12. An anchoring part as set forth in claim 10 wherein said enlargement is a flat web.

13. An anchoring part as set forth in claim 10 wherein said enlargement is of V-shaped cross-section.

14. An anchoring part as set forth in claim 10 wherein said enlargement is of circular cross-section.

15. An anchoring part as set forth in claim 10 wherein said enlargement is of semi-circular cross-section.

16. An anchoring part as set forth in claim 10 wherein said enlargement is of J-shaped cross-section.

17. An anchoring part as set forth in claim 10 wherein said bearing element is flat.

18. A metal tibial anchoring part for a partial knee joint prosthesis, said part comprising

a flat semicircular bearing element defining a tibial plateau for receiving a plastic bearing element for a femur condyle;

and

a fixing element secured to and extending perpendicularly from said bearing element, said fixing element having a distal edge sloping at an angle relative to said tibial plateau and having a cutting edge along a dorsal front edge.

19. An anchoring part as set forth in claim 18 wherein said fixing element has an enlargement at said distal edge.

20. An anchoring part as set forth in claim 19 wherein said enlargement is inclined at an angle of between 15°

and 20°

relative to said tibial plateau.